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Merge branch 'topic/iio' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie...
authorMark Brown <broonie@kernel.org>
Thu, 11 Jan 2018 10:39:26 +0000 (10:39 +0000)
committerMark Brown <broonie@kernel.org>
Thu, 11 Jan 2018 10:39:26 +0000 (10:39 +0000)
21 files changed:
Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 [new file with mode: 0644]
Documentation/devicetree/bindings/iio/adc/sigma-delta-modulator.txt [new file with mode: 0644]
Documentation/devicetree/bindings/iio/adc/st,stm32-dfsdm-adc.txt [new file with mode: 0644]
Documentation/driver-api/iio/hw-consumer.rst [new file with mode: 0644]
Documentation/driver-api/iio/index.rst
drivers/iio/adc/Kconfig
drivers/iio/adc/Makefile
drivers/iio/adc/sd_adc_modulator.c [new file with mode: 0644]
drivers/iio/adc/stm32-dfsdm-adc.c [new file with mode: 0644]
drivers/iio/adc/stm32-dfsdm-core.c [new file with mode: 0644]
drivers/iio/adc/stm32-dfsdm.h [new file with mode: 0644]
drivers/iio/buffer/Kconfig
drivers/iio/buffer/Makefile
drivers/iio/buffer/industrialio-buffer-cb.c
drivers/iio/buffer/industrialio-hw-consumer.c [new file with mode: 0644]
drivers/iio/inkern.c
include/linux/iio/adc/stm32-dfsdm-adc.h [new file with mode: 0644]
include/linux/iio/consumer.h
include/linux/iio/hw-consumer.h [new file with mode: 0644]
include/linux/iio/iio.h
include/linux/iio/types.h

diff --git a/Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 b/Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32
new file mode 100644 (file)
index 0000000..da98223
--- /dev/null
@@ -0,0 +1,16 @@
+What:          /sys/bus/iio/devices/iio:deviceX/in_voltage_spi_clk_freq
+KernelVersion: 4.14
+Contact:       arnaud.pouliquen@st.com
+Description:
+               For audio purpose only.
+               Used by audio driver to set/get the spi input frequency.
+               This is mandatory if DFSDM is slave on SPI bus, to
+               provide information on the SPI clock frequency during runtime
+               Notice that the SPI frequency should be a multiple of sample
+               frequency to ensure the precision.
+               if DFSDM input is SPI master
+                       Reading  SPI clkout frequency,
+                       error on writing
+               If DFSDM input is SPI Slave:
+                       Reading returns value previously set.
+                       Writing value before starting conversions.
\ No newline at end of file
diff --git a/Documentation/devicetree/bindings/iio/adc/sigma-delta-modulator.txt b/Documentation/devicetree/bindings/iio/adc/sigma-delta-modulator.txt
new file mode 100644 (file)
index 0000000..e9ebb8a
--- /dev/null
@@ -0,0 +1,13 @@
+Device-Tree bindings for sigma delta modulator
+
+Required properties:
+- compatible: should be "ads1201", "sd-modulator". "sd-modulator" can be use
+       as a generic SD modulator if modulator not specified in compatible list.
+- #io-channel-cells = <1>: See the IIO bindings section "IIO consumers".
+
+Example node:
+
+       ads1202: adc@0 {
+               compatible = "sd-modulator";
+               #io-channel-cells = <1>;
+       };
diff --git a/Documentation/devicetree/bindings/iio/adc/st,stm32-dfsdm-adc.txt b/Documentation/devicetree/bindings/iio/adc/st,stm32-dfsdm-adc.txt
new file mode 100644 (file)
index 0000000..911492d
--- /dev/null
@@ -0,0 +1,128 @@
+STMicroelectronics STM32 DFSDM ADC device driver
+
+
+STM32 DFSDM ADC is a sigma delta analog-to-digital converter dedicated to
+interface external sigma delta modulators to STM32 micro controllers.
+It is mainly targeted for:
+- Sigma delta modulators (motor control, metering...)
+- PDM microphones (audio digital microphone)
+
+It features up to 8 serial digital interfaces (SPI or Manchester) and
+up to 4 filters on stm32h7.
+
+Each child node match with a filter instance.
+
+Contents of a STM32 DFSDM root node:
+------------------------------------
+Required properties:
+- compatible: Should be "st,stm32h7-dfsdm".
+- reg: Offset and length of the DFSDM block register set.
+- clocks: IP and serial interfaces clocking. Should be set according
+               to rcc clock ID and "clock-names".
+- clock-names: Input clock name "dfsdm" must be defined,
+               "audio" is optional. If defined CLKOUT is based on the audio
+               clock, else "dfsdm" is used.
+- #interrupt-cells = <1>;
+- #address-cells = <1>;
+- #size-cells = <0>;
+
+Optional properties:
+- spi-max-frequency: Requested only for SPI master mode.
+                 SPI clock OUT frequency (Hz). This clock must be set according
+                 to "clock" property. Frequency must be a multiple of the rcc
+                 clock frequency. If not, SPI CLKOUT frequency will not be
+                 accurate.
+
+Contents of a STM32 DFSDM child nodes:
+--------------------------------------
+
+Required properties:
+- compatible: Must be:
+       "st,stm32-dfsdm-adc" for sigma delta ADCs
+       "st,stm32-dfsdm-dmic" for audio digital microphone.
+- reg: Specifies the DFSDM filter instance used.
+- interrupts: IRQ lines connected to each DFSDM filter instance.
+- st,adc-channels:     List of single-ended channels muxed for this ADC.
+                       valid values:
+                               "st,stm32h7-dfsdm" compatibility: 0 to 7.
+- st,adc-channel-names:        List of single-ended channel names.
+- st,filter-order:  SinC filter order from 0 to 5.
+                       0: FastSinC
+                       [1-5]: order 1 to 5.
+                       For audio purpose it is recommended to use order 3 to 5.
+- #io-channel-cells = <1>: See the IIO bindings section "IIO consumers".
+
+Required properties for "st,stm32-dfsdm-adc" compatibility:
+- io-channels: From common IIO binding. Used to pipe external sigma delta
+               modulator or internal ADC output to DFSDM channel.
+               This is not required for "st,stm32-dfsdm-pdm" compatibility as
+               PDM microphone is binded in Audio DT node.
+
+Required properties for "st,stm32-dfsdm-pdm" compatibility:
+- #sound-dai-cells: Must be set to 0.
+- dma: DMA controller phandle and DMA request line associated to the
+               filter instance (specified by the field "reg")
+- dma-names: Must be "rx"
+
+Optional properties:
+- st,adc-channel-types:        Single-ended channel input type.
+                       - "SPI_R": SPI with data on rising edge (default)
+                       - "SPI_F": SPI with data on falling edge
+                       - "MANCH_R": manchester codec, rising edge = logic 0
+                       - "MANCH_F": manchester codec, falling edge = logic 1
+- st,adc-channel-clk-src: Conversion clock source.
+                         - "CLKIN": external SPI clock (CLKIN x)
+                         - "CLKOUT": internal SPI clock (CLKOUT) (default)
+                         - "CLKOUT_F": internal SPI clock divided by 2 (falling edge).
+                         - "CLKOUT_R": internal SPI clock divided by 2 (rising edge).
+
+- st,adc-alt-channel: Must be defined if two sigma delta modulator are
+                         connected on same SPI input.
+                         If not set, channel n is connected to SPI input n.
+                         If set, channel n is connected to SPI input n + 1.
+
+- st,filter0-sync: Set to 1 to synchronize with DFSDM filter instance 0.
+                  Used for multi microphones synchronization.
+
+Example of a sigma delta adc connected on DFSDM SPI port 0
+and a pdm microphone connected on DFSDM SPI port 1:
+
+       ads1202: simple_sd_adc@0 {
+               compatible = "ads1202";
+               #io-channel-cells = <1>;
+       };
+
+       dfsdm: dfsdm@40017000 {
+               compatible = "st,stm32h7-dfsdm";
+               reg = <0x40017000 0x400>;
+               clocks = <&rcc DFSDM1_CK>;
+               clock-names = "dfsdm";
+               #interrupt-cells = <1>;
+               #address-cells = <1>;
+               #size-cells = <0>;
+
+               dfsdm_adc0: filter@0 {
+                       compatible = "st,stm32-dfsdm-adc";
+                       #io-channel-cells = <1>;
+                       reg = <0>;
+                       interrupts = <110>;
+                       st,adc-channels = <0>;
+                       st,adc-channel-names = "sd_adc0";
+                       st,adc-channel-types = "SPI_F";
+                       st,adc-channel-clk-src = "CLKOUT";
+                       io-channels = <&ads1202 0>;
+                       st,filter-order = <3>;
+               };
+               dfsdm_pdm1: filter@1 {
+                       compatible = "st,stm32-dfsdm-dmic";
+                       reg = <1>;
+                       interrupts = <111>;
+                       dmas = <&dmamux1 102 0x400 0x00>;
+                       dma-names = "rx";
+                       st,adc-channels = <1>;
+                       st,adc-channel-names = "dmic1";
+                       st,adc-channel-types = "SPI_R";
+                       st,adc-channel-clk-src = "CLKOUT";
+                       st,filter-order = <5>;
+               };
+       }
diff --git a/Documentation/driver-api/iio/hw-consumer.rst b/Documentation/driver-api/iio/hw-consumer.rst
new file mode 100644 (file)
index 0000000..8facce6
--- /dev/null
@@ -0,0 +1,51 @@
+===========
+HW consumer
+===========
+An IIO device can be directly connected to another device in hardware. in this
+case the buffers between IIO provider and IIO consumer are handled by hardware.
+The Industrial I/O HW consumer offers a way to bond these IIO devices without
+software buffer for data. The implementation can be found under
+:file:`drivers/iio/buffer/hw-consumer.c`
+
+
+* struct :c:type:`iio_hw_consumer` — Hardware consumer structure
+* :c:func:`iio_hw_consumer_alloc` — Allocate IIO hardware consumer
+* :c:func:`iio_hw_consumer_free` — Free IIO hardware consumer
+* :c:func:`iio_hw_consumer_enable` — Enable IIO hardware consumer
+* :c:func:`iio_hw_consumer_disable` — Disable IIO hardware consumer
+
+
+HW consumer setup
+=================
+
+As standard IIO device the implementation is based on IIO provider/consumer.
+A typical IIO HW consumer setup looks like this::
+
+       static struct iio_hw_consumer *hwc;
+
+       static const struct iio_info adc_info = {
+               .read_raw = adc_read_raw,
+       };
+
+       static int adc_read_raw(struct iio_dev *indio_dev,
+                               struct iio_chan_spec const *chan, int *val,
+                               int *val2, long mask)
+       {
+               ret = iio_hw_consumer_enable(hwc);
+
+               /* Acquire data */
+
+               ret = iio_hw_consumer_disable(hwc);
+       }
+
+       static int adc_probe(struct platform_device *pdev)
+       {
+               hwc = devm_iio_hw_consumer_alloc(&iio->dev);
+       }
+
+More details
+============
+.. kernel-doc:: include/linux/iio/hw-consumer.h
+.. kernel-doc:: drivers/iio/buffer/industrialio-hw-consumer.c
+   :export:
+
index e5c3922..7fba341 100644 (file)
@@ -15,3 +15,4 @@ Contents:
    buffers
    triggers
    triggered-buffers
+   hw-consumer
index ef86296..39e3b34 100644 (file)
@@ -629,6 +629,18 @@ config SPEAR_ADC
          To compile this driver as a module, choose M here: the
          module will be called spear_adc.
 
+config SD_ADC_MODULATOR
+       tristate "Generic sigma delta modulator"
+       depends on OF
+       select IIO_BUFFER
+       select IIO_TRIGGERED_BUFFER
+       help
+         Select this option to enables sigma delta modulator. This driver can
+         support generic sigma delta modulators.
+
+         This driver can also be built as a module.  If so, the module
+         will be called sd_adc_modulator.
+
 config STM32_ADC_CORE
        tristate "STMicroelectronics STM32 adc core"
        depends on ARCH_STM32 || COMPILE_TEST
@@ -656,6 +668,31 @@ config STM32_ADC
          This driver can also be built as a module.  If so, the module
          will be called stm32-adc.
 
+config STM32_DFSDM_CORE
+       tristate "STMicroelectronics STM32 DFSDM core"
+       depends on (ARCH_STM32 && OF) || COMPILE_TEST
+       select REGMAP
+       select REGMAP_MMIO
+       help
+         Select this option to enable the  driver for STMicroelectronics
+         STM32 digital filter for sigma delta converter.
+
+         This driver can also be built as a module.  If so, the module
+         will be called stm32-dfsdm-core.
+
+config STM32_DFSDM_ADC
+       tristate "STMicroelectronics STM32 dfsdm adc"
+       depends on (ARCH_STM32 && OF) || COMPILE_TEST
+       select STM32_DFSDM_CORE
+       select REGMAP_MMIO
+       select IIO_BUFFER_HW_CONSUMER
+       help
+         Select this option to support ADCSigma delta modulator for
+         STMicroelectronics STM32 digital filter for sigma delta converter.
+
+         This driver can also be built as a module.  If so, the module
+         will be called stm32-dfsdm-adc.
+
 config STX104
        tristate "Apex Embedded Systems STX104 driver"
        depends on PC104 && X86 && ISA_BUS_API
index 9572c10..28a9423 100644 (file)
@@ -64,6 +64,8 @@ obj-$(CONFIG_STX104) += stx104.o
 obj-$(CONFIG_SUN4I_GPADC) += sun4i-gpadc-iio.o
 obj-$(CONFIG_STM32_ADC_CORE) += stm32-adc-core.o
 obj-$(CONFIG_STM32_ADC) += stm32-adc.o
+obj-$(CONFIG_STM32_DFSDM_CORE) += stm32-dfsdm-core.o
+obj-$(CONFIG_STM32_DFSDM_ADC) += stm32-dfsdm-adc.o
 obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o
 obj-$(CONFIG_TI_ADC0832) += ti-adc0832.o
 obj-$(CONFIG_TI_ADC084S021) += ti-adc084s021.o
@@ -82,3 +84,4 @@ obj-$(CONFIG_VF610_ADC) += vf610_adc.o
 obj-$(CONFIG_VIPERBOARD_ADC) += viperboard_adc.o
 xilinx-xadc-y := xilinx-xadc-core.o xilinx-xadc-events.o
 obj-$(CONFIG_XILINX_XADC) += xilinx-xadc.o
+obj-$(CONFIG_SD_ADC_MODULATOR) += sd_adc_modulator.o
diff --git a/drivers/iio/adc/sd_adc_modulator.c b/drivers/iio/adc/sd_adc_modulator.c
new file mode 100644 (file)
index 0000000..560d8c7
--- /dev/null
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Generic sigma delta modulator driver
+ *
+ * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
+ * Author: Arnaud Pouliquen <arnaud.pouliquen@st.com>.
+ */
+
+#include <linux/iio/iio.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+
+static const struct iio_info iio_sd_mod_iio_info;
+
+static const struct iio_chan_spec iio_sd_mod_ch = {
+       .type = IIO_VOLTAGE,
+       .indexed = 1,
+       .scan_type = {
+               .sign = 'u',
+               .realbits = 1,
+               .shift = 0,
+       },
+};
+
+static int iio_sd_mod_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct iio_dev *iio;
+
+       iio = devm_iio_device_alloc(dev, 0);
+       if (!iio)
+               return -ENOMEM;
+
+       iio->dev.parent = dev;
+       iio->dev.of_node = dev->of_node;
+       iio->name = dev_name(dev);
+       iio->info = &iio_sd_mod_iio_info;
+       iio->modes = INDIO_BUFFER_HARDWARE;
+
+       iio->num_channels = 1;
+       iio->channels = &iio_sd_mod_ch;
+
+       platform_set_drvdata(pdev, iio);
+
+       return devm_iio_device_register(&pdev->dev, iio);
+}
+
+static const struct of_device_id sd_adc_of_match[] = {
+       { .compatible = "sd-modulator" },
+       { .compatible = "ads1201" },
+       { }
+};
+MODULE_DEVICE_TABLE(of, sd_adc_of_match);
+
+static struct platform_driver iio_sd_mod_adc = {
+       .driver = {
+               .name = "iio_sd_adc_mod",
+               .of_match_table = of_match_ptr(sd_adc_of_match),
+       },
+       .probe = iio_sd_mod_probe,
+};
+
+module_platform_driver(iio_sd_mod_adc);
+
+MODULE_DESCRIPTION("Basic sigma delta modulator");
+MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c
new file mode 100644 (file)
index 0000000..e628d04
--- /dev/null
@@ -0,0 +1,1216 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * This file is the ADC part of the STM32 DFSDM driver
+ *
+ * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
+ * Author: Arnaud Pouliquen <arnaud.pouliquen@st.com>.
+ */
+
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/hw-consumer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#include "stm32-dfsdm.h"
+
+#define DFSDM_DMA_BUFFER_SIZE (4 * PAGE_SIZE)
+
+/* Conversion timeout */
+#define DFSDM_TIMEOUT_US 100000
+#define DFSDM_TIMEOUT (msecs_to_jiffies(DFSDM_TIMEOUT_US / 1000))
+
+/* Oversampling attribute default */
+#define DFSDM_DEFAULT_OVERSAMPLING  100
+
+/* Oversampling max values */
+#define DFSDM_MAX_INT_OVERSAMPLING 256
+#define DFSDM_MAX_FL_OVERSAMPLING 1024
+
+/* Max sample resolutions */
+#define DFSDM_MAX_RES BIT(31)
+#define DFSDM_DATA_RES BIT(23)
+
+enum sd_converter_type {
+       DFSDM_AUDIO,
+       DFSDM_IIO,
+};
+
+struct stm32_dfsdm_dev_data {
+       int type;
+       int (*init)(struct iio_dev *indio_dev);
+       unsigned int num_channels;
+       const struct regmap_config *regmap_cfg;
+};
+
+struct stm32_dfsdm_adc {
+       struct stm32_dfsdm *dfsdm;
+       const struct stm32_dfsdm_dev_data *dev_data;
+       unsigned int fl_id;
+       unsigned int ch_id;
+
+       /* ADC specific */
+       unsigned int oversamp;
+       struct iio_hw_consumer *hwc;
+       struct completion completion;
+       u32 *buffer;
+
+       /* Audio specific */
+       unsigned int spi_freq;  /* SPI bus clock frequency */
+       unsigned int sample_freq; /* Sample frequency after filter decimation */
+       int (*cb)(const void *data, size_t size, void *cb_priv);
+       void *cb_priv;
+
+       /* DMA */
+       u8 *rx_buf;
+       unsigned int bufi; /* Buffer current position */
+       unsigned int buf_sz; /* Buffer size */
+       struct dma_chan *dma_chan;
+       dma_addr_t dma_buf;
+};
+
+struct stm32_dfsdm_str2field {
+       const char      *name;
+       unsigned int    val;
+};
+
+/* DFSDM channel serial interface type */
+static const struct stm32_dfsdm_str2field stm32_dfsdm_chan_type[] = {
+       { "SPI_R", 0 }, /* SPI with data on rising edge */
+       { "SPI_F", 1 }, /* SPI with data on falling edge */
+       { "MANCH_R", 2 }, /* Manchester codec, rising edge = logic 0 */
+       { "MANCH_F", 3 }, /* Manchester codec, falling edge = logic 1 */
+       {},
+};
+
+/* DFSDM channel clock source */
+static const struct stm32_dfsdm_str2field stm32_dfsdm_chan_src[] = {
+       /* External SPI clock (CLKIN x) */
+       { "CLKIN", DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL },
+       /* Internal SPI clock (CLKOUT) */
+       { "CLKOUT", DFSDM_CHANNEL_SPI_CLOCK_INTERNAL },
+       /* Internal SPI clock divided by 2 (falling edge) */
+       { "CLKOUT_F", DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_FALLING },
+       /* Internal SPI clock divided by 2 (falling edge) */
+       { "CLKOUT_R", DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_RISING },
+       {},
+};
+
+static int stm32_dfsdm_str2val(const char *str,
+                              const struct stm32_dfsdm_str2field *list)
+{
+       const struct stm32_dfsdm_str2field *p = list;
+
+       for (p = list; p && p->name; p++)
+               if (!strcmp(p->name, str))
+                       return p->val;
+
+       return -EINVAL;
+}
+
+static int stm32_dfsdm_set_osrs(struct stm32_dfsdm_filter *fl,
+                               unsigned int fast, unsigned int oversamp)
+{
+       unsigned int i, d, fosr, iosr;
+       u64 res;
+       s64 delta;
+       unsigned int m = 1;     /* multiplication factor */
+       unsigned int p = fl->ford;      /* filter order (ford) */
+
+       pr_debug("%s: Requested oversampling: %d\n",  __func__, oversamp);
+       /*
+        * This function tries to compute filter oversampling and integrator
+        * oversampling, base on oversampling ratio requested by user.
+        *
+        * Decimation d depends on the filter order and the oversampling ratios.
+        * ford: filter order
+        * fosr: filter over sampling ratio
+        * iosr: integrator over sampling ratio
+        */
+       if (fl->ford == DFSDM_FASTSINC_ORDER) {
+               m = 2;
+               p = 2;
+       }
+
+       /*
+        * Look for filter and integrator oversampling ratios which allows
+        * to reach 24 bits data output resolution.
+        * Leave as soon as if exact resolution if reached.
+        * Otherwise the higher resolution below 32 bits is kept.
+        */
+       for (fosr = 1; fosr <= DFSDM_MAX_FL_OVERSAMPLING; fosr++) {
+               for (iosr = 1; iosr <= DFSDM_MAX_INT_OVERSAMPLING; iosr++) {
+                       if (fast)
+                               d = fosr * iosr;
+                       else if (fl->ford == DFSDM_FASTSINC_ORDER)
+                               d = fosr * (iosr + 3) + 2;
+                       else
+                               d = fosr * (iosr - 1 + p) + p;
+
+                       if (d > oversamp)
+                               break;
+                       else if (d != oversamp)
+                               continue;
+                       /*
+                        * Check resolution (limited to signed 32 bits)
+                        *   res <= 2^31
+                        * Sincx filters:
+                        *   res = m * fosr^p x iosr (with m=1, p=ford)
+                        * FastSinc filter
+                        *   res = m * fosr^p x iosr (with m=2, p=2)
+                        */
+                       res = fosr;
+                       for (i = p - 1; i > 0; i--) {
+                               res = res * (u64)fosr;
+                               if (res > DFSDM_MAX_RES)
+                                       break;
+                       }
+                       if (res > DFSDM_MAX_RES)
+                               continue;
+                       res = res * (u64)m * (u64)iosr;
+                       if (res > DFSDM_MAX_RES)
+                               continue;
+
+                       delta = res - DFSDM_DATA_RES;
+
+                       if (res >= fl->res) {
+                               fl->res = res;
+                               fl->fosr = fosr;
+                               fl->iosr = iosr;
+                               fl->fast = fast;
+                               pr_debug("%s: fosr = %d, iosr = %d\n",
+                                        __func__, fl->fosr, fl->iosr);
+                       }
+
+                       if (!delta)
+                               return 0;
+               }
+       }
+
+       if (!fl->fosr)
+               return -EINVAL;
+
+       return 0;
+}
+
+static int stm32_dfsdm_start_channel(struct stm32_dfsdm *dfsdm,
+                                    unsigned int ch_id)
+{
+       return regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(ch_id),
+                                 DFSDM_CHCFGR1_CHEN_MASK,
+                                 DFSDM_CHCFGR1_CHEN(1));
+}
+
+static void stm32_dfsdm_stop_channel(struct stm32_dfsdm *dfsdm,
+                                    unsigned int ch_id)
+{
+       regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(ch_id),
+                          DFSDM_CHCFGR1_CHEN_MASK, DFSDM_CHCFGR1_CHEN(0));
+}
+
+static int stm32_dfsdm_chan_configure(struct stm32_dfsdm *dfsdm,
+                                     struct stm32_dfsdm_channel *ch)
+{
+       unsigned int id = ch->id;
+       struct regmap *regmap = dfsdm->regmap;
+       int ret;
+
+       ret = regmap_update_bits(regmap, DFSDM_CHCFGR1(id),
+                                DFSDM_CHCFGR1_SITP_MASK,
+                                DFSDM_CHCFGR1_SITP(ch->type));
+       if (ret < 0)
+               return ret;
+       ret = regmap_update_bits(regmap, DFSDM_CHCFGR1(id),
+                                DFSDM_CHCFGR1_SPICKSEL_MASK,
+                                DFSDM_CHCFGR1_SPICKSEL(ch->src));
+       if (ret < 0)
+               return ret;
+       return regmap_update_bits(regmap, DFSDM_CHCFGR1(id),
+                                 DFSDM_CHCFGR1_CHINSEL_MASK,
+                                 DFSDM_CHCFGR1_CHINSEL(ch->alt_si));
+}
+
+static int stm32_dfsdm_start_filter(struct stm32_dfsdm *dfsdm,
+                                   unsigned int fl_id)
+{
+       int ret;
+
+       /* Enable filter */
+       ret = regmap_update_bits(dfsdm->regmap, DFSDM_CR1(fl_id),
+                                DFSDM_CR1_DFEN_MASK, DFSDM_CR1_DFEN(1));
+       if (ret < 0)
+               return ret;
+
+       /* Start conversion */
+       return regmap_update_bits(dfsdm->regmap, DFSDM_CR1(fl_id),
+                                 DFSDM_CR1_RSWSTART_MASK,
+                                 DFSDM_CR1_RSWSTART(1));
+}
+
+static void stm32_dfsdm_stop_filter(struct stm32_dfsdm *dfsdm, unsigned int fl_id)
+{
+       /* Disable conversion */
+       regmap_update_bits(dfsdm->regmap, DFSDM_CR1(fl_id),
+                          DFSDM_CR1_DFEN_MASK, DFSDM_CR1_DFEN(0));
+}
+
+static int stm32_dfsdm_filter_configure(struct stm32_dfsdm *dfsdm,
+                                       unsigned int fl_id, unsigned int ch_id)
+{
+       struct regmap *regmap = dfsdm->regmap;
+       struct stm32_dfsdm_filter *fl = &dfsdm->fl_list[fl_id];
+       int ret;
+
+       /* Average integrator oversampling */
+       ret = regmap_update_bits(regmap, DFSDM_FCR(fl_id), DFSDM_FCR_IOSR_MASK,
+                                DFSDM_FCR_IOSR(fl->iosr - 1));
+       if (ret)
+               return ret;
+
+       /* Filter order and Oversampling */
+       ret = regmap_update_bits(regmap, DFSDM_FCR(fl_id), DFSDM_FCR_FOSR_MASK,
+                                DFSDM_FCR_FOSR(fl->fosr - 1));
+       if (ret)
+               return ret;
+
+       ret = regmap_update_bits(regmap, DFSDM_FCR(fl_id), DFSDM_FCR_FORD_MASK,
+                                DFSDM_FCR_FORD(fl->ford));
+       if (ret)
+               return ret;
+
+       /* No scan mode supported for the moment */
+       ret = regmap_update_bits(regmap, DFSDM_CR1(fl_id), DFSDM_CR1_RCH_MASK,
+                                DFSDM_CR1_RCH(ch_id));
+       if (ret)
+               return ret;
+
+       return regmap_update_bits(regmap, DFSDM_CR1(fl_id),
+                                 DFSDM_CR1_RSYNC_MASK,
+                                 DFSDM_CR1_RSYNC(fl->sync_mode));
+}
+
+static int stm32_dfsdm_channel_parse_of(struct stm32_dfsdm *dfsdm,
+                                       struct iio_dev *indio_dev,
+                                       struct iio_chan_spec *ch)
+{
+       struct stm32_dfsdm_channel *df_ch;
+       const char *of_str;
+       int chan_idx = ch->scan_index;
+       int ret, val;
+
+       ret = of_property_read_u32_index(indio_dev->dev.of_node,
+                                        "st,adc-channels", chan_idx,
+                                        &ch->channel);
+       if (ret < 0) {
+               dev_err(&indio_dev->dev,
+                       " Error parsing 'st,adc-channels' for idx %d\n",
+                       chan_idx);
+               return ret;
+       }
+       if (ch->channel >= dfsdm->num_chs) {
+               dev_err(&indio_dev->dev,
+                       " Error bad channel number %d (max = %d)\n",
+                       ch->channel, dfsdm->num_chs);
+               return -EINVAL;
+       }
+
+       ret = of_property_read_string_index(indio_dev->dev.of_node,
+                                           "st,adc-channel-names", chan_idx,
+                                           &ch->datasheet_name);
+       if (ret < 0) {
+               dev_err(&indio_dev->dev,
+                       " Error parsing 'st,adc-channel-names' for idx %d\n",
+                       chan_idx);
+               return ret;
+       }
+
+       df_ch =  &dfsdm->ch_list[ch->channel];
+       df_ch->id = ch->channel;
+
+       ret = of_property_read_string_index(indio_dev->dev.of_node,
+                                           "st,adc-channel-types", chan_idx,
+                                           &of_str);
+       if (!ret) {
+               val  = stm32_dfsdm_str2val(of_str, stm32_dfsdm_chan_type);
+               if (val < 0)
+                       return val;
+       } else {
+               val = 0;
+       }
+       df_ch->type = val;
+
+       ret = of_property_read_string_index(indio_dev->dev.of_node,
+                                           "st,adc-channel-clk-src", chan_idx,
+                                           &of_str);
+       if (!ret) {
+               val  = stm32_dfsdm_str2val(of_str, stm32_dfsdm_chan_src);
+               if (val < 0)
+                       return val;
+       } else {
+               val = 0;
+       }
+       df_ch->src = val;
+
+       ret = of_property_read_u32_index(indio_dev->dev.of_node,
+                                        "st,adc-alt-channel", chan_idx,
+                                        &df_ch->alt_si);
+       if (ret < 0)
+               df_ch->alt_si = 0;
+
+       return 0;
+}
+
+static ssize_t dfsdm_adc_audio_get_spiclk(struct iio_dev *indio_dev,
+                                         uintptr_t priv,
+                                         const struct iio_chan_spec *chan,
+                                         char *buf)
+{
+       struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+
+       return snprintf(buf, PAGE_SIZE, "%d\n", adc->spi_freq);
+}
+
+static ssize_t dfsdm_adc_audio_set_spiclk(struct iio_dev *indio_dev,
+                                         uintptr_t priv,
+                                         const struct iio_chan_spec *chan,
+                                         const char *buf, size_t len)
+{
+       struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+       struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id];
+       struct stm32_dfsdm_channel *ch = &adc->dfsdm->ch_list[adc->ch_id];
+       unsigned int sample_freq = adc->sample_freq;
+       unsigned int spi_freq;
+       int ret;
+
+       dev_err(&indio_dev->dev, "enter %s\n", __func__);
+       /* If DFSDM is master on SPI, SPI freq can not be updated */
+       if (ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL)
+               return -EPERM;
+
+       ret = kstrtoint(buf, 0, &spi_freq);
+       if (ret)
+               return ret;
+
+       if (!spi_freq)
+               return -EINVAL;
+
+       if (sample_freq) {
+               if (spi_freq % sample_freq)
+                       dev_warn(&indio_dev->dev,
+                                "Sampling rate not accurate (%d)\n",
+                                spi_freq / (spi_freq / sample_freq));
+
+               ret = stm32_dfsdm_set_osrs(fl, 0, (spi_freq / sample_freq));
+               if (ret < 0) {
+                       dev_err(&indio_dev->dev,
+                               "No filter parameters that match!\n");
+                       return ret;
+               }
+       }
+       adc->spi_freq = spi_freq;
+
+       return len;
+}
+
+static int stm32_dfsdm_start_conv(struct stm32_dfsdm_adc *adc, bool dma)
+{
+       struct regmap *regmap = adc->dfsdm->regmap;
+       int ret;
+       unsigned int dma_en = 0, cont_en = 0;
+
+       ret = stm32_dfsdm_start_channel(adc->dfsdm, adc->ch_id);
+       if (ret < 0)
+               return ret;
+
+       ret = stm32_dfsdm_filter_configure(adc->dfsdm, adc->fl_id,
+                                          adc->ch_id);
+       if (ret < 0)
+               goto stop_channels;
+
+       if (dma) {
+               /* Enable DMA transfer*/
+               dma_en =  DFSDM_CR1_RDMAEN(1);
+               /* Enable conversion triggered by SPI clock*/
+               cont_en = DFSDM_CR1_RCONT(1);
+       }
+       /* Enable DMA transfer*/
+       ret = regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
+                                DFSDM_CR1_RDMAEN_MASK, dma_en);
+       if (ret < 0)
+               goto stop_channels;
+
+       /* Enable conversion triggered by SPI clock*/
+       ret = regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
+                                DFSDM_CR1_RCONT_MASK, cont_en);
+       if (ret < 0)
+               goto stop_channels;
+
+       ret = stm32_dfsdm_start_filter(adc->dfsdm, adc->fl_id);
+       if (ret < 0)
+               goto stop_channels;
+
+       return 0;
+
+stop_channels:
+       regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
+                          DFSDM_CR1_RDMAEN_MASK, 0);
+
+       regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
+                          DFSDM_CR1_RCONT_MASK, 0);
+       stm32_dfsdm_stop_channel(adc->dfsdm, adc->fl_id);
+
+       return ret;
+}
+
+static void stm32_dfsdm_stop_conv(struct stm32_dfsdm_adc *adc)
+{
+       struct regmap *regmap = adc->dfsdm->regmap;
+
+       stm32_dfsdm_stop_filter(adc->dfsdm, adc->fl_id);
+
+       /* Clean conversion options */
+       regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
+                          DFSDM_CR1_RDMAEN_MASK, 0);
+
+       regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
+                          DFSDM_CR1_RCONT_MASK, 0);
+
+       stm32_dfsdm_stop_channel(adc->dfsdm, adc->ch_id);
+}
+
+static int stm32_dfsdm_set_watermark(struct iio_dev *indio_dev,
+                                    unsigned int val)
+{
+       struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+       unsigned int watermark = DFSDM_DMA_BUFFER_SIZE / 2;
+
+       /*
+        * DMA cyclic transfers are used, buffer is split into two periods.
+        * There should be :
+        * - always one buffer (period) DMA is working on
+        * - one buffer (period) driver pushed to ASoC side.
+        */
+       watermark = min(watermark, val * (unsigned int)(sizeof(u32)));
+       adc->buf_sz = watermark * 2;
+
+       return 0;
+}
+
+static unsigned int stm32_dfsdm_adc_dma_residue(struct stm32_dfsdm_adc *adc)
+{
+       struct dma_tx_state state;
+       enum dma_status status;
+
+       status = dmaengine_tx_status(adc->dma_chan,
+                                    adc->dma_chan->cookie,
+                                    &state);
+       if (status == DMA_IN_PROGRESS) {
+               /* Residue is size in bytes from end of buffer */
+               unsigned int i = adc->buf_sz - state.residue;
+               unsigned int size;
+
+               /* Return available bytes */
+               if (i >= adc->bufi)
+                       size = i - adc->bufi;
+               else
+                       size = adc->buf_sz + i - adc->bufi;
+
+               return size;
+       }
+
+       return 0;
+}
+
+static void stm32_dfsdm_audio_dma_buffer_done(void *data)
+{
+       struct iio_dev *indio_dev = data;
+       struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+       int available = stm32_dfsdm_adc_dma_residue(adc);
+       size_t old_pos;
+
+       /*
+        * FIXME: In Kernel interface does not support cyclic DMA buffer,and
+        * offers only an interface to push data samples per samples.
+        * For this reason IIO buffer interface is not used and interface is
+        * bypassed using a private callback registered by ASoC.
+        * This should be a temporary solution waiting a cyclic DMA engine
+        * support in IIO.
+        */
+
+       dev_dbg(&indio_dev->dev, "%s: pos = %d, available = %d\n", __func__,
+               adc->bufi, available);
+       old_pos = adc->bufi;
+
+       while (available >= indio_dev->scan_bytes) {
+               u32 *buffer = (u32 *)&adc->rx_buf[adc->bufi];
+
+               /* Mask 8 LSB that contains the channel ID */
+               *buffer = (*buffer & 0xFFFFFF00) << 8;
+               available -= indio_dev->scan_bytes;
+               adc->bufi += indio_dev->scan_bytes;
+               if (adc->bufi >= adc->buf_sz) {
+                       if (adc->cb)
+                               adc->cb(&adc->rx_buf[old_pos],
+                                        adc->buf_sz - old_pos, adc->cb_priv);
+                       adc->bufi = 0;
+                       old_pos = 0;
+               }
+       }
+       if (adc->cb)
+               adc->cb(&adc->rx_buf[old_pos], adc->bufi - old_pos,
+                       adc->cb_priv);
+}
+
+static int stm32_dfsdm_adc_dma_start(struct iio_dev *indio_dev)
+{
+       struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+       struct dma_async_tx_descriptor *desc;
+       dma_cookie_t cookie;
+       int ret;
+
+       if (!adc->dma_chan)
+               return -EINVAL;
+
+       dev_dbg(&indio_dev->dev, "%s size=%d watermark=%d\n", __func__,
+               adc->buf_sz, adc->buf_sz / 2);
+
+       /* Prepare a DMA cyclic transaction */
+       desc = dmaengine_prep_dma_cyclic(adc->dma_chan,
+                                        adc->dma_buf,
+                                        adc->buf_sz, adc->buf_sz / 2,
+                                        DMA_DEV_TO_MEM,
+                                        DMA_PREP_INTERRUPT);
+       if (!desc)
+               return -EBUSY;
+
+       desc->callback = stm32_dfsdm_audio_dma_buffer_done;
+       desc->callback_param = indio_dev;
+
+       cookie = dmaengine_submit(desc);
+       ret = dma_submit_error(cookie);
+       if (ret) {
+               dmaengine_terminate_all(adc->dma_chan);
+               return ret;
+       }
+
+       /* Issue pending DMA requests */
+       dma_async_issue_pending(adc->dma_chan);
+
+       return 0;
+}
+
+static int stm32_dfsdm_postenable(struct iio_dev *indio_dev)
+{
+       struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+       int ret;
+
+       /* Reset adc buffer index */
+       adc->bufi = 0;
+
+       ret = stm32_dfsdm_start_dfsdm(adc->dfsdm);
+       if (ret < 0)
+               return ret;
+
+       ret = stm32_dfsdm_start_conv(adc, true);
+       if (ret) {
+               dev_err(&indio_dev->dev, "Can't start conversion\n");
+               goto stop_dfsdm;
+       }
+
+       if (adc->dma_chan) {
+               ret = stm32_dfsdm_adc_dma_start(indio_dev);
+               if (ret) {
+                       dev_err(&indio_dev->dev, "Can't start DMA\n");
+                       goto err_stop_conv;
+               }
+       }
+
+       return 0;
+
+err_stop_conv:
+       stm32_dfsdm_stop_conv(adc);
+stop_dfsdm:
+       stm32_dfsdm_stop_dfsdm(adc->dfsdm);
+
+       return ret;
+}
+
+static int stm32_dfsdm_predisable(struct iio_dev *indio_dev)
+{
+       struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+
+       if (adc->dma_chan)
+               dmaengine_terminate_all(adc->dma_chan);
+
+       stm32_dfsdm_stop_conv(adc);
+
+       stm32_dfsdm_stop_dfsdm(adc->dfsdm);
+
+       return 0;
+}
+
+static const struct iio_buffer_setup_ops stm32_dfsdm_buffer_setup_ops = {
+       .postenable = &stm32_dfsdm_postenable,
+       .predisable = &stm32_dfsdm_predisable,
+};
+
+/**
+ * stm32_dfsdm_get_buff_cb() - register a callback that will be called when
+ *                             DMA transfer period is achieved.
+ *
+ * @iio_dev: Handle to IIO device.
+ * @cb: Pointer to callback function:
+ *      - data: pointer to data buffer
+ *      - size: size in byte of the data buffer
+ *      - private: pointer to consumer private structure.
+ * @private: Pointer to consumer private structure.
+ */
+int stm32_dfsdm_get_buff_cb(struct iio_dev *iio_dev,
+                           int (*cb)(const void *data, size_t size,
+                                     void *private),
+                           void *private)
+{
+       struct stm32_dfsdm_adc *adc;
+
+       if (!iio_dev)
+               return -EINVAL;
+       adc = iio_priv(iio_dev);
+
+       adc->cb = cb;
+       adc->cb_priv = private;
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(stm32_dfsdm_get_buff_cb);
+
+/**
+ * stm32_dfsdm_release_buff_cb - unregister buffer callback
+ *
+ * @iio_dev: Handle to IIO device.
+ */
+int stm32_dfsdm_release_buff_cb(struct iio_dev *iio_dev)
+{
+       struct stm32_dfsdm_adc *adc;
+
+       if (!iio_dev)
+               return -EINVAL;
+       adc = iio_priv(iio_dev);
+
+       adc->cb = NULL;
+       adc->cb_priv = NULL;
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(stm32_dfsdm_release_buff_cb);
+
+static int stm32_dfsdm_single_conv(struct iio_dev *indio_dev,
+                                  const struct iio_chan_spec *chan, int *res)
+{
+       struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+       long timeout;
+       int ret;
+
+       reinit_completion(&adc->completion);
+
+       adc->buffer = res;
+
+       ret = stm32_dfsdm_start_dfsdm(adc->dfsdm);
+       if (ret < 0)
+               return ret;
+
+       ret = regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR2(adc->fl_id),
+                                DFSDM_CR2_REOCIE_MASK, DFSDM_CR2_REOCIE(1));
+       if (ret < 0)
+               goto stop_dfsdm;
+
+       ret = stm32_dfsdm_start_conv(adc, false);
+       if (ret < 0) {
+               regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR2(adc->fl_id),
+                                  DFSDM_CR2_REOCIE_MASK, DFSDM_CR2_REOCIE(0));
+               goto stop_dfsdm;
+       }
+
+       timeout = wait_for_completion_interruptible_timeout(&adc->completion,
+                                                           DFSDM_TIMEOUT);
+
+       /* Mask IRQ for regular conversion achievement*/
+       regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR2(adc->fl_id),
+                          DFSDM_CR2_REOCIE_MASK, DFSDM_CR2_REOCIE(0));
+
+       if (timeout == 0)
+               ret = -ETIMEDOUT;
+       else if (timeout < 0)
+               ret = timeout;
+       else
+               ret = IIO_VAL_INT;
+
+       stm32_dfsdm_stop_conv(adc);
+
+stop_dfsdm:
+       stm32_dfsdm_stop_dfsdm(adc->dfsdm);
+
+       return ret;
+}
+
+static int stm32_dfsdm_write_raw(struct iio_dev *indio_dev,
+                                struct iio_chan_spec const *chan,
+                                int val, int val2, long mask)
+{
+       struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+       struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id];
+       struct stm32_dfsdm_channel *ch = &adc->dfsdm->ch_list[adc->ch_id];
+       unsigned int spi_freq = adc->spi_freq;
+       int ret = -EINVAL;
+
+       switch (mask) {
+       case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+               ret = stm32_dfsdm_set_osrs(fl, 0, val);
+               if (!ret)
+                       adc->oversamp = val;
+
+               return ret;
+
+       case IIO_CHAN_INFO_SAMP_FREQ:
+               if (!val)
+                       return -EINVAL;
+               if (ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL)
+                       spi_freq = adc->dfsdm->spi_master_freq;
+
+               if (spi_freq % val)
+                       dev_warn(&indio_dev->dev,
+                                "Sampling rate not accurate (%d)\n",
+                                spi_freq / (spi_freq / val));
+
+               ret = stm32_dfsdm_set_osrs(fl, 0, (spi_freq / val));
+               if (ret < 0) {
+                       dev_err(&indio_dev->dev,
+                               "Not able to find parameter that match!\n");
+                       return ret;
+               }
+               adc->sample_freq = val;
+
+               return 0;
+       }
+
+       return -EINVAL;
+}
+
+static int stm32_dfsdm_read_raw(struct iio_dev *indio_dev,
+                               struct iio_chan_spec const *chan, int *val,
+                               int *val2, long mask)
+{
+       struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+       int ret;
+
+       switch (mask) {
+       case IIO_CHAN_INFO_RAW:
+               ret = iio_hw_consumer_enable(adc->hwc);
+               if (ret < 0) {
+                       dev_err(&indio_dev->dev,
+                               "%s: IIO enable failed (channel %d)\n",
+                               __func__, chan->channel);
+                       return ret;
+               }
+               ret = stm32_dfsdm_single_conv(indio_dev, chan, val);
+               iio_hw_consumer_disable(adc->hwc);
+               if (ret < 0) {
+                       dev_err(&indio_dev->dev,
+                               "%s: Conversion failed (channel %d)\n",
+                               __func__, chan->channel);
+                       return ret;
+               }
+               return IIO_VAL_INT;
+
+       case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+               *val = adc->oversamp;
+
+               return IIO_VAL_INT;
+
+       case IIO_CHAN_INFO_SAMP_FREQ:
+               *val = adc->sample_freq;
+
+               return IIO_VAL_INT;
+       }
+
+       return -EINVAL;
+}
+
+static const struct iio_info stm32_dfsdm_info_audio = {
+       .hwfifo_set_watermark = stm32_dfsdm_set_watermark,
+       .read_raw = stm32_dfsdm_read_raw,
+       .write_raw = stm32_dfsdm_write_raw,
+};
+
+static const struct iio_info stm32_dfsdm_info_adc = {
+       .read_raw = stm32_dfsdm_read_raw,
+       .write_raw = stm32_dfsdm_write_raw,
+};
+
+static irqreturn_t stm32_dfsdm_irq(int irq, void *arg)
+{
+       struct stm32_dfsdm_adc *adc = arg;
+       struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+       struct regmap *regmap = adc->dfsdm->regmap;
+       unsigned int status, int_en;
+
+       regmap_read(regmap, DFSDM_ISR(adc->fl_id), &status);
+       regmap_read(regmap, DFSDM_CR2(adc->fl_id), &int_en);
+
+       if (status & DFSDM_ISR_REOCF_MASK) {
+               /* Read the data register clean the IRQ status */
+               regmap_read(regmap, DFSDM_RDATAR(adc->fl_id), adc->buffer);
+               complete(&adc->completion);
+       }
+
+       if (status & DFSDM_ISR_ROVRF_MASK) {
+               if (int_en & DFSDM_CR2_ROVRIE_MASK)
+                       dev_warn(&indio_dev->dev, "Overrun detected\n");
+               regmap_update_bits(regmap, DFSDM_ICR(adc->fl_id),
+                                  DFSDM_ICR_CLRROVRF_MASK,
+                                  DFSDM_ICR_CLRROVRF_MASK);
+       }
+
+       return IRQ_HANDLED;
+}
+
+/*
+ * Define external info for SPI Frequency and audio sampling rate that can be
+ * configured by ASoC driver through consumer.h API
+ */
+static const struct iio_chan_spec_ext_info dfsdm_adc_audio_ext_info[] = {
+       /* spi_clk_freq : clock freq on SPI/manchester bus used by channel */
+       {
+               .name = "spi_clk_freq",
+               .shared = IIO_SHARED_BY_TYPE,
+               .read = dfsdm_adc_audio_get_spiclk,
+               .write = dfsdm_adc_audio_set_spiclk,
+       },
+       {},
+};
+
+static void stm32_dfsdm_dma_release(struct iio_dev *indio_dev)
+{
+       struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+
+       if (adc->dma_chan) {
+               dma_free_coherent(adc->dma_chan->device->dev,
+                                 DFSDM_DMA_BUFFER_SIZE,
+                                 adc->rx_buf, adc->dma_buf);
+               dma_release_channel(adc->dma_chan);
+       }
+}
+
+static int stm32_dfsdm_dma_request(struct iio_dev *indio_dev)
+{
+       struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+       struct dma_slave_config config = {
+               .src_addr = (dma_addr_t)adc->dfsdm->phys_base +
+                       DFSDM_RDATAR(adc->fl_id),
+               .src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
+       };
+       int ret;
+
+       adc->dma_chan = dma_request_slave_channel(&indio_dev->dev, "rx");
+       if (!adc->dma_chan)
+               return -EINVAL;
+
+       adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev,
+                                        DFSDM_DMA_BUFFER_SIZE,
+                                        &adc->dma_buf, GFP_KERNEL);
+       if (!adc->rx_buf) {
+               ret = -ENOMEM;
+               goto err_release;
+       }
+
+       ret = dmaengine_slave_config(adc->dma_chan, &config);
+       if (ret)
+               goto err_free;
+
+       return 0;
+
+err_free:
+       dma_free_coherent(adc->dma_chan->device->dev, DFSDM_DMA_BUFFER_SIZE,
+                         adc->rx_buf, adc->dma_buf);
+err_release:
+       dma_release_channel(adc->dma_chan);
+
+       return ret;
+}
+
+static int stm32_dfsdm_adc_chan_init_one(struct iio_dev *indio_dev,
+                                        struct iio_chan_spec *ch)
+{
+       struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+       int ret;
+
+       ret = stm32_dfsdm_channel_parse_of(adc->dfsdm, indio_dev, ch);
+       if (ret < 0)
+               return ret;
+
+       ch->type = IIO_VOLTAGE;
+       ch->indexed = 1;
+
+       /*
+        * IIO_CHAN_INFO_RAW: used to compute regular conversion
+        * IIO_CHAN_INFO_OVERSAMPLING_RATIO: used to set oversampling
+        */
+       ch->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
+       ch->info_mask_shared_by_all = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO);
+
+       if (adc->dev_data->type == DFSDM_AUDIO) {
+               ch->scan_type.sign = 's';
+               ch->ext_info = dfsdm_adc_audio_ext_info;
+       } else {
+               ch->scan_type.sign = 'u';
+       }
+       ch->scan_type.realbits = 24;
+       ch->scan_type.storagebits = 32;
+       adc->ch_id = ch->channel;
+
+       return stm32_dfsdm_chan_configure(adc->dfsdm,
+                                         &adc->dfsdm->ch_list[ch->channel]);
+}
+
+static int stm32_dfsdm_audio_init(struct iio_dev *indio_dev)
+{
+       struct iio_chan_spec *ch;
+       struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+       struct stm32_dfsdm_channel *d_ch;
+       int ret;
+
+       indio_dev->modes |= INDIO_BUFFER_SOFTWARE;
+       indio_dev->setup_ops = &stm32_dfsdm_buffer_setup_ops;
+
+       ch = devm_kzalloc(&indio_dev->dev, sizeof(*ch), GFP_KERNEL);
+       if (!ch)
+               return -ENOMEM;
+
+       ch->scan_index = 0;
+
+       ret = stm32_dfsdm_adc_chan_init_one(indio_dev, ch);
+       if (ret < 0) {
+               dev_err(&indio_dev->dev, "Channels init failed\n");
+               return ret;
+       }
+       ch->info_mask_separate = BIT(IIO_CHAN_INFO_SAMP_FREQ);
+
+       d_ch = &adc->dfsdm->ch_list[adc->ch_id];
+       if (d_ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL)
+               adc->spi_freq = adc->dfsdm->spi_master_freq;
+
+       indio_dev->num_channels = 1;
+       indio_dev->channels = ch;
+
+       return stm32_dfsdm_dma_request(indio_dev);
+}
+
+static int stm32_dfsdm_adc_init(struct iio_dev *indio_dev)
+{
+       struct iio_chan_spec *ch;
+       struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+       int num_ch;
+       int ret, chan_idx;
+
+       adc->oversamp = DFSDM_DEFAULT_OVERSAMPLING;
+       ret = stm32_dfsdm_set_osrs(&adc->dfsdm->fl_list[adc->fl_id], 0,
+                                  adc->oversamp);
+       if (ret < 0)
+               return ret;
+
+       num_ch = of_property_count_u32_elems(indio_dev->dev.of_node,
+                                            "st,adc-channels");
+       if (num_ch < 0 || num_ch > adc->dfsdm->num_chs) {
+               dev_err(&indio_dev->dev, "Bad st,adc-channels\n");
+               return num_ch < 0 ? num_ch : -EINVAL;
+       }
+
+       /* Bind to SD modulator IIO device */
+       adc->hwc = devm_iio_hw_consumer_alloc(&indio_dev->dev);
+       if (IS_ERR(adc->hwc))
+               return -EPROBE_DEFER;
+
+       ch = devm_kcalloc(&indio_dev->dev, num_ch, sizeof(*ch),
+                         GFP_KERNEL);
+       if (!ch)
+               return -ENOMEM;
+
+       for (chan_idx = 0; chan_idx < num_ch; chan_idx++) {
+               ch->scan_index = chan_idx;
+               ret = stm32_dfsdm_adc_chan_init_one(indio_dev, ch);
+               if (ret < 0) {
+                       dev_err(&indio_dev->dev, "Channels init failed\n");
+                       return ret;
+               }
+       }
+
+       indio_dev->num_channels = num_ch;
+       indio_dev->channels = ch;
+
+       init_completion(&adc->completion);
+
+       return 0;
+}
+
+static const struct stm32_dfsdm_dev_data stm32h7_dfsdm_adc_data = {
+       .type = DFSDM_IIO,
+       .init = stm32_dfsdm_adc_init,
+};
+
+static const struct stm32_dfsdm_dev_data stm32h7_dfsdm_audio_data = {
+       .type = DFSDM_AUDIO,
+       .init = stm32_dfsdm_audio_init,
+};
+
+static const struct of_device_id stm32_dfsdm_adc_match[] = {
+       {
+               .compatible = "st,stm32-dfsdm-adc",
+               .data = &stm32h7_dfsdm_adc_data,
+       },
+       {
+               .compatible = "st,stm32-dfsdm-dmic",
+               .data = &stm32h7_dfsdm_audio_data,
+       },
+       {}
+};
+
+static int stm32_dfsdm_adc_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct stm32_dfsdm_adc *adc;
+       struct device_node *np = dev->of_node;
+       const struct stm32_dfsdm_dev_data *dev_data;
+       struct iio_dev *iio;
+       const struct of_device_id *of_id;
+       char *name;
+       int ret, irq, val;
+
+       of_id = of_match_node(stm32_dfsdm_adc_match, np);
+       if (!of_id->data) {
+               dev_err(&pdev->dev, "Data associated to device is missing\n");
+               return -EINVAL;
+       }
+
+       dev_data = (const struct stm32_dfsdm_dev_data *)of_id->data;
+
+       iio = devm_iio_device_alloc(dev, sizeof(*adc));
+       if (IS_ERR(iio)) {
+               dev_err(dev, "%s: Failed to allocate IIO\n", __func__);
+               return PTR_ERR(iio);
+       }
+
+       adc = iio_priv(iio);
+       if (IS_ERR(adc)) {
+               dev_err(dev, "%s: Failed to allocate ADC\n", __func__);
+               return PTR_ERR(adc);
+       }
+       adc->dfsdm = dev_get_drvdata(dev->parent);
+
+       iio->dev.parent = dev;
+       iio->dev.of_node = np;
+       iio->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
+
+       platform_set_drvdata(pdev, adc);
+
+       ret = of_property_read_u32(dev->of_node, "reg", &adc->fl_id);
+       if (ret != 0) {
+               dev_err(dev, "Missing reg property\n");
+               return -EINVAL;
+       }
+
+       name = devm_kzalloc(dev, sizeof("dfsdm-adc0"), GFP_KERNEL);
+       if (!name)
+               return -ENOMEM;
+       if (dev_data->type == DFSDM_AUDIO) {
+               iio->info = &stm32_dfsdm_info_audio;
+               snprintf(name, sizeof("dfsdm-pdm0"), "dfsdm-pdm%d", adc->fl_id);
+       } else {
+               iio->info = &stm32_dfsdm_info_adc;
+               snprintf(name, sizeof("dfsdm-adc0"), "dfsdm-adc%d", adc->fl_id);
+       }
+       iio->name = name;
+
+       /*
+        * In a first step IRQs generated for channels are not treated.
+        * So IRQ associated to filter instance 0 is dedicated to the Filter 0.
+        */
+       irq = platform_get_irq(pdev, 0);
+       ret = devm_request_irq(dev, irq, stm32_dfsdm_irq,
+                              0, pdev->name, adc);
+       if (ret < 0) {
+               dev_err(dev, "Failed to request IRQ\n");
+               return ret;
+       }
+
+       ret = of_property_read_u32(dev->of_node, "st,filter-order", &val);
+       if (ret < 0) {
+               dev_err(dev, "Failed to set filter order\n");
+               return ret;
+       }
+
+       adc->dfsdm->fl_list[adc->fl_id].ford = val;
+
+       ret = of_property_read_u32(dev->of_node, "st,filter0-sync", &val);
+       if (!ret)
+               adc->dfsdm->fl_list[adc->fl_id].sync_mode = val;
+
+       adc->dev_data = dev_data;
+       ret = dev_data->init(iio);
+       if (ret < 0)
+               return ret;
+
+       ret = iio_device_register(iio);
+       if (ret < 0)
+               goto err_cleanup;
+
+       dev_err(dev, "of_platform_populate\n");
+       if (dev_data->type == DFSDM_AUDIO) {
+               ret = of_platform_populate(np, NULL, NULL, dev);
+               if (ret < 0) {
+                       dev_err(dev, "Failed to find an audio DAI\n");
+                       goto err_unregister;
+               }
+       }
+
+       return 0;
+
+err_unregister:
+       iio_device_unregister(iio);
+err_cleanup:
+       stm32_dfsdm_dma_release(iio);
+
+       return ret;
+}
+
+static int stm32_dfsdm_adc_remove(struct platform_device *pdev)
+{
+       struct stm32_dfsdm_adc *adc = platform_get_drvdata(pdev);
+       struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+
+       if (adc->dev_data->type == DFSDM_AUDIO)
+               of_platform_depopulate(&pdev->dev);
+       iio_device_unregister(indio_dev);
+       stm32_dfsdm_dma_release(indio_dev);
+
+       return 0;
+}
+
+static struct platform_driver stm32_dfsdm_adc_driver = {
+       .driver = {
+               .name = "stm32-dfsdm-adc",
+               .of_match_table = stm32_dfsdm_adc_match,
+       },
+       .probe = stm32_dfsdm_adc_probe,
+       .remove = stm32_dfsdm_adc_remove,
+};
+module_platform_driver(stm32_dfsdm_adc_driver);
+
+MODULE_DESCRIPTION("STM32 sigma delta ADC");
+MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/adc/stm32-dfsdm-core.c b/drivers/iio/adc/stm32-dfsdm-core.c
new file mode 100644 (file)
index 0000000..7242741
--- /dev/null
@@ -0,0 +1,309 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * This file is part the core part STM32 DFSDM driver
+ *
+ * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
+ * Author(s): Arnaud Pouliquen <arnaud.pouliquen@st.com> for STMicroelectronics.
+ */
+
+#include <linux/clk.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#include "stm32-dfsdm.h"
+
+struct stm32_dfsdm_dev_data {
+       unsigned int num_filters;
+       unsigned int num_channels;
+       const struct regmap_config *regmap_cfg;
+};
+
+#define STM32H7_DFSDM_NUM_FILTERS      4
+#define STM32H7_DFSDM_NUM_CHANNELS     8
+
+static bool stm32_dfsdm_volatile_reg(struct device *dev, unsigned int reg)
+{
+       if (reg < DFSDM_FILTER_BASE_ADR)
+               return false;
+
+       /*
+        * Mask is done on register to avoid to list registers of all
+        * filter instances.
+        */
+       switch (reg & DFSDM_FILTER_REG_MASK) {
+       case DFSDM_CR1(0) & DFSDM_FILTER_REG_MASK:
+       case DFSDM_ISR(0) & DFSDM_FILTER_REG_MASK:
+       case DFSDM_JDATAR(0) & DFSDM_FILTER_REG_MASK:
+       case DFSDM_RDATAR(0) & DFSDM_FILTER_REG_MASK:
+               return true;
+       }
+
+       return false;
+}
+
+static const struct regmap_config stm32h7_dfsdm_regmap_cfg = {
+       .reg_bits = 32,
+       .val_bits = 32,
+       .reg_stride = sizeof(u32),
+       .max_register = 0x2B8,
+       .volatile_reg = stm32_dfsdm_volatile_reg,
+       .fast_io = true,
+};
+
+static const struct stm32_dfsdm_dev_data stm32h7_dfsdm_data = {
+       .num_filters = STM32H7_DFSDM_NUM_FILTERS,
+       .num_channels = STM32H7_DFSDM_NUM_CHANNELS,
+       .regmap_cfg = &stm32h7_dfsdm_regmap_cfg,
+};
+
+struct dfsdm_priv {
+       struct platform_device *pdev; /* platform device */
+
+       struct stm32_dfsdm dfsdm; /* common data exported for all instances */
+
+       unsigned int spi_clk_out_div; /* SPI clkout divider value */
+       atomic_t n_active_ch;   /* number of current active channels */
+
+       struct clk *clk; /* DFSDM clock */
+       struct clk *aclk; /* audio clock */
+};
+
+/**
+ * stm32_dfsdm_start_dfsdm - start global dfsdm interface.
+ *
+ * Enable interface if n_active_ch is not null.
+ * @dfsdm: Handle used to retrieve dfsdm context.
+ */
+int stm32_dfsdm_start_dfsdm(struct stm32_dfsdm *dfsdm)
+{
+       struct dfsdm_priv *priv = container_of(dfsdm, struct dfsdm_priv, dfsdm);
+       struct device *dev = &priv->pdev->dev;
+       unsigned int clk_div = priv->spi_clk_out_div;
+       int ret;
+
+       if (atomic_inc_return(&priv->n_active_ch) == 1) {
+               ret = clk_prepare_enable(priv->clk);
+               if (ret < 0) {
+                       dev_err(dev, "Failed to start clock\n");
+                       goto error_ret;
+               }
+               if (priv->aclk) {
+                       ret = clk_prepare_enable(priv->aclk);
+                       if (ret < 0) {
+                               dev_err(dev, "Failed to start audio clock\n");
+                               goto disable_clk;
+                       }
+               }
+
+               /* Output the SPI CLKOUT (if clk_div == 0 clock if OFF) */
+               ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
+                                        DFSDM_CHCFGR1_CKOUTDIV_MASK,
+                                        DFSDM_CHCFGR1_CKOUTDIV(clk_div));
+               if (ret < 0)
+                       goto disable_aclk;
+
+               /* Global enable of DFSDM interface */
+               ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
+                                        DFSDM_CHCFGR1_DFSDMEN_MASK,
+                                        DFSDM_CHCFGR1_DFSDMEN(1));
+               if (ret < 0)
+                       goto disable_aclk;
+       }
+
+       dev_dbg(dev, "%s: n_active_ch %d\n", __func__,
+               atomic_read(&priv->n_active_ch));
+
+       return 0;
+
+disable_aclk:
+       clk_disable_unprepare(priv->aclk);
+disable_clk:
+       clk_disable_unprepare(priv->clk);
+
+error_ret:
+       atomic_dec(&priv->n_active_ch);
+
+       return ret;
+}
+EXPORT_SYMBOL_GPL(stm32_dfsdm_start_dfsdm);
+
+/**
+ * stm32_dfsdm_stop_dfsdm - stop global DFSDM interface.
+ *
+ * Disable interface if n_active_ch is null
+ * @dfsdm: Handle used to retrieve dfsdm context.
+ */
+int stm32_dfsdm_stop_dfsdm(struct stm32_dfsdm *dfsdm)
+{
+       struct dfsdm_priv *priv = container_of(dfsdm, struct dfsdm_priv, dfsdm);
+       int ret;
+
+       if (atomic_dec_and_test(&priv->n_active_ch)) {
+               /* Global disable of DFSDM interface */
+               ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
+                                        DFSDM_CHCFGR1_DFSDMEN_MASK,
+                                        DFSDM_CHCFGR1_DFSDMEN(0));
+               if (ret < 0)
+                       return ret;
+
+               /* Stop SPI CLKOUT */
+               ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
+                                        DFSDM_CHCFGR1_CKOUTDIV_MASK,
+                                        DFSDM_CHCFGR1_CKOUTDIV(0));
+               if (ret < 0)
+                       return ret;
+
+               clk_disable_unprepare(priv->clk);
+               if (priv->aclk)
+                       clk_disable_unprepare(priv->aclk);
+       }
+       dev_dbg(&priv->pdev->dev, "%s: n_active_ch %d\n", __func__,
+               atomic_read(&priv->n_active_ch));
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(stm32_dfsdm_stop_dfsdm);
+
+static int stm32_dfsdm_parse_of(struct platform_device *pdev,
+                               struct dfsdm_priv *priv)
+{
+       struct device_node *node = pdev->dev.of_node;
+       struct resource *res;
+       unsigned long clk_freq;
+       unsigned int spi_freq, rem;
+       int ret;
+
+       if (!node)
+               return -EINVAL;
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (!res) {
+               dev_err(&pdev->dev, "Failed to get memory resource\n");
+               return -ENODEV;
+       }
+       priv->dfsdm.phys_base = res->start;
+       priv->dfsdm.base = devm_ioremap_resource(&pdev->dev, res);
+
+       /*
+        * "dfsdm" clock is mandatory for DFSDM peripheral clocking.
+        * "dfsdm" or "audio" clocks can be used as source clock for
+        * the SPI clock out signal and internal processing, depending
+        * on use case.
+        */
+       priv->clk = devm_clk_get(&pdev->dev, "dfsdm");
+       if (IS_ERR(priv->clk)) {
+               dev_err(&pdev->dev, "No stm32_dfsdm_clk clock found\n");
+               return -EINVAL;
+       }
+
+       priv->aclk = devm_clk_get(&pdev->dev, "audio");
+       if (IS_ERR(priv->aclk))
+               priv->aclk = NULL;
+
+       if (priv->aclk)
+               clk_freq = clk_get_rate(priv->aclk);
+       else
+               clk_freq = clk_get_rate(priv->clk);
+
+       /* SPI clock out frequency */
+       ret = of_property_read_u32(pdev->dev.of_node, "spi-max-frequency",
+                                  &spi_freq);
+       if (ret < 0) {
+               /* No SPI master mode */
+               return 0;
+       }
+
+       priv->spi_clk_out_div = div_u64_rem(clk_freq, spi_freq, &rem) - 1;
+       priv->dfsdm.spi_master_freq = spi_freq;
+
+       if (rem) {
+               dev_warn(&pdev->dev, "SPI clock not accurate\n");
+               dev_warn(&pdev->dev, "%ld = %d * %d + %d\n",
+                        clk_freq, spi_freq, priv->spi_clk_out_div + 1, rem);
+       }
+
+       return 0;
+};
+
+static const struct of_device_id stm32_dfsdm_of_match[] = {
+       {
+               .compatible = "st,stm32h7-dfsdm",
+               .data = &stm32h7_dfsdm_data,
+       },
+       {}
+};
+MODULE_DEVICE_TABLE(of, stm32_dfsdm_of_match);
+
+static int stm32_dfsdm_probe(struct platform_device *pdev)
+{
+       struct dfsdm_priv *priv;
+       struct device_node *pnode = pdev->dev.of_node;
+       const struct of_device_id *of_id;
+       const struct stm32_dfsdm_dev_data *dev_data;
+       struct stm32_dfsdm *dfsdm;
+       int ret;
+
+       priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+       if (!priv)
+               return -ENOMEM;
+
+       priv->pdev = pdev;
+
+       of_id = of_match_node(stm32_dfsdm_of_match, pnode);
+       if (!of_id->data) {
+               dev_err(&pdev->dev, "Data associated to device is missing\n");
+               return -EINVAL;
+       }
+
+       dev_data = (const struct stm32_dfsdm_dev_data *)of_id->data;
+       dfsdm = &priv->dfsdm;
+       dfsdm->fl_list = devm_kcalloc(&pdev->dev, dev_data->num_filters,
+                                     sizeof(*dfsdm->fl_list), GFP_KERNEL);
+       if (!dfsdm->fl_list)
+               return -ENOMEM;
+
+       dfsdm->num_fls = dev_data->num_filters;
+       dfsdm->ch_list = devm_kcalloc(&pdev->dev, dev_data->num_channels,
+                                     sizeof(*dfsdm->ch_list),
+                                     GFP_KERNEL);
+       if (!dfsdm->ch_list)
+               return -ENOMEM;
+       dfsdm->num_chs = dev_data->num_channels;
+
+       ret = stm32_dfsdm_parse_of(pdev, priv);
+       if (ret < 0)
+               return ret;
+
+       dfsdm->regmap = devm_regmap_init_mmio_clk(&pdev->dev, "dfsdm",
+                                                 dfsdm->base,
+                                                 &stm32h7_dfsdm_regmap_cfg);
+       if (IS_ERR(dfsdm->regmap)) {
+               ret = PTR_ERR(dfsdm->regmap);
+               dev_err(&pdev->dev, "%s: Failed to allocate regmap: %d\n",
+                       __func__, ret);
+               return ret;
+       }
+
+       platform_set_drvdata(pdev, dfsdm);
+
+       return devm_of_platform_populate(&pdev->dev);
+}
+
+static struct platform_driver stm32_dfsdm_driver = {
+       .probe = stm32_dfsdm_probe,
+       .driver = {
+               .name = "stm32-dfsdm",
+               .of_match_table = stm32_dfsdm_of_match,
+       },
+};
+
+module_platform_driver(stm32_dfsdm_driver);
+
+MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics STM32 dfsdm driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/adc/stm32-dfsdm.h b/drivers/iio/adc/stm32-dfsdm.h
new file mode 100644 (file)
index 0000000..8708394
--- /dev/null
@@ -0,0 +1,310 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * This file is part of STM32 DFSDM driver
+ *
+ * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
+ * Author(s): Arnaud Pouliquen <arnaud.pouliquen@st.com>.
+ */
+
+#ifndef MDF_STM32_DFSDM__H
+#define MDF_STM32_DFSDM__H
+
+#include <linux/bitfield.h>
+
+/*
+ * STM32 DFSDM - global register map
+ * ________________________________________________________
+ * | Offset |                 Registers block             |
+ * --------------------------------------------------------
+ * | 0x000  |      CHANNEL 0 + COMMON CHANNEL FIELDS      |
+ * --------------------------------------------------------
+ * | 0x020  |                CHANNEL 1                    |
+ * --------------------------------------------------------
+ * | ...    |                .....                        |
+ * --------------------------------------------------------
+ * | 0x0E0  |                CHANNEL 7                    |
+ * --------------------------------------------------------
+ * | 0x100  |      FILTER  0 + COMMON  FILTER FIELDs      |
+ * --------------------------------------------------------
+ * | 0x200  |                FILTER  1                    |
+ * --------------------------------------------------------
+ * | 0x300  |                FILTER  2                    |
+ * --------------------------------------------------------
+ * | 0x400  |                FILTER  3                    |
+ * --------------------------------------------------------
+ */
+
+/*
+ * Channels register definitions
+ */
+#define DFSDM_CHCFGR1(y)  ((y) * 0x20 + 0x00)
+#define DFSDM_CHCFGR2(y)  ((y) * 0x20 + 0x04)
+#define DFSDM_AWSCDR(y)   ((y) * 0x20 + 0x08)
+#define DFSDM_CHWDATR(y)  ((y) * 0x20 + 0x0C)
+#define DFSDM_CHDATINR(y) ((y) * 0x20 + 0x10)
+
+/* CHCFGR1: Channel configuration register 1 */
+#define DFSDM_CHCFGR1_SITP_MASK     GENMASK(1, 0)
+#define DFSDM_CHCFGR1_SITP(v)       FIELD_PREP(DFSDM_CHCFGR1_SITP_MASK, v)
+#define DFSDM_CHCFGR1_SPICKSEL_MASK GENMASK(3, 2)
+#define DFSDM_CHCFGR1_SPICKSEL(v)   FIELD_PREP(DFSDM_CHCFGR1_SPICKSEL_MASK, v)
+#define DFSDM_CHCFGR1_SCDEN_MASK    BIT(5)
+#define DFSDM_CHCFGR1_SCDEN(v)      FIELD_PREP(DFSDM_CHCFGR1_SCDEN_MASK, v)
+#define DFSDM_CHCFGR1_CKABEN_MASK   BIT(6)
+#define DFSDM_CHCFGR1_CKABEN(v)     FIELD_PREP(DFSDM_CHCFGR1_CKABEN_MASK, v)
+#define DFSDM_CHCFGR1_CHEN_MASK     BIT(7)
+#define DFSDM_CHCFGR1_CHEN(v)       FIELD_PREP(DFSDM_CHCFGR1_CHEN_MASK, v)
+#define DFSDM_CHCFGR1_CHINSEL_MASK  BIT(8)
+#define DFSDM_CHCFGR1_CHINSEL(v)    FIELD_PREP(DFSDM_CHCFGR1_CHINSEL_MASK, v)
+#define DFSDM_CHCFGR1_DATMPX_MASK   GENMASK(13, 12)
+#define DFSDM_CHCFGR1_DATMPX(v)     FIELD_PREP(DFSDM_CHCFGR1_DATMPX_MASK, v)
+#define DFSDM_CHCFGR1_DATPACK_MASK  GENMASK(15, 14)
+#define DFSDM_CHCFGR1_DATPACK(v)    FIELD_PREP(DFSDM_CHCFGR1_DATPACK_MASK, v)
+#define DFSDM_CHCFGR1_CKOUTDIV_MASK GENMASK(23, 16)
+#define DFSDM_CHCFGR1_CKOUTDIV(v)   FIELD_PREP(DFSDM_CHCFGR1_CKOUTDIV_MASK, v)
+#define DFSDM_CHCFGR1_CKOUTSRC_MASK BIT(30)
+#define DFSDM_CHCFGR1_CKOUTSRC(v)   FIELD_PREP(DFSDM_CHCFGR1_CKOUTSRC_MASK, v)
+#define DFSDM_CHCFGR1_DFSDMEN_MASK  BIT(31)
+#define DFSDM_CHCFGR1_DFSDMEN(v)    FIELD_PREP(DFSDM_CHCFGR1_DFSDMEN_MASK, v)
+
+/* CHCFGR2: Channel configuration register 2 */
+#define DFSDM_CHCFGR2_DTRBS_MASK    GENMASK(7, 3)
+#define DFSDM_CHCFGR2_DTRBS(v)      FIELD_PREP(DFSDM_CHCFGR2_DTRBS_MASK, v)
+#define DFSDM_CHCFGR2_OFFSET_MASK   GENMASK(31, 8)
+#define DFSDM_CHCFGR2_OFFSET(v)     FIELD_PREP(DFSDM_CHCFGR2_OFFSET_MASK, v)
+
+/* AWSCDR: Channel analog watchdog and short circuit detector */
+#define DFSDM_AWSCDR_SCDT_MASK    GENMASK(7, 0)
+#define DFSDM_AWSCDR_SCDT(v)      FIELD_PREP(DFSDM_AWSCDR_SCDT_MASK, v)
+#define DFSDM_AWSCDR_BKSCD_MASK   GENMASK(15, 12)
+#define DFSDM_AWSCDR_BKSCD(v)    FIELD_PREP(DFSDM_AWSCDR_BKSCD_MASK, v)
+#define DFSDM_AWSCDR_AWFOSR_MASK  GENMASK(20, 16)
+#define DFSDM_AWSCDR_AWFOSR(v)    FIELD_PREP(DFSDM_AWSCDR_AWFOSR_MASK, v)
+#define DFSDM_AWSCDR_AWFORD_MASK  GENMASK(23, 22)
+#define DFSDM_AWSCDR_AWFORD(v)    FIELD_PREP(DFSDM_AWSCDR_AWFORD_MASK, v)
+
+/*
+ * Filters register definitions
+ */
+#define DFSDM_FILTER_BASE_ADR          0x100
+#define DFSDM_FILTER_REG_MASK          0x7F
+#define DFSDM_FILTER_X_BASE_ADR(x)     ((x) * 0x80 + DFSDM_FILTER_BASE_ADR)
+
+#define DFSDM_CR1(x)     (DFSDM_FILTER_X_BASE_ADR(x)  + 0x00)
+#define DFSDM_CR2(x)     (DFSDM_FILTER_X_BASE_ADR(x)  + 0x04)
+#define DFSDM_ISR(x)     (DFSDM_FILTER_X_BASE_ADR(x)  + 0x08)
+#define DFSDM_ICR(x)     (DFSDM_FILTER_X_BASE_ADR(x)  + 0x0C)
+#define DFSDM_JCHGR(x)   (DFSDM_FILTER_X_BASE_ADR(x)  + 0x10)
+#define DFSDM_FCR(x)     (DFSDM_FILTER_X_BASE_ADR(x)  + 0x14)
+#define DFSDM_JDATAR(x)  (DFSDM_FILTER_X_BASE_ADR(x)  + 0x18)
+#define DFSDM_RDATAR(x)  (DFSDM_FILTER_X_BASE_ADR(x)  + 0x1C)
+#define DFSDM_AWHTR(x)   (DFSDM_FILTER_X_BASE_ADR(x)  + 0x20)
+#define DFSDM_AWLTR(x)   (DFSDM_FILTER_X_BASE_ADR(x)  + 0x24)
+#define DFSDM_AWSR(x)    (DFSDM_FILTER_X_BASE_ADR(x)  + 0x28)
+#define DFSDM_AWCFR(x)   (DFSDM_FILTER_X_BASE_ADR(x)  + 0x2C)
+#define DFSDM_EXMAX(x)   (DFSDM_FILTER_X_BASE_ADR(x)  + 0x30)
+#define DFSDM_EXMIN(x)   (DFSDM_FILTER_X_BASE_ADR(x)  + 0x34)
+#define DFSDM_CNVTIMR(x) (DFSDM_FILTER_X_BASE_ADR(x)  + 0x38)
+
+/* CR1 Control register 1 */
+#define DFSDM_CR1_DFEN_MASK    BIT(0)
+#define DFSDM_CR1_DFEN(v)      FIELD_PREP(DFSDM_CR1_DFEN_MASK, v)
+#define DFSDM_CR1_JSWSTART_MASK        BIT(1)
+#define DFSDM_CR1_JSWSTART(v)  FIELD_PREP(DFSDM_CR1_JSWSTART_MASK, v)
+#define DFSDM_CR1_JSYNC_MASK   BIT(3)
+#define DFSDM_CR1_JSYNC(v)     FIELD_PREP(DFSDM_CR1_JSYNC_MASK, v)
+#define DFSDM_CR1_JSCAN_MASK   BIT(4)
+#define DFSDM_CR1_JSCAN(v)     FIELD_PREP(DFSDM_CR1_JSCAN_MASK, v)
+#define DFSDM_CR1_JDMAEN_MASK  BIT(5)
+#define DFSDM_CR1_JDMAEN(v)    FIELD_PREP(DFSDM_CR1_JDMAEN_MASK, v)
+#define DFSDM_CR1_JEXTSEL_MASK GENMASK(12, 8)
+#define DFSDM_CR1_JEXTSEL(v)   FIELD_PREP(DFSDM_CR1_JEXTSEL_MASK, v)
+#define DFSDM_CR1_JEXTEN_MASK  GENMASK(14, 13)
+#define DFSDM_CR1_JEXTEN(v)    FIELD_PREP(DFSDM_CR1_JEXTEN_MASK, v)
+#define DFSDM_CR1_RSWSTART_MASK        BIT(17)
+#define DFSDM_CR1_RSWSTART(v)  FIELD_PREP(DFSDM_CR1_RSWSTART_MASK, v)
+#define DFSDM_CR1_RCONT_MASK   BIT(18)
+#define DFSDM_CR1_RCONT(v)     FIELD_PREP(DFSDM_CR1_RCONT_MASK, v)
+#define DFSDM_CR1_RSYNC_MASK   BIT(19)
+#define DFSDM_CR1_RSYNC(v)     FIELD_PREP(DFSDM_CR1_RSYNC_MASK, v)
+#define DFSDM_CR1_RDMAEN_MASK  BIT(21)
+#define DFSDM_CR1_RDMAEN(v)    FIELD_PREP(DFSDM_CR1_RDMAEN_MASK, v)
+#define DFSDM_CR1_RCH_MASK     GENMASK(26, 24)
+#define DFSDM_CR1_RCH(v)       FIELD_PREP(DFSDM_CR1_RCH_MASK, v)
+#define DFSDM_CR1_FAST_MASK    BIT(29)
+#define DFSDM_CR1_FAST(v)      FIELD_PREP(DFSDM_CR1_FAST_MASK, v)
+#define DFSDM_CR1_AWFSEL_MASK  BIT(30)
+#define DFSDM_CR1_AWFSEL(v)    FIELD_PREP(DFSDM_CR1_AWFSEL_MASK, v)
+
+/* CR2: Control register 2 */
+#define DFSDM_CR2_IE_MASK      GENMASK(6, 0)
+#define DFSDM_CR2_IE(v)                FIELD_PREP(DFSDM_CR2_IE_MASK, v)
+#define DFSDM_CR2_JEOCIE_MASK  BIT(0)
+#define DFSDM_CR2_JEOCIE(v)    FIELD_PREP(DFSDM_CR2_JEOCIE_MASK, v)
+#define DFSDM_CR2_REOCIE_MASK  BIT(1)
+#define DFSDM_CR2_REOCIE(v)    FIELD_PREP(DFSDM_CR2_REOCIE_MASK, v)
+#define DFSDM_CR2_JOVRIE_MASK  BIT(2)
+#define DFSDM_CR2_JOVRIE(v)    FIELD_PREP(DFSDM_CR2_JOVRIE_MASK, v)
+#define DFSDM_CR2_ROVRIE_MASK  BIT(3)
+#define DFSDM_CR2_ROVRIE(v)    FIELD_PREP(DFSDM_CR2_ROVRIE_MASK, v)
+#define DFSDM_CR2_AWDIE_MASK   BIT(4)
+#define DFSDM_CR2_AWDIE(v)     FIELD_PREP(DFSDM_CR2_AWDIE_MASK, v)
+#define DFSDM_CR2_SCDIE_MASK   BIT(5)
+#define DFSDM_CR2_SCDIE(v)     FIELD_PREP(DFSDM_CR2_SCDIE_MASK, v)
+#define DFSDM_CR2_CKABIE_MASK  BIT(6)
+#define DFSDM_CR2_CKABIE(v)    FIELD_PREP(DFSDM_CR2_CKABIE_MASK, v)
+#define DFSDM_CR2_EXCH_MASK    GENMASK(15, 8)
+#define DFSDM_CR2_EXCH(v)      FIELD_PREP(DFSDM_CR2_EXCH_MASK, v)
+#define DFSDM_CR2_AWDCH_MASK   GENMASK(23, 16)
+#define DFSDM_CR2_AWDCH(v)     FIELD_PREP(DFSDM_CR2_AWDCH_MASK, v)
+
+/* ISR: Interrupt status register */
+#define DFSDM_ISR_JEOCF_MASK   BIT(0)
+#define DFSDM_ISR_JEOCF(v)     FIELD_PREP(DFSDM_ISR_JEOCF_MASK, v)
+#define DFSDM_ISR_REOCF_MASK   BIT(1)
+#define DFSDM_ISR_REOCF(v)     FIELD_PREP(DFSDM_ISR_REOCF_MASK, v)
+#define DFSDM_ISR_JOVRF_MASK   BIT(2)
+#define DFSDM_ISR_JOVRF(v)     FIELD_PREP(DFSDM_ISR_JOVRF_MASK, v)
+#define DFSDM_ISR_ROVRF_MASK   BIT(3)
+#define DFSDM_ISR_ROVRF(v)     FIELD_PREP(DFSDM_ISR_ROVRF_MASK, v)
+#define DFSDM_ISR_AWDF_MASK    BIT(4)
+#define DFSDM_ISR_AWDF(v)      FIELD_PREP(DFSDM_ISR_AWDF_MASK, v)
+#define DFSDM_ISR_JCIP_MASK    BIT(13)
+#define DFSDM_ISR_JCIP(v)      FIELD_PREP(DFSDM_ISR_JCIP_MASK, v)
+#define DFSDM_ISR_RCIP_MASK    BIT(14)
+#define DFSDM_ISR_RCIP(v)      FIELD_PREP(DFSDM_ISR_RCIP, v)
+#define DFSDM_ISR_CKABF_MASK   GENMASK(23, 16)
+#define DFSDM_ISR_CKABF(v)     FIELD_PREP(DFSDM_ISR_CKABF_MASK, v)
+#define DFSDM_ISR_SCDF_MASK    GENMASK(31, 24)
+#define DFSDM_ISR_SCDF(v)      FIELD_PREP(DFSDM_ISR_SCDF_MASK, v)
+
+/* ICR: Interrupt flag clear register */
+#define DFSDM_ICR_CLRJOVRF_MASK              BIT(2)
+#define DFSDM_ICR_CLRJOVRF(v)        FIELD_PREP(DFSDM_ICR_CLRJOVRF_MASK, v)
+#define DFSDM_ICR_CLRROVRF_MASK              BIT(3)
+#define DFSDM_ICR_CLRROVRF(v)        FIELD_PREP(DFSDM_ICR_CLRROVRF_MASK, v)
+#define DFSDM_ICR_CLRCKABF_MASK              GENMASK(23, 16)
+#define DFSDM_ICR_CLRCKABF(v)        FIELD_PREP(DFSDM_ICR_CLRCKABF_MASK, v)
+#define DFSDM_ICR_CLRCKABF_CH_MASK(y) BIT(16 + (y))
+#define DFSDM_ICR_CLRCKABF_CH(v, y)   \
+                          (((v) << (16 + (y))) & DFSDM_ICR_CLRCKABF_CH_MASK(y))
+#define DFSDM_ICR_CLRSCDF_MASK       GENMASK(31, 24)
+#define DFSDM_ICR_CLRSCDF(v)         FIELD_PREP(DFSDM_ICR_CLRSCDF_MASK, v)
+#define DFSDM_ICR_CLRSCDF_CH_MASK(y)  BIT(24 + (y))
+#define DFSDM_ICR_CLRSCDF_CH(v, y)    \
+                              (((v) << (24 + (y))) & DFSDM_ICR_CLRSCDF_MASK(y))
+
+/* FCR: Filter control register */
+#define DFSDM_FCR_IOSR_MASK    GENMASK(7, 0)
+#define DFSDM_FCR_IOSR(v)      FIELD_PREP(DFSDM_FCR_IOSR_MASK, v)
+#define DFSDM_FCR_FOSR_MASK    GENMASK(25, 16)
+#define DFSDM_FCR_FOSR(v)      FIELD_PREP(DFSDM_FCR_FOSR_MASK, v)
+#define DFSDM_FCR_FORD_MASK    GENMASK(31, 29)
+#define DFSDM_FCR_FORD(v)      FIELD_PREP(DFSDM_FCR_FORD_MASK, v)
+
+/* RDATAR: Filter data register for regular channel */
+#define DFSDM_DATAR_CH_MASK    GENMASK(2, 0)
+#define DFSDM_DATAR_DATA_OFFSET 8
+#define DFSDM_DATAR_DATA_MASK  GENMASK(31, DFSDM_DATAR_DATA_OFFSET)
+
+/* AWLTR: Filter analog watchdog low threshold register */
+#define DFSDM_AWLTR_BKAWL_MASK GENMASK(3, 0)
+#define DFSDM_AWLTR_BKAWL(v)   FIELD_PREP(DFSDM_AWLTR_BKAWL_MASK, v)
+#define DFSDM_AWLTR_AWLT_MASK  GENMASK(31, 8)
+#define DFSDM_AWLTR_AWLT(v)    FIELD_PREP(DFSDM_AWLTR_AWLT_MASK, v)
+
+/* AWHTR: Filter analog watchdog low threshold register */
+#define DFSDM_AWHTR_BKAWH_MASK GENMASK(3, 0)
+#define DFSDM_AWHTR_BKAWH(v)   FIELD_PREP(DFSDM_AWHTR_BKAWH_MASK, v)
+#define DFSDM_AWHTR_AWHT_MASK  GENMASK(31, 8)
+#define DFSDM_AWHTR_AWHT(v)    FIELD_PREP(DFSDM_AWHTR_AWHT_MASK, v)
+
+/* AWSR: Filter watchdog status register */
+#define DFSDM_AWSR_AWLTF_MASK  GENMASK(7, 0)
+#define DFSDM_AWSR_AWLTF(v)    FIELD_PREP(DFSDM_AWSR_AWLTF_MASK, v)
+#define DFSDM_AWSR_AWHTF_MASK  GENMASK(15, 8)
+#define DFSDM_AWSR_AWHTF(v)    FIELD_PREP(DFSDM_AWSR_AWHTF_MASK, v)
+
+/* AWCFR: Filter watchdog status register */
+#define DFSDM_AWCFR_AWLTF_MASK GENMASK(7, 0)
+#define DFSDM_AWCFR_AWLTF(v)   FIELD_PREP(DFSDM_AWCFR_AWLTF_MASK, v)
+#define DFSDM_AWCFR_AWHTF_MASK GENMASK(15, 8)
+#define DFSDM_AWCFR_AWHTF(v)   FIELD_PREP(DFSDM_AWCFR_AWHTF_MASK, v)
+
+/* DFSDM filter order  */
+enum stm32_dfsdm_sinc_order {
+       DFSDM_FASTSINC_ORDER, /* FastSinc filter type */
+       DFSDM_SINC1_ORDER,    /* Sinc 1 filter type */
+       DFSDM_SINC2_ORDER,    /* Sinc 2 filter type */
+       DFSDM_SINC3_ORDER,    /* Sinc 3 filter type */
+       DFSDM_SINC4_ORDER,    /* Sinc 4 filter type (N.A. for watchdog) */
+       DFSDM_SINC5_ORDER,    /* Sinc 5 filter type (N.A. for watchdog) */
+       DFSDM_NB_SINC_ORDER,
+};
+
+/**
+ * struct stm32_dfsdm_filter - structure relative to stm32 FDSDM filter
+ * @iosr: integrator oversampling
+ * @fosr: filter oversampling
+ * @ford: filter order
+ * @res: output sample resolution
+ * @sync_mode: filter synchronized with filter 0
+ * @fast: filter fast mode
+ */
+struct stm32_dfsdm_filter {
+       unsigned int iosr;
+       unsigned int fosr;
+       enum stm32_dfsdm_sinc_order ford;
+       u64 res;
+       unsigned int sync_mode;
+       unsigned int fast;
+};
+
+/**
+ * struct stm32_dfsdm_channel - structure relative to stm32 FDSDM channel
+ * @id: id of the channel
+ * @type: interface type linked to stm32_dfsdm_chan_type
+ * @src: interface type linked to stm32_dfsdm_chan_src
+ * @alt_si: alternative serial input interface
+ */
+struct stm32_dfsdm_channel {
+       unsigned int id;
+       unsigned int type;
+       unsigned int src;
+       unsigned int alt_si;
+};
+
+/**
+ * struct stm32_dfsdm - stm32 FDSDM driver common data (for all instances)
+ * @base:      control registers base cpu addr
+ * @phys_base: DFSDM IP register physical address
+ * @regmap:    regmap for register read/write
+ * @fl_list:   filter resources list
+ * @num_fls:   number of filter resources available
+ * @ch_list:   channel resources list
+ * @num_chs:   number of channel resources available
+ * @spi_master_freq: SPI clock out frequency
+ */
+struct stm32_dfsdm {
+       void __iomem    *base;
+       phys_addr_t     phys_base;
+       struct regmap *regmap;
+       struct stm32_dfsdm_filter *fl_list;
+       unsigned int num_fls;
+       struct stm32_dfsdm_channel *ch_list;
+       unsigned int num_chs;
+       unsigned int spi_master_freq;
+};
+
+/* DFSDM channel serial spi clock source */
+enum stm32_dfsdm_spi_clk_src {
+       DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL,
+       DFSDM_CHANNEL_SPI_CLOCK_INTERNAL,
+       DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_FALLING,
+       DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_RISING
+};
+
+int stm32_dfsdm_start_dfsdm(struct stm32_dfsdm *dfsdm);
+int stm32_dfsdm_stop_dfsdm(struct stm32_dfsdm *dfsdm);
+
+#endif
index 4ffd3db..338774c 100644 (file)
@@ -29,6 +29,16 @@ config IIO_BUFFER_DMAENGINE
 
          Should be selected by drivers that want to use this functionality.
 
+config IIO_BUFFER_HW_CONSUMER
+       tristate "Industrial I/O HW buffering"
+       help
+         Provides a way to bonding when an IIO device has a direct connection
+         to another device in hardware. In this case buffers for data transfers
+         are handled by hardware.
+
+         Should be selected by drivers that want to use the generic Hw consumer
+         interface.
+
 config IIO_KFIFO_BUF
        tristate "Industrial I/O buffering based on kfifo"
        help
index 95f9f41..1403eb2 100644 (file)
@@ -7,5 +7,6 @@
 obj-$(CONFIG_IIO_BUFFER_CB) += industrialio-buffer-cb.o
 obj-$(CONFIG_IIO_BUFFER_DMA) += industrialio-buffer-dma.o
 obj-$(CONFIG_IIO_BUFFER_DMAENGINE) += industrialio-buffer-dmaengine.o
+obj-$(CONFIG_IIO_BUFFER_HW_CONSUMER) += industrialio-hw-consumer.o
 obj-$(CONFIG_IIO_TRIGGERED_BUFFER) += industrialio-triggered-buffer.o
 obj-$(CONFIG_IIO_KFIFO_BUF) += kfifo_buf.o
index 4847534..ea63c83 100644 (file)
@@ -104,6 +104,17 @@ error_free_cb_buff:
 }
 EXPORT_SYMBOL_GPL(iio_channel_get_all_cb);
 
+int iio_channel_cb_set_buffer_watermark(struct iio_cb_buffer *cb_buff,
+                                       size_t watermark)
+{
+       if (!watermark)
+               return -EINVAL;
+       cb_buff->buffer.watermark = watermark;
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(iio_channel_cb_set_buffer_watermark);
+
 int iio_channel_start_all_cb(struct iio_cb_buffer *cb_buff)
 {
        return iio_update_buffers(cb_buff->indio_dev, &cb_buff->buffer,
diff --git a/drivers/iio/buffer/industrialio-hw-consumer.c b/drivers/iio/buffer/industrialio-hw-consumer.c
new file mode 100644 (file)
index 0000000..9516569
--- /dev/null
@@ -0,0 +1,247 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2017 Analog Devices Inc.
+ *  Author: Lars-Peter Clausen <lars@metafoo.de>
+ */
+
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/consumer.h>
+#include <linux/iio/hw-consumer.h>
+#include <linux/iio/buffer_impl.h>
+
+/**
+ * struct iio_hw_consumer - IIO hw consumer block
+ * @buffers: hardware buffers list head.
+ * @channels: IIO provider channels.
+ */
+struct iio_hw_consumer {
+       struct list_head buffers;
+       struct iio_channel *channels;
+};
+
+struct hw_consumer_buffer {
+       struct list_head head;
+       struct iio_dev *indio_dev;
+       struct iio_buffer buffer;
+       long scan_mask[];
+};
+
+static struct hw_consumer_buffer *iio_buffer_to_hw_consumer_buffer(
+       struct iio_buffer *buffer)
+{
+       return container_of(buffer, struct hw_consumer_buffer, buffer);
+}
+
+static void iio_hw_buf_release(struct iio_buffer *buffer)
+{
+       struct hw_consumer_buffer *hw_buf =
+               iio_buffer_to_hw_consumer_buffer(buffer);
+       kfree(hw_buf);
+}
+
+static const struct iio_buffer_access_funcs iio_hw_buf_access = {
+       .release = &iio_hw_buf_release,
+       .modes = INDIO_BUFFER_HARDWARE,
+};
+
+static struct hw_consumer_buffer *iio_hw_consumer_get_buffer(
+       struct iio_hw_consumer *hwc, struct iio_dev *indio_dev)
+{
+       size_t mask_size = BITS_TO_LONGS(indio_dev->masklength) * sizeof(long);
+       struct hw_consumer_buffer *buf;
+
+       list_for_each_entry(buf, &hwc->buffers, head) {
+               if (buf->indio_dev == indio_dev)
+                       return buf;
+       }
+
+       buf = kzalloc(sizeof(*buf) + mask_size, GFP_KERNEL);
+       if (!buf)
+               return NULL;
+
+       buf->buffer.access = &iio_hw_buf_access;
+       buf->indio_dev = indio_dev;
+       buf->buffer.scan_mask = buf->scan_mask;
+
+       iio_buffer_init(&buf->buffer);
+       list_add_tail(&buf->head, &hwc->buffers);
+
+       return buf;
+}
+
+/**
+ * iio_hw_consumer_alloc() - Allocate IIO hardware consumer
+ * @dev: Pointer to consumer device.
+ *
+ * Returns a valid iio_hw_consumer on success or a ERR_PTR() on failure.
+ */
+struct iio_hw_consumer *iio_hw_consumer_alloc(struct device *dev)
+{
+       struct hw_consumer_buffer *buf;
+       struct iio_hw_consumer *hwc;
+       struct iio_channel *chan;
+       int ret;
+
+       hwc = kzalloc(sizeof(*hwc), GFP_KERNEL);
+       if (!hwc)
+               return ERR_PTR(-ENOMEM);
+
+       INIT_LIST_HEAD(&hwc->buffers);
+
+       hwc->channels = iio_channel_get_all(dev);
+       if (IS_ERR(hwc->channels)) {
+               ret = PTR_ERR(hwc->channels);
+               goto err_free_hwc;
+       }
+
+       chan = &hwc->channels[0];
+       while (chan->indio_dev) {
+               buf = iio_hw_consumer_get_buffer(hwc, chan->indio_dev);
+               if (!buf) {
+                       ret = -ENOMEM;
+                       goto err_put_buffers;
+               }
+               set_bit(chan->channel->scan_index, buf->buffer.scan_mask);
+               chan++;
+       }
+
+       return hwc;
+
+err_put_buffers:
+       list_for_each_entry(buf, &hwc->buffers, head)
+               iio_buffer_put(&buf->buffer);
+       iio_channel_release_all(hwc->channels);
+err_free_hwc:
+       kfree(hwc);
+       return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(iio_hw_consumer_alloc);
+
+/**
+ * iio_hw_consumer_free() - Free IIO hardware consumer
+ * @hwc: hw consumer to free.
+ */
+void iio_hw_consumer_free(struct iio_hw_consumer *hwc)
+{
+       struct hw_consumer_buffer *buf, *n;
+
+       iio_channel_release_all(hwc->channels);
+       list_for_each_entry_safe(buf, n, &hwc->buffers, head)
+               iio_buffer_put(&buf->buffer);
+       kfree(hwc);
+}
+EXPORT_SYMBOL_GPL(iio_hw_consumer_free);
+
+static void devm_iio_hw_consumer_release(struct device *dev, void *res)
+{
+       iio_hw_consumer_free(*(struct iio_hw_consumer **)res);
+}
+
+static int devm_iio_hw_consumer_match(struct device *dev, void *res, void *data)
+{
+       struct iio_hw_consumer **r = res;
+
+       if (!r || !*r) {
+               WARN_ON(!r || !*r);
+               return 0;
+       }
+       return *r == data;
+}
+
+/**
+ * devm_iio_hw_consumer_alloc - Resource-managed iio_hw_consumer_alloc()
+ * @dev: Pointer to consumer device.
+ *
+ * Managed iio_hw_consumer_alloc. iio_hw_consumer allocated with this function
+ * is automatically freed on driver detach.
+ *
+ * If an iio_hw_consumer allocated with this function needs to be freed
+ * separately, devm_iio_hw_consumer_free() must be used.
+ *
+ * returns pointer to allocated iio_hw_consumer on success, NULL on failure.
+ */
+struct iio_hw_consumer *devm_iio_hw_consumer_alloc(struct device *dev)
+{
+       struct iio_hw_consumer **ptr, *iio_hwc;
+
+       ptr = devres_alloc(devm_iio_hw_consumer_release, sizeof(*ptr),
+                          GFP_KERNEL);
+       if (!ptr)
+               return NULL;
+
+       iio_hwc = iio_hw_consumer_alloc(dev);
+       if (IS_ERR(iio_hwc)) {
+               devres_free(ptr);
+       } else {
+               *ptr = iio_hwc;
+               devres_add(dev, ptr);
+       }
+
+       return iio_hwc;
+}
+EXPORT_SYMBOL_GPL(devm_iio_hw_consumer_alloc);
+
+/**
+ * devm_iio_hw_consumer_free - Resource-managed iio_hw_consumer_free()
+ * @dev: Pointer to consumer device.
+ * @hwc: iio_hw_consumer to free.
+ *
+ * Free iio_hw_consumer allocated with devm_iio_hw_consumer_alloc().
+ */
+void devm_iio_hw_consumer_free(struct device *dev, struct iio_hw_consumer *hwc)
+{
+       int rc;
+
+       rc = devres_release(dev, devm_iio_hw_consumer_release,
+                           devm_iio_hw_consumer_match, hwc);
+       WARN_ON(rc);
+}
+EXPORT_SYMBOL_GPL(devm_iio_hw_consumer_free);
+
+/**
+ * iio_hw_consumer_enable() - Enable IIO hardware consumer
+ * @hwc: iio_hw_consumer to enable.
+ *
+ * Returns 0 on success.
+ */
+int iio_hw_consumer_enable(struct iio_hw_consumer *hwc)
+{
+       struct hw_consumer_buffer *buf;
+       int ret;
+
+       list_for_each_entry(buf, &hwc->buffers, head) {
+               ret = iio_update_buffers(buf->indio_dev, &buf->buffer, NULL);
+               if (ret)
+                       goto err_disable_buffers;
+       }
+
+       return 0;
+
+err_disable_buffers:
+       list_for_each_entry_continue_reverse(buf, &hwc->buffers, head)
+               iio_update_buffers(buf->indio_dev, NULL, &buf->buffer);
+       return ret;
+}
+EXPORT_SYMBOL_GPL(iio_hw_consumer_enable);
+
+/**
+ * iio_hw_consumer_disable() - Disable IIO hardware consumer
+ * @hwc: iio_hw_consumer to disable.
+ */
+void iio_hw_consumer_disable(struct iio_hw_consumer *hwc)
+{
+       struct hw_consumer_buffer *buf;
+
+       list_for_each_entry(buf, &hwc->buffers, head)
+               iio_update_buffers(buf->indio_dev, NULL, &buf->buffer);
+}
+EXPORT_SYMBOL_GPL(iio_hw_consumer_disable);
+
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
+MODULE_DESCRIPTION("Hardware consumer buffer the IIO framework");
+MODULE_LICENSE("GPL v2");
index 069defc..ec98790 100644 (file)
@@ -664,9 +664,8 @@ err_unlock:
 }
 EXPORT_SYMBOL_GPL(iio_convert_raw_to_processed);
 
-static int iio_read_channel_attribute(struct iio_channel *chan,
-                                     int *val, int *val2,
-                                     enum iio_chan_info_enum attribute)
+int iio_read_channel_attribute(struct iio_channel *chan, int *val, int *val2,
+                              enum iio_chan_info_enum attribute)
 {
        int ret;
 
@@ -682,6 +681,7 @@ err_unlock:
 
        return ret;
 }
+EXPORT_SYMBOL_GPL(iio_read_channel_attribute);
 
 int iio_read_channel_offset(struct iio_channel *chan, int *val, int *val2)
 {
@@ -850,7 +850,8 @@ static int iio_channel_write(struct iio_channel *chan, int val, int val2,
                                                chan->channel, val, val2, info);
 }
 
-int iio_write_channel_raw(struct iio_channel *chan, int val)
+int iio_write_channel_attribute(struct iio_channel *chan, int val, int val2,
+                               enum iio_chan_info_enum attribute)
 {
        int ret;
 
@@ -860,12 +861,18 @@ int iio_write_channel_raw(struct iio_channel *chan, int val)
                goto err_unlock;
        }
 
-       ret = iio_channel_write(chan, val, 0, IIO_CHAN_INFO_RAW);
+       ret = iio_channel_write(chan, val, val2, attribute);
 err_unlock:
        mutex_unlock(&chan->indio_dev->info_exist_lock);
 
        return ret;
 }
+EXPORT_SYMBOL_GPL(iio_write_channel_attribute);
+
+int iio_write_channel_raw(struct iio_channel *chan, int val)
+{
+       return iio_write_channel_attribute(chan, val, 0, IIO_CHAN_INFO_RAW);
+}
 EXPORT_SYMBOL_GPL(iio_write_channel_raw);
 
 unsigned int iio_get_channel_ext_info_count(struct iio_channel *chan)
diff --git a/include/linux/iio/adc/stm32-dfsdm-adc.h b/include/linux/iio/adc/stm32-dfsdm-adc.h
new file mode 100644 (file)
index 0000000..e7dc7a5
--- /dev/null
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * This file discribe the STM32 DFSDM IIO driver API for audio part
+ *
+ * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
+ * Author(s): Arnaud Pouliquen <arnaud.pouliquen@st.com>.
+ */
+
+#ifndef STM32_DFSDM_ADC_H
+#define STM32_DFSDM_ADC_H
+
+int stm32_dfsdm_get_buff_cb(struct iio_dev *iio_dev,
+                           int (*cb)(const void *data, size_t size,
+                                     void *private),
+                           void *private);
+int stm32_dfsdm_release_buff_cb(struct iio_dev *iio_dev);
+
+#endif
index 5e347a9..9887f4f 100644 (file)
@@ -134,6 +134,17 @@ struct iio_cb_buffer *iio_channel_get_all_cb(struct device *dev,
                                                       void *private),
                                             void *private);
 /**
+ * iio_channel_cb_set_buffer_watermark() - set the buffer watermark.
+ * @cb_buffer:         The callback buffer from whom we want the channel
+ *                     information.
+ * @watermark: buffer watermark in bytes.
+ *
+ * This function allows to configure the buffer watermark.
+ */
+int iio_channel_cb_set_buffer_watermark(struct iio_cb_buffer *cb_buffer,
+                                       size_t watermark);
+
+/**
  * iio_channel_release_all_cb() - release and unregister the callback.
  * @cb_buffer:         The callback buffer that was allocated.
  */
@@ -216,6 +227,32 @@ int iio_read_channel_average_raw(struct iio_channel *chan, int *val);
 int iio_read_channel_processed(struct iio_channel *chan, int *val);
 
 /**
+ * iio_write_channel_attribute() - Write values to the device attribute.
+ * @chan:      The channel being queried.
+ * @val:       Value being written.
+ * @val2:      Value being written.val2 use depends on attribute type.
+ * @attribute: info attribute to be read.
+ *
+ * Returns an error code or 0.
+ */
+int iio_write_channel_attribute(struct iio_channel *chan, int val,
+                               int val2, enum iio_chan_info_enum attribute);
+
+/**
+ * iio_read_channel_attribute() - Read values from the device attribute.
+ * @chan:      The channel being queried.
+ * @val:       Value being written.
+ * @val2:      Value being written.Val2 use depends on attribute type.
+ * @attribute: info attribute to be written.
+ *
+ * Returns an error code if failed. Else returns a description of what is in val
+ * and val2, such as IIO_VAL_INT_PLUS_MICRO telling us we have a value of val
+ * + val2/1e6
+ */
+int iio_read_channel_attribute(struct iio_channel *chan, int *val,
+                              int *val2, enum iio_chan_info_enum attribute);
+
+/**
  * iio_write_channel_raw() - write to a given channel
  * @chan:              The channel being queried.
  * @val:               Value being written.
diff --git a/include/linux/iio/hw-consumer.h b/include/linux/iio/hw-consumer.h
new file mode 100644 (file)
index 0000000..44d48bb
--- /dev/null
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Industrial I/O in kernel hardware consumer interface
+ *
+ * Copyright 2017 Analog Devices Inc.
+ *  Author: Lars-Peter Clausen <lars@metafoo.de>
+ */
+
+#ifndef LINUX_IIO_HW_CONSUMER_H
+#define LINUX_IIO_HW_CONSUMER_H
+
+struct iio_hw_consumer;
+
+struct iio_hw_consumer *iio_hw_consumer_alloc(struct device *dev);
+void iio_hw_consumer_free(struct iio_hw_consumer *hwc);
+struct iio_hw_consumer *devm_iio_hw_consumer_alloc(struct device *dev);
+void devm_iio_hw_consumer_free(struct device *dev, struct iio_hw_consumer *hwc);
+int iio_hw_consumer_enable(struct iio_hw_consumer *hwc);
+void iio_hw_consumer_disable(struct iio_hw_consumer *hwc);
+
+#endif
index 20b6134..f12a61b 100644 (file)
  * Currently assumes nano seconds.
  */
 
-enum iio_chan_info_enum {
-       IIO_CHAN_INFO_RAW = 0,
-       IIO_CHAN_INFO_PROCESSED,
-       IIO_CHAN_INFO_SCALE,
-       IIO_CHAN_INFO_OFFSET,
-       IIO_CHAN_INFO_CALIBSCALE,
-       IIO_CHAN_INFO_CALIBBIAS,
-       IIO_CHAN_INFO_PEAK,
-       IIO_CHAN_INFO_PEAK_SCALE,
-       IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW,
-       IIO_CHAN_INFO_AVERAGE_RAW,
-       IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY,
-       IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY,
-       IIO_CHAN_INFO_SAMP_FREQ,
-       IIO_CHAN_INFO_FREQUENCY,
-       IIO_CHAN_INFO_PHASE,
-       IIO_CHAN_INFO_HARDWAREGAIN,
-       IIO_CHAN_INFO_HYSTERESIS,
-       IIO_CHAN_INFO_INT_TIME,
-       IIO_CHAN_INFO_ENABLE,
-       IIO_CHAN_INFO_CALIBHEIGHT,
-       IIO_CHAN_INFO_CALIBWEIGHT,
-       IIO_CHAN_INFO_DEBOUNCE_COUNT,
-       IIO_CHAN_INFO_DEBOUNCE_TIME,
-       IIO_CHAN_INFO_CALIBEMISSIVITY,
-       IIO_CHAN_INFO_OVERSAMPLING_RATIO,
-};
-
 enum iio_shared_by {
        IIO_SEPARATE,
        IIO_SHARED_BY_TYPE,
index 2aa7b63..6eb3d68 100644 (file)
@@ -34,4 +34,32 @@ enum iio_available_type {
        IIO_AVAIL_RANGE,
 };
 
+enum iio_chan_info_enum {
+       IIO_CHAN_INFO_RAW = 0,
+       IIO_CHAN_INFO_PROCESSED,
+       IIO_CHAN_INFO_SCALE,
+       IIO_CHAN_INFO_OFFSET,
+       IIO_CHAN_INFO_CALIBSCALE,
+       IIO_CHAN_INFO_CALIBBIAS,
+       IIO_CHAN_INFO_PEAK,
+       IIO_CHAN_INFO_PEAK_SCALE,
+       IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW,
+       IIO_CHAN_INFO_AVERAGE_RAW,
+       IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY,
+       IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY,
+       IIO_CHAN_INFO_SAMP_FREQ,
+       IIO_CHAN_INFO_FREQUENCY,
+       IIO_CHAN_INFO_PHASE,
+       IIO_CHAN_INFO_HARDWAREGAIN,
+       IIO_CHAN_INFO_HYSTERESIS,
+       IIO_CHAN_INFO_INT_TIME,
+       IIO_CHAN_INFO_ENABLE,
+       IIO_CHAN_INFO_CALIBHEIGHT,
+       IIO_CHAN_INFO_CALIBWEIGHT,
+       IIO_CHAN_INFO_DEBOUNCE_COUNT,
+       IIO_CHAN_INFO_DEBOUNCE_TIME,
+       IIO_CHAN_INFO_CALIBEMISSIVITY,
+       IIO_CHAN_INFO_OVERSAMPLING_RATIO,
+};
+
 #endif /* _IIO_TYPES_H_ */