staging: iio: dac: ad5446: Enable driver support for AD5620/AD5640/AD5660 DA converters

Initial support for single channel, 12-/14-/16-Bit nanoDAC with On-Chip Reference

staging: iio: dac: ad5446: Fix according to review feedback

Review feedback by Jonathan Cameron:
	Use kernel doc style to document headers.
	Turn data into a union
	Add some comments for clarity

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/staging/iio/dac/Kconfig b/drivers/staging/iio/dac/Kconfig
index 9c497cc..9191bd2 100644 (file)
--- a/drivers/staging/iio/dac/Kconfig
+++ b/drivers/staging/iio/dac/Kconfig
@@ -11,11 +11,11 @@ config AD5624R_SPI
          AD5664R convertors (DAC). This driver uses the common SPI interface.
 
 config AD5446
-       tristate "Analog Devices AD5444, AD5446 and AD5541A, AD5512A DAC SPI driver"
+       tristate "Analog Devices AD5444/6, AD5620/40/60 and AD5541A/12A DAC SPI driver"
        depends on SPI
        help
-         Say yes here to build support for Analog Devices AD5444, AD5446
-         and AD5541A, AD5512A DACs.
+         Say yes here to build support for Analog Devices AD5444, AD5446,
+         AD5620, AD5640, AD5660 and AD5541A, AD5512A DACs.
 
          To compile this driver as a module, choose M here: the
          module will be called ad5446.

diff --git a/drivers/staging/iio/dac/ad5446.c b/drivers/staging/iio/dac/ad5446.c
index ac3165b..4d65d27 100644 (file)
--- a/drivers/staging/iio/dac/ad5446.c
+++ b/drivers/staging/iio/dac/ad5446.c
@@ -23,6 +23,31 @@
 
 #include "ad5446.h"
 
+static void ad5446_store_sample(struct ad5446_state *st, unsigned val)
+{
+       st->data.d16 = cpu_to_be16(AD5446_LOAD |
+                                       (val << st->chip_info->left_shift));
+}
+
+static void ad5542_store_sample(struct ad5446_state *st, unsigned val)
+{
+       st->data.d16 = cpu_to_be16(val << st->chip_info->left_shift);
+}
+
+static void ad5620_store_sample(struct ad5446_state *st, unsigned val)
+{
+       st->data.d16 = cpu_to_be16(AD5620_LOAD |
+                                       (val << st->chip_info->left_shift));
+}
+
+static void ad5660_store_sample(struct ad5446_state *st, unsigned val)
+{
+       val |= AD5660_LOAD;
+       st->data.d24[0] = (val >> 16) & 0xFF;
+       st->data.d24[1] = (val >> 8) & 0xFF;
+       st->data.d24[2] = val & 0xFF;
+}
+
 static ssize_t ad5446_write(struct device *dev,
                struct device_attribute *attr,
                const char *buf,
@@ -43,18 +68,7 @@ static ssize_t ad5446_write(struct device *dev,
        }
 
        mutex_lock(&dev_info->mlock);
-       switch (spi_get_device_id(st->spi)->driver_data) {
-       case ID_AD5444:
-       case ID_AD5446:
-                       st->data = cpu_to_be16(AD5446_LOAD |
-                                       (val << st->chip_info->left_shift));
-                       break;
-       case ID_AD5542A:
-       case ID_AD5512A:
-                       st->data = cpu_to_be16(val << st->chip_info->left_shift);
-                       break;
-       }
-
+       st->chip_info->store_sample(st, val);
        ret = spi_sync(st->spi, &st->msg);
        mutex_unlock(&dev_info->mlock);
 
@@ -105,24 +119,76 @@ static const struct ad5446_chip_info ad5446_chip_info_tbl[] = {
                .storagebits = 16,
                .left_shift = 2,
                .sign = 'u', /* IIO_SCAN_EL_TYPE_UNSIGNED */
+               .store_sample = ad5446_store_sample,
        },
        [ID_AD5446] = {
                .bits = 14,
                .storagebits = 16,
                .left_shift = 0,
                .sign = 'u', /* IIO_SCAN_EL_TYPE_UNSIGNED */
+               .store_sample = ad5446_store_sample,
        },
        [ID_AD5542A] = {
                .bits = 16,
                .storagebits = 16,
                .left_shift = 0,
                .sign = 'u', /* IIO_SCAN_EL_TYPE_UNSIGNED */
+               .store_sample = ad5542_store_sample,
        },
        [ID_AD5512A] = {
                .bits = 12,
                .storagebits = 16,
                .left_shift = 4,
                .sign = 'u', /* IIO_SCAN_EL_TYPE_UNSIGNED */
+               .store_sample = ad5542_store_sample,
+       },
+       [ID_AD5620_2500] = {
+               .bits = 12,
+               .storagebits = 16,
+               .left_shift = 2,
+               .sign = 'u', /* IIO_SCAN_EL_TYPE_UNSIGNED */
+               .int_vref_mv = 2500,
+               .store_sample = ad5620_store_sample,
+       },
+       [ID_AD5620_1250] = {
+               .bits = 12,
+               .storagebits = 16,
+               .left_shift = 2,
+               .sign = 'u', /* IIO_SCAN_EL_TYPE_UNSIGNED */
+               .int_vref_mv = 1250,
+               .store_sample = ad5620_store_sample,
+       },
+       [ID_AD5640_2500] = {
+               .bits = 14,
+               .storagebits = 16,
+               .left_shift = 0,
+               .sign = 'u', /* IIO_SCAN_EL_TYPE_UNSIGNED */
+               .int_vref_mv = 2500,
+               .store_sample = ad5620_store_sample,
+       },
+       [ID_AD5640_1250] = {
+               .bits = 14,
+               .storagebits = 16,
+               .left_shift = 0,
+               .sign = 'u', /* IIO_SCAN_EL_TYPE_UNSIGNED */
+               .int_vref_mv = 1250,
+               .store_sample = ad5620_store_sample,
+       },
+       [ID_AD5660_2500] = {
+               .bits = 16,
+               .storagebits = 24,
+               .left_shift = 0,
+               .sign = 'u', /* IIO_SCAN_EL_TYPE_UNSIGNED */
+               .int_vref_mv = 2500,
+               .store_sample = ad5660_store_sample,
+       },
+       [ID_AD5660_1250] = {
+               .bits = 16,
+               .storagebits = 24,
+               .left_shift = 0,
+               .sign = 'u', /* IIO_SCAN_EL_TYPE_UNSIGNED */
+               .int_vref_mv = 1250,
+               .store_sample = ad5660_store_sample,
        },
 };
 
@@ -168,16 +234,28 @@ static int __devinit ad5446_probe(struct spi_device *spi)
 
        /* Setup default message */
 
-       st->xfer.tx_buf = &st->data,
-       st->xfer.len = 2,
+       st->xfer.tx_buf = &st->data;
+       st->xfer.len = st->chip_info->storagebits / 8;
 
        spi_message_init(&st->msg);
        spi_message_add_tail(&st->xfer, &st->msg);
 
-       if (voltage_uv)
-               st->vref_mv = voltage_uv / 1000;
-       else
-               dev_warn(&spi->dev, "reference voltage unspecified\n");
+       switch (spi_get_device_id(spi)->driver_data) {
+               case ID_AD5620_2500:
+               case ID_AD5620_1250:
+               case ID_AD5640_2500:
+               case ID_AD5640_1250:
+               case ID_AD5660_2500:
+               case ID_AD5660_1250:
+                       st->vref_mv = st->chip_info->int_vref_mv;
+                       break;
+               default:
+                       if (voltage_uv)
+                               st->vref_mv = voltage_uv / 1000;
+                       else
+                               dev_warn(&spi->dev,
+                                        "reference voltage unspecified\n");
+       }
 
        ret = iio_device_register(st->indio_dev);
        if (ret)
@@ -217,6 +295,12 @@ static const struct spi_device_id ad5446_id[] = {
        {"ad5446", ID_AD5446},
        {"ad5542a", ID_AD5542A},
        {"ad5512a", ID_AD5512A},
+       {"ad5620-2500", ID_AD5620_2500}, /* AD5620/40/60: */
+       {"ad5620-1250", ID_AD5620_1250}, /* part numbers may look differently */
+       {"ad5640-2500", ID_AD5640_2500},
+       {"ad5640-1250", ID_AD5640_1250},
+       {"ad5660-2500", ID_AD5660_2500},
+       {"ad5660-1250", ID_AD5660_1250},
        {}
 };
 

diff --git a/drivers/staging/iio/dac/ad5446.h b/drivers/staging/iio/dac/ad5446.h
index 24a9cda..ca795a9 100644 (file)
--- a/drivers/staging/iio/dac/ad5446.h
+++ b/drivers/staging/iio/dac/ad5446.h
@@ -5,8 +5,8 @@
  *
  * Licensed under the GPL-2 or later.
  */
-#ifndef IIO_ADC_AD5446_H_
-#define IIO_ADC_AD5446_H_
+#ifndef IIO_DAC_AD5446_H_
+#define IIO_DAC_AD5446_H_
 
 /* DAC Control Bits */
 
@@ -15,14 +15,30 @@
 #define AD5446_NOP             (0x2 << 14) /* No operation */
 #define AD5446_CLK_RISING      (0x3 << 14) /* Clock data on rising edge */
 
+#define AD5620_LOAD            (0x0 << 14) /* Load and update Norm Operation*/
+#define AD5620_PWRDWN_1k       (0x1 << 14) /* Power-down: 1kOhm to GND */
+#define AD5620_PWRDWN_100k     (0x2 << 14) /* Power-down: 100kOhm to GND */
+#define AD5620_PWRDWN_TRISTATE (0x3 << 14) /* Power-down: Three-state */
+
+#define AD5660_LOAD            (0x0 << 16) /* Load and update Norm Operation*/
+#define AD5660_PWRDWN_1k       (0x1 << 16) /* Power-down: 1kOhm to GND */
+#define AD5660_PWRDWN_100k     (0x2 << 16) /* Power-down: 100kOhm to GND */
+#define AD5660_PWRDWN_TRISTATE (0x3 << 16) /* Power-down: Three-state */
+
 #define RES_MASK(bits) ((1 << (bits)) - 1)
 
-struct ad5446_chip_info {
-       u8                              bits;           /* number of DAC bits */
-       u8                              storagebits;    /* number of bits written to the DAC */
-       u8                              left_shift;     /* number of bits the datum must be shifted */
-       char                            sign;           /* [s]igned or [u]nsigned */
-};
+/**
+ * struct ad5446_state - driver instance specific data
+ * @indio_dev:         the industrial I/O device
+ * @spi:               spi_device
+ * @chip_info:         chip model specific constants, available modes etc
+ * @reg:               supply regulator
+ * @poll_work:         bottom half of polling interrupt handler
+ * @vref_mv:           actual reference voltage used
+ * @xfer:              default spi transfer
+ * @msg:               default spi message
+ * @data:              spi transmit buffer
+ */
 
 struct ad5446_state {
        struct iio_dev                  *indio_dev;
@@ -33,14 +49,50 @@ struct ad5446_state {
        unsigned short                  vref_mv;
        struct spi_transfer             xfer;
        struct spi_message              msg;
-       unsigned short                  data;
+       union {
+               unsigned short          d16;
+               unsigned char           d24[3];
+       } data;
+};
+
+/**
+ * struct ad5446_chip_info - chip specifc information
+ * @bits:              accuracy of the DAC in bits
+ * @storagebits:       number of bits written to the DAC
+ * @left_shift:                number of bits the datum must be shifted
+ * @sign:              data representation [s]igned or [u]nsigned
+ * @int_vref_mv:       AD5620/40/60: the internal reference voltage
+ * @store_sample:      chip specifc helper function to store the datum
+ */
+
+struct ad5446_chip_info {
+       u8                              bits;
+       u8                              storagebits;
+       u8                              left_shift;
+       char                            sign;
+       u16                             int_vref_mv;
+       void (*store_sample)            (struct ad5446_state *st, unsigned val);
 };
 
+/**
+ * ad5446_supported_device_ids:
+ * The AD5620/40/60 parts are available in different fixed internal reference
+ * voltage options. The actual part numbers may look differently
+ * (and a bit cryptic), however this style is used to make clear which
+ * parts are supported here.
+ */
+
 enum ad5446_supported_device_ids {
        ID_AD5444,
        ID_AD5446,
        ID_AD5542A,
        ID_AD5512A,
+       ID_AD5620_2500,
+       ID_AD5620_1250,
+       ID_AD5640_2500,
+       ID_AD5640_1250,
+       ID_AD5660_2500,
+       ID_AD5660_1250,
 };
 
-#endif /* IIO_ADC_AD5446_H_ */
+#endif /* IIO_DAC_AD5446_H_ */