mux: adgs1408: new driver for Analog Devices ADGS1408/1409 mux

This patch adds basic support for Analog Device ADGS1408/09 SPI mux
controller.

The device is probed and set to a disabled state. It uses the new mux
controller framework.

Signed-off-by: Mircea Caprioru <mircea.caprioru@analog.com>
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/mux/Kconfig b/drivers/mux/Kconfig
index 6241678..7659d6c 100644 (file)
--- a/drivers/mux/Kconfig
+++ b/drivers/mux/Kconfig
@@ -21,6 +21,16 @@ config MUX_ADG792A
          To compile the driver as a module, choose M here: the module will
          be called mux-adg792a.
 
+config MUX_ADGS1408
+       tristate "Analog Devices ADGS1408/ADGS1409 Multiplexers"
+       depends on SPI
+       help
+         ADGS1408 8:1 multiplexer and ADGS1409 double 4:1 multiplexer
+         switches.
+
+         To compile the driver as a module, choose M here: the module will
+         be called mux-adgs1408.
+
 config MUX_GPIO
        tristate "GPIO-controlled Multiplexer"
        depends on GPIOLIB || COMPILE_TEST

diff --git a/drivers/mux/Makefile b/drivers/mux/Makefile
index c3d8839..6e9fa47 100644 (file)
--- a/drivers/mux/Makefile
+++ b/drivers/mux/Makefile
@@ -5,10 +5,12 @@
 
 mux-core-objs                  := core.o
 mux-adg792a-objs               := adg792a.o
+mux-adgs1408-objs              := adgs1408.o
 mux-gpio-objs                  := gpio.o
 mux-mmio-objs                  := mmio.o
 
 obj-$(CONFIG_MULTIPLEXER)      += mux-core.o
 obj-$(CONFIG_MUX_ADG792A)      += mux-adg792a.o
+obj-$(CONFIG_MUX_ADGS1408)     += mux-adgs1408.o
 obj-$(CONFIG_MUX_GPIO)         += mux-gpio.o
 obj-$(CONFIG_MUX_MMIO)         += mux-mmio.o

diff --git a/drivers/mux/adgs1408.c b/drivers/mux/adgs1408.c
new file mode 100644 (file)
index 0000000..0f7cf54
--- /dev/null
+++ b/drivers/mux/adgs1408.c
@@ -0,0 +1,131 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * ADGS1408/ADGS1409 SPI MUX driver
+ *
+ * Copyright 2018 Analog Devices Inc.
+ */
+
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/mux/driver.h>
+#include <linux/of_platform.h>
+#include <linux/property.h>
+#include <linux/spi/spi.h>
+
+#define ADGS1408_SW_DATA       (0x01)
+#define ADGS1408_REG_READ(reg) ((reg) | 0x80)
+#define ADGS1408_DISABLE       (0x00)
+#define ADGS1408_MUX(state)    (((state) << 1) | 1)
+
+enum adgs1408_chip_id {
+       ADGS1408 = 1,
+       ADGS1409,
+};
+
+static int adgs1408_spi_reg_write(struct spi_device *spi,
+                                 u8 reg_addr, u8 reg_data)
+{
+       u8 tx_buf[2];
+
+       tx_buf[0] = reg_addr;
+       tx_buf[1] = reg_data;
+
+       return spi_write_then_read(spi, tx_buf, sizeof(tx_buf), NULL, 0);
+}
+
+static int adgs1408_set(struct mux_control *mux, int state)
+{
+       struct spi_device *spi = to_spi_device(mux->chip->dev.parent);
+       u8 reg;
+
+       if (state == MUX_IDLE_DISCONNECT)
+               reg = ADGS1408_DISABLE;
+       else
+               reg = ADGS1408_MUX(state);
+
+       return adgs1408_spi_reg_write(spi, ADGS1408_SW_DATA, reg);
+}
+
+static const struct mux_control_ops adgs1408_ops = {
+       .set = adgs1408_set,
+};
+
+static int adgs1408_probe(struct spi_device *spi)
+{
+       struct device *dev = &spi->dev;
+       enum adgs1408_chip_id chip_id;
+       struct mux_chip *mux_chip;
+       struct mux_control *mux;
+       s32 idle_state;
+       int ret;
+
+       chip_id = (enum adgs1408_chip_id)of_device_get_match_data(dev);
+       if (!chip_id)
+               chip_id = spi_get_device_id(spi)->driver_data;
+
+       mux_chip = devm_mux_chip_alloc(dev, 1, 0);
+       if (IS_ERR(mux_chip))
+               return PTR_ERR(mux_chip);
+
+       mux_chip->ops = &adgs1408_ops;
+
+       ret = adgs1408_spi_reg_write(spi, ADGS1408_SW_DATA, ADGS1408_DISABLE);
+       if (ret < 0)
+               return ret;
+
+       ret = device_property_read_u32(dev, "idle-state", (u32 *)&idle_state);
+       if (ret < 0)
+               idle_state = MUX_IDLE_AS_IS;
+
+       mux = mux_chip->mux;
+
+       if (chip_id == ADGS1408)
+               mux->states = 8;
+       else
+               mux->states = 4;
+
+       switch (idle_state) {
+       case MUX_IDLE_DISCONNECT:
+       case MUX_IDLE_AS_IS:
+       case 0 ... 7:
+               /* adgs1409 supports only 4 states */
+               if (idle_state < mux->states) {
+                       mux->idle_state = idle_state;
+                       break;
+               }
+               /* fall through */
+       default:
+               dev_err(dev, "invalid idle-state %d\n", idle_state);
+               return -EINVAL;
+       }
+
+       return devm_mux_chip_register(dev, mux_chip);
+}
+
+static const struct spi_device_id adgs1408_spi_id[] = {
+       { "adgs1408", ADGS1408 },
+       { "adgs1409", ADGS1409 },
+       { }
+};
+MODULE_DEVICE_TABLE(spi, adgs1408_spi_id);
+
+static const struct of_device_id adgs1408_of_match[] = {
+       { .compatible = "adi,adgs1408", .data = (void *)ADGS1408, },
+       { .compatible = "adi,adgs1409", .data = (void *)ADGS1409, },
+       { }
+};
+MODULE_DEVICE_TABLE(of, adgs1408_of_match);
+
+static struct spi_driver adgs1408_driver = {
+       .driver = {
+               .name = "adgs1408",
+               .of_match_table = of_match_ptr(adgs1408_of_match),
+       },
+       .probe = adgs1408_probe,
+       .id_table = adgs1408_spi_id,
+};
+module_spi_driver(adgs1408_driver);
+
+MODULE_AUTHOR("Mircea Caprioru <mircea.caprioru@analog.com>");
+MODULE_DESCRIPTION("Analog Devices ADGS1408 MUX driver");
+MODULE_LICENSE("GPL v2");