5 files changed, 254 insertions, 15 deletions

diff --git a/drivers/iio/potentiometer/Kconfig b/drivers/iio/potentiometer/Kconfig
index 79ec2eba4969..6303cbe79903 100644
--- a/drivers/iio/potentiometer/Kconfig
+++ b/drivers/iio/potentiometer/Kconfig
@@ -90,6 +90,18 @@ config MCP4531
 	  To compile this driver as a module, choose M here: the
 	  module will be called mcp4531.
 
+config MCP41010
+	tristate "Microchip MCP41xxx/MCP42xxx Digital Potentiometer driver"
+	depends on SPI
+	help
+	  Say yes here to build support for the Microchip
+	  MCP41010, MCP41050, MCP41100,
+	  MCP42010, MCP42050, MCP42100
+	  digital potentiometer chips.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called mcp41010.
+
 config TPL0102
 	tristate "Texas Instruments digital potentiometer driver"
 	depends on I2C
diff --git a/drivers/iio/potentiometer/Makefile b/drivers/iio/potentiometer/Makefile
index 4af657883c3f..8ff55138cf12 100644
--- a/drivers/iio/potentiometer/Makefile
+++ b/drivers/iio/potentiometer/Makefile
@@ -11,4 +11,5 @@ obj-$(CONFIG_MAX5487) += max5487.o
 obj-$(CONFIG_MCP4018) += mcp4018.o
 obj-$(CONFIG_MCP4131) += mcp4131.o
 obj-$(CONFIG_MCP4531) += mcp4531.o
+obj-$(CONFIG_MCP41010) += mcp41010.o
 obj-$(CONFIG_TPL0102) += tpl0102.o
diff --git a/drivers/iio/potentiometer/mcp41010.c b/drivers/iio/potentiometer/mcp41010.c
new file mode 100644
index 000000000000..2368b39debf5
--- /dev/null
+++ b/drivers/iio/potentiometer/mcp41010.c
@@ -0,0 +1,203 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Industrial I/O driver for Microchip digital potentiometers
+ *
+ * Copyright (c) 2018 Chris Coffey <cmc@babblebit.net>
+ * Based on: Slawomir Stepien's code from mcp4131.c
+ *
+ * Datasheet: http://ww1.microchip.com/downloads/en/devicedoc/11195c.pdf
+ *
+ * DEVID	#Wipers	#Positions	Resistance (kOhm)
+ * mcp41010	1	256		10
+ * mcp41050	1	256		50
+ * mcp41100	1	256		100
+ * mcp42010	2	256		10
+ * mcp42050	2	256		50
+ * mcp42100	2	256		100
+ */
+
+#include <linux/cache.h>
+#include <linux/err.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/types.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/spi/spi.h>
+
+#define MCP41010_MAX_WIPERS	2
+#define MCP41010_WRITE		BIT(4)
+#define MCP41010_WIPER_MAX	255
+#define MCP41010_WIPER_CHANNEL	BIT(0)
+
+struct mcp41010_cfg {
+	char name[16];
+	int wipers;
+	int kohms;
+};
+
+enum mcp41010_type {
+	MCP41010,
+	MCP41050,
+	MCP41100,
+	MCP42010,
+	MCP42050,
+	MCP42100,
+};
+
+static const struct mcp41010_cfg mcp41010_cfg[] = {
+	[MCP41010] = { .name = "mcp41010", .wipers = 1, .kohms =  10, },
+	[MCP41050] = { .name = "mcp41050", .wipers = 1, .kohms =  50, },
+	[MCP41100] = { .name = "mcp41100", .wipers = 1, .kohms = 100, },
+	[MCP42010] = { .name = "mcp42010", .wipers = 2, .kohms =  10, },
+	[MCP42050] = { .name = "mcp42050", .wipers = 2, .kohms =  50, },
+	[MCP42100] = { .name = "mcp42100", .wipers = 2, .kohms = 100, },
+};
+
+struct mcp41010_data {
+	struct spi_device *spi;
+	const struct mcp41010_cfg *cfg;
+	struct mutex lock; /* Protect write sequences */
+	unsigned int value[MCP41010_MAX_WIPERS]; /* Cache wiper values */
+	u8 buf[2] ____cacheline_aligned;
+};
+
+#define MCP41010_CHANNEL(ch) {					\
+	.type = IIO_RESISTANCE,					\
+	.indexed = 1,						\
+	.output = 1,						\
+	.channel = (ch),					\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
+}
+
+static const struct iio_chan_spec mcp41010_channels[] = {
+	MCP41010_CHANNEL(0),
+	MCP41010_CHANNEL(1),
+};
+
+static int mcp41010_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int *val, int *val2, long mask)
+{
+	struct mcp41010_data *data = iio_priv(indio_dev);
+	int channel = chan->channel;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		*val = data->value[channel];
+		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_SCALE:
+		*val = 1000 * data->cfg->kohms;
+		*val2 = MCP41010_WIPER_MAX;
+		return IIO_VAL_FRACTIONAL;
+	}
+
+	return -EINVAL;
+}
+
+static int mcp41010_write_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     int val, int val2, long mask)
+{
+	int err;
+	struct mcp41010_data *data = iio_priv(indio_dev);
+	int channel = chan->channel;
+
+	if (mask != IIO_CHAN_INFO_RAW)
+		return -EINVAL;
+
+	if (val > MCP41010_WIPER_MAX || val < 0)
+		return -EINVAL;
+
+	mutex_lock(&data->lock);
+
+	data->buf[0] = MCP41010_WIPER_CHANNEL << channel;
+	data->buf[0] |= MCP41010_WRITE;
+	data->buf[1] = val & 0xff;
+
+	err = spi_write(data->spi, data->buf, sizeof(data->buf));
+	if (!err)
+		data->value[channel] = val;
+
+	mutex_unlock(&data->lock);
+
+	return err;
+}
+
+static const struct iio_info mcp41010_info = {
+	.read_raw = mcp41010_read_raw,
+	.write_raw = mcp41010_write_raw,
+};
+
+static int mcp41010_probe(struct spi_device *spi)
+{
+	int err;
+	struct device *dev = &spi->dev;
+	struct mcp41010_data *data;
+	struct iio_dev *indio_dev;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+	spi_set_drvdata(spi, indio_dev);
+	data->spi = spi;
+	data->cfg = of_device_get_match_data(&spi->dev);
+	if (!data->cfg)
+		data->cfg = &mcp41010_cfg[spi_get_device_id(spi)->driver_data];
+
+	mutex_init(&data->lock);
+
+	indio_dev->dev.parent = dev;
+	indio_dev->info = &mcp41010_info;
+	indio_dev->channels = mcp41010_channels;
+	indio_dev->num_channels = data->cfg->wipers;
+	indio_dev->name = data->cfg->name;
+
+	err = devm_iio_device_register(dev, indio_dev);
+	if (err)
+		dev_info(&spi->dev, "Unable to register %s\n", indio_dev->name);
+
+	return err;
+}
+
+static const struct of_device_id mcp41010_match[] = {
+	{ .compatible = "microchip,mcp41010", .data = &mcp41010_cfg[MCP41010] },
+	{ .compatible = "microchip,mcp41050", .data = &mcp41010_cfg[MCP41050] },
+	{ .compatible = "microchip,mcp41100", .data = &mcp41010_cfg[MCP41100] },
+	{ .compatible = "microchip,mcp42010", .data = &mcp41010_cfg[MCP42010] },
+	{ .compatible = "microchip,mcp42050", .data = &mcp41010_cfg[MCP42050] },
+	{ .compatible = "microchip,mcp42100", .data = &mcp41010_cfg[MCP42100] },
+	{}
+};
+MODULE_DEVICE_TABLE(of, mcp41010_match);
+
+static const struct spi_device_id mcp41010_id[] = {
+	{ "mcp41010", MCP41010 },
+	{ "mcp41050", MCP41050 },
+	{ "mcp41100", MCP41100 },
+	{ "mcp42010", MCP42010 },
+	{ "mcp42050", MCP42050 },
+	{ "mcp42100", MCP42100 },
+	{}
+};
+MODULE_DEVICE_TABLE(spi, mcp41010_id);
+
+static struct spi_driver mcp41010_driver = {
+	.driver = {
+		.name	= "mcp41010",
+		.of_match_table = mcp41010_match,
+	},
+	.probe		= mcp41010_probe,
+	.id_table	= mcp41010_id,
+};
+
+module_spi_driver(mcp41010_driver);
+
+MODULE_AUTHOR("Chris Coffey <cmc@babblebit.net>");
+MODULE_DESCRIPTION("MCP41010 digital potentiometer");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/potentiometer/mcp4131.c b/drivers/iio/potentiometer/mcp4131.c
index b3e30db246cc..efe035ce010d 100644
--- a/drivers/iio/potentiometer/mcp4131.c
+++ b/drivers/iio/potentiometer/mcp4131.c
@@ -42,6 +42,7 @@
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/spi/spi.h>
 
 #define MCP4131_WRITE		(0x00 << 2)
@@ -243,7 +244,7 @@ static int mcp4131_probe(struct spi_device *spi)
 {
 	int err;
 	struct device *dev = &spi->dev;
-	unsigned long devid = spi_get_device_id(spi)->driver_data;
+	unsigned long devid;
 	struct mcp4131_data *data;
 	struct iio_dev *indio_dev;
 
@@ -254,7 +255,11 @@ static int mcp4131_probe(struct spi_device *spi)
 	data = iio_priv(indio_dev);
 	spi_set_drvdata(spi, indio_dev);
 	data->spi = spi;
-	data->cfg = &mcp4131_cfg[devid];
+	data->cfg = of_device_get_match_data(&spi->dev);
+	if (!data->cfg) {
+		devid = spi_get_device_id(spi)->driver_data;
+		data->cfg = &mcp4131_cfg[devid];
+	}
 
 	mutex_init(&data->lock);
 
@@ -273,7 +278,6 @@ static int mcp4131_probe(struct spi_device *spi)
 	return 0;
 }
 
-#if defined(CONFIG_OF)
 static const struct of_device_id mcp4131_dt_ids[] = {
 	{ .compatible = "microchip,mcp4131-502",
 		.data = &mcp4131_cfg[MCP413x_502] },
@@ -406,7 +410,6 @@ static const struct of_device_id mcp4131_dt_ids[] = {
 	{}
 };
 MODULE_DEVICE_TABLE(of, mcp4131_dt_ids);
-#endif /* CONFIG_OF */
 
 static const struct spi_device_id mcp4131_id[] = {
 	{ "mcp4131-502", MCP413x_502 },
diff --git a/drivers/iio/potentiometer/tpl0102.c b/drivers/iio/potentiometer/tpl0102.c
index ca1cce58fe20..a0a07e47f13f 100644
--- a/drivers/iio/potentiometer/tpl0102.c
+++ b/drivers/iio/potentiometer/tpl0102.c
@@ -15,7 +15,7 @@
 
 struct tpl0102_cfg {
 	int wipers;
-	int max_pos;
+	int avail[3];
 	int kohms;
 };
 
@@ -28,16 +28,16 @@ enum tpl0102_type {
 
 static const struct tpl0102_cfg tpl0102_cfg[] = {
 	/* on-semiconductor parts */
-	[CAT5140_503] = { .wipers = 1, .max_pos = 256, .kohms = 50, },
-	[CAT5140_104] = { .wipers = 1, .max_pos = 256, .kohms = 100, },
+	[CAT5140_503] = { .wipers = 1, .avail = { 0, 1, 255 }, .kohms = 50, },
+	[CAT5140_104] = { .wipers = 1, .avail = { 0, 1, 255 }, .kohms = 100, },
 	/* ti parts */
-	[TPL0102_104] = { .wipers = 2, .max_pos = 256, .kohms = 100 },
-	[TPL0401_103] = { .wipers = 1, .max_pos = 128, .kohms = 10, },
+	[TPL0102_104] = { .wipers = 2, .avail = { 0, 1, 255 }, .kohms = 100 },
+	[TPL0401_103] = { .wipers = 1, .avail = { 0, 1, 127 }, .kohms = 10, },
 };
 
 struct tpl0102_data {
 	struct regmap *regmap;
-	unsigned long devid;
+	const struct tpl0102_cfg *cfg;
 };
 
 static const struct regmap_config tpl0102_regmap_config = {
@@ -52,6 +52,7 @@ static const struct regmap_config tpl0102_regmap_config = {
 	.channel = (ch),					\
 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
+	.info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW),	\
 }
 
 static const struct iio_chan_spec tpl0102_channels[] = {
@@ -72,14 +73,32 @@ static int tpl0102_read_raw(struct iio_dev *indio_dev,
 		return ret ? ret : IIO_VAL_INT;
 	}
 	case IIO_CHAN_INFO_SCALE:
-		*val = 1000 * tpl0102_cfg[data->devid].kohms;
-		*val2 = tpl0102_cfg[data->devid].max_pos;
+		*val = 1000 * data->cfg->kohms;
+		*val2 = data->cfg->avail[2] + 1;
 		return IIO_VAL_FRACTIONAL;
 	}
 
 	return -EINVAL;
 }
 
+static int tpl0102_read_avail(struct iio_dev *indio_dev,
+			      struct iio_chan_spec const *chan,
+			      const int **vals, int *type, int *length,
+			      long mask)
+{
+	struct tpl0102_data *data = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		*length = ARRAY_SIZE(data->cfg->avail);
+		*vals = data->cfg->avail;
+		*type = IIO_VAL_INT;
+		return IIO_AVAIL_RANGE;
+	}
+
+	return -EINVAL;
+}
+
 static int tpl0102_write_raw(struct iio_dev *indio_dev,
 			     struct iio_chan_spec const *chan,
 			     int val, int val2, long mask)
@@ -89,7 +108,7 @@ static int tpl0102_write_raw(struct iio_dev *indio_dev,
 	if (mask != IIO_CHAN_INFO_RAW)
 		return -EINVAL;
 
-	if (val >= tpl0102_cfg[data->devid].max_pos || val < 0)
+	if (val > data->cfg->avail[2] || val < 0)
 		return -EINVAL;
 
 	return regmap_write(data->regmap, chan->channel, val);
@@ -97,6 +116,7 @@ static int tpl0102_write_raw(struct iio_dev *indio_dev,
 
 static const struct iio_info tpl0102_info = {
 	.read_raw = tpl0102_read_raw,
+	.read_avail = tpl0102_read_avail,
 	.write_raw = tpl0102_write_raw,
 };
 
@@ -113,7 +133,7 @@ static int tpl0102_probe(struct i2c_client *client,
 	data = iio_priv(indio_dev);
 	i2c_set_clientdata(client, indio_dev);
 
-	data->devid = id->driver_data;
+	data->cfg = &tpl0102_cfg[id->driver_data];
 	data->regmap = devm_regmap_init_i2c(client, &tpl0102_regmap_config);
 	if (IS_ERR(data->regmap)) {
 		dev_err(dev, "regmap initialization failed\n");
@@ -123,7 +143,7 @@ static int tpl0102_probe(struct i2c_client *client,
 	indio_dev->dev.parent = dev;
 	indio_dev->info = &tpl0102_info;
 	indio_dev->channels = tpl0102_channels;
-	indio_dev->num_channels = tpl0102_cfg[data->devid].wipers;
+	indio_dev->num_channels = data->cfg->wipers;
 	indio_dev->name = client->name;
 
 	return devm_iio_device_register(dev, indio_dev);