iio: potentiometer: add TI tpl0102 support

Add support for the TI family of digital potentiometers.

Signed-off-by: Matt Ranostay <mranostay@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/drivers/iio/potentiometer/Kconfig b/drivers/iio/potentiometer/Kconfig
index fd75db73e5825a49c426d94581468f266160d044..ffc735c168fbd0887b262890bae06e5cb1834e17 100644 (file)
--- a/drivers/iio/potentiometer/Kconfig
+++ b/drivers/iio/potentiometer/Kconfig
@@ -17,4 +17,16 @@ config MCP4531
          To compile this driver as a module, choose M here: the
          module will be called mcp4531.
 
+config TPL0102
+       tristate "Texas Instruments digital potentiometer driver"
+       depends on I2C
+       select REGMAP_I2C
+       help
+         Say yes here to build support for the Texas Instruments
+         TPL0102, TPL0402
+         digital potentiometer chips.
+
+         To compile this driver as a module, choose M here: the
+         module will be called tpl0102.
+
 endmenu

diff --git a/drivers/iio/potentiometer/Makefile b/drivers/iio/potentiometer/Makefile
index 8afe492270124a5cd88112389f07b4c95a86ff2b..b563b492b4867a05aa039073aad42c6e17c329e3 100644 (file)
--- a/drivers/iio/potentiometer/Makefile
+++ b/drivers/iio/potentiometer/Makefile
@@ -4,3 +4,4 @@
 
 # When adding new entries keep the list in alphabetical order
 obj-$(CONFIG_MCP4531) += mcp4531.o
+obj-$(CONFIG_TPL0102) += tpl0102.o

diff --git a/drivers/iio/potentiometer/tpl0102.c b/drivers/iio/potentiometer/tpl0102.c
new file mode 100644 (file)
index 0000000..313124b
--- /dev/null
+++ b/drivers/iio/potentiometer/tpl0102.c
@@ -0,0 +1,166 @@
+/*
+ * tpl0102.c - Support for Texas Instruments digital potentiometers
+ *
+ * Copyright (C) 2016 Matt Ranostay <mranostay@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * TODO: enable/disable hi-z output control
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/regmap.h>
+#include <linux/iio/iio.h>
+
+struct tpl0102_cfg {
+       int wipers;
+       int max_pos;
+       int kohms;
+};
+
+enum tpl0102_type {
+       CAT5140_503,
+       CAT5140_104,
+       TPL0102_104,
+       TPL0401_103,
+};
+
+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, },
+       /* ti parts */
+       [TPL0102_104] = { .wipers = 2, .max_pos = 256, .kohms = 100 },
+       [TPL0401_103] = { .wipers = 1, .max_pos = 128, .kohms = 10, },
+};
+
+struct tpl0102_data {
+       struct regmap *regmap;
+       unsigned long devid;
+};
+
+static const struct regmap_config tpl0102_regmap_config = {
+       .reg_bits = 8,
+       .val_bits = 8,
+};
+
+#define TPL0102_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 tpl0102_channels[] = {
+       TPL0102_CHANNEL(0),
+       TPL0102_CHANNEL(1),
+};
+
+static int tpl0102_read_raw(struct iio_dev *indio_dev,
+                           struct iio_chan_spec const *chan,
+                           int *val, int *val2, long mask)
+{
+       struct tpl0102_data *data = iio_priv(indio_dev);
+
+       switch (mask) {
+       case IIO_CHAN_INFO_RAW: {
+               int ret = regmap_read(data->regmap, chan->channel, val);
+
+               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;
+               return IIO_VAL_FRACTIONAL;
+       }
+
+       return -EINVAL;
+}
+
+static int tpl0102_write_raw(struct iio_dev *indio_dev,
+                            struct iio_chan_spec const *chan,
+                            int val, int val2, long mask)
+{
+       struct tpl0102_data *data = iio_priv(indio_dev);
+
+       if (mask != IIO_CHAN_INFO_RAW)
+               return -EINVAL;
+
+       if (val >= tpl0102_cfg[data->devid].max_pos || val < 0)
+               return -EINVAL;
+
+       return regmap_write(data->regmap, chan->channel, val);
+}
+
+static const struct iio_info tpl0102_info = {
+       .read_raw = tpl0102_read_raw,
+       .write_raw = tpl0102_write_raw,
+       .driver_module = THIS_MODULE,
+};
+
+static int tpl0102_probe(struct i2c_client *client,
+                        const struct i2c_device_id *id)
+{
+       struct device *dev = &client->dev;
+       struct tpl0102_data *data;
+       struct iio_dev *indio_dev;
+
+       if (!i2c_check_functionality(client->adapter,
+                                    I2C_FUNC_SMBUS_WORD_DATA))
+               return -ENOTSUPP;
+
+       indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+       if (!indio_dev)
+               return -ENOMEM;
+       data = iio_priv(indio_dev);
+       i2c_set_clientdata(client, indio_dev);
+
+       data->devid = 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");
+               return PTR_ERR(data->regmap);
+       }
+
+       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->name = client->name;
+
+       return devm_iio_device_register(dev, indio_dev);
+}
+
+static const struct i2c_device_id tpl0102_id[] = {
+       { "cat5140-503", CAT5140_503 },
+       { "cat5140-104", CAT5140_104 },
+       { "tpl0102-104", TPL0102_104 },
+       { "tpl0401-103", TPL0401_103 },
+       {}
+};
+MODULE_DEVICE_TABLE(i2c, tpl0102_id);
+
+static struct i2c_driver tpl0102_driver = {
+       .driver = {
+               .name = "tpl0102",
+       },
+       .probe = tpl0102_probe,
+       .id_table = tpl0102_id,
+};
+
+module_i2c_driver(tpl0102_driver);
+
+MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
+MODULE_DESCRIPTION("TPL0102 digital potentiometer");
+MODULE_LICENSE("GPL");