Add support for the TI family of digital potentiometers.
Signed-off-by: Matt Ranostay <mranostay@xxxxxxxxx>
---
Changes from v1:
* Re-order alphabetically chipids
* Removed unneeded local variable, and mask checks
* Use return code from regmap_read()
* Switched to devm_iio_device_register()
drivers/iio/potentiometer/Kconfig | 12 +++
drivers/iio/potentiometer/Makefile | 1 +
drivers/iio/potentiometer/tpl0102.c | 166 ++++++++++++++++++++++++++++++++++++
3 files changed, 179 insertions(+)
create mode 100644 drivers/iio/potentiometer/tpl0102.c
diff --git a/drivers/iio/potentiometer/Kconfig b/drivers/iio/potentiometer/Kconfig
index fd75db7..ffc735c 100644
--- 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 8afe492..b563b49 100644
--- 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
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@xxxxxxxxx>
+ *
+ * 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@xxxxxxxxx>");
+MODULE_DESCRIPTION("TPL0102 digital potentiometer");
+MODULE_LICENSE("GPL");
--
2.7.0
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