On 21 February 2016 03:21:31 GMT+00:00, Matt Ranostay <mranostay@xxxxxxxxx> wrote:
>Add support for the TI family of digital potentiometers.
>
>Signed-off-by: Matt Ranostay <mranostay@xxxxxxxxx>
Various comments inline but basically a nice simple driver.
Jonathan
>---
> drivers/iio/potentiometer/Kconfig | 11 +++
> drivers/iio/potentiometer/Makefile | 1 +
>drivers/iio/potentiometer/tpl0102.c | 166
>++++++++++++++++++++++++++++++++++++
> 3 files changed, 178 insertions(+)
> create mode 100644 drivers/iio/potentiometer/tpl0102.c
>
>diff --git a/drivers/iio/potentiometer/Kconfig
>b/drivers/iio/potentiometer/Kconfig
>index fd75db7..9d7aa66 100644
>--- a/drivers/iio/potentiometer/Kconfig
>+++ b/drivers/iio/potentiometer/Kconfig
>@@ -17,4 +17,15 @@ 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
Regmap depency as well.
>+ 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..6f610b2
>--- /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 {
>+ TPL0102_104,
>+ TPL0401_103,
>+ CAT5140_503,
>+ CAT5140_104,
Numeric / alphabetical order preferred.
>+};
>+
>+static const struct tpl0102_cfg tpl0102_cfg[] = {
>+ /* ti parts */
>+ [TPL0102_104] = { .wipers = 2, .max_pos = 256, .kohms = 100 },
>+ [TPL0401_103] = { .wipers = 1, .max_pos = 128, .kohms = 10, },
>+ /* on-semiconductor parts */
>+ [CAT5140_503] = { .wipers = 1, .max_pos = 256, .kohms = 50, },
>+ [CAT5140_104] = { .wipers = 1, .max_pos = 256, .kohms = 100, },
Alphabetical order would be a little better.
>+};
>+
>+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: {
>+ return regmap_read(data->regmap, chan->channel, val)
>+ ? -EIO : IIO_VAL_INT;
>+ }
Doesn't regmap_read return specific errors?
>+ 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 & 0xff);
Mask add anything given you have already checked the range?
>+}
>+
>+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;
Local dev variable doesn't add anything here and makes code slightly less obvious.
>+ struct tpl0102_data *data;
>+ long devid = id->driver_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 = devid;
Why local devid variable?
>+ 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[devid].wipers;
>+ indio_dev->name = client->name;
>+
>+ return iio_device_register(indio_dev);
devm_ or you need to explicitly unregister in a remove function.
>+}
>+
>+static const struct i2c_device_id tpl0102_id[] = {
>+ { "tpl0102-104", TPL0102_104 },
>+ { "tpl0401-103", TPL0401_103 },
>+ { "cat5140-503", CAT5140_503 },
>+ { "cat5140-104", CAT5140_104 },
>+ {}
>+};
>+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");
--
Sent from my Android device with K-9 Mail. Please excuse my brevity.
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