diff options
Diffstat (limited to 'drivers/iio/potentiometer/tpl0102.c')
| -rw-r--r-- | drivers/iio/potentiometer/tpl0102.c | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/drivers/iio/potentiometer/tpl0102.c b/drivers/iio/potentiometer/tpl0102.c new file mode 100644 index 000000000..313124b6f --- /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"); |