154 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			154 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0+
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| /*
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|  * tpl0102.c - Support for Texas Instruments digital potentiometers
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|  *
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|  * Copyright (C) 2016, 2018
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|  * Author: Matt Ranostay <matt.ranostay@konsulko.com>
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|  *
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|  * TODO: enable/disable hi-z output control
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|  */
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| 
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| #include <linux/module.h>
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| #include <linux/i2c.h>
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| #include <linux/regmap.h>
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| #include <linux/iio/iio.h>
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| 
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| struct tpl0102_cfg {
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| 	int wipers;
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| 	int max_pos;
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| 	int kohms;
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| };
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| 
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| enum tpl0102_type {
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| 	CAT5140_503,
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| 	CAT5140_104,
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| 	TPL0102_104,
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| 	TPL0401_103,
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| };
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| 
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| static const struct tpl0102_cfg tpl0102_cfg[] = {
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| 	/* on-semiconductor parts */
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| 	[CAT5140_503] = { .wipers = 1, .max_pos = 256, .kohms = 50, },
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| 	[CAT5140_104] = { .wipers = 1, .max_pos = 256, .kohms = 100, },
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| 	/* ti parts */
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| 	[TPL0102_104] = { .wipers = 2, .max_pos = 256, .kohms = 100 },
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| 	[TPL0401_103] = { .wipers = 1, .max_pos = 128, .kohms = 10, },
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| };
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| 
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| struct tpl0102_data {
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| 	struct regmap *regmap;
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| 	unsigned long devid;
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| };
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| 
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| static const struct regmap_config tpl0102_regmap_config = {
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| 	.reg_bits = 8,
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| 	.val_bits = 8,
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| };
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| 
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| #define TPL0102_CHANNEL(ch) {					\
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| 	.type = IIO_RESISTANCE,					\
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| 	.indexed = 1,						\
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| 	.output = 1,						\
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| 	.channel = (ch),					\
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| 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
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| 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
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| }
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| 
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| static const struct iio_chan_spec tpl0102_channels[] = {
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| 	TPL0102_CHANNEL(0),
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| 	TPL0102_CHANNEL(1),
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| };
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| 
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| static int tpl0102_read_raw(struct iio_dev *indio_dev,
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| 			    struct iio_chan_spec const *chan,
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| 			    int *val, int *val2, long mask)
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| {
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| 	struct tpl0102_data *data = iio_priv(indio_dev);
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| 
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| 	switch (mask) {
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| 	case IIO_CHAN_INFO_RAW: {
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| 		int ret = regmap_read(data->regmap, chan->channel, val);
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| 
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| 		return ret ? ret : IIO_VAL_INT;
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| 	}
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| 	case IIO_CHAN_INFO_SCALE:
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| 		*val = 1000 * tpl0102_cfg[data->devid].kohms;
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| 		*val2 = tpl0102_cfg[data->devid].max_pos;
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| 		return IIO_VAL_FRACTIONAL;
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| 	}
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| 
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| 	return -EINVAL;
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| }
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| 
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| static int tpl0102_write_raw(struct iio_dev *indio_dev,
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| 			     struct iio_chan_spec const *chan,
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| 			     int val, int val2, long mask)
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| {
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| 	struct tpl0102_data *data = iio_priv(indio_dev);
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| 
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| 	if (mask != IIO_CHAN_INFO_RAW)
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| 		return -EINVAL;
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| 
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| 	if (val >= tpl0102_cfg[data->devid].max_pos || val < 0)
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| 		return -EINVAL;
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| 
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| 	return regmap_write(data->regmap, chan->channel, val);
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| }
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| 
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| static const struct iio_info tpl0102_info = {
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| 	.read_raw = tpl0102_read_raw,
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| 	.write_raw = tpl0102_write_raw,
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| };
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| 
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| static int tpl0102_probe(struct i2c_client *client,
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| 			 const struct i2c_device_id *id)
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| {
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| 	struct device *dev = &client->dev;
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| 	struct tpl0102_data *data;
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| 	struct iio_dev *indio_dev;
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| 
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| 	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
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| 	if (!indio_dev)
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| 		return -ENOMEM;
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| 	data = iio_priv(indio_dev);
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| 	i2c_set_clientdata(client, indio_dev);
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| 
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| 	data->devid = id->driver_data;
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| 	data->regmap = devm_regmap_init_i2c(client, &tpl0102_regmap_config);
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| 	if (IS_ERR(data->regmap)) {
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| 		dev_err(dev, "regmap initialization failed\n");
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| 		return PTR_ERR(data->regmap);
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| 	}
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| 
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| 	indio_dev->dev.parent = dev;
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| 	indio_dev->info = &tpl0102_info;
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| 	indio_dev->channels = tpl0102_channels;
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| 	indio_dev->num_channels = tpl0102_cfg[data->devid].wipers;
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| 	indio_dev->name = client->name;
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| 
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| 	return devm_iio_device_register(dev, indio_dev);
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| }
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| 
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| static const struct i2c_device_id tpl0102_id[] = {
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| 	{ "cat5140-503", CAT5140_503 },
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| 	{ "cat5140-104", CAT5140_104 },
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| 	{ "tpl0102-104", TPL0102_104 },
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| 	{ "tpl0401-103", TPL0401_103 },
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| 	{}
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| };
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| MODULE_DEVICE_TABLE(i2c, tpl0102_id);
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| 
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| static struct i2c_driver tpl0102_driver = {
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| 	.driver = {
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| 		.name = "tpl0102",
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| 	},
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| 	.probe = tpl0102_probe,
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| 	.id_table = tpl0102_id,
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| };
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| 
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| module_i2c_driver(tpl0102_driver);
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| 
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| MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
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| MODULE_DESCRIPTION("TPL0102 digital potentiometer");
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| MODULE_LICENSE("GPL");
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