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330 lines
7.0 KiB
330 lines
7.0 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Maxim Integrated |
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* 7-bit, Multi-Channel Sink/Source Current DAC Driver |
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* Copyright (C) 2017 Maxim Integrated |
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*/ |
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/i2c.h> |
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#include <linux/regulator/consumer.h> |
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#include <linux/err.h> |
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#include <linux/delay.h> |
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#include <linux/iio/iio.h> |
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#include <linux/iio/driver.h> |
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#include <linux/iio/machine.h> |
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#include <linux/iio/consumer.h> |
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#define DS4422_MAX_DAC_CHANNELS 2 |
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#define DS4424_MAX_DAC_CHANNELS 4 |
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#define DS4424_DAC_ADDR(chan) ((chan) + 0xf8) |
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#define DS4424_SOURCE_I 1 |
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#define DS4424_SINK_I 0 |
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#define DS4424_CHANNEL(chan) { \ |
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.type = IIO_CURRENT, \ |
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.indexed = 1, \ |
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.output = 1, \ |
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.channel = chan, \ |
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ |
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} |
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/* |
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* DS4424 DAC control register 8 bits |
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* [7] 0: to sink; 1: to source |
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* [6:0] steps to sink/source |
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* bit[7] looks like a sign bit, but the value of the register is |
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* not a two's complement code considering the bit[6:0] is a absolute |
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* distance from the zero point. |
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*/ |
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union ds4424_raw_data { |
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struct { |
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u8 dx:7; |
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u8 source_bit:1; |
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}; |
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u8 bits; |
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}; |
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enum ds4424_device_ids { |
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ID_DS4422, |
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ID_DS4424, |
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}; |
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struct ds4424_data { |
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struct i2c_client *client; |
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struct mutex lock; |
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uint8_t save[DS4424_MAX_DAC_CHANNELS]; |
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struct regulator *vcc_reg; |
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uint8_t raw[DS4424_MAX_DAC_CHANNELS]; |
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}; |
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static const struct iio_chan_spec ds4424_channels[] = { |
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DS4424_CHANNEL(0), |
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DS4424_CHANNEL(1), |
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DS4424_CHANNEL(2), |
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DS4424_CHANNEL(3), |
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}; |
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static int ds4424_get_value(struct iio_dev *indio_dev, |
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int *val, int channel) |
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{ |
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struct ds4424_data *data = iio_priv(indio_dev); |
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int ret; |
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mutex_lock(&data->lock); |
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ret = i2c_smbus_read_byte_data(data->client, DS4424_DAC_ADDR(channel)); |
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if (ret < 0) |
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goto fail; |
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*val = ret; |
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fail: |
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mutex_unlock(&data->lock); |
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return ret; |
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} |
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static int ds4424_set_value(struct iio_dev *indio_dev, |
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int val, struct iio_chan_spec const *chan) |
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{ |
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struct ds4424_data *data = iio_priv(indio_dev); |
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int ret; |
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mutex_lock(&data->lock); |
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ret = i2c_smbus_write_byte_data(data->client, |
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DS4424_DAC_ADDR(chan->channel), val); |
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if (ret < 0) |
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goto fail; |
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data->raw[chan->channel] = val; |
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fail: |
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mutex_unlock(&data->lock); |
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return ret; |
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} |
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static int ds4424_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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union ds4424_raw_data raw; |
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int ret; |
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switch (mask) { |
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case IIO_CHAN_INFO_RAW: |
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ret = ds4424_get_value(indio_dev, val, chan->channel); |
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if (ret < 0) { |
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pr_err("%s : ds4424_get_value returned %d\n", |
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__func__, ret); |
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return ret; |
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} |
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raw.bits = *val; |
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*val = raw.dx; |
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if (raw.source_bit == DS4424_SINK_I) |
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*val = -*val; |
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return IIO_VAL_INT; |
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default: |
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return -EINVAL; |
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} |
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} |
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static int ds4424_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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union ds4424_raw_data raw; |
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if (val2 != 0) |
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return -EINVAL; |
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switch (mask) { |
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case IIO_CHAN_INFO_RAW: |
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if (val < S8_MIN || val > S8_MAX) |
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return -EINVAL; |
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if (val > 0) { |
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raw.source_bit = DS4424_SOURCE_I; |
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raw.dx = val; |
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} else { |
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raw.source_bit = DS4424_SINK_I; |
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raw.dx = -val; |
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} |
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return ds4424_set_value(indio_dev, raw.bits, chan); |
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default: |
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return -EINVAL; |
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} |
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} |
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static int ds4424_verify_chip(struct iio_dev *indio_dev) |
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{ |
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int ret, val; |
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ret = ds4424_get_value(indio_dev, &val, 0); |
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if (ret < 0) |
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dev_err(&indio_dev->dev, |
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"%s failed. ret: %d\n", __func__, ret); |
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return ret; |
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} |
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static int __maybe_unused ds4424_suspend(struct device *dev) |
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{ |
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struct i2c_client *client = to_i2c_client(dev); |
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struct iio_dev *indio_dev = i2c_get_clientdata(client); |
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struct ds4424_data *data = iio_priv(indio_dev); |
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int ret = 0; |
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int i; |
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for (i = 0; i < indio_dev->num_channels; i++) { |
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data->save[i] = data->raw[i]; |
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ret = ds4424_set_value(indio_dev, 0, |
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&indio_dev->channels[i]); |
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if (ret < 0) |
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return ret; |
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} |
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return ret; |
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} |
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static int __maybe_unused ds4424_resume(struct device *dev) |
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{ |
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struct i2c_client *client = to_i2c_client(dev); |
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struct iio_dev *indio_dev = i2c_get_clientdata(client); |
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struct ds4424_data *data = iio_priv(indio_dev); |
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int ret = 0; |
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int i; |
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for (i = 0; i < indio_dev->num_channels; i++) { |
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ret = ds4424_set_value(indio_dev, data->save[i], |
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&indio_dev->channels[i]); |
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if (ret < 0) |
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return ret; |
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} |
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return ret; |
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} |
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static SIMPLE_DEV_PM_OPS(ds4424_pm_ops, ds4424_suspend, ds4424_resume); |
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static const struct iio_info ds4424_info = { |
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.read_raw = ds4424_read_raw, |
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.write_raw = ds4424_write_raw, |
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}; |
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static int ds4424_probe(struct i2c_client *client, |
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const struct i2c_device_id *id) |
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{ |
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struct ds4424_data *data; |
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struct iio_dev *indio_dev; |
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int ret; |
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indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); |
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if (!indio_dev) { |
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dev_err(&client->dev, "iio dev alloc failed.\n"); |
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return -ENOMEM; |
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} |
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data = iio_priv(indio_dev); |
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i2c_set_clientdata(client, indio_dev); |
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data->client = client; |
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indio_dev->name = id->name; |
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data->vcc_reg = devm_regulator_get(&client->dev, "vcc"); |
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if (IS_ERR(data->vcc_reg)) { |
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dev_err(&client->dev, |
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"Failed to get vcc-supply regulator. err: %ld\n", |
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PTR_ERR(data->vcc_reg)); |
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return PTR_ERR(data->vcc_reg); |
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} |
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mutex_init(&data->lock); |
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ret = regulator_enable(data->vcc_reg); |
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if (ret < 0) { |
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dev_err(&client->dev, |
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"Unable to enable the regulator.\n"); |
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return ret; |
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} |
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usleep_range(1000, 1200); |
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ret = ds4424_verify_chip(indio_dev); |
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if (ret < 0) |
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goto fail; |
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switch (id->driver_data) { |
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case ID_DS4422: |
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indio_dev->num_channels = DS4422_MAX_DAC_CHANNELS; |
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break; |
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case ID_DS4424: |
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indio_dev->num_channels = DS4424_MAX_DAC_CHANNELS; |
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break; |
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default: |
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dev_err(&client->dev, |
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"ds4424: Invalid chip id.\n"); |
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ret = -ENXIO; |
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goto fail; |
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} |
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indio_dev->channels = ds4424_channels; |
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indio_dev->modes = INDIO_DIRECT_MODE; |
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indio_dev->info = &ds4424_info; |
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ret = iio_device_register(indio_dev); |
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if (ret < 0) { |
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dev_err(&client->dev, |
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"iio_device_register failed. ret: %d\n", ret); |
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goto fail; |
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} |
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return ret; |
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fail: |
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regulator_disable(data->vcc_reg); |
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return ret; |
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} |
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static int ds4424_remove(struct i2c_client *client) |
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{ |
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struct iio_dev *indio_dev = i2c_get_clientdata(client); |
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struct ds4424_data *data = iio_priv(indio_dev); |
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iio_device_unregister(indio_dev); |
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regulator_disable(data->vcc_reg); |
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return 0; |
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} |
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static const struct i2c_device_id ds4424_id[] = { |
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{ "ds4422", ID_DS4422 }, |
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{ "ds4424", ID_DS4424 }, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(i2c, ds4424_id); |
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static const struct of_device_id ds4424_of_match[] = { |
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{ .compatible = "maxim,ds4422" }, |
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{ .compatible = "maxim,ds4424" }, |
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{ }, |
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}; |
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MODULE_DEVICE_TABLE(of, ds4424_of_match); |
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static struct i2c_driver ds4424_driver = { |
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.driver = { |
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.name = "ds4424", |
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.of_match_table = ds4424_of_match, |
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.pm = &ds4424_pm_ops, |
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}, |
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.probe = ds4424_probe, |
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.remove = ds4424_remove, |
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.id_table = ds4424_id, |
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}; |
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module_i2c_driver(ds4424_driver); |
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MODULE_DESCRIPTION("Maxim DS4424 DAC Driver"); |
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MODULE_AUTHOR("Ismail H. Kose <[email protected]>"); |
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MODULE_AUTHOR("Vishal Sood <[email protected]>"); |
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MODULE_AUTHOR("David Jung <[email protected]>"); |
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MODULE_LICENSE("GPL v2");
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