diff options
Diffstat (limited to 'drivers/iio/dac/ds4424.c')
| -rw-r--r-- | drivers/iio/dac/ds4424.c | 335 |
1 files changed, 335 insertions, 0 deletions
diff --git a/drivers/iio/dac/ds4424.c b/drivers/iio/dac/ds4424.c new file mode 100644 index 000000000..ae9be7926 --- /dev/null +++ b/drivers/iio/dac/ds4424.c @@ -0,0 +1,335 @@ +/* + * Maxim Integrated + * 7-bit, Multi-Channel Sink/Source Current DAC Driver + * Copyright (C) 2017 Maxim Integrated + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/i2c.h> +#include <linux/regulator/consumer.h> +#include <linux/err.h> +#include <linux/delay.h> +#include <linux/iio/iio.h> +#include <linux/iio/driver.h> +#include <linux/iio/machine.h> +#include <linux/iio/consumer.h> + +#define DS4422_MAX_DAC_CHANNELS 2 +#define DS4424_MAX_DAC_CHANNELS 4 + +#define DS4424_DAC_ADDR(chan) ((chan) + 0xf8) +#define DS4424_SOURCE_I 1 +#define DS4424_SINK_I 0 + +#define DS4424_CHANNEL(chan) { \ + .type = IIO_CURRENT, \ + .indexed = 1, \ + .output = 1, \ + .channel = chan, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ +} + +/* + * DS4424 DAC control register 8 bits + * [7] 0: to sink; 1: to source + * [6:0] steps to sink/source + * bit[7] looks like a sign bit, but the value of the register is + * not a two's complement code considering the bit[6:0] is a absolute + * distance from the zero point. + */ +union ds4424_raw_data { + struct { + u8 dx:7; + u8 source_bit:1; + }; + u8 bits; +}; + +enum ds4424_device_ids { + ID_DS4422, + ID_DS4424, +}; + +struct ds4424_data { + struct i2c_client *client; + struct mutex lock; + uint8_t save[DS4424_MAX_DAC_CHANNELS]; + struct regulator *vcc_reg; + uint8_t raw[DS4424_MAX_DAC_CHANNELS]; +}; + +static const struct iio_chan_spec ds4424_channels[] = { + DS4424_CHANNEL(0), + DS4424_CHANNEL(1), + DS4424_CHANNEL(2), + DS4424_CHANNEL(3), +}; + +static int ds4424_get_value(struct iio_dev *indio_dev, + int *val, int channel) +{ + struct ds4424_data *data = iio_priv(indio_dev); + int ret; + + mutex_lock(&data->lock); + ret = i2c_smbus_read_byte_data(data->client, DS4424_DAC_ADDR(channel)); + if (ret < 0) + goto fail; + + *val = ret; + +fail: + mutex_unlock(&data->lock); + return ret; +} + +static int ds4424_set_value(struct iio_dev *indio_dev, + int val, struct iio_chan_spec const *chan) +{ + struct ds4424_data *data = iio_priv(indio_dev); + int ret; + + mutex_lock(&data->lock); + ret = i2c_smbus_write_byte_data(data->client, + DS4424_DAC_ADDR(chan->channel), val); + if (ret < 0) + goto fail; + + data->raw[chan->channel] = val; + +fail: + mutex_unlock(&data->lock); + return ret; +} + +static int ds4424_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + union ds4424_raw_data raw; + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + ret = ds4424_get_value(indio_dev, val, chan->channel); + if (ret < 0) { + pr_err("%s : ds4424_get_value returned %d\n", + __func__, ret); + return ret; + } + raw.bits = *val; + *val = raw.dx; + if (raw.source_bit == DS4424_SINK_I) + *val = -*val; + return IIO_VAL_INT; + + default: + return -EINVAL; + } +} + +static int ds4424_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + union ds4424_raw_data raw; + + if (val2 != 0) + return -EINVAL; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + if (val < S8_MIN || val > S8_MAX) + return -EINVAL; + + if (val > 0) { + raw.source_bit = DS4424_SOURCE_I; + raw.dx = val; + } else { + raw.source_bit = DS4424_SINK_I; + raw.dx = -val; + } + + return ds4424_set_value(indio_dev, raw.bits, chan); + + default: + return -EINVAL; + } +} + +static int ds4424_verify_chip(struct iio_dev *indio_dev) +{ + int ret, val; + + ret = ds4424_get_value(indio_dev, &val, 0); + if (ret < 0) + dev_err(&indio_dev->dev, + "%s failed. ret: %d\n", __func__, ret); + + return ret; +} + +static int __maybe_unused ds4424_suspend(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct iio_dev *indio_dev = i2c_get_clientdata(client); + struct ds4424_data *data = iio_priv(indio_dev); + int ret = 0; + int i; + + for (i = 0; i < indio_dev->num_channels; i++) { + data->save[i] = data->raw[i]; + ret = ds4424_set_value(indio_dev, 0, + &indio_dev->channels[i]); + if (ret < 0) + return ret; + } + return ret; +} + +static int __maybe_unused ds4424_resume(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct iio_dev *indio_dev = i2c_get_clientdata(client); + struct ds4424_data *data = iio_priv(indio_dev); + int ret = 0; + int i; + + for (i = 0; i < indio_dev->num_channels; i++) { + ret = ds4424_set_value(indio_dev, data->save[i], + &indio_dev->channels[i]); + if (ret < 0) + return ret; + } + return ret; +} + +static SIMPLE_DEV_PM_OPS(ds4424_pm_ops, ds4424_suspend, ds4424_resume); + +static const struct iio_info ds4424_info = { + .read_raw = ds4424_read_raw, + .write_raw = ds4424_write_raw, +}; + +static int ds4424_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct ds4424_data *data; + struct iio_dev *indio_dev; + int ret; + + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); + if (!indio_dev) { + dev_err(&client->dev, "iio dev alloc failed.\n"); + return -ENOMEM; + } + + data = iio_priv(indio_dev); + i2c_set_clientdata(client, indio_dev); + data->client = client; + indio_dev->name = id->name; + indio_dev->dev.of_node = client->dev.of_node; + indio_dev->dev.parent = &client->dev; + + data->vcc_reg = devm_regulator_get(&client->dev, "vcc"); + if (IS_ERR(data->vcc_reg)) { + dev_err(&client->dev, + "Failed to get vcc-supply regulator. err: %ld\n", + PTR_ERR(data->vcc_reg)); + return PTR_ERR(data->vcc_reg); + } + + mutex_init(&data->lock); + ret = regulator_enable(data->vcc_reg); + if (ret < 0) { + dev_err(&client->dev, + "Unable to enable the regulator.\n"); + return ret; + } + + usleep_range(1000, 1200); + ret = ds4424_verify_chip(indio_dev); + if (ret < 0) + goto fail; + + switch (id->driver_data) { + case ID_DS4422: + indio_dev->num_channels = DS4422_MAX_DAC_CHANNELS; + break; + case ID_DS4424: + indio_dev->num_channels = DS4424_MAX_DAC_CHANNELS; + break; + default: + dev_err(&client->dev, + "ds4424: Invalid chip id.\n"); + ret = -ENXIO; + goto fail; + } + + indio_dev->channels = ds4424_channels; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->info = &ds4424_info; + + ret = iio_device_register(indio_dev); + if (ret < 0) { + dev_err(&client->dev, + "iio_device_register failed. ret: %d\n", ret); + goto fail; + } + + return ret; + +fail: + regulator_disable(data->vcc_reg); + return ret; +} + +static int ds4424_remove(struct i2c_client *client) +{ + struct iio_dev *indio_dev = i2c_get_clientdata(client); + struct ds4424_data *data = iio_priv(indio_dev); + + iio_device_unregister(indio_dev); + regulator_disable(data->vcc_reg); + + return 0; +} + +static const struct i2c_device_id ds4424_id[] = { + { "ds4422", ID_DS4422 }, + { "ds4424", ID_DS4424 }, + { } +}; + +MODULE_DEVICE_TABLE(i2c, ds4424_id); + +static const struct of_device_id ds4424_of_match[] = { + { .compatible = "maxim,ds4422" }, + { .compatible = "maxim,ds4424" }, + { }, +}; + +MODULE_DEVICE_TABLE(of, ds4424_of_match); + +static struct i2c_driver ds4424_driver = { + .driver = { + .name = "ds4424", + .of_match_table = ds4424_of_match, + .pm = &ds4424_pm_ops, + }, + .probe = ds4424_probe, + .remove = ds4424_remove, + .id_table = ds4424_id, +}; +module_i2c_driver(ds4424_driver); + +MODULE_DESCRIPTION("Maxim DS4424 DAC Driver"); +MODULE_AUTHOR("Ismail H. Kose <ismail.kose@maximintegrated.com>"); +MODULE_AUTHOR("Vishal Sood <vishal.sood@maximintegrated.com>"); +MODULE_AUTHOR("David Jung <david.jung@maximintegrated.com>"); +MODULE_LICENSE("GPL v2"); |