diff options
Diffstat (limited to 'drivers/iio/dac/m62332.c')
| -rw-r--r-- | drivers/iio/dac/m62332.c | 269 |
1 files changed, 269 insertions, 0 deletions
diff --git a/drivers/iio/dac/m62332.c b/drivers/iio/dac/m62332.c new file mode 100644 index 000000000..c23d7fa88 --- /dev/null +++ b/drivers/iio/dac/m62332.c @@ -0,0 +1,269 @@ +/* + * m62332.c - Support for Mitsubishi m62332 DAC + * + * Copyright (c) 2014 Dmitry Eremin-Solenikov + * + * Based on max517 driver: + * Copyright (C) 2010, 2011 Roland Stigge <stigge@antcom.de> + * + * 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. + */ + +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/i2c.h> +#include <linux/err.h> + +#include <linux/iio/iio.h> +#include <linux/iio/driver.h> + +#include <linux/regulator/consumer.h> + +#define M62332_CHANNELS 2 + +struct m62332_data { + struct i2c_client *client; + u16 vref_mv; + struct regulator *vcc; + struct mutex mutex; + u8 raw[M62332_CHANNELS]; +#ifdef CONFIG_PM_SLEEP + u8 save[M62332_CHANNELS]; +#endif +}; + +static int m62332_set_value(struct iio_dev *indio_dev, + u8 val, int channel) +{ + struct m62332_data *data = iio_priv(indio_dev); + struct i2c_client *client = data->client; + u8 outbuf[2]; + int res; + + if (val == data->raw[channel]) + return 0; + + outbuf[0] = channel; + outbuf[1] = val; + + mutex_lock(&data->mutex); + + if (val) { + res = regulator_enable(data->vcc); + if (res) + goto out; + } + + res = i2c_master_send(client, outbuf, 2); + if (res >= 0 && res != 2) + res = -EIO; + if (res < 0) + goto out; + + data->raw[channel] = val; + + if (!val) + regulator_disable(data->vcc); + + mutex_unlock(&data->mutex); + + return 0; + +out: + mutex_unlock(&data->mutex); + + return res; +} + +static int m62332_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, + int *val2, + long m) +{ + struct m62332_data *data = iio_priv(indio_dev); + + switch (m) { + case IIO_CHAN_INFO_SCALE: + /* Corresponds to Vref / 2^(bits) */ + *val = data->vref_mv; + *val2 = 8; + return IIO_VAL_FRACTIONAL_LOG2; + case IIO_CHAN_INFO_RAW: + *val = data->raw[chan->channel]; + return IIO_VAL_INT; + case IIO_CHAN_INFO_OFFSET: + *val = 1; + return IIO_VAL_INT; + default: + break; + } + return -EINVAL; +} + +static int m62332_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int val, int val2, long mask) +{ + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + if (val < 0 || val > 255) + return -EINVAL; + + ret = m62332_set_value(indio_dev, val, chan->channel); + break; + default: + ret = -EINVAL; + break; + } + + return ret; +} + +#ifdef CONFIG_PM_SLEEP +static int m62332_suspend(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct iio_dev *indio_dev = i2c_get_clientdata(client); + struct m62332_data *data = iio_priv(indio_dev); + int ret; + + data->save[0] = data->raw[0]; + data->save[1] = data->raw[1]; + + ret = m62332_set_value(indio_dev, 0, 0); + if (ret < 0) + return ret; + + return m62332_set_value(indio_dev, 0, 1); +} + +static int m62332_resume(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct iio_dev *indio_dev = i2c_get_clientdata(client); + struct m62332_data *data = iio_priv(indio_dev); + int ret; + + ret = m62332_set_value(indio_dev, data->save[0], 0); + if (ret < 0) + return ret; + + return m62332_set_value(indio_dev, data->save[1], 1); +} + +static SIMPLE_DEV_PM_OPS(m62332_pm_ops, m62332_suspend, m62332_resume); +#define M62332_PM_OPS (&m62332_pm_ops) +#else +#define M62332_PM_OPS NULL +#endif + +static const struct iio_info m62332_info = { + .read_raw = m62332_read_raw, + .write_raw = m62332_write_raw, + .driver_module = THIS_MODULE, +}; + +#define M62332_CHANNEL(chan) { \ + .type = IIO_VOLTAGE, \ + .indexed = 1, \ + .output = 1, \ + .channel = (chan), \ + .datasheet_name = "CH" #chan, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ + BIT(IIO_CHAN_INFO_SCALE) | \ + BIT(IIO_CHAN_INFO_OFFSET), \ +} + +static const struct iio_chan_spec m62332_channels[M62332_CHANNELS] = { + M62332_CHANNEL(0), + M62332_CHANNEL(1) +}; + +static int m62332_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct m62332_data *data; + struct iio_dev *indio_dev; + int ret; + + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); + if (!indio_dev) + return -ENOMEM; + data = iio_priv(indio_dev); + i2c_set_clientdata(client, indio_dev); + data->client = client; + + mutex_init(&data->mutex); + + data->vcc = devm_regulator_get(&client->dev, "VCC"); + if (IS_ERR(data->vcc)) + return PTR_ERR(data->vcc); + + /* establish that the iio_dev is a child of the i2c device */ + indio_dev->dev.parent = &client->dev; + + indio_dev->num_channels = M62332_CHANNELS; + indio_dev->channels = m62332_channels; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->info = &m62332_info; + + ret = regulator_get_voltage(data->vcc); + if (ret < 0) + return ret; + data->vref_mv = ret / 1000; /* mV */ + + ret = iio_map_array_register(indio_dev, client->dev.platform_data); + if (ret < 0) + return ret; + + ret = iio_device_register(indio_dev); + if (ret < 0) + goto err; + + return 0; + +err: + iio_map_array_unregister(indio_dev); + return ret; +} + +static int m62332_remove(struct i2c_client *client) +{ + struct iio_dev *indio_dev = i2c_get_clientdata(client); + + iio_device_unregister(indio_dev); + iio_map_array_unregister(indio_dev); + + return 0; +} + +static const struct i2c_device_id m62332_id[] = { + { "m62332", }, + { } +}; +MODULE_DEVICE_TABLE(i2c, m62332_id); + +static struct i2c_driver m62332_driver = { + .driver = { + .name = "m62332", + .pm = M62332_PM_OPS, + }, + .probe = m62332_probe, + .remove = m62332_remove, + .id_table = m62332_id, +}; +module_i2c_driver(m62332_driver); + +MODULE_AUTHOR("Dmitry Eremin-Solenikov"); +MODULE_DESCRIPTION("M62332 8-bit DAC"); +MODULE_LICENSE("GPL v2"); |