| /* |
| * 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"); |