diff options
Diffstat (limited to 'drivers/iio/dac/max517.c')
| -rw-r--r-- | drivers/iio/dac/max517.c | 243 |
1 files changed, 243 insertions, 0 deletions
diff --git a/drivers/iio/dac/max517.c b/drivers/iio/dac/max517.c new file mode 100644 index 000000000000..92c77c82026c --- /dev/null +++ b/drivers/iio/dac/max517.c @@ -0,0 +1,243 @@ +/* + * max517.c - Support for Maxim MAX517, MAX518 and MAX519 + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/jiffies.h> +#include <linux/i2c.h> +#include <linux/err.h> + +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/iio/dac/max517.h> + +#define MAX517_DRV_NAME "max517" + +/* Commands */ +#define COMMAND_CHANNEL0 0x00 +#define COMMAND_CHANNEL1 0x01 /* for MAX518 and MAX519 */ +#define COMMAND_PD 0x08 /* Power Down */ + +enum max517_device_ids { + ID_MAX517, + ID_MAX518, + ID_MAX519, +}; + +struct max517_data { + struct iio_dev *indio_dev; + struct i2c_client *client; + unsigned short vref_mv[2]; +}; + +/* + * channel: bit 0: channel 1 + * bit 1: channel 2 + * (this way, it's possible to set both channels at once) + */ +static int max517_set_value(struct iio_dev *indio_dev, + long val, int channel) +{ + struct max517_data *data = iio_priv(indio_dev); + struct i2c_client *client = data->client; + u8 outbuf[2]; + int res; + + if (val < 0 || val > 255) + return -EINVAL; + + outbuf[0] = channel; + outbuf[1] = val; + + res = i2c_master_send(client, outbuf, 2); + if (res < 0) + return res; + else if (res != 2) + return -EIO; + else + return 0; +} + +static int max517_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, + int *val2, + long m) +{ + struct max517_data *data = iio_priv(indio_dev); + unsigned int scale_uv; + + switch (m) { + case IIO_CHAN_INFO_SCALE: + /* Corresponds to Vref / 2^(bits) */ + scale_uv = (data->vref_mv[chan->channel] * 1000) >> 8; + *val = scale_uv / 1000000; + *val2 = scale_uv % 1000000; + return IIO_VAL_INT_PLUS_MICRO; + default: + break; + } + return -EINVAL; +} + +static int max517_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: + ret = max517_set_value(indio_dev, val, chan->channel); + break; + default: + ret = -EINVAL; + break; + } + + return ret; +} + +#ifdef CONFIG_PM_SLEEP +static int max517_suspend(struct device *dev) +{ + u8 outbuf = COMMAND_PD; + + return i2c_master_send(to_i2c_client(dev), &outbuf, 1); +} + +static int max517_resume(struct device *dev) +{ + u8 outbuf = 0; + + return i2c_master_send(to_i2c_client(dev), &outbuf, 1); +} + +static SIMPLE_DEV_PM_OPS(max517_pm_ops, max517_suspend, max517_resume); +#define MAX517_PM_OPS (&max517_pm_ops) +#else +#define MAX517_PM_OPS NULL +#endif + +static const struct iio_info max517_info = { + .read_raw = max517_read_raw, + .write_raw = max517_write_raw, + .driver_module = THIS_MODULE, +}; + +#define MAX517_CHANNEL(chan) { \ + .type = IIO_VOLTAGE, \ + .indexed = 1, \ + .output = 1, \ + .channel = (chan), \ + .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | \ + IIO_CHAN_INFO_SCALE_SEPARATE_BIT, \ + .scan_type = IIO_ST('u', 8, 8, 0), \ +} + +static const struct iio_chan_spec max517_channels[] = { + MAX517_CHANNEL(0), + MAX517_CHANNEL(1) +}; + +static int max517_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct max517_data *data; + struct iio_dev *indio_dev; + struct max517_platform_data *platform_data = client->dev.platform_data; + int err; + + indio_dev = iio_device_alloc(sizeof(*data)); + if (indio_dev == NULL) { + err = -ENOMEM; + goto exit; + } + data = iio_priv(indio_dev); + i2c_set_clientdata(client, indio_dev); + data->client = client; + + /* establish that the iio_dev is a child of the i2c device */ + indio_dev->dev.parent = &client->dev; + + /* reduced channel set for MAX517 */ + if (id->driver_data == ID_MAX517) + indio_dev->num_channels = 1; + else + indio_dev->num_channels = 2; + indio_dev->channels = max517_channels; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->info = &max517_info; + + /* + * Reference voltage on MAX518 and default is 5V, else take vref_mv + * from platform_data + */ + if (id->driver_data == ID_MAX518 || !platform_data) { + data->vref_mv[0] = data->vref_mv[1] = 5000; /* mV */ + } else { + data->vref_mv[0] = platform_data->vref_mv[0]; + data->vref_mv[1] = platform_data->vref_mv[1]; + } + + err = iio_device_register(indio_dev); + if (err) + goto exit_free_device; + + dev_info(&client->dev, "DAC registered\n"); + + return 0; + +exit_free_device: + iio_device_free(indio_dev); +exit: + return err; +} + +static int max517_remove(struct i2c_client *client) +{ + iio_device_unregister(i2c_get_clientdata(client)); + iio_device_free(i2c_get_clientdata(client)); + + return 0; +} + +static const struct i2c_device_id max517_id[] = { + { "max517", ID_MAX517 }, + { "max518", ID_MAX518 }, + { "max519", ID_MAX519 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, max517_id); + +static struct i2c_driver max517_driver = { + .driver = { + .name = MAX517_DRV_NAME, + .pm = MAX517_PM_OPS, + }, + .probe = max517_probe, + .remove = max517_remove, + .id_table = max517_id, +}; +module_i2c_driver(max517_driver); + +MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>"); +MODULE_DESCRIPTION("MAX517/MAX518/MAX519 8-bit DAC"); +MODULE_LICENSE("GPL"); |