2 * max517.c - Support for Maxim MAX517, MAX518 and MAX519
4 * Copyright (C) 2010, 2011 Roland Stigge <stigge@antcom.de>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 #include <linux/module.h>
22 #include <linux/slab.h>
23 #include <linux/jiffies.h>
24 #include <linux/i2c.h>
25 #include <linux/err.h>
27 #include <linux/iio/iio.h>
28 #include <linux/iio/sysfs.h>
29 #include <linux/iio/dac/max517.h>
31 #define MAX517_DRV_NAME "max517"
34 #define COMMAND_CHANNEL0 0x00
35 #define COMMAND_CHANNEL1 0x01 /* for MAX518 and MAX519 */
36 #define COMMAND_PD 0x08 /* Power Down */
38 enum max517_device_ids {
45 struct i2c_client *client;
46 unsigned short vref_mv[2];
50 * channel: bit 0: channel 1
52 * (this way, it's possible to set both channels at once)
54 static int max517_set_value(struct iio_dev *indio_dev,
55 long val, int channel)
57 struct max517_data *data = iio_priv(indio_dev);
58 struct i2c_client *client = data->client;
62 if (val < 0 || val > 255)
68 res = i2c_master_send(client, outbuf, 2);
77 static int max517_read_raw(struct iio_dev *indio_dev,
78 struct iio_chan_spec const *chan,
83 struct max517_data *data = iio_priv(indio_dev);
86 case IIO_CHAN_INFO_SCALE:
87 /* Corresponds to Vref / 2^(bits) */
88 *val = data->vref_mv[chan->channel];
90 return IIO_VAL_FRACTIONAL_LOG2;
97 static int max517_write_raw(struct iio_dev *indio_dev,
98 struct iio_chan_spec const *chan, int val, int val2, long mask)
103 case IIO_CHAN_INFO_RAW:
104 ret = max517_set_value(indio_dev, val, chan->channel);
114 #ifdef CONFIG_PM_SLEEP
115 static int max517_suspend(struct device *dev)
117 u8 outbuf = COMMAND_PD;
119 return i2c_master_send(to_i2c_client(dev), &outbuf, 1);
122 static int max517_resume(struct device *dev)
126 return i2c_master_send(to_i2c_client(dev), &outbuf, 1);
129 static SIMPLE_DEV_PM_OPS(max517_pm_ops, max517_suspend, max517_resume);
130 #define MAX517_PM_OPS (&max517_pm_ops)
132 #define MAX517_PM_OPS NULL
135 static const struct iio_info max517_info = {
136 .read_raw = max517_read_raw,
137 .write_raw = max517_write_raw,
138 .driver_module = THIS_MODULE,
141 #define MAX517_CHANNEL(chan) { \
142 .type = IIO_VOLTAGE, \
146 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
147 BIT(IIO_CHAN_INFO_SCALE), \
150 static const struct iio_chan_spec max517_channels[] = {
155 static int max517_probe(struct i2c_client *client,
156 const struct i2c_device_id *id)
158 struct max517_data *data;
159 struct iio_dev *indio_dev;
160 struct max517_platform_data *platform_data = client->dev.platform_data;
162 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
165 data = iio_priv(indio_dev);
166 i2c_set_clientdata(client, indio_dev);
167 data->client = client;
169 /* establish that the iio_dev is a child of the i2c device */
170 indio_dev->dev.parent = &client->dev;
172 /* reduced channel set for MAX517 */
173 if (id->driver_data == ID_MAX517)
174 indio_dev->num_channels = 1;
176 indio_dev->num_channels = 2;
177 indio_dev->channels = max517_channels;
178 indio_dev->modes = INDIO_DIRECT_MODE;
179 indio_dev->info = &max517_info;
182 * Reference voltage on MAX518 and default is 5V, else take vref_mv
185 if (id->driver_data == ID_MAX518 || !platform_data) {
186 data->vref_mv[0] = data->vref_mv[1] = 5000; /* mV */
188 data->vref_mv[0] = platform_data->vref_mv[0];
189 data->vref_mv[1] = platform_data->vref_mv[1];
192 return iio_device_register(indio_dev);
195 static int max517_remove(struct i2c_client *client)
197 iio_device_unregister(i2c_get_clientdata(client));
201 static const struct i2c_device_id max517_id[] = {
202 { "max517", ID_MAX517 },
203 { "max518", ID_MAX518 },
204 { "max519", ID_MAX519 },
207 MODULE_DEVICE_TABLE(i2c, max517_id);
209 static struct i2c_driver max517_driver = {
211 .name = MAX517_DRV_NAME,
214 .probe = max517_probe,
215 .remove = max517_remove,
216 .id_table = max517_id,
218 module_i2c_driver(max517_driver);
220 MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
221 MODULE_DESCRIPTION("MAX517/MAX518/MAX519 8-bit DAC");
222 MODULE_LICENSE("GPL");