2 * AK09911 3-axis compass driver
3 * Copyright (c) 2014, Intel Corporation.
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms and conditions of the GNU General Public License,
7 * version 2, as published by the Free Software Foundation.
9 * This program is distributed in the hope it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/init.h>
18 #include <linux/types.h>
19 #include <linux/slab.h>
20 #include <linux/delay.h>
21 #include <linux/i2c.h>
22 #include <linux/acpi.h>
23 #include <linux/iio/iio.h>
25 #define AK09911_REG_WIA1 0x00
26 #define AK09911_REG_WIA2 0x01
27 #define AK09911_WIA1_VALUE 0x48
28 #define AK09911_WIA2_VALUE 0x05
30 #define AK09911_REG_ST1 0x10
31 #define AK09911_REG_HXL 0x11
32 #define AK09911_REG_HXH 0x12
33 #define AK09911_REG_HYL 0x13
34 #define AK09911_REG_HYH 0x14
35 #define AK09911_REG_HZL 0x15
36 #define AK09911_REG_HZH 0x16
38 #define AK09911_REG_ASAX 0x60
39 #define AK09911_REG_ASAY 0x61
40 #define AK09911_REG_ASAZ 0x62
42 #define AK09911_REG_CNTL1 0x30
43 #define AK09911_REG_CNTL2 0x31
44 #define AK09911_REG_CNTL3 0x32
46 #define AK09911_MODE_SNG_MEASURE 0x01
47 #define AK09911_MODE_SELF_TEST 0x10
48 #define AK09911_MODE_FUSE_ACCESS 0x1F
49 #define AK09911_MODE_POWERDOWN 0x00
50 #define AK09911_RESET_DATA 0x01
52 #define AK09911_REG_CNTL1 0x30
53 #define AK09911_REG_CNTL2 0x31
54 #define AK09911_REG_CNTL3 0x32
56 #define AK09911_RAW_TO_GAUSS(asa) ((((asa) + 128) * 6000) / 256)
58 #define AK09911_MAX_CONVERSION_TIMEOUT_MS 500
59 #define AK09911_CONVERSION_DONE_POLL_TIME_MS 10
62 struct i2c_client *client;
68 static const int ak09911_index_to_reg[] = {
69 AK09911_REG_HXL, AK09911_REG_HYL, AK09911_REG_HZL,
72 static int ak09911_set_mode(struct i2c_client *client, u8 mode)
77 case AK09911_MODE_SNG_MEASURE:
78 case AK09911_MODE_SELF_TEST:
79 case AK09911_MODE_FUSE_ACCESS:
80 case AK09911_MODE_POWERDOWN:
81 ret = i2c_smbus_write_byte_data(client,
82 AK09911_REG_CNTL2, mode);
84 dev_err(&client->dev, "set_mode error\n");
87 /* After mode change wait atleast 100us */
88 usleep_range(100, 500);
92 "%s: Unknown mode(%d).", __func__, mode);
99 /* Get Sensitivity Adjustment value */
100 static int ak09911_get_asa(struct i2c_client *client)
102 struct iio_dev *indio_dev = i2c_get_clientdata(client);
103 struct ak09911_data *data = iio_priv(indio_dev);
106 ret = ak09911_set_mode(client, AK09911_MODE_FUSE_ACCESS);
110 /* Get asa data and store in the device data. */
111 ret = i2c_smbus_read_i2c_block_data(client, AK09911_REG_ASAX,
114 dev_err(&client->dev, "Not able to read asa data\n");
118 ret = ak09911_set_mode(client, AK09911_MODE_POWERDOWN);
122 data->raw_to_gauss[0] = AK09911_RAW_TO_GAUSS(data->asa[0]);
123 data->raw_to_gauss[1] = AK09911_RAW_TO_GAUSS(data->asa[1]);
124 data->raw_to_gauss[2] = AK09911_RAW_TO_GAUSS(data->asa[2]);
129 static int ak09911_verify_chip_id(struct i2c_client *client)
134 ret = i2c_smbus_read_i2c_block_data(client, AK09911_REG_WIA1,
137 dev_err(&client->dev, "Error reading WIA\n");
141 dev_dbg(&client->dev, "WIA %02x %02x\n", wia_val[0], wia_val[1]);
143 if (wia_val[0] != AK09911_WIA1_VALUE ||
144 wia_val[1] != AK09911_WIA2_VALUE) {
145 dev_err(&client->dev, "Device ak09911 not found\n");
152 static int wait_conversion_complete_polled(struct ak09911_data *data)
154 struct i2c_client *client = data->client;
156 u32 timeout_ms = AK09911_MAX_CONVERSION_TIMEOUT_MS;
159 /* Wait for the conversion to complete. */
161 msleep_interruptible(AK09911_CONVERSION_DONE_POLL_TIME_MS);
162 ret = i2c_smbus_read_byte_data(client, AK09911_REG_ST1);
164 dev_err(&client->dev, "Error in reading ST1\n");
167 read_status = ret & 0x01;
170 timeout_ms -= AK09911_CONVERSION_DONE_POLL_TIME_MS;
173 dev_err(&client->dev, "Conversion timeout happened\n");
180 static int ak09911_read_axis(struct iio_dev *indio_dev, int index, int *val)
182 struct ak09911_data *data = iio_priv(indio_dev);
183 struct i2c_client *client = data->client;
186 mutex_lock(&data->lock);
188 ret = ak09911_set_mode(client, AK09911_MODE_SNG_MEASURE);
192 ret = wait_conversion_complete_polled(data);
197 ret = i2c_smbus_read_word_data(client, ak09911_index_to_reg[index]);
199 dev_err(&client->dev, "Read axis data fails\n");
203 mutex_unlock(&data->lock);
205 /* Clamp to valid range. */
206 *val = sign_extend32(clamp_t(s16, ret, -8192, 8191), 13);
211 mutex_unlock(&data->lock);
216 static int ak09911_read_raw(struct iio_dev *indio_dev,
217 struct iio_chan_spec const *chan,
221 struct ak09911_data *data = iio_priv(indio_dev);
224 case IIO_CHAN_INFO_RAW:
225 return ak09911_read_axis(indio_dev, chan->address, val);
226 case IIO_CHAN_INFO_SCALE:
228 *val2 = data->raw_to_gauss[chan->address];
229 return IIO_VAL_INT_PLUS_MICRO;
235 #define AK09911_CHANNEL(axis, index) \
239 .channel2 = IIO_MOD_##axis, \
240 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
241 BIT(IIO_CHAN_INFO_SCALE), \
245 static const struct iio_chan_spec ak09911_channels[] = {
246 AK09911_CHANNEL(X, 0), AK09911_CHANNEL(Y, 1), AK09911_CHANNEL(Z, 2),
249 static const struct iio_info ak09911_info = {
250 .read_raw = &ak09911_read_raw,
251 .driver_module = THIS_MODULE,
254 static const struct acpi_device_id ak_acpi_match[] = {
258 MODULE_DEVICE_TABLE(acpi, ak_acpi_match);
260 static int ak09911_probe(struct i2c_client *client,
261 const struct i2c_device_id *id)
263 struct iio_dev *indio_dev;
264 struct ak09911_data *data;
268 ret = ak09911_verify_chip_id(client);
270 dev_err(&client->dev, "AK00911 not detected\n");
274 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
275 if (indio_dev == NULL)
278 data = iio_priv(indio_dev);
279 i2c_set_clientdata(client, indio_dev);
281 data->client = client;
282 mutex_init(&data->lock);
284 ret = ak09911_get_asa(client);
290 else if (ACPI_HANDLE(&client->dev))
291 name = dev_name(&client->dev);
295 dev_dbg(&client->dev, "Asahi compass chip %s\n", name);
297 indio_dev->dev.parent = &client->dev;
298 indio_dev->channels = ak09911_channels;
299 indio_dev->num_channels = ARRAY_SIZE(ak09911_channels);
300 indio_dev->info = &ak09911_info;
301 indio_dev->modes = INDIO_DIRECT_MODE;
302 indio_dev->name = name;
304 return devm_iio_device_register(&client->dev, indio_dev);
307 static const struct i2c_device_id ak09911_id[] = {
312 MODULE_DEVICE_TABLE(i2c, ak09911_id);
314 static struct i2c_driver ak09911_driver = {
317 .acpi_match_table = ACPI_PTR(ak_acpi_match),
319 .probe = ak09911_probe,
320 .id_table = ak09911_id,
322 module_i2c_driver(ak09911_driver);
324 MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
325 MODULE_LICENSE("GPL v2");
326 MODULE_DESCRIPTION("AK09911 Compass driver");