1 /*
2 * AK09911 3-axis compass driver
3 * Copyright (c) 2014, Intel Corporation.
4 *
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.
8 *
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
12 * more details.
13 */
14
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>
24
25 #define AK09911_REG_WIA1 0x00
26 #define AK09911_REG_WIA2 0x01
27 #define AK09911_WIA1_VALUE 0x48
28 #define AK09911_WIA2_VALUE 0x05
29
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
37
38 #define AK09911_REG_ASAX 0x60
39 #define AK09911_REG_ASAY 0x61
40 #define AK09911_REG_ASAZ 0x62
41
42 #define AK09911_REG_CNTL1 0x30
43 #define AK09911_REG_CNTL2 0x31
44 #define AK09911_REG_CNTL3 0x32
45
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
51
52 #define AK09911_REG_CNTL1 0x30
53 #define AK09911_REG_CNTL2 0x31
54 #define AK09911_REG_CNTL3 0x32
55
56 #define AK09911_RAW_TO_GAUSS(asa) ((((asa) + 128) * 6000) / 256)
57
58 #define AK09911_MAX_CONVERSION_TIMEOUT_MS 500
59 #define AK09911_CONVERSION_DONE_POLL_TIME_MS 10
60
61 struct ak09911_data {
62 struct i2c_client *client;
63 struct mutex lock;
64 u8 asa[3];
65 long raw_to_gauss[3];
66 };
67
68 static const int ak09911_index_to_reg[] = {
69 AK09911_REG_HXL, AK09911_REG_HYL, AK09911_REG_HZL,
70 };
71
ak09911_set_mode(struct i2c_client * client,u8 mode)72 static int ak09911_set_mode(struct i2c_client *client, u8 mode)
73 {
74 int ret;
75
76 switch (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);
83 if (ret < 0) {
84 dev_err(&client->dev, "set_mode error\n");
85 return ret;
86 }
87 /* After mode change wait atleast 100us */
88 usleep_range(100, 500);
89 break;
90 default:
91 dev_err(&client->dev,
92 "%s: Unknown mode(%d).", __func__, mode);
93 return -EINVAL;
94 }
95
96 return ret;
97 }
98
99 /* Get Sensitivity Adjustment value */
ak09911_get_asa(struct i2c_client * client)100 static int ak09911_get_asa(struct i2c_client *client)
101 {
102 struct iio_dev *indio_dev = i2c_get_clientdata(client);
103 struct ak09911_data *data = iio_priv(indio_dev);
104 int ret;
105
106 ret = ak09911_set_mode(client, AK09911_MODE_FUSE_ACCESS);
107 if (ret < 0)
108 return ret;
109
110 /* Get asa data and store in the device data. */
111 ret = i2c_smbus_read_i2c_block_data(client, AK09911_REG_ASAX,
112 3, data->asa);
113 if (ret < 0) {
114 dev_err(&client->dev, "Not able to read asa data\n");
115 return ret;
116 }
117
118 ret = ak09911_set_mode(client, AK09911_MODE_POWERDOWN);
119 if (ret < 0)
120 return ret;
121
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]);
125
126 return 0;
127 }
128
ak09911_verify_chip_id(struct i2c_client * client)129 static int ak09911_verify_chip_id(struct i2c_client *client)
130 {
131 u8 wia_val[2];
132 int ret;
133
134 ret = i2c_smbus_read_i2c_block_data(client, AK09911_REG_WIA1,
135 2, wia_val);
136 if (ret < 0) {
137 dev_err(&client->dev, "Error reading WIA\n");
138 return ret;
139 }
140
141 dev_dbg(&client->dev, "WIA %02x %02x\n", wia_val[0], wia_val[1]);
142
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");
146 return -ENODEV;
147 }
148
149 return 0;
150 }
151
wait_conversion_complete_polled(struct ak09911_data * data)152 static int wait_conversion_complete_polled(struct ak09911_data *data)
153 {
154 struct i2c_client *client = data->client;
155 u8 read_status;
156 u32 timeout_ms = AK09911_MAX_CONVERSION_TIMEOUT_MS;
157 int ret;
158
159 /* Wait for the conversion to complete. */
160 while (timeout_ms) {
161 msleep_interruptible(AK09911_CONVERSION_DONE_POLL_TIME_MS);
162 ret = i2c_smbus_read_byte_data(client, AK09911_REG_ST1);
163 if (ret < 0) {
164 dev_err(&client->dev, "Error in reading ST1\n");
165 return ret;
166 }
167 read_status = ret & 0x01;
168 if (read_status)
169 break;
170 timeout_ms -= AK09911_CONVERSION_DONE_POLL_TIME_MS;
171 }
172 if (!timeout_ms) {
173 dev_err(&client->dev, "Conversion timeout happened\n");
174 return -EIO;
175 }
176
177 return read_status;
178 }
179
ak09911_read_axis(struct iio_dev * indio_dev,int index,int * val)180 static int ak09911_read_axis(struct iio_dev *indio_dev, int index, int *val)
181 {
182 struct ak09911_data *data = iio_priv(indio_dev);
183 struct i2c_client *client = data->client;
184 int ret;
185
186 mutex_lock(&data->lock);
187
188 ret = ak09911_set_mode(client, AK09911_MODE_SNG_MEASURE);
189 if (ret < 0)
190 goto fn_exit;
191
192 ret = wait_conversion_complete_polled(data);
193 if (ret < 0)
194 goto fn_exit;
195
196 /* Read data */
197 ret = i2c_smbus_read_word_data(client, ak09911_index_to_reg[index]);
198 if (ret < 0) {
199 dev_err(&client->dev, "Read axis data fails\n");
200 goto fn_exit;
201 }
202
203 mutex_unlock(&data->lock);
204
205 /* Clamp to valid range. */
206 *val = sign_extend32(clamp_t(s16, ret, -8192, 8191), 13);
207
208 return IIO_VAL_INT;
209
210 fn_exit:
211 mutex_unlock(&data->lock);
212
213 return ret;
214 }
215
ak09911_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)216 static int ak09911_read_raw(struct iio_dev *indio_dev,
217 struct iio_chan_spec const *chan,
218 int *val, int *val2,
219 long mask)
220 {
221 struct ak09911_data *data = iio_priv(indio_dev);
222
223 switch (mask) {
224 case IIO_CHAN_INFO_RAW:
225 return ak09911_read_axis(indio_dev, chan->address, val);
226 case IIO_CHAN_INFO_SCALE:
227 *val = 0;
228 *val2 = data->raw_to_gauss[chan->address];
229 return IIO_VAL_INT_PLUS_MICRO;
230 }
231
232 return -EINVAL;
233 }
234
235 #define AK09911_CHANNEL(axis, index) \
236 { \
237 .type = IIO_MAGN, \
238 .modified = 1, \
239 .channel2 = IIO_MOD_##axis, \
240 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
241 BIT(IIO_CHAN_INFO_SCALE), \
242 .address = index, \
243 }
244
245 static const struct iio_chan_spec ak09911_channels[] = {
246 AK09911_CHANNEL(X, 0), AK09911_CHANNEL(Y, 1), AK09911_CHANNEL(Z, 2),
247 };
248
249 static const struct iio_info ak09911_info = {
250 .read_raw = &ak09911_read_raw,
251 .driver_module = THIS_MODULE,
252 };
253
254 static const struct acpi_device_id ak_acpi_match[] = {
255 {"AK009911", 0},
256 { },
257 };
258 MODULE_DEVICE_TABLE(acpi, ak_acpi_match);
259
ak09911_probe(struct i2c_client * client,const struct i2c_device_id * id)260 static int ak09911_probe(struct i2c_client *client,
261 const struct i2c_device_id *id)
262 {
263 struct iio_dev *indio_dev;
264 struct ak09911_data *data;
265 const char *name;
266 int ret;
267
268 ret = ak09911_verify_chip_id(client);
269 if (ret) {
270 dev_err(&client->dev, "AK00911 not detected\n");
271 return -ENODEV;
272 }
273
274 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
275 if (indio_dev == NULL)
276 return -ENOMEM;
277
278 data = iio_priv(indio_dev);
279 i2c_set_clientdata(client, indio_dev);
280
281 data->client = client;
282 mutex_init(&data->lock);
283
284 ret = ak09911_get_asa(client);
285 if (ret)
286 return ret;
287
288 if (id)
289 name = id->name;
290 else if (ACPI_HANDLE(&client->dev))
291 name = dev_name(&client->dev);
292 else
293 return -ENODEV;
294
295 dev_dbg(&client->dev, "Asahi compass chip %s\n", name);
296
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;
303
304 return devm_iio_device_register(&client->dev, indio_dev);
305 }
306
307 static const struct i2c_device_id ak09911_id[] = {
308 {"ak09911", 0},
309 {}
310 };
311
312 MODULE_DEVICE_TABLE(i2c, ak09911_id);
313
314 static struct i2c_driver ak09911_driver = {
315 .driver = {
316 .name = "ak09911",
317 .acpi_match_table = ACPI_PTR(ak_acpi_match),
318 },
319 .probe = ak09911_probe,
320 .id_table = ak09911_id,
321 };
322 module_i2c_driver(ak09911_driver);
323
324 MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
325 MODULE_LICENSE("GPL v2");
326 MODULE_DESCRIPTION("AK09911 Compass driver");
327