1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * itg3200_core.c -- support InvenSense ITG3200
4 * Digital 3-Axis Gyroscope driver
5 *
6 * Copyright (c) 2011 Christian Strobel <christian.strobel@iis.fraunhofer.de>
7 * Copyright (c) 2011 Manuel Stahl <manuel.stahl@iis.fraunhofer.de>
8 * Copyright (c) 2012 Thorsten Nowak <thorsten.nowak@iis.fraunhofer.de>
9 *
10 * TODO:
11 * - Support digital low pass filter
12 * - Support power management
13 */
14
15 #include <linux/interrupt.h>
16 #include <linux/irq.h>
17 #include <linux/i2c.h>
18 #include <linux/slab.h>
19 #include <linux/stat.h>
20 #include <linux/module.h>
21 #include <linux/mutex.h>
22 #include <linux/delay.h>
23
24 #include <linux/iio/iio.h>
25 #include <linux/iio/sysfs.h>
26 #include <linux/iio/events.h>
27 #include <linux/iio/buffer.h>
28
29 #include <linux/iio/gyro/itg3200.h>
30
31
itg3200_write_reg_8(struct iio_dev * indio_dev,u8 reg_address,u8 val)32 int itg3200_write_reg_8(struct iio_dev *indio_dev,
33 u8 reg_address, u8 val)
34 {
35 struct itg3200 *st = iio_priv(indio_dev);
36
37 return i2c_smbus_write_byte_data(st->i2c, 0x80 | reg_address, val);
38 }
39
itg3200_read_reg_8(struct iio_dev * indio_dev,u8 reg_address,u8 * val)40 int itg3200_read_reg_8(struct iio_dev *indio_dev,
41 u8 reg_address, u8 *val)
42 {
43 struct itg3200 *st = iio_priv(indio_dev);
44 int ret;
45
46 ret = i2c_smbus_read_byte_data(st->i2c, reg_address);
47 if (ret < 0)
48 return ret;
49 *val = ret;
50 return 0;
51 }
52
itg3200_read_reg_s16(struct iio_dev * indio_dev,u8 lower_reg_address,int * val)53 static int itg3200_read_reg_s16(struct iio_dev *indio_dev, u8 lower_reg_address,
54 int *val)
55 {
56 struct itg3200 *st = iio_priv(indio_dev);
57 struct i2c_client *client = st->i2c;
58 int ret;
59 s16 out;
60
61 struct i2c_msg msg[2] = {
62 {
63 .addr = client->addr,
64 .flags = client->flags,
65 .len = 1,
66 .buf = (char *)&lower_reg_address,
67 },
68 {
69 .addr = client->addr,
70 .flags = client->flags | I2C_M_RD,
71 .len = 2,
72 .buf = (char *)&out,
73 },
74 };
75
76 lower_reg_address |= 0x80;
77 ret = i2c_transfer(client->adapter, msg, 2);
78 be16_to_cpus(&out);
79 *val = out;
80
81 return (ret == 2) ? 0 : ret;
82 }
83
itg3200_read_raw(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,int * val,int * val2,long info)84 static int itg3200_read_raw(struct iio_dev *indio_dev,
85 const struct iio_chan_spec *chan,
86 int *val, int *val2, long info)
87 {
88 int ret = 0;
89 u8 reg;
90 u8 regval;
91
92 switch (info) {
93 case IIO_CHAN_INFO_RAW:
94 reg = (u8)chan->address;
95 ret = itg3200_read_reg_s16(indio_dev, reg, val);
96 return IIO_VAL_INT;
97 case IIO_CHAN_INFO_SCALE:
98 *val = 0;
99 if (chan->type == IIO_TEMP)
100 *val2 = 1000000000/280;
101 else
102 *val2 = 1214142; /* (1 / 14,375) * (PI / 180) */
103 return IIO_VAL_INT_PLUS_NANO;
104 case IIO_CHAN_INFO_OFFSET:
105 /* Only the temperature channel has an offset */
106 *val = 23000;
107 return IIO_VAL_INT;
108 case IIO_CHAN_INFO_SAMP_FREQ:
109 ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, ®val);
110 if (ret)
111 return ret;
112
113 *val = (regval & ITG3200_DLPF_CFG_MASK) ? 1000 : 8000;
114
115 ret = itg3200_read_reg_8(indio_dev,
116 ITG3200_REG_SAMPLE_RATE_DIV,
117 ®val);
118 if (ret)
119 return ret;
120
121 *val /= regval + 1;
122 return IIO_VAL_INT;
123
124 default:
125 return -EINVAL;
126 }
127 }
128
itg3200_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)129 static int itg3200_write_raw(struct iio_dev *indio_dev,
130 struct iio_chan_spec const *chan,
131 int val,
132 int val2,
133 long mask)
134 {
135 struct itg3200 *st = iio_priv(indio_dev);
136 int ret;
137 u8 t;
138
139 switch (mask) {
140 case IIO_CHAN_INFO_SAMP_FREQ:
141 if (val == 0 || val2 != 0)
142 return -EINVAL;
143
144 mutex_lock(&st->lock);
145
146 ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &t);
147 if (ret) {
148 mutex_unlock(&st->lock);
149 return ret;
150 }
151 t = ((t & ITG3200_DLPF_CFG_MASK) ? 1000u : 8000u) / val - 1;
152
153 ret = itg3200_write_reg_8(indio_dev,
154 ITG3200_REG_SAMPLE_RATE_DIV,
155 t);
156
157 mutex_unlock(&st->lock);
158 return ret;
159
160 default:
161 return -EINVAL;
162 }
163 }
164
165 /*
166 * Reset device and internal registers to the power-up-default settings
167 * Use the gyro clock as reference, as suggested by the datasheet
168 */
itg3200_reset(struct iio_dev * indio_dev)169 static int itg3200_reset(struct iio_dev *indio_dev)
170 {
171 struct itg3200 *st = iio_priv(indio_dev);
172 int ret;
173
174 dev_dbg(&st->i2c->dev, "reset device");
175
176 ret = itg3200_write_reg_8(indio_dev,
177 ITG3200_REG_POWER_MANAGEMENT,
178 ITG3200_RESET);
179 if (ret) {
180 dev_err(&st->i2c->dev, "error resetting device");
181 goto error_ret;
182 }
183
184 /* Wait for PLL (1ms according to datasheet) */
185 udelay(1500);
186
187 ret = itg3200_write_reg_8(indio_dev,
188 ITG3200_REG_IRQ_CONFIG,
189 ITG3200_IRQ_ACTIVE_HIGH |
190 ITG3200_IRQ_PUSH_PULL |
191 ITG3200_IRQ_LATCH_50US_PULSE |
192 ITG3200_IRQ_LATCH_CLEAR_ANY);
193
194 if (ret)
195 dev_err(&st->i2c->dev, "error init device");
196
197 error_ret:
198 return ret;
199 }
200
201 /* itg3200_enable_full_scale() - Disables the digital low pass filter */
itg3200_enable_full_scale(struct iio_dev * indio_dev)202 static int itg3200_enable_full_scale(struct iio_dev *indio_dev)
203 {
204 u8 val;
205 int ret;
206
207 ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &val);
208 if (ret)
209 goto err_ret;
210
211 val |= ITG3200_DLPF_FS_SEL_2000;
212 return itg3200_write_reg_8(indio_dev, ITG3200_REG_DLPF, val);
213
214 err_ret:
215 return ret;
216 }
217
itg3200_initial_setup(struct iio_dev * indio_dev)218 static int itg3200_initial_setup(struct iio_dev *indio_dev)
219 {
220 struct itg3200 *st = iio_priv(indio_dev);
221 int ret;
222 u8 val;
223
224 ret = itg3200_reset(indio_dev);
225 if (ret)
226 goto err_ret;
227
228 ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_ADDRESS, &val);
229 if (ret)
230 goto err_ret;
231
232 if (((val >> 1) & 0x3f) != 0x34) {
233 dev_err(&st->i2c->dev, "invalid reg value 0x%02x", val);
234 ret = -ENXIO;
235 goto err_ret;
236 }
237
238 ret = itg3200_enable_full_scale(indio_dev);
239 err_ret:
240 return ret;
241 }
242
243 static const struct iio_mount_matrix *
itg3200_get_mount_matrix(const struct iio_dev * indio_dev,const struct iio_chan_spec * chan)244 itg3200_get_mount_matrix(const struct iio_dev *indio_dev,
245 const struct iio_chan_spec *chan)
246 {
247 struct itg3200 *data = iio_priv(indio_dev);
248
249 return &data->orientation;
250 }
251
252 static const struct iio_chan_spec_ext_info itg3200_ext_info[] = {
253 IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, itg3200_get_mount_matrix),
254 { }
255 };
256
257 #define ITG3200_ST \
258 { .sign = 's', .realbits = 16, .storagebits = 16, .endianness = IIO_BE }
259
260 #define ITG3200_GYRO_CHAN(_mod) { \
261 .type = IIO_ANGL_VEL, \
262 .modified = 1, \
263 .channel2 = IIO_MOD_ ## _mod, \
264 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
265 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
266 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
267 .address = ITG3200_REG_GYRO_ ## _mod ## OUT_H, \
268 .scan_index = ITG3200_SCAN_GYRO_ ## _mod, \
269 .scan_type = ITG3200_ST, \
270 .ext_info = itg3200_ext_info, \
271 }
272
273 static const struct iio_chan_spec itg3200_channels[] = {
274 {
275 .type = IIO_TEMP,
276 .channel2 = IIO_NO_MOD,
277 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
278 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
279 BIT(IIO_CHAN_INFO_SCALE),
280 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
281 .address = ITG3200_REG_TEMP_OUT_H,
282 .scan_index = ITG3200_SCAN_TEMP,
283 .scan_type = ITG3200_ST,
284 },
285 ITG3200_GYRO_CHAN(X),
286 ITG3200_GYRO_CHAN(Y),
287 ITG3200_GYRO_CHAN(Z),
288 IIO_CHAN_SOFT_TIMESTAMP(ITG3200_SCAN_ELEMENTS),
289 };
290
291 static const struct iio_info itg3200_info = {
292 .read_raw = &itg3200_read_raw,
293 .write_raw = &itg3200_write_raw,
294 };
295
296 static const unsigned long itg3200_available_scan_masks[] = { 0xffffffff, 0x0 };
297
itg3200_probe(struct i2c_client * client)298 static int itg3200_probe(struct i2c_client *client)
299 {
300 int ret;
301 struct itg3200 *st;
302 struct iio_dev *indio_dev;
303
304 dev_dbg(&client->dev, "probe I2C dev with IRQ %i", client->irq);
305
306 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
307 if (!indio_dev)
308 return -ENOMEM;
309
310 st = iio_priv(indio_dev);
311
312 ret = iio_read_mount_matrix(&client->dev, &st->orientation);
313 if (ret)
314 return ret;
315
316 i2c_set_clientdata(client, indio_dev);
317 st->i2c = client;
318
319 indio_dev->name = client->dev.driver->name;
320 indio_dev->channels = itg3200_channels;
321 indio_dev->num_channels = ARRAY_SIZE(itg3200_channels);
322 indio_dev->available_scan_masks = itg3200_available_scan_masks;
323 indio_dev->info = &itg3200_info;
324 indio_dev->modes = INDIO_DIRECT_MODE;
325
326 ret = itg3200_buffer_configure(indio_dev);
327 if (ret)
328 return ret;
329
330 if (client->irq) {
331 ret = itg3200_probe_trigger(indio_dev);
332 if (ret)
333 goto error_unconfigure_buffer;
334 }
335
336 ret = itg3200_initial_setup(indio_dev);
337 if (ret)
338 goto error_remove_trigger;
339
340 mutex_init(&st->lock);
341
342 ret = iio_device_register(indio_dev);
343 if (ret)
344 goto error_remove_trigger;
345
346 return 0;
347
348 error_remove_trigger:
349 if (client->irq)
350 itg3200_remove_trigger(indio_dev);
351 error_unconfigure_buffer:
352 itg3200_buffer_unconfigure(indio_dev);
353 return ret;
354 }
355
itg3200_remove(struct i2c_client * client)356 static void itg3200_remove(struct i2c_client *client)
357 {
358 struct iio_dev *indio_dev = i2c_get_clientdata(client);
359
360 iio_device_unregister(indio_dev);
361
362 if (client->irq)
363 itg3200_remove_trigger(indio_dev);
364
365 itg3200_buffer_unconfigure(indio_dev);
366 }
367
itg3200_suspend(struct device * dev)368 static int itg3200_suspend(struct device *dev)
369 {
370 struct iio_dev *indio_dev = dev_get_drvdata(dev);
371 struct itg3200 *st = iio_priv(indio_dev);
372
373 dev_dbg(&st->i2c->dev, "suspend device");
374
375 return itg3200_write_reg_8(indio_dev, ITG3200_REG_POWER_MANAGEMENT,
376 ITG3200_SLEEP);
377 }
378
itg3200_resume(struct device * dev)379 static int itg3200_resume(struct device *dev)
380 {
381 struct iio_dev *indio_dev = dev_get_drvdata(dev);
382
383 return itg3200_initial_setup(indio_dev);
384 }
385
386 static DEFINE_SIMPLE_DEV_PM_OPS(itg3200_pm_ops, itg3200_suspend,
387 itg3200_resume);
388
389 static const struct i2c_device_id itg3200_id[] = {
390 { "itg3200", 0 },
391 { }
392 };
393 MODULE_DEVICE_TABLE(i2c, itg3200_id);
394
395 static const struct of_device_id itg3200_of_match[] = {
396 { .compatible = "invensense,itg3200" },
397 { }
398 };
399 MODULE_DEVICE_TABLE(of, itg3200_of_match);
400
401 static struct i2c_driver itg3200_driver = {
402 .driver = {
403 .name = "itg3200",
404 .of_match_table = itg3200_of_match,
405 .pm = pm_sleep_ptr(&itg3200_pm_ops),
406 },
407 .id_table = itg3200_id,
408 .probe = itg3200_probe,
409 .remove = itg3200_remove,
410 };
411
412 module_i2c_driver(itg3200_driver);
413
414 MODULE_AUTHOR("Christian Strobel <christian.strobel@iis.fraunhofer.de>");
415 MODULE_DESCRIPTION("ITG3200 Gyroscope I2C driver");
416 MODULE_LICENSE("GPL v2");
417