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9dbf091d MS |
1 | /* |
2 | * itg3200_core.c -- support InvenSense ITG3200 | |
3 | * Digital 3-Axis Gyroscope driver | |
4 | * | |
5 | * Copyright (c) 2011 Christian Strobel <christian.strobel@iis.fraunhofer.de> | |
6 | * Copyright (c) 2011 Manuel Stahl <manuel.stahl@iis.fraunhofer.de> | |
7 | * Copyright (c) 2012 Thorsten Nowak <thorsten.nowak@iis.fraunhofer.de> | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License version 2 as | |
11 | * published by the Free Software Foundation. | |
12 | * | |
13 | * TODO: | |
14 | * - Support digital low pass filter | |
15 | * - Support power management | |
16 | */ | |
17 | ||
18 | #include <linux/interrupt.h> | |
19 | #include <linux/irq.h> | |
20 | #include <linux/i2c.h> | |
21 | #include <linux/gpio.h> | |
22 | #include <linux/slab.h> | |
23 | #include <linux/stat.h> | |
24 | #include <linux/module.h> | |
25 | #include <linux/delay.h> | |
26 | ||
27 | #include <linux/iio/iio.h> | |
28 | #include <linux/iio/sysfs.h> | |
29 | #include <linux/iio/events.h> | |
30 | #include <linux/iio/buffer.h> | |
31 | ||
32 | #include <linux/iio/gyro/itg3200.h> | |
33 | ||
34 | ||
35 | int itg3200_write_reg_8(struct iio_dev *indio_dev, | |
36 | u8 reg_address, u8 val) | |
37 | { | |
38 | struct itg3200 *st = iio_priv(indio_dev); | |
39 | ||
40 | return i2c_smbus_write_byte_data(st->i2c, 0x80 | reg_address, val); | |
41 | } | |
42 | ||
43 | int itg3200_read_reg_8(struct iio_dev *indio_dev, | |
44 | u8 reg_address, u8 *val) | |
45 | { | |
46 | struct itg3200 *st = iio_priv(indio_dev); | |
47 | int ret; | |
48 | ||
49 | ret = i2c_smbus_read_byte_data(st->i2c, reg_address); | |
50 | if (ret < 0) | |
51 | return ret; | |
52 | *val = ret; | |
53 | return 0; | |
54 | } | |
55 | ||
56 | static int itg3200_read_reg_s16(struct iio_dev *indio_dev, u8 lower_reg_address, | |
57 | int *val) | |
58 | { | |
59 | struct itg3200 *st = iio_priv(indio_dev); | |
60 | struct i2c_client *client = st->i2c; | |
61 | int ret; | |
62 | s16 out; | |
63 | ||
64 | struct i2c_msg msg[2] = { | |
65 | { | |
66 | .addr = client->addr, | |
67 | .flags = client->flags, | |
68 | .len = 1, | |
69 | .buf = (char *)&lower_reg_address, | |
70 | }, | |
71 | { | |
72 | .addr = client->addr, | |
73 | .flags = client->flags | I2C_M_RD, | |
74 | .len = 2, | |
75 | .buf = (char *)&out, | |
76 | }, | |
77 | }; | |
78 | ||
79 | lower_reg_address |= 0x80; | |
80 | ret = i2c_transfer(client->adapter, msg, 2); | |
81 | be16_to_cpus(&out); | |
82 | *val = out; | |
83 | ||
84 | return (ret == 2) ? 0 : ret; | |
85 | } | |
86 | ||
87 | static int itg3200_read_raw(struct iio_dev *indio_dev, | |
88 | const struct iio_chan_spec *chan, | |
89 | int *val, int *val2, long info) | |
90 | { | |
91 | int ret = 0; | |
92 | u8 reg; | |
93 | ||
94 | switch (info) { | |
95 | case IIO_CHAN_INFO_RAW: | |
96 | reg = (u8)chan->address; | |
97 | ret = itg3200_read_reg_s16(indio_dev, reg, val); | |
98 | return IIO_VAL_INT; | |
99 | case IIO_CHAN_INFO_SCALE: | |
100 | *val = 0; | |
101 | if (chan->type == IIO_TEMP) | |
102 | *val2 = 1000000000/280; | |
103 | else | |
104 | *val2 = 1214142; /* (1 / 14,375) * (PI / 180) */ | |
105 | return IIO_VAL_INT_PLUS_NANO; | |
106 | case IIO_CHAN_INFO_OFFSET: | |
107 | /* Only the temperature channel has an offset */ | |
108 | *val = 23000; | |
109 | return IIO_VAL_INT; | |
110 | default: | |
111 | return -EINVAL; | |
112 | } | |
113 | ||
114 | return ret; | |
115 | } | |
116 | ||
117 | static ssize_t itg3200_read_frequency(struct device *dev, | |
118 | struct device_attribute *attr, char *buf) | |
119 | { | |
120 | struct iio_dev *indio_dev = dev_to_iio_dev(dev); | |
121 | int ret, sps; | |
122 | u8 val; | |
123 | ||
124 | ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &val); | |
125 | if (ret) | |
126 | return ret; | |
127 | ||
128 | sps = (val & ITG3200_DLPF_CFG_MASK) ? 1000 : 8000; | |
129 | ||
130 | ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_SAMPLE_RATE_DIV, &val); | |
131 | if (ret) | |
132 | return ret; | |
133 | ||
134 | sps /= val + 1; | |
135 | ||
136 | return sprintf(buf, "%d\n", sps); | |
137 | } | |
138 | ||
139 | static ssize_t itg3200_write_frequency(struct device *dev, | |
140 | struct device_attribute *attr, | |
141 | const char *buf, | |
142 | size_t len) | |
143 | { | |
144 | struct iio_dev *indio_dev = dev_to_iio_dev(dev); | |
145 | unsigned val; | |
146 | int ret; | |
147 | u8 t; | |
148 | ||
149 | ret = kstrtouint(buf, 10, &val); | |
150 | if (ret) | |
151 | return ret; | |
152 | ||
153 | mutex_lock(&indio_dev->mlock); | |
154 | ||
155 | ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &t); | |
156 | if (ret) | |
157 | goto err_ret; | |
158 | ||
159 | if (val == 0) { | |
160 | ret = -EINVAL; | |
161 | goto err_ret; | |
162 | } | |
163 | t = ((t & ITG3200_DLPF_CFG_MASK) ? 1000u : 8000u) / val - 1; | |
164 | ||
165 | ret = itg3200_write_reg_8(indio_dev, ITG3200_REG_SAMPLE_RATE_DIV, t); | |
166 | ||
167 | err_ret: | |
168 | mutex_unlock(&indio_dev->mlock); | |
169 | ||
170 | return ret ? ret : len; | |
171 | } | |
172 | ||
173 | /* | |
174 | * Reset device and internal registers to the power-up-default settings | |
175 | * Use the gyro clock as reference, as suggested by the datasheet | |
176 | */ | |
177 | static int itg3200_reset(struct iio_dev *indio_dev) | |
178 | { | |
179 | struct itg3200 *st = iio_priv(indio_dev); | |
180 | int ret; | |
181 | ||
182 | dev_dbg(&st->i2c->dev, "reset device"); | |
183 | ||
184 | ret = itg3200_write_reg_8(indio_dev, | |
185 | ITG3200_REG_POWER_MANAGEMENT, | |
186 | ITG3200_RESET); | |
187 | if (ret) { | |
188 | dev_err(&st->i2c->dev, "error resetting device"); | |
189 | goto error_ret; | |
190 | } | |
191 | ||
192 | /* Wait for PLL (1ms according to datasheet) */ | |
193 | udelay(1500); | |
194 | ||
195 | ret = itg3200_write_reg_8(indio_dev, | |
196 | ITG3200_REG_IRQ_CONFIG, | |
197 | ITG3200_IRQ_ACTIVE_HIGH | | |
198 | ITG3200_IRQ_PUSH_PULL | | |
199 | ITG3200_IRQ_LATCH_50US_PULSE | | |
200 | ITG3200_IRQ_LATCH_CLEAR_ANY); | |
201 | ||
202 | if (ret) | |
203 | dev_err(&st->i2c->dev, "error init device"); | |
204 | ||
205 | error_ret: | |
206 | return ret; | |
207 | } | |
208 | ||
209 | /* itg3200_enable_full_scale() - Disables the digital low pass filter */ | |
210 | static int itg3200_enable_full_scale(struct iio_dev *indio_dev) | |
211 | { | |
212 | u8 val; | |
213 | int ret; | |
214 | ||
215 | ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &val); | |
216 | if (ret) | |
217 | goto err_ret; | |
218 | ||
219 | val |= ITG3200_DLPF_FS_SEL_2000; | |
220 | return itg3200_write_reg_8(indio_dev, ITG3200_REG_DLPF, val); | |
221 | ||
222 | err_ret: | |
223 | return ret; | |
224 | } | |
225 | ||
226 | static int itg3200_initial_setup(struct iio_dev *indio_dev) | |
227 | { | |
228 | struct itg3200 *st = iio_priv(indio_dev); | |
229 | int ret; | |
230 | u8 val; | |
231 | ||
232 | ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_ADDRESS, &val); | |
233 | if (ret) | |
234 | goto err_ret; | |
235 | ||
236 | if (((val >> 1) & 0x3f) != 0x34) { | |
237 | dev_err(&st->i2c->dev, "invalid reg value 0x%02x", val); | |
238 | ret = -ENXIO; | |
239 | goto err_ret; | |
240 | } | |
241 | ||
242 | ret = itg3200_reset(indio_dev); | |
243 | if (ret) | |
244 | goto err_ret; | |
245 | ||
246 | ret = itg3200_enable_full_scale(indio_dev); | |
247 | err_ret: | |
248 | return ret; | |
249 | } | |
250 | ||
251 | #define ITG3200_TEMP_INFO_MASK (IIO_CHAN_INFO_OFFSET_SHARED_BIT | \ | |
252 | IIO_CHAN_INFO_SCALE_SHARED_BIT | \ | |
253 | IIO_CHAN_INFO_RAW_SEPARATE_BIT) | |
254 | #define ITG3200_GYRO_INFO_MASK (IIO_CHAN_INFO_SCALE_SHARED_BIT | \ | |
255 | IIO_CHAN_INFO_RAW_SEPARATE_BIT) | |
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 = ITG3200_GYRO_INFO_MASK, \ | |
265 | .address = ITG3200_REG_GYRO_ ## _mod ## OUT_H, \ | |
266 | .scan_index = ITG3200_SCAN_GYRO_ ## _mod, \ | |
267 | .scan_type = ITG3200_ST, \ | |
268 | } | |
269 | ||
270 | static const struct iio_chan_spec itg3200_channels[] = { | |
271 | { | |
272 | .type = IIO_TEMP, | |
273 | .channel2 = IIO_NO_MOD, | |
274 | .info_mask = ITG3200_TEMP_INFO_MASK, | |
275 | .address = ITG3200_REG_TEMP_OUT_H, | |
276 | .scan_index = ITG3200_SCAN_TEMP, | |
277 | .scan_type = ITG3200_ST, | |
278 | }, | |
279 | ITG3200_GYRO_CHAN(X), | |
280 | ITG3200_GYRO_CHAN(Y), | |
281 | ITG3200_GYRO_CHAN(Z), | |
282 | IIO_CHAN_SOFT_TIMESTAMP(ITG3200_SCAN_ELEMENTS), | |
283 | }; | |
284 | ||
285 | /* IIO device attributes */ | |
286 | static IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR | S_IRUGO, itg3200_read_frequency, | |
287 | itg3200_write_frequency); | |
288 | ||
289 | static struct attribute *itg3200_attributes[] = { | |
290 | &iio_dev_attr_sampling_frequency.dev_attr.attr, | |
291 | NULL | |
292 | }; | |
293 | ||
294 | static const struct attribute_group itg3200_attribute_group = { | |
295 | .attrs = itg3200_attributes, | |
296 | }; | |
297 | ||
298 | static const struct iio_info itg3200_info = { | |
299 | .attrs = &itg3200_attribute_group, | |
300 | .read_raw = &itg3200_read_raw, | |
301 | .driver_module = THIS_MODULE, | |
302 | }; | |
303 | ||
304 | static const unsigned long itg3200_available_scan_masks[] = { 0xffffffff, 0x0 }; | |
305 | ||
306 | static int itg3200_probe(struct i2c_client *client, | |
307 | const struct i2c_device_id *id) | |
308 | { | |
309 | int ret; | |
310 | struct itg3200 *st; | |
311 | struct iio_dev *indio_dev; | |
312 | ||
313 | dev_dbg(&client->dev, "probe I2C dev with IRQ %i", client->irq); | |
314 | ||
315 | indio_dev = iio_device_alloc(sizeof(*st)); | |
316 | if (indio_dev == NULL) { | |
317 | ret = -ENOMEM; | |
318 | goto error_ret; | |
319 | } | |
320 | ||
321 | st = iio_priv(indio_dev); | |
322 | ||
323 | i2c_set_clientdata(client, indio_dev); | |
324 | st->i2c = client; | |
325 | ||
326 | indio_dev->dev.parent = &client->dev; | |
327 | indio_dev->name = client->dev.driver->name; | |
328 | indio_dev->channels = itg3200_channels; | |
329 | indio_dev->num_channels = ARRAY_SIZE(itg3200_channels); | |
330 | indio_dev->available_scan_masks = itg3200_available_scan_masks; | |
331 | indio_dev->info = &itg3200_info; | |
332 | indio_dev->modes = INDIO_DIRECT_MODE; | |
333 | ||
334 | ret = itg3200_buffer_configure(indio_dev); | |
335 | if (ret) | |
336 | goto error_free_dev; | |
337 | ||
338 | if (client->irq) { | |
339 | ret = itg3200_probe_trigger(indio_dev); | |
340 | if (ret) | |
341 | goto error_unconfigure_buffer; | |
342 | } | |
343 | ||
344 | ret = itg3200_initial_setup(indio_dev); | |
345 | if (ret) | |
346 | goto error_remove_trigger; | |
347 | ||
348 | ret = iio_device_register(indio_dev); | |
349 | if (ret) | |
350 | goto error_remove_trigger; | |
351 | ||
352 | return 0; | |
353 | ||
354 | error_remove_trigger: | |
355 | if (client->irq) | |
356 | itg3200_remove_trigger(indio_dev); | |
357 | error_unconfigure_buffer: | |
358 | itg3200_buffer_unconfigure(indio_dev); | |
359 | error_free_dev: | |
360 | iio_device_free(indio_dev); | |
361 | error_ret: | |
362 | return ret; | |
363 | } | |
364 | ||
365 | static int itg3200_remove(struct i2c_client *client) | |
366 | { | |
367 | struct iio_dev *indio_dev = i2c_get_clientdata(client); | |
368 | ||
369 | iio_device_unregister(indio_dev); | |
370 | ||
371 | if (client->irq) | |
372 | itg3200_remove_trigger(indio_dev); | |
373 | ||
374 | itg3200_buffer_unconfigure(indio_dev); | |
375 | ||
376 | iio_device_free(indio_dev); | |
377 | ||
378 | return 0; | |
379 | } | |
380 | ||
381 | static const struct i2c_device_id itg3200_id[] = { | |
382 | { "itg3200", 0 }, | |
383 | { } | |
384 | }; | |
385 | MODULE_DEVICE_TABLE(i2c, itg3200_id); | |
386 | ||
387 | static struct i2c_driver itg3200_driver = { | |
388 | .driver = { | |
389 | .owner = THIS_MODULE, | |
390 | .name = "itg3200", | |
391 | }, | |
392 | .id_table = itg3200_id, | |
393 | .probe = itg3200_probe, | |
394 | .remove = itg3200_remove, | |
395 | }; | |
396 | ||
397 | module_i2c_driver(itg3200_driver); | |
398 | ||
399 | MODULE_AUTHOR("Christian Strobel <christian.strobel@iis.fraunhofer.de>"); | |
400 | MODULE_DESCRIPTION("ITG3200 Gyroscope I2C driver"); | |
401 | MODULE_LICENSE("GPL v2"); |