xref: /openbmc/linux/drivers/iio/gyro/itg3200_core.c (revision c4a11bf4) 
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/delay.h>
22 
23 #include <linux/iio/iio.h>
24 #include <linux/iio/sysfs.h>
25 #include <linux/iio/events.h>
26 #include <linux/iio/buffer.h>
27 
28 #include <linux/iio/gyro/itg3200.h>
29 
30 
31 int itg3200_write_reg_8(struct iio_dev *indio_dev,
32 		u8 reg_address, u8 val)
33 {
34 	struct itg3200 *st = iio_priv(indio_dev);
35 
36 	return i2c_smbus_write_byte_data(st->i2c, 0x80 | reg_address, val);
37 }
38 
39 int itg3200_read_reg_8(struct iio_dev *indio_dev,
40 		u8 reg_address, u8 *val)
41 {
42 	struct itg3200 *st = iio_priv(indio_dev);
43 	int ret;
44 
45 	ret = i2c_smbus_read_byte_data(st->i2c, reg_address);
46 	if (ret < 0)
47 		return ret;
48 	*val = ret;
49 	return 0;
50 }
51 
52 static int itg3200_read_reg_s16(struct iio_dev *indio_dev, u8 lower_reg_address,
53 		int *val)
54 {
55 	struct itg3200 *st = iio_priv(indio_dev);
56 	struct i2c_client *client = st->i2c;
57 	int ret;
58 	s16 out;
59 
60 	struct i2c_msg msg[2] = {
61 		{
62 			.addr = client->addr,
63 			.flags = client->flags,
64 			.len = 1,
65 			.buf = (char *)&lower_reg_address,
66 		},
67 		{
68 			.addr = client->addr,
69 			.flags = client->flags | I2C_M_RD,
70 			.len = 2,
71 			.buf = (char *)&out,
72 		},
73 	};
74 
75 	lower_reg_address |= 0x80;
76 	ret = i2c_transfer(client->adapter, msg, 2);
77 	be16_to_cpus(&out);
78 	*val = out;
79 
80 	return (ret == 2) ? 0 : ret;
81 }
82 
83 static int itg3200_read_raw(struct iio_dev *indio_dev,
84 		const struct iio_chan_spec *chan,
85 		int *val, int *val2, long info)
86 {
87 	int ret = 0;
88 	u8 reg;
89 	u8 regval;
90 
91 	switch (info) {
92 	case IIO_CHAN_INFO_RAW:
93 		reg = (u8)chan->address;
94 		ret = itg3200_read_reg_s16(indio_dev, reg, val);
95 		return IIO_VAL_INT;
96 	case IIO_CHAN_INFO_SCALE:
97 		*val = 0;
98 		if (chan->type == IIO_TEMP)
99 			*val2 = 1000000000/280;
100 		else
101 			*val2 = 1214142; /* (1 / 14,375) * (PI / 180) */
102 		return IIO_VAL_INT_PLUS_NANO;
103 	case IIO_CHAN_INFO_OFFSET:
104 		/* Only the temperature channel has an offset */
105 		*val = 23000;
106 		return IIO_VAL_INT;
107 	case IIO_CHAN_INFO_SAMP_FREQ:
108 		ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &regval);
109 		if (ret)
110 			return ret;
111 
112 		*val = (regval & ITG3200_DLPF_CFG_MASK) ? 1000 : 8000;
113 
114 		ret = itg3200_read_reg_8(indio_dev,
115 					 ITG3200_REG_SAMPLE_RATE_DIV,
116 					 &regval);
117 		if (ret)
118 			return ret;
119 
120 		*val /= regval + 1;
121 		return IIO_VAL_INT;
122 
123 	default:
124 		return -EINVAL;
125 	}
126 }
127 
128 static int itg3200_write_raw(struct iio_dev *indio_dev,
129 			     struct iio_chan_spec const *chan,
130 			     int val,
131 			     int val2,
132 			     long mask)
133 {
134 	int ret;
135 	u8 t;
136 
137 	switch (mask) {
138 	case IIO_CHAN_INFO_SAMP_FREQ:
139 		if (val == 0 || val2 != 0)
140 			return -EINVAL;
141 
142 		mutex_lock(&indio_dev->mlock);
143 
144 		ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &t);
145 		if (ret) {
146 			mutex_unlock(&indio_dev->mlock);
147 			return ret;
148 		}
149 		t = ((t & ITG3200_DLPF_CFG_MASK) ? 1000u : 8000u) / val - 1;
150 
151 		ret = itg3200_write_reg_8(indio_dev,
152 					  ITG3200_REG_SAMPLE_RATE_DIV,
153 					  t);
154 
155 		mutex_unlock(&indio_dev->mlock);
156 		return ret;
157 
158 	default:
159 		return -EINVAL;
160 	}
161 }
162 
163 /*
164  * Reset device and internal registers to the power-up-default settings
165  * Use the gyro clock as reference, as suggested by the datasheet
166  */
167 static int itg3200_reset(struct iio_dev *indio_dev)
168 {
169 	struct itg3200 *st = iio_priv(indio_dev);
170 	int ret;
171 
172 	dev_dbg(&st->i2c->dev, "reset device");
173 
174 	ret = itg3200_write_reg_8(indio_dev,
175 			ITG3200_REG_POWER_MANAGEMENT,
176 			ITG3200_RESET);
177 	if (ret) {
178 		dev_err(&st->i2c->dev, "error resetting device");
179 		goto error_ret;
180 	}
181 
182 	/* Wait for PLL (1ms according to datasheet) */
183 	udelay(1500);
184 
185 	ret = itg3200_write_reg_8(indio_dev,
186 			ITG3200_REG_IRQ_CONFIG,
187 			ITG3200_IRQ_ACTIVE_HIGH |
188 			ITG3200_IRQ_PUSH_PULL |
189 			ITG3200_IRQ_LATCH_50US_PULSE |
190 			ITG3200_IRQ_LATCH_CLEAR_ANY);
191 
192 	if (ret)
193 		dev_err(&st->i2c->dev, "error init device");
194 
195 error_ret:
196 	return ret;
197 }
198 
199 /* itg3200_enable_full_scale() - Disables the digital low pass filter */
200 static int itg3200_enable_full_scale(struct iio_dev *indio_dev)
201 {
202 	u8 val;
203 	int ret;
204 
205 	ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &val);
206 	if (ret)
207 		goto err_ret;
208 
209 	val |= ITG3200_DLPF_FS_SEL_2000;
210 	return itg3200_write_reg_8(indio_dev, ITG3200_REG_DLPF, val);
211 
212 err_ret:
213 	return ret;
214 }
215 
216 static int itg3200_initial_setup(struct iio_dev *indio_dev)
217 {
218 	struct itg3200 *st = iio_priv(indio_dev);
219 	int ret;
220 	u8 val;
221 
222 	ret = itg3200_reset(indio_dev);
223 	if (ret)
224 		goto err_ret;
225 
226 	ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_ADDRESS, &val);
227 	if (ret)
228 		goto err_ret;
229 
230 	if (((val >> 1) & 0x3f) != 0x34) {
231 		dev_err(&st->i2c->dev, "invalid reg value 0x%02x", val);
232 		ret = -ENXIO;
233 		goto err_ret;
234 	}
235 
236 	ret = itg3200_enable_full_scale(indio_dev);
237 err_ret:
238 	return ret;
239 }
240 
241 static const struct iio_mount_matrix *
242 itg3200_get_mount_matrix(const struct iio_dev *indio_dev,
243 			  const struct iio_chan_spec *chan)
244 {
245 	struct itg3200 *data = iio_priv(indio_dev);
246 
247 	return &data->orientation;
248 }
249 
250 static const struct iio_chan_spec_ext_info itg3200_ext_info[] = {
251 	IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, itg3200_get_mount_matrix),
252 	{ }
253 };
254 
255 #define ITG3200_ST						\
256 	{ .sign = 's', .realbits = 16, .storagebits = 16, .endianness = IIO_BE }
257 
258 #define ITG3200_GYRO_CHAN(_mod) { \
259 	.type = IIO_ANGL_VEL, \
260 	.modified = 1, \
261 	.channel2 = IIO_MOD_ ## _mod, \
262 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
263 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
264 	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
265 	.address = ITG3200_REG_GYRO_ ## _mod ## OUT_H, \
266 	.scan_index = ITG3200_SCAN_GYRO_ ## _mod, \
267 	.scan_type = ITG3200_ST, \
268 	.ext_info = itg3200_ext_info, \
269 }
270 
271 static const struct iio_chan_spec itg3200_channels[] = {
272 	{
273 		.type = IIO_TEMP,
274 		.channel2 = IIO_NO_MOD,
275 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
276 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
277 		BIT(IIO_CHAN_INFO_SCALE),
278 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
279 		.address = ITG3200_REG_TEMP_OUT_H,
280 		.scan_index = ITG3200_SCAN_TEMP,
281 		.scan_type = ITG3200_ST,
282 	},
283 	ITG3200_GYRO_CHAN(X),
284 	ITG3200_GYRO_CHAN(Y),
285 	ITG3200_GYRO_CHAN(Z),
286 	IIO_CHAN_SOFT_TIMESTAMP(ITG3200_SCAN_ELEMENTS),
287 };
288 
289 static const struct iio_info itg3200_info = {
290 	.read_raw = &itg3200_read_raw,
291 	.write_raw = &itg3200_write_raw,
292 };
293 
294 static const unsigned long itg3200_available_scan_masks[] = { 0xffffffff, 0x0 };
295 
296 static int itg3200_probe(struct i2c_client *client,
297 		const struct i2c_device_id *id)
298 {
299 	int ret;
300 	struct itg3200 *st;
301 	struct iio_dev *indio_dev;
302 
303 	dev_dbg(&client->dev, "probe I2C dev with IRQ %i", client->irq);
304 
305 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
306 	if (!indio_dev)
307 		return -ENOMEM;
308 
309 	st = iio_priv(indio_dev);
310 
311 	ret = iio_read_mount_matrix(&client->dev, &st->orientation);
312 	if (ret)
313 		return ret;
314 
315 	i2c_set_clientdata(client, indio_dev);
316 	st->i2c = client;
317 
318 	indio_dev->name = client->dev.driver->name;
319 	indio_dev->channels = itg3200_channels;
320 	indio_dev->num_channels = ARRAY_SIZE(itg3200_channels);
321 	indio_dev->available_scan_masks = itg3200_available_scan_masks;
322 	indio_dev->info = &itg3200_info;
323 	indio_dev->modes = INDIO_DIRECT_MODE;
324 
325 	ret = itg3200_buffer_configure(indio_dev);
326 	if (ret)
327 		return ret;
328 
329 	if (client->irq) {
330 		ret = itg3200_probe_trigger(indio_dev);
331 		if (ret)
332 			goto error_unconfigure_buffer;
333 	}
334 
335 	ret = itg3200_initial_setup(indio_dev);
336 	if (ret)
337 		goto error_remove_trigger;
338 
339 	ret = iio_device_register(indio_dev);
340 	if (ret)
341 		goto error_remove_trigger;
342 
343 	return 0;
344 
345 error_remove_trigger:
346 	if (client->irq)
347 		itg3200_remove_trigger(indio_dev);
348 error_unconfigure_buffer:
349 	itg3200_buffer_unconfigure(indio_dev);
350 	return ret;
351 }
352 
353 static int itg3200_remove(struct i2c_client *client)
354 {
355 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
356 
357 	iio_device_unregister(indio_dev);
358 
359 	if (client->irq)
360 		itg3200_remove_trigger(indio_dev);
361 
362 	itg3200_buffer_unconfigure(indio_dev);
363 
364 	return 0;
365 }
366 
367 static int __maybe_unused itg3200_suspend(struct device *dev)
368 {
369 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
370 	struct itg3200 *st = iio_priv(indio_dev);
371 
372 	dev_dbg(&st->i2c->dev, "suspend device");
373 
374 	return itg3200_write_reg_8(indio_dev, ITG3200_REG_POWER_MANAGEMENT,
375 				   ITG3200_SLEEP);
376 }
377 
378 static int __maybe_unused itg3200_resume(struct device *dev)
379 {
380 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
381 
382 	return itg3200_initial_setup(indio_dev);
383 }
384 
385 static SIMPLE_DEV_PM_OPS(itg3200_pm_ops, itg3200_suspend, itg3200_resume);
386 
387 static const struct i2c_device_id itg3200_id[] = {
388 	{ "itg3200", 0 },
389 	{ }
390 };
391 MODULE_DEVICE_TABLE(i2c, itg3200_id);
392 
393 static const struct of_device_id itg3200_of_match[] = {
394 	{ .compatible = "invensense,itg3200" },
395 	{ }
396 };
397 MODULE_DEVICE_TABLE(of, itg3200_of_match);
398 
399 static struct i2c_driver itg3200_driver = {
400 	.driver = {
401 		.name	= "itg3200",
402 		.of_match_table = itg3200_of_match,
403 		.pm	= &itg3200_pm_ops,
404 	},
405 	.id_table	= itg3200_id,
406 	.probe		= itg3200_probe,
407 	.remove		= itg3200_remove,
408 };
409 
410 module_i2c_driver(itg3200_driver);
411 
412 MODULE_AUTHOR("Christian Strobel <christian.strobel@iis.fraunhofer.de>");
413 MODULE_DESCRIPTION("ITG3200 Gyroscope I2C driver");
414 MODULE_LICENSE("GPL v2");
415