itg3200_core.c

  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
 32int 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
 40int 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
 53static 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
 84static 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		if (ret)
 97			return ret;
 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	case IIO_CHAN_INFO_SAMP_FREQ:
111		ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &regval);
112		if (ret)
113			return ret;
114
115		*val = (regval & ITG3200_DLPF_CFG_MASK) ? 1000 : 8000;
116
117		ret = itg3200_read_reg_8(indio_dev,
118					 ITG3200_REG_SAMPLE_RATE_DIV,
119					 &regval);
120		if (ret)
121			return ret;
122
123		*val /= regval + 1;
124		return IIO_VAL_INT;
125
126	default:
127		return -EINVAL;
128	}
129}
130
131static int itg3200_write_raw(struct iio_dev *indio_dev,
132			     struct iio_chan_spec const *chan,
133			     int val,
134			     int val2,
135			     long mask)
136{
137	struct itg3200 *st = iio_priv(indio_dev);
138	int ret;
139	u8 t;
140
141	switch (mask) {
142	case IIO_CHAN_INFO_SAMP_FREQ:
143		if (val == 0 || val2 != 0)
144			return -EINVAL;
145
146		mutex_lock(&st->lock);
147
148		ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &t);
149		if (ret) {
150			mutex_unlock(&st->lock);
151			return ret;
152		}
153		t = ((t & ITG3200_DLPF_CFG_MASK) ? 1000u : 8000u) / val - 1;
154
155		ret = itg3200_write_reg_8(indio_dev,
156					  ITG3200_REG_SAMPLE_RATE_DIV,
157					  t);
158
159		mutex_unlock(&st->lock);
160		return ret;
161
162	default:
163		return -EINVAL;
164	}
165}
166
167/*
168 * Reset device and internal registers to the power-up-default settings
169 * Use the gyro clock as reference, as suggested by the datasheet
170 */
171static int itg3200_reset(struct iio_dev *indio_dev)
172{
173	struct itg3200 *st = iio_priv(indio_dev);
174	int ret;
175
176	dev_dbg(&st->i2c->dev, "reset device");
177
178	ret = itg3200_write_reg_8(indio_dev,
179			ITG3200_REG_POWER_MANAGEMENT,
180			ITG3200_RESET);
181	if (ret) {
182		dev_err(&st->i2c->dev, "error resetting device");
183		goto error_ret;
184	}
185
186	/* Wait for PLL (1ms according to datasheet) */
187	udelay(1500);
188
189	ret = itg3200_write_reg_8(indio_dev,
190			ITG3200_REG_IRQ_CONFIG,
191			ITG3200_IRQ_ACTIVE_HIGH |
192			ITG3200_IRQ_PUSH_PULL |
193			ITG3200_IRQ_LATCH_50US_PULSE |
194			ITG3200_IRQ_LATCH_CLEAR_ANY);
195
196	if (ret)
197		dev_err(&st->i2c->dev, "error init device");
198
199error_ret:
200	return ret;
201}
202
203/* itg3200_enable_full_scale() - Disables the digital low pass filter */
204static int itg3200_enable_full_scale(struct iio_dev *indio_dev)
205{
206	u8 val;
207	int ret;
208
209	ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &val);
210	if (ret)
211		goto err_ret;
212
213	val |= ITG3200_DLPF_FS_SEL_2000;
214	return itg3200_write_reg_8(indio_dev, ITG3200_REG_DLPF, val);
215
216err_ret:
217	return ret;
218}
219
220static int itg3200_initial_setup(struct iio_dev *indio_dev)
221{
222	struct itg3200 *st = iio_priv(indio_dev);
223	int ret;
224	u8 val;
225
226	ret = itg3200_reset(indio_dev);
227	if (ret)
228		goto err_ret;
229
230	ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_ADDRESS, &val);
231	if (ret)
232		goto err_ret;
233
234	if (((val >> 1) & 0x3f) != 0x34) {
235		dev_err(&st->i2c->dev, "invalid reg value 0x%02x", val);
236		ret = -ENXIO;
237		goto err_ret;
238	}
239
240	ret = itg3200_enable_full_scale(indio_dev);
241err_ret:
242	return ret;
243}
244
245static const struct iio_mount_matrix *
246itg3200_get_mount_matrix(const struct iio_dev *indio_dev,
247			  const struct iio_chan_spec *chan)
248{
249	struct itg3200 *data = iio_priv(indio_dev);
250
251	return &data->orientation;
252}
253
254static const struct iio_chan_spec_ext_info itg3200_ext_info[] = {
255	IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, itg3200_get_mount_matrix),
256	{ }
257};
258
259#define ITG3200_ST						\
260	{ .sign = 's', .realbits = 16, .storagebits = 16, .endianness = IIO_BE }
261
262#define ITG3200_GYRO_CHAN(_mod) { \
263	.type = IIO_ANGL_VEL, \
264	.modified = 1, \
265	.channel2 = IIO_MOD_ ## _mod, \
266	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
267	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
268	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
269	.address = ITG3200_REG_GYRO_ ## _mod ## OUT_H, \
270	.scan_index = ITG3200_SCAN_GYRO_ ## _mod, \
271	.scan_type = ITG3200_ST, \
272	.ext_info = itg3200_ext_info, \
273}
274
275static const struct iio_chan_spec itg3200_channels[] = {
276	{
277		.type = IIO_TEMP,
278		.channel2 = IIO_NO_MOD,
279		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
280		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
281		BIT(IIO_CHAN_INFO_SCALE),
282		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
283		.address = ITG3200_REG_TEMP_OUT_H,
284		.scan_index = ITG3200_SCAN_TEMP,
285		.scan_type = ITG3200_ST,
286	},
287	ITG3200_GYRO_CHAN(X),
288	ITG3200_GYRO_CHAN(Y),
289	ITG3200_GYRO_CHAN(Z),
290	IIO_CHAN_SOFT_TIMESTAMP(ITG3200_SCAN_ELEMENTS),
291};
292
293static const struct iio_info itg3200_info = {
294	.read_raw = &itg3200_read_raw,
295	.write_raw = &itg3200_write_raw,
296};
297
298static const unsigned long itg3200_available_scan_masks[] = { 0xffffffff, 0x0 };
299
300static int itg3200_probe(struct i2c_client *client)
301{
302	int ret;
303	struct itg3200 *st;
304	struct iio_dev *indio_dev;
305
306	dev_dbg(&client->dev, "probe I2C dev with IRQ %i", client->irq);
307
308	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
309	if (!indio_dev)
310		return -ENOMEM;
311
312	st = iio_priv(indio_dev);
313
314	ret = iio_read_mount_matrix(&client->dev, &st->orientation);
315	if (ret)
316		return ret;
317
318	i2c_set_clientdata(client, indio_dev);
319	st->i2c = client;
320
321	indio_dev->name = client->dev.driver->name;
322	indio_dev->channels = itg3200_channels;
323	indio_dev->num_channels = ARRAY_SIZE(itg3200_channels);
324	indio_dev->available_scan_masks = itg3200_available_scan_masks;
325	indio_dev->info = &itg3200_info;
326	indio_dev->modes = INDIO_DIRECT_MODE;
327
328	ret = itg3200_buffer_configure(indio_dev);
329	if (ret)
330		return ret;
331
332	if (client->irq) {
333		ret = itg3200_probe_trigger(indio_dev);
334		if (ret)
335			goto error_unconfigure_buffer;
336	}
337
338	ret = itg3200_initial_setup(indio_dev);
339	if (ret)
340		goto error_remove_trigger;
341
342	mutex_init(&st->lock);
343
344	ret = iio_device_register(indio_dev);
345	if (ret)
346		goto error_remove_trigger;
347
348	return 0;
349
350error_remove_trigger:
351	if (client->irq)
352		itg3200_remove_trigger(indio_dev);
353error_unconfigure_buffer:
354	itg3200_buffer_unconfigure(indio_dev);
355	return ret;
356}
357
358static void itg3200_remove(struct i2c_client *client)
359{
360	struct iio_dev *indio_dev = i2c_get_clientdata(client);
361
362	iio_device_unregister(indio_dev);
363
364	if (client->irq)
365		itg3200_remove_trigger(indio_dev);
366
367	itg3200_buffer_unconfigure(indio_dev);
368}
369
370static int itg3200_suspend(struct device *dev)
371{
372	struct iio_dev *indio_dev = dev_get_drvdata(dev);
373	struct itg3200 *st = iio_priv(indio_dev);
374
375	dev_dbg(&st->i2c->dev, "suspend device");
376
377	return itg3200_write_reg_8(indio_dev, ITG3200_REG_POWER_MANAGEMENT,
378				   ITG3200_SLEEP);
379}
380
381static int itg3200_resume(struct device *dev)
382{
383	struct iio_dev *indio_dev = dev_get_drvdata(dev);
384
385	return itg3200_initial_setup(indio_dev);
386}
387
388static DEFINE_SIMPLE_DEV_PM_OPS(itg3200_pm_ops, itg3200_suspend,
389				itg3200_resume);
390
391static const struct i2c_device_id itg3200_id[] = {
392	{ "itg3200" },
393	{ }
394};
395MODULE_DEVICE_TABLE(i2c, itg3200_id);
396
397static const struct of_device_id itg3200_of_match[] = {
398	{ .compatible = "invensense,itg3200" },
399	{ }
400};
401MODULE_DEVICE_TABLE(of, itg3200_of_match);
402
403static struct i2c_driver itg3200_driver = {
404	.driver = {
405		.name	= "itg3200",
406		.of_match_table = itg3200_of_match,
407		.pm	= pm_sleep_ptr(&itg3200_pm_ops),
408	},
409	.id_table	= itg3200_id,
410	.probe		= itg3200_probe,
411	.remove		= itg3200_remove,
412};
413
414module_i2c_driver(itg3200_driver);
415
416MODULE_AUTHOR("Christian Strobel <christian.strobel@iis.fraunhofer.de>");
417MODULE_DESCRIPTION("ITG3200 Gyroscope I2C driver");
418MODULE_LICENSE("GPL v2");