2 * itg3200_core.c -- support InvenSense ITG3200
3 * Digital 3-Axis Gyroscope driver
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>
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.
14 * - Support digital low pass filter
15 * - Support power management
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>
27 #include <linux/iio/iio.h>
28 #include <linux/iio/sysfs.h>
29 #include <linux/iio/events.h>
30 #include <linux/iio/buffer.h>
32 #include <linux/iio/gyro/itg3200.h>
35 int itg3200_write_reg_8(struct iio_dev *indio_dev,
36 u8 reg_address, u8 val)
38 struct itg3200 *st = iio_priv(indio_dev);
40 return i2c_smbus_write_byte_data(st->i2c, 0x80 | reg_address, val);
43 int itg3200_read_reg_8(struct iio_dev *indio_dev,
44 u8 reg_address, u8 *val)
46 struct itg3200 *st = iio_priv(indio_dev);
49 ret = i2c_smbus_read_byte_data(st->i2c, reg_address);
56 static int itg3200_read_reg_s16(struct iio_dev *indio_dev, u8 lower_reg_address,
59 struct itg3200 *st = iio_priv(indio_dev);
60 struct i2c_client *client = st->i2c;
64 struct i2c_msg msg[2] = {
67 .flags = client->flags,
69 .buf = (char *)&lower_reg_address,
73 .flags = client->flags | I2C_M_RD,
79 lower_reg_address |= 0x80;
80 ret = i2c_transfer(client->adapter, msg, 2);
84 return (ret == 2) ? 0 : ret;
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)
95 case IIO_CHAN_INFO_RAW:
96 reg = (u8)chan->address;
97 ret = itg3200_read_reg_s16(indio_dev, reg, val);
99 case IIO_CHAN_INFO_SCALE:
101 if (chan->type == IIO_TEMP)
102 *val2 = 1000000000/280;
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 */
115 static ssize_t itg3200_read_frequency(struct device *dev,
116 struct device_attribute *attr, char *buf)
118 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
122 ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &val);
126 sps = (val & ITG3200_DLPF_CFG_MASK) ? 1000 : 8000;
128 ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_SAMPLE_RATE_DIV, &val);
134 return sprintf(buf, "%d\n", sps);
137 static ssize_t itg3200_write_frequency(struct device *dev,
138 struct device_attribute *attr,
142 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
147 ret = kstrtouint(buf, 10, &val);
151 mutex_lock(&indio_dev->mlock);
153 ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &t);
161 t = ((t & ITG3200_DLPF_CFG_MASK) ? 1000u : 8000u) / val - 1;
163 ret = itg3200_write_reg_8(indio_dev, ITG3200_REG_SAMPLE_RATE_DIV, t);
166 mutex_unlock(&indio_dev->mlock);
168 return ret ? ret : len;
172 * Reset device and internal registers to the power-up-default settings
173 * Use the gyro clock as reference, as suggested by the datasheet
175 static int itg3200_reset(struct iio_dev *indio_dev)
177 struct itg3200 *st = iio_priv(indio_dev);
180 dev_dbg(&st->i2c->dev, "reset device");
182 ret = itg3200_write_reg_8(indio_dev,
183 ITG3200_REG_POWER_MANAGEMENT,
186 dev_err(&st->i2c->dev, "error resetting device");
190 /* Wait for PLL (1ms according to datasheet) */
193 ret = itg3200_write_reg_8(indio_dev,
194 ITG3200_REG_IRQ_CONFIG,
195 ITG3200_IRQ_ACTIVE_HIGH |
196 ITG3200_IRQ_PUSH_PULL |
197 ITG3200_IRQ_LATCH_50US_PULSE |
198 ITG3200_IRQ_LATCH_CLEAR_ANY);
201 dev_err(&st->i2c->dev, "error init device");
207 /* itg3200_enable_full_scale() - Disables the digital low pass filter */
208 static int itg3200_enable_full_scale(struct iio_dev *indio_dev)
213 ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &val);
217 val |= ITG3200_DLPF_FS_SEL_2000;
218 return itg3200_write_reg_8(indio_dev, ITG3200_REG_DLPF, val);
224 static int itg3200_initial_setup(struct iio_dev *indio_dev)
226 struct itg3200 *st = iio_priv(indio_dev);
230 ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_ADDRESS, &val);
234 if (((val >> 1) & 0x3f) != 0x34) {
235 dev_err(&st->i2c->dev, "invalid reg value 0x%02x", val);
240 ret = itg3200_reset(indio_dev);
244 ret = itg3200_enable_full_scale(indio_dev);
250 { .sign = 's', .realbits = 16, .storagebits = 16, .endianness = IIO_BE }
252 #define ITG3200_GYRO_CHAN(_mod) { \
253 .type = IIO_ANGL_VEL, \
255 .channel2 = IIO_MOD_ ## _mod, \
256 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
257 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
258 .address = ITG3200_REG_GYRO_ ## _mod ## OUT_H, \
259 .scan_index = ITG3200_SCAN_GYRO_ ## _mod, \
260 .scan_type = ITG3200_ST, \
263 static const struct iio_chan_spec itg3200_channels[] = {
266 .channel2 = IIO_NO_MOD,
267 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
268 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
269 BIT(IIO_CHAN_INFO_SCALE),
270 .address = ITG3200_REG_TEMP_OUT_H,
271 .scan_index = ITG3200_SCAN_TEMP,
272 .scan_type = ITG3200_ST,
274 ITG3200_GYRO_CHAN(X),
275 ITG3200_GYRO_CHAN(Y),
276 ITG3200_GYRO_CHAN(Z),
277 IIO_CHAN_SOFT_TIMESTAMP(ITG3200_SCAN_ELEMENTS),
280 /* IIO device attributes */
281 static IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR | S_IRUGO, itg3200_read_frequency,
282 itg3200_write_frequency);
284 static struct attribute *itg3200_attributes[] = {
285 &iio_dev_attr_sampling_frequency.dev_attr.attr,
289 static const struct attribute_group itg3200_attribute_group = {
290 .attrs = itg3200_attributes,
293 static const struct iio_info itg3200_info = {
294 .attrs = &itg3200_attribute_group,
295 .read_raw = &itg3200_read_raw,
296 .driver_module = THIS_MODULE,
299 static const unsigned long itg3200_available_scan_masks[] = { 0xffffffff, 0x0 };
301 static int itg3200_probe(struct i2c_client *client,
302 const struct i2c_device_id *id)
306 struct iio_dev *indio_dev;
308 dev_dbg(&client->dev, "probe I2C dev with IRQ %i", client->irq);
310 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
314 st = iio_priv(indio_dev);
316 i2c_set_clientdata(client, indio_dev);
319 indio_dev->dev.parent = &client->dev;
320 indio_dev->name = client->dev.driver->name;
321 indio_dev->channels = itg3200_channels;
322 indio_dev->num_channels = ARRAY_SIZE(itg3200_channels);
323 indio_dev->available_scan_masks = itg3200_available_scan_masks;
324 indio_dev->info = &itg3200_info;
325 indio_dev->modes = INDIO_DIRECT_MODE;
327 ret = itg3200_buffer_configure(indio_dev);
332 ret = itg3200_probe_trigger(indio_dev);
334 goto error_unconfigure_buffer;
337 ret = itg3200_initial_setup(indio_dev);
339 goto error_remove_trigger;
341 ret = iio_device_register(indio_dev);
343 goto error_remove_trigger;
347 error_remove_trigger:
349 itg3200_remove_trigger(indio_dev);
350 error_unconfigure_buffer:
351 itg3200_buffer_unconfigure(indio_dev);
355 static int itg3200_remove(struct i2c_client *client)
357 struct iio_dev *indio_dev = i2c_get_clientdata(client);
359 iio_device_unregister(indio_dev);
362 itg3200_remove_trigger(indio_dev);
364 itg3200_buffer_unconfigure(indio_dev);
369 static const struct i2c_device_id itg3200_id[] = {
373 MODULE_DEVICE_TABLE(i2c, itg3200_id);
375 static struct i2c_driver itg3200_driver = {
377 .owner = THIS_MODULE,
380 .id_table = itg3200_id,
381 .probe = itg3200_probe,
382 .remove = itg3200_remove,
385 module_i2c_driver(itg3200_driver);
387 MODULE_AUTHOR("Christian Strobel <christian.strobel@iis.fraunhofer.de>");
388 MODULE_DESCRIPTION("ITG3200 Gyroscope I2C driver");
389 MODULE_LICENSE("GPL v2");