diff options
Diffstat (limited to 'drivers/iio/gyro/itg3200_core.c')
| -rw-r--r-- | drivers/iio/gyro/itg3200_core.c | 401 |
1 files changed, 401 insertions, 0 deletions
diff --git a/drivers/iio/gyro/itg3200_core.c b/drivers/iio/gyro/itg3200_core.c new file mode 100644 index 00000000000..df2e6aa5d73 --- /dev/null +++ b/drivers/iio/gyro/itg3200_core.c @@ -0,0 +1,401 @@ +/* + * itg3200_core.c -- support InvenSense ITG3200 + * Digital 3-Axis Gyroscope driver + * + * Copyright (c) 2011 Christian Strobel <christian.strobel@iis.fraunhofer.de> + * Copyright (c) 2011 Manuel Stahl <manuel.stahl@iis.fraunhofer.de> + * Copyright (c) 2012 Thorsten Nowak <thorsten.nowak@iis.fraunhofer.de> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * TODO: + * - Support digital low pass filter + * - Support power management + */ + +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/i2c.h> +#include <linux/gpio.h> +#include <linux/slab.h> +#include <linux/stat.h> +#include <linux/module.h> +#include <linux/delay.h> + +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/iio/events.h> +#include <linux/iio/buffer.h> + +#include <linux/iio/gyro/itg3200.h> + + +int itg3200_write_reg_8(struct iio_dev *indio_dev, + u8 reg_address, u8 val) +{ + struct itg3200 *st = iio_priv(indio_dev); + + return i2c_smbus_write_byte_data(st->i2c, 0x80 | reg_address, val); +} + +int itg3200_read_reg_8(struct iio_dev *indio_dev, + u8 reg_address, u8 *val) +{ + struct itg3200 *st = iio_priv(indio_dev); + int ret; + + ret = i2c_smbus_read_byte_data(st->i2c, reg_address); + if (ret < 0) + return ret; + *val = ret; + return 0; +} + +static int itg3200_read_reg_s16(struct iio_dev *indio_dev, u8 lower_reg_address, + int *val) +{ + struct itg3200 *st = iio_priv(indio_dev); + struct i2c_client *client = st->i2c; + int ret; + s16 out; + + struct i2c_msg msg[2] = { + { + .addr = client->addr, + .flags = client->flags, + .len = 1, + .buf = (char *)&lower_reg_address, + }, + { + .addr = client->addr, + .flags = client->flags | I2C_M_RD, + .len = 2, + .buf = (char *)&out, + }, + }; + + lower_reg_address |= 0x80; + ret = i2c_transfer(client->adapter, msg, 2); + be16_to_cpus(&out); + *val = out; + + return (ret == 2) ? 0 : ret; +} + +static int itg3200_read_raw(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + int *val, int *val2, long info) +{ + int ret = 0; + u8 reg; + + switch (info) { + case IIO_CHAN_INFO_RAW: + reg = (u8)chan->address; + ret = itg3200_read_reg_s16(indio_dev, reg, val); + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + *val = 0; + if (chan->type == IIO_TEMP) + *val2 = 1000000000/280; + else + *val2 = 1214142; /* (1 / 14,375) * (PI / 180) */ + return IIO_VAL_INT_PLUS_NANO; + case IIO_CHAN_INFO_OFFSET: + /* Only the temperature channel has an offset */ + *val = 23000; + return IIO_VAL_INT; + default: + return -EINVAL; + } + + return ret; +} + +static ssize_t itg3200_read_frequency(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct iio_dev *indio_dev = dev_to_iio_dev(dev); + int ret, sps; + u8 val; + + ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &val); + if (ret) + return ret; + + sps = (val & ITG3200_DLPF_CFG_MASK) ? 1000 : 8000; + + ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_SAMPLE_RATE_DIV, &val); + if (ret) + return ret; + + sps /= val + 1; + + return sprintf(buf, "%d\n", sps); +} + +static ssize_t itg3200_write_frequency(struct device *dev, + struct device_attribute *attr, + const char *buf, + size_t len) +{ + struct iio_dev *indio_dev = dev_to_iio_dev(dev); + unsigned val; + int ret; + u8 t; + + ret = kstrtouint(buf, 10, &val); + if (ret) + return ret; + + mutex_lock(&indio_dev->mlock); + + ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &t); + if (ret) + goto err_ret; + + if (val == 0) { + ret = -EINVAL; + goto err_ret; + } + t = ((t & ITG3200_DLPF_CFG_MASK) ? 1000u : 8000u) / val - 1; + + ret = itg3200_write_reg_8(indio_dev, ITG3200_REG_SAMPLE_RATE_DIV, t); + +err_ret: + mutex_unlock(&indio_dev->mlock); + + return ret ? ret : len; +} + +/* + * Reset device and internal registers to the power-up-default settings + * Use the gyro clock as reference, as suggested by the datasheet + */ +static int itg3200_reset(struct iio_dev *indio_dev) +{ + struct itg3200 *st = iio_priv(indio_dev); + int ret; + + dev_dbg(&st->i2c->dev, "reset device"); + + ret = itg3200_write_reg_8(indio_dev, + ITG3200_REG_POWER_MANAGEMENT, + ITG3200_RESET); + if (ret) { + dev_err(&st->i2c->dev, "error resetting device"); + goto error_ret; + } + + /* Wait for PLL (1ms according to datasheet) */ + udelay(1500); + + ret = itg3200_write_reg_8(indio_dev, + ITG3200_REG_IRQ_CONFIG, + ITG3200_IRQ_ACTIVE_HIGH | + ITG3200_IRQ_PUSH_PULL | + ITG3200_IRQ_LATCH_50US_PULSE | + ITG3200_IRQ_LATCH_CLEAR_ANY); + + if (ret) + dev_err(&st->i2c->dev, "error init device"); + +error_ret: + return ret; +} + +/* itg3200_enable_full_scale() - Disables the digital low pass filter */ +static int itg3200_enable_full_scale(struct iio_dev *indio_dev) +{ + u8 val; + int ret; + + ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &val); + if (ret) + goto err_ret; + + val |= ITG3200_DLPF_FS_SEL_2000; + return itg3200_write_reg_8(indio_dev, ITG3200_REG_DLPF, val); + +err_ret: + return ret; +} + +static int itg3200_initial_setup(struct iio_dev *indio_dev) +{ + struct itg3200 *st = iio_priv(indio_dev); + int ret; + u8 val; + + ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_ADDRESS, &val); + if (ret) + goto err_ret; + + if (((val >> 1) & 0x3f) != 0x34) { + dev_err(&st->i2c->dev, "invalid reg value 0x%02x", val); + ret = -ENXIO; + goto err_ret; + } + + ret = itg3200_reset(indio_dev); + if (ret) + goto err_ret; + + ret = itg3200_enable_full_scale(indio_dev); +err_ret: + return ret; +} + +#define ITG3200_TEMP_INFO_MASK (IIO_CHAN_INFO_OFFSET_SHARED_BIT | \ + IIO_CHAN_INFO_SCALE_SHARED_BIT | \ + IIO_CHAN_INFO_RAW_SEPARATE_BIT) +#define ITG3200_GYRO_INFO_MASK (IIO_CHAN_INFO_SCALE_SHARED_BIT | \ + IIO_CHAN_INFO_RAW_SEPARATE_BIT) + +#define ITG3200_ST \ + { .sign = 's', .realbits = 16, .storagebits = 16, .endianness = IIO_BE } + +#define ITG3200_GYRO_CHAN(_mod) { \ + .type = IIO_ANGL_VEL, \ + .modified = 1, \ + .channel2 = IIO_MOD_ ## _mod, \ + .info_mask = ITG3200_GYRO_INFO_MASK, \ + .address = ITG3200_REG_GYRO_ ## _mod ## OUT_H, \ + .scan_index = ITG3200_SCAN_GYRO_ ## _mod, \ + .scan_type = ITG3200_ST, \ +} + +static const struct iio_chan_spec itg3200_channels[] = { + { + .type = IIO_TEMP, + .channel2 = IIO_NO_MOD, + .info_mask = ITG3200_TEMP_INFO_MASK, + .address = ITG3200_REG_TEMP_OUT_H, + .scan_index = ITG3200_SCAN_TEMP, + .scan_type = ITG3200_ST, + }, + ITG3200_GYRO_CHAN(X), + ITG3200_GYRO_CHAN(Y), + ITG3200_GYRO_CHAN(Z), + IIO_CHAN_SOFT_TIMESTAMP(ITG3200_SCAN_ELEMENTS), +}; + +/* IIO device attributes */ +static IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR | S_IRUGO, itg3200_read_frequency, + itg3200_write_frequency); + +static struct attribute *itg3200_attributes[] = { + &iio_dev_attr_sampling_frequency.dev_attr.attr, + NULL +}; + +static const struct attribute_group itg3200_attribute_group = { + .attrs = itg3200_attributes, +}; + +static const struct iio_info itg3200_info = { + .attrs = &itg3200_attribute_group, + .read_raw = &itg3200_read_raw, + .driver_module = THIS_MODULE, +}; + +static const unsigned long itg3200_available_scan_masks[] = { 0xffffffff, 0x0 }; + +static int itg3200_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + int ret; + struct itg3200 *st; + struct iio_dev *indio_dev; + + dev_dbg(&client->dev, "probe I2C dev with IRQ %i", client->irq); + + indio_dev = iio_device_alloc(sizeof(*st)); + if (indio_dev == NULL) { + ret = -ENOMEM; + goto error_ret; + } + + st = iio_priv(indio_dev); + + i2c_set_clientdata(client, indio_dev); + st->i2c = client; + + indio_dev->dev.parent = &client->dev; + indio_dev->name = client->dev.driver->name; + indio_dev->channels = itg3200_channels; + indio_dev->num_channels = ARRAY_SIZE(itg3200_channels); + indio_dev->available_scan_masks = itg3200_available_scan_masks; + indio_dev->info = &itg3200_info; + indio_dev->modes = INDIO_DIRECT_MODE; + + ret = itg3200_buffer_configure(indio_dev); + if (ret) + goto error_free_dev; + + if (client->irq) { + ret = itg3200_probe_trigger(indio_dev); + if (ret) + goto error_unconfigure_buffer; + } + + ret = itg3200_initial_setup(indio_dev); + if (ret) + goto error_remove_trigger; + + ret = iio_device_register(indio_dev); + if (ret) + goto error_remove_trigger; + + return 0; + +error_remove_trigger: + if (client->irq) + itg3200_remove_trigger(indio_dev); +error_unconfigure_buffer: + itg3200_buffer_unconfigure(indio_dev); +error_free_dev: + iio_device_free(indio_dev); +error_ret: + return ret; +} + +static int itg3200_remove(struct i2c_client *client) +{ + struct iio_dev *indio_dev = i2c_get_clientdata(client); + + iio_device_unregister(indio_dev); + + if (client->irq) + itg3200_remove_trigger(indio_dev); + + itg3200_buffer_unconfigure(indio_dev); + + iio_device_free(indio_dev); + + return 0; +} + +static const struct i2c_device_id itg3200_id[] = { + { "itg3200", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, itg3200_id); + +static struct i2c_driver itg3200_driver = { + .driver = { + .owner = THIS_MODULE, + .name = "itg3200", + }, + .id_table = itg3200_id, + .probe = itg3200_probe, + .remove = itg3200_remove, +}; + +module_i2c_driver(itg3200_driver); + +MODULE_AUTHOR("Christian Strobel <christian.strobel@iis.fraunhofer.de>"); +MODULE_DESCRIPTION("ITG3200 Gyroscope I2C driver"); +MODULE_LICENSE("GPL v2"); |