401 lines
9.0 KiB
C
401 lines
9.0 KiB
C
/*
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* itg3200_core.c -- support InvenSense ITG3200
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* Digital 3-Axis Gyroscope driver
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*
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* Copyright (c) 2011 Christian Strobel <christian.strobel@iis.fraunhofer.de>
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* Copyright (c) 2011 Manuel Stahl <manuel.stahl@iis.fraunhofer.de>
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* Copyright (c) 2012 Thorsten Nowak <thorsten.nowak@iis.fraunhofer.de>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* TODO:
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* - Support digital low pass filter
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* - Support power management
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*/
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#include <linux/interrupt.h>
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#include <linux/irq.h>
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#include <linux/i2c.h>
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#include <linux/gpio.h>
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#include <linux/slab.h>
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#include <linux/stat.h>
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#include <linux/module.h>
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#include <linux/delay.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/sysfs.h>
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#include <linux/iio/events.h>
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#include <linux/iio/buffer.h>
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#include <linux/iio/gyro/itg3200.h>
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int itg3200_write_reg_8(struct iio_dev *indio_dev,
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u8 reg_address, u8 val)
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{
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struct itg3200 *st = iio_priv(indio_dev);
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return i2c_smbus_write_byte_data(st->i2c, 0x80 | reg_address, val);
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}
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int itg3200_read_reg_8(struct iio_dev *indio_dev,
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u8 reg_address, u8 *val)
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{
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struct itg3200 *st = iio_priv(indio_dev);
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int ret;
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ret = i2c_smbus_read_byte_data(st->i2c, reg_address);
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if (ret < 0)
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return ret;
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*val = ret;
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return 0;
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}
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static int itg3200_read_reg_s16(struct iio_dev *indio_dev, u8 lower_reg_address,
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int *val)
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{
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struct itg3200 *st = iio_priv(indio_dev);
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struct i2c_client *client = st->i2c;
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int ret;
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s16 out;
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struct i2c_msg msg[2] = {
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{
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.addr = client->addr,
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.flags = client->flags,
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.len = 1,
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.buf = (char *)&lower_reg_address,
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},
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{
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.addr = client->addr,
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.flags = client->flags | I2C_M_RD,
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.len = 2,
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.buf = (char *)&out,
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},
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};
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lower_reg_address |= 0x80;
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ret = i2c_transfer(client->adapter, msg, 2);
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be16_to_cpus(&out);
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*val = out;
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return (ret == 2) ? 0 : ret;
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}
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static int itg3200_read_raw(struct iio_dev *indio_dev,
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const struct iio_chan_spec *chan,
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int *val, int *val2, long info)
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{
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int ret = 0;
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u8 reg;
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u8 regval;
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switch (info) {
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case IIO_CHAN_INFO_RAW:
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reg = (u8)chan->address;
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ret = itg3200_read_reg_s16(indio_dev, reg, val);
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return IIO_VAL_INT;
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case IIO_CHAN_INFO_SCALE:
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*val = 0;
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if (chan->type == IIO_TEMP)
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*val2 = 1000000000/280;
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else
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*val2 = 1214142; /* (1 / 14,375) * (PI / 180) */
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return IIO_VAL_INT_PLUS_NANO;
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case IIO_CHAN_INFO_OFFSET:
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/* Only the temperature channel has an offset */
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*val = 23000;
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return IIO_VAL_INT;
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case IIO_CHAN_INFO_SAMP_FREQ:
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ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, ®val);
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if (ret)
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return ret;
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*val = (regval & ITG3200_DLPF_CFG_MASK) ? 1000 : 8000;
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ret = itg3200_read_reg_8(indio_dev,
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ITG3200_REG_SAMPLE_RATE_DIV,
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®val);
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if (ret)
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return ret;
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*val /= regval + 1;
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return IIO_VAL_INT;
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default:
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return -EINVAL;
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}
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}
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static int itg3200_write_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int val,
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int val2,
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long mask)
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{
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int ret;
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u8 t;
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switch (mask) {
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case IIO_CHAN_INFO_SAMP_FREQ:
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if (val == 0 || val2 != 0)
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return -EINVAL;
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mutex_lock(&indio_dev->mlock);
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ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &t);
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if (ret) {
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mutex_unlock(&indio_dev->mlock);
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return ret;
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}
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t = ((t & ITG3200_DLPF_CFG_MASK) ? 1000u : 8000u) / val - 1;
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ret = itg3200_write_reg_8(indio_dev,
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ITG3200_REG_SAMPLE_RATE_DIV,
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t);
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mutex_unlock(&indio_dev->mlock);
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return ret;
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default:
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return -EINVAL;
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}
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}
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/*
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* Reset device and internal registers to the power-up-default settings
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* Use the gyro clock as reference, as suggested by the datasheet
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*/
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static int itg3200_reset(struct iio_dev *indio_dev)
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{
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struct itg3200 *st = iio_priv(indio_dev);
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int ret;
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dev_dbg(&st->i2c->dev, "reset device");
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ret = itg3200_write_reg_8(indio_dev,
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ITG3200_REG_POWER_MANAGEMENT,
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ITG3200_RESET);
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if (ret) {
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dev_err(&st->i2c->dev, "error resetting device");
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goto error_ret;
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}
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/* Wait for PLL (1ms according to datasheet) */
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udelay(1500);
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ret = itg3200_write_reg_8(indio_dev,
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ITG3200_REG_IRQ_CONFIG,
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ITG3200_IRQ_ACTIVE_HIGH |
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ITG3200_IRQ_PUSH_PULL |
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ITG3200_IRQ_LATCH_50US_PULSE |
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ITG3200_IRQ_LATCH_CLEAR_ANY);
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if (ret)
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dev_err(&st->i2c->dev, "error init device");
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error_ret:
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return ret;
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}
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/* itg3200_enable_full_scale() - Disables the digital low pass filter */
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static int itg3200_enable_full_scale(struct iio_dev *indio_dev)
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{
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u8 val;
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int ret;
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ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &val);
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if (ret)
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goto err_ret;
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val |= ITG3200_DLPF_FS_SEL_2000;
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return itg3200_write_reg_8(indio_dev, ITG3200_REG_DLPF, val);
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err_ret:
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return ret;
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}
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static int itg3200_initial_setup(struct iio_dev *indio_dev)
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{
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struct itg3200 *st = iio_priv(indio_dev);
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int ret;
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u8 val;
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ret = itg3200_reset(indio_dev);
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if (ret)
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goto err_ret;
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ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_ADDRESS, &val);
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if (ret)
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goto err_ret;
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if (((val >> 1) & 0x3f) != 0x34) {
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dev_err(&st->i2c->dev, "invalid reg value 0x%02x", val);
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ret = -ENXIO;
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goto err_ret;
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}
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ret = itg3200_enable_full_scale(indio_dev);
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err_ret:
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return ret;
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}
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#define ITG3200_ST \
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{ .sign = 's', .realbits = 16, .storagebits = 16, .endianness = IIO_BE }
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#define ITG3200_GYRO_CHAN(_mod) { \
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.type = IIO_ANGL_VEL, \
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.modified = 1, \
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.channel2 = IIO_MOD_ ## _mod, \
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
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.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
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.address = ITG3200_REG_GYRO_ ## _mod ## OUT_H, \
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.scan_index = ITG3200_SCAN_GYRO_ ## _mod, \
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.scan_type = ITG3200_ST, \
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}
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static const struct iio_chan_spec itg3200_channels[] = {
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{
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.type = IIO_TEMP,
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.channel2 = IIO_NO_MOD,
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
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BIT(IIO_CHAN_INFO_SCALE),
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.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
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.address = ITG3200_REG_TEMP_OUT_H,
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.scan_index = ITG3200_SCAN_TEMP,
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.scan_type = ITG3200_ST,
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},
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ITG3200_GYRO_CHAN(X),
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ITG3200_GYRO_CHAN(Y),
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ITG3200_GYRO_CHAN(Z),
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IIO_CHAN_SOFT_TIMESTAMP(ITG3200_SCAN_ELEMENTS),
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};
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static const struct iio_info itg3200_info = {
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.read_raw = &itg3200_read_raw,
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.write_raw = &itg3200_write_raw,
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};
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static const unsigned long itg3200_available_scan_masks[] = { 0xffffffff, 0x0 };
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static int itg3200_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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int ret;
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struct itg3200 *st;
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struct iio_dev *indio_dev;
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dev_dbg(&client->dev, "probe I2C dev with IRQ %i", client->irq);
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indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
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if (!indio_dev)
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return -ENOMEM;
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st = iio_priv(indio_dev);
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i2c_set_clientdata(client, indio_dev);
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st->i2c = client;
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indio_dev->dev.parent = &client->dev;
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indio_dev->name = client->dev.driver->name;
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indio_dev->channels = itg3200_channels;
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indio_dev->num_channels = ARRAY_SIZE(itg3200_channels);
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indio_dev->available_scan_masks = itg3200_available_scan_masks;
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indio_dev->info = &itg3200_info;
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indio_dev->modes = INDIO_DIRECT_MODE;
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ret = itg3200_buffer_configure(indio_dev);
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if (ret)
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return ret;
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if (client->irq) {
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ret = itg3200_probe_trigger(indio_dev);
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if (ret)
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goto error_unconfigure_buffer;
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}
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ret = itg3200_initial_setup(indio_dev);
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if (ret)
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goto error_remove_trigger;
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ret = iio_device_register(indio_dev);
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if (ret)
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goto error_remove_trigger;
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return 0;
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error_remove_trigger:
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if (client->irq)
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itg3200_remove_trigger(indio_dev);
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error_unconfigure_buffer:
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itg3200_buffer_unconfigure(indio_dev);
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return ret;
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}
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static int itg3200_remove(struct i2c_client *client)
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{
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struct iio_dev *indio_dev = i2c_get_clientdata(client);
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iio_device_unregister(indio_dev);
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if (client->irq)
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itg3200_remove_trigger(indio_dev);
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itg3200_buffer_unconfigure(indio_dev);
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return 0;
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}
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static int __maybe_unused itg3200_suspend(struct device *dev)
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{
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struct iio_dev *indio_dev = dev_get_drvdata(dev);
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struct itg3200 *st = iio_priv(indio_dev);
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dev_dbg(&st->i2c->dev, "suspend device");
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return itg3200_write_reg_8(indio_dev, ITG3200_REG_POWER_MANAGEMENT,
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ITG3200_SLEEP);
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}
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static int __maybe_unused itg3200_resume(struct device *dev)
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{
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struct iio_dev *indio_dev = dev_get_drvdata(dev);
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return itg3200_initial_setup(indio_dev);
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}
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static SIMPLE_DEV_PM_OPS(itg3200_pm_ops, itg3200_suspend, itg3200_resume);
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static const struct i2c_device_id itg3200_id[] = {
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{ "itg3200", 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, itg3200_id);
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static const struct of_device_id itg3200_of_match[] = {
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{ .compatible = "invensense,itg3200" },
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{ }
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};
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MODULE_DEVICE_TABLE(of, itg3200_of_match);
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static struct i2c_driver itg3200_driver = {
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.driver = {
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.name = "itg3200",
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.of_match_table = itg3200_of_match,
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.pm = &itg3200_pm_ops,
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},
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.id_table = itg3200_id,
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.probe = itg3200_probe,
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.remove = itg3200_remove,
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};
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module_i2c_driver(itg3200_driver);
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MODULE_AUTHOR("Christian Strobel <christian.strobel@iis.fraunhofer.de>");
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MODULE_DESCRIPTION("ITG3200 Gyroscope I2C driver");
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MODULE_LICENSE("GPL v2");
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