iio: imu: inv_mpu6050: helpers for using i2c master on auxiliary bus
Add helper functions to use the i2c auxiliary bus with the MPU i2c master block. Support only register based chip, reading and 1 byte writing. These will be useful for initializing magnetometers inside MPU9x50 chips. Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Jean-Baptiste Maneyrol
Jonathan Cameron
parent
9d8261dbc4
commit
16ef433769
@ -4,7 +4,8 @@
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#
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obj-$(CONFIG_INV_MPU6050_IIO) += inv-mpu6050.o
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inv-mpu6050-y := inv_mpu_core.o inv_mpu_ring.o inv_mpu_trigger.o
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inv-mpu6050-y := inv_mpu_core.o inv_mpu_ring.o inv_mpu_trigger.o \
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inv_mpu_aux.o
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obj-$(CONFIG_INV_MPU6050_I2C) += inv-mpu6050-i2c.o
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inv-mpu6050-i2c-y := inv_mpu_i2c.o inv_mpu_acpi.o
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204
drivers/iio/imu/inv_mpu6050/inv_mpu_aux.c
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204
drivers/iio/imu/inv_mpu6050/inv_mpu_aux.c
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@ -0,0 +1,204 @@
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// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2019 TDK-InvenSense, Inc.
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*/
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#include <linux/kernel.h>
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#include <linux/device.h>
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#include <linux/regmap.h>
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#include <linux/delay.h>
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#include "inv_mpu_aux.h"
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#include "inv_mpu_iio.h"
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/*
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* i2c master auxiliary bus transfer function.
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* Requires the i2c operations to be correctly setup before.
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*/
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static int inv_mpu_i2c_master_xfer(const struct inv_mpu6050_state *st)
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{
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/* use 50hz frequency for xfer */
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const unsigned int freq = 50;
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const unsigned int period_ms = 1000 / freq;
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uint8_t d;
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unsigned int user_ctrl;
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int ret;
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/* set sample rate */
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d = INV_MPU6050_FIFO_RATE_TO_DIVIDER(freq);
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ret = regmap_write(st->map, st->reg->sample_rate_div, d);
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if (ret)
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return ret;
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/* start i2c master */
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user_ctrl = st->chip_config.user_ctrl | INV_MPU6050_BIT_I2C_MST_EN;
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ret = regmap_write(st->map, st->reg->user_ctrl, user_ctrl);
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if (ret)
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goto error_restore_rate;
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/* wait for xfer: 1 period + half-period margin */
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msleep(period_ms + period_ms / 2);
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/* stop i2c master */
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user_ctrl = st->chip_config.user_ctrl;
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ret = regmap_write(st->map, st->reg->user_ctrl, user_ctrl);
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if (ret)
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goto error_stop_i2c;
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/* restore sample rate */
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d = st->chip_config.divider;
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ret = regmap_write(st->map, st->reg->sample_rate_div, d);
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if (ret)
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goto error_restore_rate;
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return 0;
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error_stop_i2c:
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regmap_write(st->map, st->reg->user_ctrl, st->chip_config.user_ctrl);
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error_restore_rate:
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regmap_write(st->map, st->reg->sample_rate_div, st->chip_config.divider);
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return ret;
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}
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/**
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* inv_mpu_aux_init() - init i2c auxiliary bus
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* @st: driver internal state
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*
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* Returns 0 on success, a negative error code otherwise.
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*/
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int inv_mpu_aux_init(const struct inv_mpu6050_state *st)
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{
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unsigned int val;
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int ret;
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/* configure i2c master */
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val = INV_MPU6050_BITS_I2C_MST_CLK_400KHZ |
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INV_MPU6050_BIT_WAIT_FOR_ES;
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ret = regmap_write(st->map, INV_MPU6050_REG_I2C_MST_CTRL, val);
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if (ret)
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return ret;
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/* configure i2c master delay */
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ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV4_CTRL, 0);
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if (ret)
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return ret;
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val = INV_MPU6050_BIT_I2C_SLV0_DLY_EN |
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INV_MPU6050_BIT_I2C_SLV1_DLY_EN |
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INV_MPU6050_BIT_I2C_SLV2_DLY_EN |
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INV_MPU6050_BIT_I2C_SLV3_DLY_EN |
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INV_MPU6050_BIT_DELAY_ES_SHADOW;
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return regmap_write(st->map, INV_MPU6050_REG_I2C_MST_DELAY_CTRL, val);
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}
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/**
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* inv_mpu_aux_read() - read register function for i2c auxiliary bus
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* @st: driver internal state.
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* @addr: chip i2c Address
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* @reg: chip register address
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* @val: buffer for storing read bytes
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* @size: number of bytes to read
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*
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* Returns 0 on success, a negative error code otherwise.
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*/
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int inv_mpu_aux_read(const struct inv_mpu6050_state *st, uint8_t addr,
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uint8_t reg, uint8_t *val, size_t size)
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{
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unsigned int status;
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int ret;
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if (size > 0x0F)
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return -EINVAL;
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/* setup i2c SLV0 control: i2c addr, register, enable + size */
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ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_ADDR(0),
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INV_MPU6050_BIT_I2C_SLV_RNW | addr);
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if (ret)
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return ret;
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ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_REG(0), reg);
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if (ret)
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return ret;
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ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_CTRL(0),
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INV_MPU6050_BIT_SLV_EN | size);
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if (ret)
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return ret;
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/* do i2c xfer */
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ret = inv_mpu_i2c_master_xfer(st);
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if (ret)
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goto error_disable_i2c;
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/* disable i2c slave */
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ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_CTRL(0), 0);
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if (ret)
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goto error_disable_i2c;
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/* check i2c status */
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ret = regmap_read(st->map, INV_MPU6050_REG_I2C_MST_STATUS, &status);
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if (ret)
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return ret;
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if (status & INV_MPU6050_BIT_I2C_SLV0_NACK)
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return -EIO;
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/* read data in registers */
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return regmap_bulk_read(st->map, INV_MPU6050_REG_EXT_SENS_DATA,
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val, size);
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error_disable_i2c:
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regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_CTRL(0), 0);
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return ret;
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}
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/**
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* inv_mpu_aux_write() - write register function for i2c auxiliary bus
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* @st: driver internal state.
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* @addr: chip i2c Address
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* @reg: chip register address
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* @val: 1 byte value to write
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*
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* Returns 0 on success, a negative error code otherwise.
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*/
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int inv_mpu_aux_write(const struct inv_mpu6050_state *st, uint8_t addr,
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uint8_t reg, uint8_t val)
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{
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unsigned int status;
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int ret;
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/* setup i2c SLV0 control: i2c addr, register, value, enable + size */
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ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_ADDR(0), addr);
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if (ret)
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return ret;
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ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_REG(0), reg);
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if (ret)
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return ret;
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ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_DO(0), val);
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if (ret)
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return ret;
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ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_CTRL(0),
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INV_MPU6050_BIT_SLV_EN | 1);
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if (ret)
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return ret;
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/* do i2c xfer */
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ret = inv_mpu_i2c_master_xfer(st);
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if (ret)
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goto error_disable_i2c;
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/* disable i2c slave */
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ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_CTRL(0), 0);
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if (ret)
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goto error_disable_i2c;
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/* check i2c status */
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ret = regmap_read(st->map, INV_MPU6050_REG_I2C_MST_STATUS, &status);
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if (ret)
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return ret;
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if (status & INV_MPU6050_BIT_I2C_SLV0_NACK)
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return -EIO;
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return 0;
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error_disable_i2c:
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regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_CTRL(0), 0);
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return ret;
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}
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19
drivers/iio/imu/inv_mpu6050/inv_mpu_aux.h
Normal file
19
drivers/iio/imu/inv_mpu6050/inv_mpu_aux.h
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@ -0,0 +1,19 @@
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/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Copyright (C) 2019 TDK-InvenSense, Inc.
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*/
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#ifndef INV_MPU_AUX_H_
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#define INV_MPU_AUX_H_
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#include "inv_mpu_iio.h"
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int inv_mpu_aux_init(const struct inv_mpu6050_state *st);
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int inv_mpu_aux_read(const struct inv_mpu6050_state *st, uint8_t addr,
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uint8_t reg, uint8_t *val, size_t size);
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int inv_mpu_aux_write(const struct inv_mpu6050_state *st, uint8_t addr,
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uint8_t reg, uint8_t val);
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#endif /* INV_MPU_AUX_H_ */
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