mirror of https://gitee.com/openkylin/linux.git
325 lines
8.1 KiB
C
325 lines
8.1 KiB
C
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/*
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* MAX44000 Ambient and Infrared Proximity Sensor
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*
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* Copyright (c) 2016, Intel Corporation.
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*
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* This file is subject to the terms and conditions of version 2 of
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* the GNU General Public License. See the file COPYING in the main
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* directory of this archive for more details.
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*
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* Data sheet: https://datasheets.maximintegrated.com/en/ds/MAX44000.pdf
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*
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* 7-bit I2C slave address 0x4a
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/i2c.h>
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#include <linux/regmap.h>
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#include <linux/util_macros.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/acpi.h>
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#define MAX44000_DRV_NAME "max44000"
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/* Registers in datasheet order */
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#define MAX44000_REG_STATUS 0x00
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#define MAX44000_REG_CFG_MAIN 0x01
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#define MAX44000_REG_CFG_RX 0x02
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#define MAX44000_REG_CFG_TX 0x03
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#define MAX44000_REG_ALS_DATA_HI 0x04
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#define MAX44000_REG_ALS_DATA_LO 0x05
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#define MAX44000_REG_PRX_DATA 0x16
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#define MAX44000_REG_ALS_UPTHR_HI 0x06
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#define MAX44000_REG_ALS_UPTHR_LO 0x07
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#define MAX44000_REG_ALS_LOTHR_HI 0x08
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#define MAX44000_REG_ALS_LOTHR_LO 0x09
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#define MAX44000_REG_PST 0x0a
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#define MAX44000_REG_PRX_IND 0x0b
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#define MAX44000_REG_PRX_THR 0x0c
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#define MAX44000_REG_TRIM_GAIN_GREEN 0x0f
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#define MAX44000_REG_TRIM_GAIN_IR 0x10
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/* REG_CFG bits */
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#define MAX44000_CFG_ALSINTE 0x01
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#define MAX44000_CFG_PRXINTE 0x02
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#define MAX44000_CFG_MASK 0x1c
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#define MAX44000_CFG_MODE_SHUTDOWN 0x00
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#define MAX44000_CFG_MODE_ALS_GIR 0x04
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#define MAX44000_CFG_MODE_ALS_G 0x08
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#define MAX44000_CFG_MODE_ALS_IR 0x0c
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#define MAX44000_CFG_MODE_ALS_PRX 0x10
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#define MAX44000_CFG_MODE_PRX 0x14
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#define MAX44000_CFG_TRIM 0x20
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/*
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* Upper 4 bits are not documented but start as 1 on powerup
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* Setting them to 0 causes proximity to misbehave so set them to 1
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*/
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#define MAX44000_REG_CFG_RX_DEFAULT 0xf0
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#define MAX44000_ALSDATA_OVERFLOW 0x4000
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struct max44000_data {
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struct mutex lock;
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struct regmap *regmap;
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};
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/* Default scale is set to the minimum of 0.03125 or 1 / (1 << 5) lux */
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#define MAX44000_ALS_TO_LUX_DEFAULT_FRACTION_LOG2 5
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static const struct iio_chan_spec max44000_channels[] = {
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{
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.type = IIO_LIGHT,
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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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},
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};
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static int max44000_read_alsval(struct max44000_data *data)
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{
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u16 regval;
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int ret;
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ret = regmap_bulk_read(data->regmap, MAX44000_REG_ALS_DATA_HI,
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®val, sizeof(regval));
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if (ret < 0)
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return ret;
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regval = be16_to_cpu(regval);
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/*
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* Overflow is explained on datasheet page 17.
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*
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* It's a warning that either the G or IR channel has become saturated
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* and that the value in the register is likely incorrect.
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*
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* The recommendation is to change the scale (ALSPGA).
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* The driver just returns the max representable value.
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*/
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if (regval & MAX44000_ALSDATA_OVERFLOW)
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return 0x3FFF;
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return regval;
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}
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static int max44000_read_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int *val, int *val2, long mask)
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{
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struct max44000_data *data = iio_priv(indio_dev);
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int ret;
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switch (mask) {
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case IIO_CHAN_INFO_RAW:
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switch (chan->type) {
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case IIO_LIGHT:
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mutex_lock(&data->lock);
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ret = max44000_read_alsval(data);
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mutex_unlock(&data->lock);
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if (ret < 0)
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return ret;
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*val = ret;
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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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case IIO_CHAN_INFO_SCALE:
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switch (chan->type) {
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case IIO_LIGHT:
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*val = 1;
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*val2 = MAX44000_ALS_TO_LUX_DEFAULT_FRACTION_LOG2;
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return IIO_VAL_FRACTIONAL_LOG2;
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default:
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return -EINVAL;
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}
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default:
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return -EINVAL;
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}
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}
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static const struct iio_info max44000_info = {
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.driver_module = THIS_MODULE,
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.read_raw = max44000_read_raw,
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};
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static bool max44000_readable_reg(struct device *dev, unsigned int reg)
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{
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switch (reg) {
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case MAX44000_REG_STATUS:
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case MAX44000_REG_CFG_MAIN:
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case MAX44000_REG_CFG_RX:
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case MAX44000_REG_CFG_TX:
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case MAX44000_REG_ALS_DATA_HI:
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case MAX44000_REG_ALS_DATA_LO:
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case MAX44000_REG_PRX_DATA:
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case MAX44000_REG_ALS_UPTHR_HI:
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case MAX44000_REG_ALS_UPTHR_LO:
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case MAX44000_REG_ALS_LOTHR_HI:
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case MAX44000_REG_ALS_LOTHR_LO:
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case MAX44000_REG_PST:
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case MAX44000_REG_PRX_IND:
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case MAX44000_REG_PRX_THR:
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case MAX44000_REG_TRIM_GAIN_GREEN:
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case MAX44000_REG_TRIM_GAIN_IR:
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return true;
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default:
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return false;
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}
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}
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static bool max44000_writeable_reg(struct device *dev, unsigned int reg)
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{
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switch (reg) {
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case MAX44000_REG_CFG_MAIN:
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case MAX44000_REG_CFG_RX:
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case MAX44000_REG_CFG_TX:
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case MAX44000_REG_ALS_UPTHR_HI:
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case MAX44000_REG_ALS_UPTHR_LO:
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case MAX44000_REG_ALS_LOTHR_HI:
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case MAX44000_REG_ALS_LOTHR_LO:
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case MAX44000_REG_PST:
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case MAX44000_REG_PRX_IND:
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case MAX44000_REG_PRX_THR:
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case MAX44000_REG_TRIM_GAIN_GREEN:
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case MAX44000_REG_TRIM_GAIN_IR:
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return true;
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default:
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return false;
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}
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}
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static bool max44000_volatile_reg(struct device *dev, unsigned int reg)
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{
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switch (reg) {
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case MAX44000_REG_STATUS:
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case MAX44000_REG_ALS_DATA_HI:
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case MAX44000_REG_ALS_DATA_LO:
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case MAX44000_REG_PRX_DATA:
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return true;
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default:
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return false;
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}
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}
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static bool max44000_precious_reg(struct device *dev, unsigned int reg)
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{
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return reg == MAX44000_REG_STATUS;
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}
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static const struct regmap_config max44000_regmap_config = {
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.reg_bits = 8,
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.val_bits = 8,
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.max_register = MAX44000_REG_PRX_DATA,
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.readable_reg = max44000_readable_reg,
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.writeable_reg = max44000_writeable_reg,
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.volatile_reg = max44000_volatile_reg,
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.precious_reg = max44000_precious_reg,
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.use_single_rw = 1,
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.cache_type = REGCACHE_RBTREE,
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};
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static int max44000_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct max44000_data *data;
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struct iio_dev *indio_dev;
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int ret, reg;
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indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
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if (!indio_dev)
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return -ENOMEM;
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data = iio_priv(indio_dev);
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data->regmap = devm_regmap_init_i2c(client, &max44000_regmap_config);
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if (IS_ERR(data->regmap)) {
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dev_err(&client->dev, "regmap_init failed!\n");
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return PTR_ERR(data->regmap);
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}
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i2c_set_clientdata(client, indio_dev);
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mutex_init(&data->lock);
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indio_dev->dev.parent = &client->dev;
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indio_dev->info = &max44000_info;
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indio_dev->name = MAX44000_DRV_NAME;
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indio_dev->channels = max44000_channels;
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indio_dev->num_channels = ARRAY_SIZE(max44000_channels);
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/*
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* The device doesn't have a reset function so we just clear some
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* important bits at probe time to ensure sane operation.
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*
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* Since we don't support interrupts/events the threshold values are
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* not important. We also don't touch trim values.
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*/
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/* Reset ALS scaling bits */
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ret = regmap_write(data->regmap, MAX44000_REG_CFG_RX, MAX44000_REG_CFG_RX_DEFAULT);
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if (ret < 0) {
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dev_err(&client->dev, "failed to write default CFG_RX: %d\n", ret);
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return ret;
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}
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/* Reset CFG bits to ALS-only mode and no interrupts */
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reg = MAX44000_CFG_TRIM | MAX44000_CFG_MODE_ALS_GIR;
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ret = regmap_write(data->regmap, MAX44000_REG_CFG_MAIN, reg);
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if (ret < 0) {
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dev_err(&client->dev, "failed to write init config: %d\n", ret);
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return ret;
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}
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/* Read status at least once to clear any stale interrupt bits. */
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ret = regmap_read(data->regmap, MAX44000_REG_STATUS, ®);
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if (ret < 0) {
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dev_err(&client->dev, "failed to read init status: %d\n", ret);
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return ret;
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}
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return iio_device_register(indio_dev);
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}
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static int max44000_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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return 0;
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}
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static const struct i2c_device_id max44000_id[] = {
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{"max44000", 0},
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, max44000_id);
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#ifdef CONFIG_ACPI
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static const struct acpi_device_id max44000_acpi_match[] = {
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{"MAX44000", 0},
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{ }
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};
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MODULE_DEVICE_TABLE(acpi, max44000_acpi_match);
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#endif
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static struct i2c_driver max44000_driver = {
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.driver = {
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.name = MAX44000_DRV_NAME,
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.acpi_match_table = ACPI_PTR(max44000_acpi_match),
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},
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.probe = max44000_probe,
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.remove = max44000_remove,
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.id_table = max44000_id,
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};
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module_i2c_driver(max44000_driver);
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MODULE_AUTHOR("Crestez Dan Leonard <leonard.crestez@intel.com>");
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MODULE_DESCRIPTION("MAX44000 Ambient and Infrared Proximity Sensor");
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MODULE_LICENSE("GPL v2");
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