436 lines
10 KiB
C
436 lines
10 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* CM3232 Ambient Light Sensor
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*
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* Copyright (C) 2014-2015 Capella Microsystems Inc.
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* Author: Kevin Tsai <ktsai@capellamicro.com>
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*
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* IIO driver for CM3232 (7-bit I2C slave address 0x10).
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*/
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#include <linux/i2c.h>
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#include <linux/module.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/init.h>
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/* Registers Address */
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#define CM3232_REG_ADDR_CMD 0x00
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#define CM3232_REG_ADDR_ALS 0x50
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#define CM3232_REG_ADDR_ID 0x53
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#define CM3232_CMD_ALS_DISABLE BIT(0)
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#define CM3232_CMD_ALS_IT_SHIFT 2
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#define CM3232_CMD_ALS_IT_MASK (BIT(2) | BIT(3) | BIT(4))
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#define CM3232_CMD_ALS_IT_DEFAULT (0x01 << CM3232_CMD_ALS_IT_SHIFT)
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#define CM3232_CMD_ALS_RESET BIT(6)
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#define CM3232_CMD_DEFAULT CM3232_CMD_ALS_IT_DEFAULT
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#define CM3232_HW_ID 0x32
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#define CM3232_CALIBSCALE_DEFAULT 100000
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#define CM3232_CALIBSCALE_RESOLUTION 100000
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#define CM3232_MLUX_PER_LUX 1000
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#define CM3232_MLUX_PER_BIT_DEFAULT 64
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#define CM3232_MLUX_PER_BIT_BASE_IT 100000
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static const struct {
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int val;
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int val2;
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u8 it;
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} cm3232_als_it_scales[] = {
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{0, 100000, 0}, /* 0.100000 */
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{0, 200000, 1}, /* 0.200000 */
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{0, 400000, 2}, /* 0.400000 */
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{0, 800000, 3}, /* 0.800000 */
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{1, 600000, 4}, /* 1.600000 */
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{3, 200000, 5}, /* 3.200000 */
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};
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struct cm3232_als_info {
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u8 regs_cmd_default;
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u8 hw_id;
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int calibscale;
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int mlux_per_bit;
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int mlux_per_bit_base_it;
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};
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static struct cm3232_als_info cm3232_als_info_default = {
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.regs_cmd_default = CM3232_CMD_DEFAULT,
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.hw_id = CM3232_HW_ID,
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.calibscale = CM3232_CALIBSCALE_DEFAULT,
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.mlux_per_bit = CM3232_MLUX_PER_BIT_DEFAULT,
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.mlux_per_bit_base_it = CM3232_MLUX_PER_BIT_BASE_IT,
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};
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struct cm3232_chip {
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struct i2c_client *client;
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struct cm3232_als_info *als_info;
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u8 regs_cmd;
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u16 regs_als;
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};
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/**
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* cm3232_reg_init() - Initialize CM3232
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* @chip: pointer of struct cm3232_chip.
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*
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* Check and initialize CM3232 ambient light sensor.
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*
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* Return: 0 for success; otherwise for error code.
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*/
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static int cm3232_reg_init(struct cm3232_chip *chip)
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{
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struct i2c_client *client = chip->client;
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s32 ret;
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chip->als_info = &cm3232_als_info_default;
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/* Identify device */
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ret = i2c_smbus_read_word_data(client, CM3232_REG_ADDR_ID);
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if (ret < 0) {
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dev_err(&chip->client->dev, "Error reading addr_id\n");
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return ret;
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}
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if ((ret & 0xFF) != chip->als_info->hw_id)
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return -ENODEV;
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/* Disable and reset device */
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chip->regs_cmd = CM3232_CMD_ALS_DISABLE | CM3232_CMD_ALS_RESET;
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ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
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chip->regs_cmd);
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if (ret < 0) {
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dev_err(&chip->client->dev, "Error writing reg_cmd\n");
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return ret;
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}
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/* Register default value */
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chip->regs_cmd = chip->als_info->regs_cmd_default;
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/* Configure register */
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ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
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chip->regs_cmd);
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if (ret < 0)
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dev_err(&chip->client->dev, "Error writing reg_cmd\n");
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return ret;
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}
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/**
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* cm3232_read_als_it() - Get sensor integration time
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* @chip: pointer of struct cm3232_chip
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* @val: pointer of int to load the integration (sec).
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* @val2: pointer of int to load the integration time (microsecond).
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*
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* Report the current integration time.
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*
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* Return: IIO_VAL_INT_PLUS_MICRO for success, otherwise -EINVAL.
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*/
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static int cm3232_read_als_it(struct cm3232_chip *chip, int *val, int *val2)
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{
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u16 als_it;
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int i;
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als_it = chip->regs_cmd;
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als_it &= CM3232_CMD_ALS_IT_MASK;
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als_it >>= CM3232_CMD_ALS_IT_SHIFT;
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for (i = 0; i < ARRAY_SIZE(cm3232_als_it_scales); i++) {
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if (als_it == cm3232_als_it_scales[i].it) {
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*val = cm3232_als_it_scales[i].val;
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*val2 = cm3232_als_it_scales[i].val2;
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return IIO_VAL_INT_PLUS_MICRO;
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}
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}
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return -EINVAL;
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}
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/**
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* cm3232_write_als_it() - Write sensor integration time
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* @chip: pointer of struct cm3232_chip.
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* @val: integration time in second.
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* @val2: integration time in microsecond.
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*
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* Convert integration time to sensor value.
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*
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* Return: i2c_smbus_write_byte_data command return value.
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*/
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static int cm3232_write_als_it(struct cm3232_chip *chip, int val, int val2)
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{
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struct i2c_client *client = chip->client;
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u16 als_it, cmd;
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int i;
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s32 ret;
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for (i = 0; i < ARRAY_SIZE(cm3232_als_it_scales); i++) {
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if (val == cm3232_als_it_scales[i].val &&
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val2 == cm3232_als_it_scales[i].val2) {
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als_it = cm3232_als_it_scales[i].it;
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als_it <<= CM3232_CMD_ALS_IT_SHIFT;
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cmd = chip->regs_cmd & ~CM3232_CMD_ALS_IT_MASK;
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cmd |= als_it;
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ret = i2c_smbus_write_byte_data(client,
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CM3232_REG_ADDR_CMD,
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cmd);
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if (ret < 0)
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return ret;
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chip->regs_cmd = cmd;
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return 0;
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}
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}
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return -EINVAL;
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}
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/**
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* cm3232_get_lux() - report current lux value
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* @chip: pointer of struct cm3232_chip.
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*
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* Convert sensor data to lux. It depends on integration
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* time and calibscale variable.
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*
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* Return: Zero or positive value is lux, otherwise error code.
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*/
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static int cm3232_get_lux(struct cm3232_chip *chip)
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{
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struct i2c_client *client = chip->client;
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struct cm3232_als_info *als_info = chip->als_info;
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int ret;
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int val, val2;
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int als_it;
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u64 lux;
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/* Calculate mlux per bit based on als_it */
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ret = cm3232_read_als_it(chip, &val, &val2);
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if (ret < 0)
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return -EINVAL;
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als_it = val * 1000000 + val2;
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lux = (__force u64)als_info->mlux_per_bit;
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lux *= als_info->mlux_per_bit_base_it;
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lux = div_u64(lux, als_it);
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ret = i2c_smbus_read_word_data(client, CM3232_REG_ADDR_ALS);
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if (ret < 0) {
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dev_err(&client->dev, "Error reading reg_addr_als\n");
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return ret;
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}
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chip->regs_als = (u16)ret;
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lux *= chip->regs_als;
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lux *= als_info->calibscale;
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lux = div_u64(lux, CM3232_CALIBSCALE_RESOLUTION);
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lux = div_u64(lux, CM3232_MLUX_PER_LUX);
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if (lux > 0xFFFF)
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lux = 0xFFFF;
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return (int)lux;
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}
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static int cm3232_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 cm3232_chip *chip = iio_priv(indio_dev);
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struct cm3232_als_info *als_info = chip->als_info;
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int ret;
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switch (mask) {
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case IIO_CHAN_INFO_PROCESSED:
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ret = cm3232_get_lux(chip);
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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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case IIO_CHAN_INFO_CALIBSCALE:
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*val = als_info->calibscale;
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return IIO_VAL_INT;
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case IIO_CHAN_INFO_INT_TIME:
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return cm3232_read_als_it(chip, val, val2);
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}
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return -EINVAL;
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}
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static int cm3232_write_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 cm3232_chip *chip = iio_priv(indio_dev);
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struct cm3232_als_info *als_info = chip->als_info;
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switch (mask) {
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case IIO_CHAN_INFO_CALIBSCALE:
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als_info->calibscale = val;
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return 0;
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case IIO_CHAN_INFO_INT_TIME:
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return cm3232_write_als_it(chip, val, val2);
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}
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return -EINVAL;
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}
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/**
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* cm3232_get_it_available() - Get available ALS IT value
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* @dev: pointer of struct device.
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* @attr: pointer of struct device_attribute.
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* @buf: pointer of return string buffer.
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*
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* Display the available integration time in second.
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*
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* Return: string length.
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*/
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static ssize_t cm3232_get_it_available(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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int i, len;
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for (i = 0, len = 0; i < ARRAY_SIZE(cm3232_als_it_scales); i++)
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len += scnprintf(buf + len, PAGE_SIZE - len, "%u.%06u ",
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cm3232_als_it_scales[i].val,
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cm3232_als_it_scales[i].val2);
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return len + scnprintf(buf + len, PAGE_SIZE - len, "\n");
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}
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static const struct iio_chan_spec cm3232_channels[] = {
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{
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.type = IIO_LIGHT,
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.info_mask_separate =
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BIT(IIO_CHAN_INFO_PROCESSED) |
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BIT(IIO_CHAN_INFO_CALIBSCALE) |
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BIT(IIO_CHAN_INFO_INT_TIME),
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}
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};
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static IIO_DEVICE_ATTR(in_illuminance_integration_time_available,
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S_IRUGO, cm3232_get_it_available, NULL, 0);
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static struct attribute *cm3232_attributes[] = {
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&iio_dev_attr_in_illuminance_integration_time_available.dev_attr.attr,
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NULL,
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};
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static const struct attribute_group cm3232_attribute_group = {
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.attrs = cm3232_attributes
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};
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static const struct iio_info cm3232_info = {
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.read_raw = &cm3232_read_raw,
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.write_raw = &cm3232_write_raw,
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.attrs = &cm3232_attribute_group,
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};
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static int cm3232_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct cm3232_chip *chip;
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struct iio_dev *indio_dev;
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int ret;
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indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
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if (!indio_dev)
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return -ENOMEM;
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chip = iio_priv(indio_dev);
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i2c_set_clientdata(client, indio_dev);
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chip->client = client;
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indio_dev->dev.parent = &client->dev;
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indio_dev->channels = cm3232_channels;
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indio_dev->num_channels = ARRAY_SIZE(cm3232_channels);
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indio_dev->info = &cm3232_info;
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indio_dev->name = id->name;
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indio_dev->modes = INDIO_DIRECT_MODE;
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ret = cm3232_reg_init(chip);
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if (ret) {
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dev_err(&client->dev,
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"%s: register init failed\n",
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__func__);
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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 cm3232_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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i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
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CM3232_CMD_ALS_DISABLE);
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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 cm3232_id[] = {
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{"cm3232", 0},
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{}
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};
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#ifdef CONFIG_PM_SLEEP
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static int cm3232_suspend(struct device *dev)
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{
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struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
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struct cm3232_chip *chip = iio_priv(indio_dev);
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struct i2c_client *client = chip->client;
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int ret;
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chip->regs_cmd |= CM3232_CMD_ALS_DISABLE;
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ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
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chip->regs_cmd);
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return ret;
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}
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static int cm3232_resume(struct device *dev)
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{
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struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
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struct cm3232_chip *chip = iio_priv(indio_dev);
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struct i2c_client *client = chip->client;
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int ret;
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chip->regs_cmd &= ~CM3232_CMD_ALS_DISABLE;
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ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
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chip->regs_cmd | CM3232_CMD_ALS_RESET);
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return ret;
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}
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static const struct dev_pm_ops cm3232_pm_ops = {
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SET_SYSTEM_SLEEP_PM_OPS(cm3232_suspend, cm3232_resume)};
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#endif
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MODULE_DEVICE_TABLE(i2c, cm3232_id);
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static const struct of_device_id cm3232_of_match[] = {
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{.compatible = "capella,cm3232"},
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{}
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};
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MODULE_DEVICE_TABLE(of, cm3232_of_match);
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static struct i2c_driver cm3232_driver = {
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.driver = {
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.name = "cm3232",
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.of_match_table = of_match_ptr(cm3232_of_match),
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#ifdef CONFIG_PM_SLEEP
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.pm = &cm3232_pm_ops,
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#endif
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},
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.id_table = cm3232_id,
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.probe = cm3232_probe,
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.remove = cm3232_remove,
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};
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module_i2c_driver(cm3232_driver);
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MODULE_AUTHOR("Kevin Tsai <ktsai@capellamicro.com>");
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MODULE_DESCRIPTION("CM3232 ambient light sensor driver");
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MODULE_LICENSE("GPL");
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