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// SPDX-License-Identifier: GPL-2.0-only
/*
* CM3232 Ambient Light Sensor
*
* Copyright (C) 2014-2015 Capella Microsystems Inc.
* Author: Kevin Tsai <ktsai@capellamicro.com>
*
* IIO driver for CM3232 (7-bit I2C slave address 0x10).
*/
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/init.h>
/* Registers Address */
#define CM3232_REG_ADDR_CMD 0x00
#define CM3232_REG_ADDR_ALS 0x50
#define CM3232_REG_ADDR_ID 0x53
#define CM3232_CMD_ALS_DISABLE BIT(0)
#define CM3232_CMD_ALS_IT_SHIFT 2
#define CM3232_CMD_ALS_IT_MASK (BIT(2) | BIT(3) | BIT(4))
#define CM3232_CMD_ALS_IT_DEFAULT (0x01 << CM3232_CMD_ALS_IT_SHIFT)
#define CM3232_CMD_ALS_RESET BIT(6)
#define CM3232_CMD_DEFAULT CM3232_CMD_ALS_IT_DEFAULT
#define CM3232_HW_ID 0x32
#define CM3232_CALIBSCALE_DEFAULT 100000
#define CM3232_CALIBSCALE_RESOLUTION 100000
#define CM3232_MLUX_PER_LUX 1000
#define CM3232_MLUX_PER_BIT_DEFAULT 64
#define CM3232_MLUX_PER_BIT_BASE_IT 100000
static const struct {
int val;
int val2;
u8 it;
} cm3232_als_it_scales[] = {
{0, 100000, 0}, /* 0.100000 */
{0, 200000, 1}, /* 0.200000 */
{0, 400000, 2}, /* 0.400000 */
{0, 800000, 3}, /* 0.800000 */
{1, 600000, 4}, /* 1.600000 */
{3, 200000, 5}, /* 3.200000 */
};
struct cm3232_als_info {
u8 regs_cmd_default;
u8 hw_id;
int calibscale;
int mlux_per_bit;
int mlux_per_bit_base_it;
};
static struct cm3232_als_info cm3232_als_info_default = {
.regs_cmd_default = CM3232_CMD_DEFAULT,
.hw_id = CM3232_HW_ID,
.calibscale = CM3232_CALIBSCALE_DEFAULT,
.mlux_per_bit = CM3232_MLUX_PER_BIT_DEFAULT,
.mlux_per_bit_base_it = CM3232_MLUX_PER_BIT_BASE_IT,
};
struct cm3232_chip {
struct i2c_client *client;
struct cm3232_als_info *als_info;
u8 regs_cmd;
u16 regs_als;
};
/**
* cm3232_reg_init() - Initialize CM3232
* @chip: pointer of struct cm3232_chip.
*
* Check and initialize CM3232 ambient light sensor.
*
* Return: 0 for success; otherwise for error code.
*/
static int cm3232_reg_init(struct cm3232_chip *chip)
{
struct i2c_client *client = chip->client;
s32 ret;
chip->als_info = &cm3232_als_info_default;
/* Identify device */
ret = i2c_smbus_read_word_data(client, CM3232_REG_ADDR_ID);
if (ret < 0) {
dev_err(&chip->client->dev, "Error reading addr_id\n");
return ret;
}
if ((ret & 0xFF) != chip->als_info->hw_id)
return -ENODEV;
/* Disable and reset device */
chip->regs_cmd = CM3232_CMD_ALS_DISABLE | CM3232_CMD_ALS_RESET;
ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
chip->regs_cmd);
if (ret < 0) {
dev_err(&chip->client->dev, "Error writing reg_cmd\n");
return ret;
}
/* Register default value */
chip->regs_cmd = chip->als_info->regs_cmd_default;
/* Configure register */
ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
chip->regs_cmd);
if (ret < 0)
dev_err(&chip->client->dev, "Error writing reg_cmd\n");
return ret;
}
/**
* cm3232_read_als_it() - Get sensor integration time
* @chip: pointer of struct cm3232_chip
* @val: pointer of int to load the integration (sec).
* @val2: pointer of int to load the integration time (microsecond).
*
* Report the current integration time.
*
* Return: IIO_VAL_INT_PLUS_MICRO for success, otherwise -EINVAL.
*/
static int cm3232_read_als_it(struct cm3232_chip *chip, int *val, int *val2)
{
u16 als_it;
int i;
als_it = chip->regs_cmd;
als_it &= CM3232_CMD_ALS_IT_MASK;
als_it >>= CM3232_CMD_ALS_IT_SHIFT;
for (i = 0; i < ARRAY_SIZE(cm3232_als_it_scales); i++) {
if (als_it == cm3232_als_it_scales[i].it) {
*val = cm3232_als_it_scales[i].val;
*val2 = cm3232_als_it_scales[i].val2;
return IIO_VAL_INT_PLUS_MICRO;
}
}
return -EINVAL;
}
/**
* cm3232_write_als_it() - Write sensor integration time
* @chip: pointer of struct cm3232_chip.
* @val: integration time in second.
* @val2: integration time in microsecond.
*
* Convert integration time to sensor value.
*
* Return: i2c_smbus_write_byte_data command return value.
*/
static int cm3232_write_als_it(struct cm3232_chip *chip, int val, int val2)
{
struct i2c_client *client = chip->client;
u16 als_it, cmd;
int i;
s32 ret;
for (i = 0; i < ARRAY_SIZE(cm3232_als_it_scales); i++) {
if (val == cm3232_als_it_scales[i].val &&
val2 == cm3232_als_it_scales[i].val2) {
als_it = cm3232_als_it_scales[i].it;
als_it <<= CM3232_CMD_ALS_IT_SHIFT;
cmd = chip->regs_cmd & ~CM3232_CMD_ALS_IT_MASK;
cmd |= als_it;
ret = i2c_smbus_write_byte_data(client,
CM3232_REG_ADDR_CMD,
cmd);
if (ret < 0)
return ret;
chip->regs_cmd = cmd;
return 0;
}
}
return -EINVAL;
}
/**
* cm3232_get_lux() - report current lux value
* @chip: pointer of struct cm3232_chip.
*
* Convert sensor data to lux. It depends on integration
* time and calibscale variable.
*
* Return: Zero or positive value is lux, otherwise error code.
*/
static int cm3232_get_lux(struct cm3232_chip *chip)
{
struct i2c_client *client = chip->client;
struct cm3232_als_info *als_info = chip->als_info;
int ret;
int val, val2;
int als_it;
u64 lux;
/* Calculate mlux per bit based on als_it */
ret = cm3232_read_als_it(chip, &val, &val2);
if (ret < 0)
return -EINVAL;
als_it = val * 1000000 + val2;
lux = (__force u64)als_info->mlux_per_bit;
lux *= als_info->mlux_per_bit_base_it;
lux = div_u64(lux, als_it);
ret = i2c_smbus_read_word_data(client, CM3232_REG_ADDR_ALS);
if (ret < 0) {
dev_err(&client->dev, "Error reading reg_addr_als\n");
return ret;
}
chip->regs_als = (u16)ret;
lux *= chip->regs_als;
lux *= als_info->calibscale;
lux = div_u64(lux, CM3232_CALIBSCALE_RESOLUTION);
lux = div_u64(lux, CM3232_MLUX_PER_LUX);
if (lux > 0xFFFF)
lux = 0xFFFF;
return (int)lux;
}
static int cm3232_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct cm3232_chip *chip = iio_priv(indio_dev);
struct cm3232_als_info *als_info = chip->als_info;
int ret;
switch (mask) {
case IIO_CHAN_INFO_PROCESSED:
ret = cm3232_get_lux(chip);
if (ret < 0)
return ret;
*val = ret;
return IIO_VAL_INT;
case IIO_CHAN_INFO_CALIBSCALE:
*val = als_info->calibscale;
return IIO_VAL_INT;
case IIO_CHAN_INFO_INT_TIME:
return cm3232_read_als_it(chip, val, val2);
}
return -EINVAL;
}
static int cm3232_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
struct cm3232_chip *chip = iio_priv(indio_dev);
struct cm3232_als_info *als_info = chip->als_info;
switch (mask) {
case IIO_CHAN_INFO_CALIBSCALE:
als_info->calibscale = val;
return 0;
case IIO_CHAN_INFO_INT_TIME:
return cm3232_write_als_it(chip, val, val2);
}
return -EINVAL;
}
/**
* cm3232_get_it_available() - Get available ALS IT value
* @dev: pointer of struct device.
* @attr: pointer of struct device_attribute.
* @buf: pointer of return string buffer.
*
* Display the available integration time in second.
*
* Return: string length.
*/
static ssize_t cm3232_get_it_available(struct device *dev,
struct device_attribute *attr, char *buf)
{
int i, len;
for
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