- 根目录:
- drivers
- iio
- light
- cm3232.c
/*
* CM3232 Ambient Light Sensor
*
* Copyright (C) 2014-2015 Capella Microsystems Inc.
* Author: Kevin Tsai <ktsai@capellamicro.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2, as published
* by the Free Software Foundation.
*
* 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 0;
}
/**
* 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 (i = 0, len = 0; i < ARRAY_SIZE(cm3232_als_it_scales); i++)
len += scnprintf(buf + len, PAGE_SIZE - len, "%u.%06u ",
cm3232_als_it_scales[i].val,
cm3232_als_it_scales[i].val2);
return len + scnprintf(buf + len, PAGE_SIZE - len, "\n");
}
static const struct iio_chan_spec cm3232_channels[] = {
{
.type = IIO_LIGHT,
.info_mask_separate =
BIT(IIO_CHAN_INFO_PROCESSED) |
BIT(IIO_CHAN_INFO_CALIBSCALE) |
BIT(IIO_CHAN_INFO_INT_TIME),
}
};
static IIO_DEVICE_ATTR(in_illuminance_integration_time_available,
S_IRUGO, cm3232_get_it_available, NULL, 0);
static struct attribute *cm3232_attributes[] = {
&iio_dev_attr_in_illuminance_integration_time_available.dev_attr.attr,
NULL,
};
static const struct attribute_group cm3232_attribute_group = {
.attrs = cm3232_attributes
};
static const struct iio_info cm3232_info = {
.driver_module = THIS_MODULE,
.read_raw = &cm3232_read_raw,
.write_raw = &cm3232_write_raw,
.attrs = &cm3232_attribute_group,
};
static int cm3232_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct cm3232_chip *chip;
struct iio_dev *indio_dev;
int ret;
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
if (!indio_dev)
return -ENOMEM;
chip = iio_priv(indio_dev);
i2c_set_clientdata(client, indio_dev);
chip->client = client;
indio_dev->dev.parent = &client->dev;
indio_dev->channels = cm3232_channels;
indio_dev->num_channels = ARRAY_SIZE(cm3232_channels);
indio_dev->info = &cm3232_info;
indio_dev->name = id->name;
indio_dev->modes = INDIO_DIRECT_MODE;
ret = cm3232_reg_init(chip);
if (ret) {
dev_err(&client->dev,
"%s: register init failed\n",
__func__);
return ret;
}
return iio_device_register(indio_dev);
}
static int cm3232_remove(struct i2c_client *client)
{
struct iio_dev *indio_dev = i2c_get_clientdata(client);
i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
CM3232_CMD_ALS_DISABLE);
iio_device_unregister(indio_dev);
return 0;
}
static const struct i2c_device_id cm3232_id[] = {
{"cm3232", 0},
{}
};
#ifdef CONFIG_PM_SLEEP
static int cm3232_suspend(struct device *dev)
{
struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
struct cm3232_chip *chip = iio_priv(indio_dev);
struct i2c_client *client = chip->client;
int ret;
chip->regs_cmd |= CM3232_CMD_ALS_DISABLE;
ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
chip->regs_cmd);
return ret;
}
static int cm3232_resume(struct device *dev)
{
struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
struct cm3232_chip *chip = iio_priv(indio_dev);
struct i2c_client *client = chip->client;
int ret;
chip->regs_cmd &= ~CM3232_CMD_ALS_DISABLE;
ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
chip->regs_cmd | CM3232_CMD_ALS_RESET);
return ret;
}
static const struct dev_pm_ops cm3232_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(cm3232_suspend, cm3232_resume)};
#endif
MODULE_DEVICE_TABLE(i2c, cm3232_id);
static const struct of_device_id cm3232_of_match[] = {
{.compatible = "capella,cm3232"},
{}
};
static struct i2c_driver cm3232_driver = {
.driver = {
.name = "cm3232",
.owner = THIS_MODULE,
.of_match_table = of_match_ptr(cm3232_of_match),
#ifdef CONFIG_PM_SLEEP
.pm = &cm3232_pm_ops,
#endif
},
.id_table = cm3232_id,
.probe = cm3232_probe,
.remove = cm3232_remove,
};
module_i2c_driver(cm3232_driver);
MODULE_AUTHOR("Kevin Tsai <ktsai@capellamicro.com>");
MODULE_DESCRIPTION("CM3232 ambient light sensor driver");
MODULE_LICENSE("GPL");