diff options
Diffstat (limited to 'drivers/iio/light/cm3232.c')
| -rw-r--r-- | drivers/iio/light/cm3232.c | 403 |
1 files changed, 403 insertions, 0 deletions
diff --git a/drivers/iio/light/cm3232.c b/drivers/iio/light/cm3232.c new file mode 100644 index 00000000000..90e3519a91d --- /dev/null +++ b/drivers/iio/light/cm3232.c @@ -0,0 +1,403 @@ +/* + * 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}, + {} +}; + +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), + }, + .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"); |