| // 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 (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 = { |
| .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"}, |
| {} |
| }; |
| MODULE_DEVICE_TABLE(of, cm3232_of_match); |
| |
| static struct i2c_driver cm3232_driver = { |
| .driver = { |
| .name = "cm3232", |
| .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"); |