| /* |
| * Copyright (C) 2013 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. |
| */ |
| |
| #include <linux/delay.h> |
| #include <linux/err.h> |
| #include <linux/i2c.h> |
| #include <linux/mutex.h> |
| #include <linux/module.h> |
| #include <linux/interrupt.h> |
| #include <linux/regulator/consumer.h> |
| #include <linux/iio/iio.h> |
| #include <linux/iio/sysfs.h> |
| #include <linux/iio/events.h> |
| #include <linux/init.h> |
| |
| /* Registers Address */ |
| #define CM32181_REG_ADDR_CMD 0x00 |
| #define CM32181_REG_ADDR_ALS 0x04 |
| #define CM32181_REG_ADDR_STATUS 0x06 |
| #define CM32181_REG_ADDR_ID 0x07 |
| |
| /* Number of Configurable Registers */ |
| #define CM32181_CONF_REG_NUM 0x01 |
| |
| /* CMD register */ |
| #define CM32181_CMD_ALS_ENABLE 0x00 |
| #define CM32181_CMD_ALS_DISABLE 0x01 |
| #define CM32181_CMD_ALS_INT_EN 0x02 |
| |
| #define CM32181_CMD_ALS_IT_SHIFT 6 |
| #define CM32181_CMD_ALS_IT_MASK (0x0F << CM32181_CMD_ALS_IT_SHIFT) |
| #define CM32181_CMD_ALS_IT_DEFAULT (0x00 << CM32181_CMD_ALS_IT_SHIFT) |
| |
| #define CM32181_CMD_ALS_SM_SHIFT 11 |
| #define CM32181_CMD_ALS_SM_MASK (0x03 << CM32181_CMD_ALS_SM_SHIFT) |
| #define CM32181_CMD_ALS_SM_DEFAULT (0x01 << CM32181_CMD_ALS_SM_SHIFT) |
| |
| #define CM32181_MLUX_PER_BIT 5 /* ALS_SM=01 IT=800ms */ |
| #define CM32181_MLUX_PER_BIT_BASE_IT 800000 /* Based on IT=800ms */ |
| #define CM32181_CALIBSCALE_DEFAULT 1000 |
| #define CM32181_CALIBSCALE_RESOLUTION 1000 |
| #define MLUX_PER_LUX 1000 |
| |
| static const u8 cm32181_reg[CM32181_CONF_REG_NUM] = { |
| CM32181_REG_ADDR_CMD, |
| }; |
| |
| static const int als_it_bits[] = {12, 8, 0, 1, 2, 3}; |
| static const int als_it_value[] = {25000, 50000, 100000, 200000, 400000, |
| 800000}; |
| |
| struct cm32181_chip { |
| struct i2c_client *client; |
| struct mutex lock; |
| u16 conf_regs[CM32181_CONF_REG_NUM]; |
| int calibscale; |
| }; |
| |
| /** |
| * cm32181_reg_init() - Initialize CM32181 registers |
| * @cm32181: pointer of struct cm32181. |
| * |
| * Initialize CM32181 ambient light sensor register to default values. |
| * |
| * Return: 0 for success; otherwise for error code. |
| */ |
| static int cm32181_reg_init(struct cm32181_chip *cm32181) |
| { |
| struct i2c_client *client = cm32181->client; |
| int i; |
| s32 ret; |
| |
| ret = i2c_smbus_read_word_data(client, CM32181_REG_ADDR_ID); |
| if (ret < 0) |
| return ret; |
| |
| /* check device ID */ |
| if ((ret & 0xFF) != 0x81) |
| return -ENODEV; |
| |
| /* Default Values */ |
| cm32181->conf_regs[CM32181_REG_ADDR_CMD] = CM32181_CMD_ALS_ENABLE | |
| CM32181_CMD_ALS_IT_DEFAULT | CM32181_CMD_ALS_SM_DEFAULT; |
| cm32181->calibscale = CM32181_CALIBSCALE_DEFAULT; |
| |
| /* Initialize registers*/ |
| for (i = 0; i < CM32181_CONF_REG_NUM; i++) { |
| ret = i2c_smbus_write_word_data(client, cm32181_reg[i], |
| cm32181->conf_regs[i]); |
| if (ret < 0) |
| return ret; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * cm32181_read_als_it() - Get sensor integration time (ms) |
| * @cm32181: pointer of struct cm32181 |
| * @val2: pointer of int to load the als_it value. |
| * |
| * Report the current integartion time by millisecond. |
| * |
| * Return: IIO_VAL_INT_PLUS_MICRO for success, otherwise -EINVAL. |
| */ |
| static int cm32181_read_als_it(struct cm32181_chip *cm32181, int *val2) |
| { |
| u16 als_it; |
| int i; |
| |
| als_it = cm32181->conf_regs[CM32181_REG_ADDR_CMD]; |
| als_it &= CM32181_CMD_ALS_IT_MASK; |
| als_it >>= CM32181_CMD_ALS_IT_SHIFT; |
| for (i = 0; i < ARRAY_SIZE(als_it_bits); i++) { |
| if (als_it == als_it_bits[i]) { |
| *val2 = als_it_value[i]; |
| return IIO_VAL_INT_PLUS_MICRO; |
| } |
| } |
| |
| return -EINVAL; |
| } |
| |
| /** |
| * cm32181_write_als_it() - Write sensor integration time |
| * @cm32181: pointer of struct cm32181. |
| * @val: integration time by millisecond. |
| * |
| * Convert integration time (ms) to sensor value. |
| * |
| * Return: i2c_smbus_write_word_data command return value. |
| */ |
| static int cm32181_write_als_it(struct cm32181_chip *cm32181, int val) |
| { |
| struct i2c_client *client = cm32181->client; |
| u16 als_it; |
| int ret, i, n; |
| |
| n = ARRAY_SIZE(als_it_value); |
| for (i = 0; i < n; i++) |
| if (val <= als_it_value[i]) |
| break; |
| if (i >= n) |
| i = n - 1; |
| |
| als_it = als_it_bits[i]; |
| als_it <<= CM32181_CMD_ALS_IT_SHIFT; |
| |
| mutex_lock(&cm32181->lock); |
| cm32181->conf_regs[CM32181_REG_ADDR_CMD] &= |
| ~CM32181_CMD_ALS_IT_MASK; |
| cm32181->conf_regs[CM32181_REG_ADDR_CMD] |= |
| als_it; |
| ret = i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD, |
| cm32181->conf_regs[CM32181_REG_ADDR_CMD]); |
| mutex_unlock(&cm32181->lock); |
| |
| return ret; |
| } |
| |
| /** |
| * cm32181_get_lux() - report current lux value |
| * @cm32181: pointer of struct cm32181. |
| * |
| * Convert sensor raw data to lux. It depends on integration |
| * time and claibscale variable. |
| * |
| * Return: Positive value is lux, otherwise is error code. |
| */ |
| static int cm32181_get_lux(struct cm32181_chip *cm32181) |
| { |
| struct i2c_client *client = cm32181->client; |
| int ret; |
| int als_it; |
| unsigned long lux; |
| |
| ret = cm32181_read_als_it(cm32181, &als_it); |
| if (ret < 0) |
| return -EINVAL; |
| |
| lux = CM32181_MLUX_PER_BIT; |
| lux *= CM32181_MLUX_PER_BIT_BASE_IT; |
| lux /= als_it; |
| |
| ret = i2c_smbus_read_word_data(client, CM32181_REG_ADDR_ALS); |
| if (ret < 0) |
| return ret; |
| |
| lux *= ret; |
| lux *= cm32181->calibscale; |
| lux /= CM32181_CALIBSCALE_RESOLUTION; |
| lux /= MLUX_PER_LUX; |
| |
| if (lux > 0xFFFF) |
| lux = 0xFFFF; |
| |
| return lux; |
| } |
| |
| static int cm32181_read_raw(struct iio_dev *indio_dev, |
| struct iio_chan_spec const *chan, |
| int *val, int *val2, long mask) |
| { |
| struct cm32181_chip *cm32181 = iio_priv(indio_dev); |
| int ret; |
| |
| switch (mask) { |
| case IIO_CHAN_INFO_PROCESSED: |
| ret = cm32181_get_lux(cm32181); |
| if (ret < 0) |
| return ret; |
| *val = ret; |
| return IIO_VAL_INT; |
| case IIO_CHAN_INFO_CALIBSCALE: |
| *val = cm32181->calibscale; |
| return IIO_VAL_INT; |
| case IIO_CHAN_INFO_INT_TIME: |
| *val = 0; |
| ret = cm32181_read_als_it(cm32181, val2); |
| return ret; |
| } |
| |
| return -EINVAL; |
| } |
| |
| static int cm32181_write_raw(struct iio_dev *indio_dev, |
| struct iio_chan_spec const *chan, |
| int val, int val2, long mask) |
| { |
| struct cm32181_chip *cm32181 = iio_priv(indio_dev); |
| int ret; |
| |
| switch (mask) { |
| case IIO_CHAN_INFO_CALIBSCALE: |
| cm32181->calibscale = val; |
| return val; |
| case IIO_CHAN_INFO_INT_TIME: |
| ret = cm32181_write_als_it(cm32181, val2); |
| return ret; |
| } |
| |
| return -EINVAL; |
| } |
| |
| /** |
| * cm32181_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 values by millisecond. |
| * |
| * Return: string length. |
| */ |
| static ssize_t cm32181_get_it_available(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| int i, n, len; |
| |
| n = ARRAY_SIZE(als_it_value); |
| for (i = 0, len = 0; i < n; i++) |
| len += sprintf(buf + len, "0.%06u ", als_it_value[i]); |
| return len + sprintf(buf + len, "\n"); |
| } |
| |
| static const struct iio_chan_spec cm32181_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, cm32181_get_it_available, NULL, 0); |
| |
| static struct attribute *cm32181_attributes[] = { |
| &iio_dev_attr_in_illuminance_integration_time_available.dev_attr.attr, |
| NULL, |
| }; |
| |
| static const struct attribute_group cm32181_attribute_group = { |
| .attrs = cm32181_attributes |
| }; |
| |
| static const struct iio_info cm32181_info = { |
| .driver_module = THIS_MODULE, |
| .read_raw = &cm32181_read_raw, |
| .write_raw = &cm32181_write_raw, |
| .attrs = &cm32181_attribute_group, |
| }; |
| |
| static int cm32181_probe(struct i2c_client *client, |
| const struct i2c_device_id *id) |
| { |
| struct cm32181_chip *cm32181; |
| struct iio_dev *indio_dev; |
| int ret; |
| |
| indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*cm32181)); |
| if (!indio_dev) { |
| dev_err(&client->dev, "devm_iio_device_alloc failed\n"); |
| return -ENOMEM; |
| } |
| |
| cm32181 = iio_priv(indio_dev); |
| i2c_set_clientdata(client, indio_dev); |
| cm32181->client = client; |
| |
| mutex_init(&cm32181->lock); |
| indio_dev->dev.parent = &client->dev; |
| indio_dev->channels = cm32181_channels; |
| indio_dev->num_channels = ARRAY_SIZE(cm32181_channels); |
| indio_dev->info = &cm32181_info; |
| indio_dev->name = id->name; |
| indio_dev->modes = INDIO_DIRECT_MODE; |
| |
| ret = cm32181_reg_init(cm32181); |
| if (ret) { |
| dev_err(&client->dev, |
| "%s: register init failed\n", |
| __func__); |
| return ret; |
| } |
| |
| ret = devm_iio_device_register(&client->dev, indio_dev); |
| if (ret) { |
| dev_err(&client->dev, |
| "%s: regist device failed\n", |
| __func__); |
| return ret; |
| } |
| |
| return 0; |
| } |
| |
| static const struct i2c_device_id cm32181_id[] = { |
| { "cm32181", 0 }, |
| { } |
| }; |
| |
| MODULE_DEVICE_TABLE(i2c, cm32181_id); |
| |
| static const struct of_device_id cm32181_of_match[] = { |
| { .compatible = "capella,cm32181" }, |
| { } |
| }; |
| |
| static struct i2c_driver cm32181_driver = { |
| .driver = { |
| .name = "cm32181", |
| .of_match_table = of_match_ptr(cm32181_of_match), |
| .owner = THIS_MODULE, |
| }, |
| .id_table = cm32181_id, |
| .probe = cm32181_probe, |
| }; |
| |
| module_i2c_driver(cm32181_driver); |
| |
| MODULE_AUTHOR("Kevin Tsai <ktsai@capellamicro.com>"); |
| MODULE_DESCRIPTION("CM32181 ambient light sensor driver"); |
| MODULE_LICENSE("GPL"); |