--- /dev/null
+/*
+ * 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");
projects / platform / kernel / linux-starfive.git / commitdiff