iio: Added Capella cm3232 ambient light sensor driver.
authorKevin Tsai <ktsai@capellamicro.com>
Fri, 16 Jan 2015 01:41:04 +0000 (17:41 -0800)
committerJonathan Cameron <jic23@kernel.org>
Tue, 27 Jan 2015 18:49:48 +0000 (18:49 +0000)
CM3232 is an advanced ambient light sensor with I2C protocol interface.
The I2C slave address is internally hardwired as 0x10 (7-bit).  Writing
to configure register is byte mode, but reading ALS register requests to
use word mode for 16-bit resolution.

Signed-off-by: Kevin Tsai <ktsai@capellamicro.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Documentation/devicetree/bindings/i2c/trivial-devices.txt
MAINTAINERS
drivers/iio/light/Kconfig
drivers/iio/light/Makefile
drivers/iio/light/cm3232.c [new file with mode: 0644]

index 9f4e382..572a7c4 100644 (file)
@@ -34,6 +34,7 @@ atmel,24c512          i2c serial eeprom  (24cxx)
 atmel,24c1024          i2c serial eeprom  (24cxx)
 atmel,at97sc3204t      i2c trusted platform module (TPM)
 capella,cm32181                CM32181: Ambient Light Sensor
+capella,cm3232         CM3232: Ambient Light Sensor
 catalyst,24c32         i2c serial eeprom
 cirrus,cs42l51         Cirrus Logic CS42L51 audio codec
 dallas,ds1307          64 x 8, Serial, I2C Real-Time Clock
index 2fa3853..8d2d9a2 100644 (file)
@@ -2379,6 +2379,12 @@ F:       security/capability.c
 F:     security/commoncap.c
 F:     kernel/capability.c
 
+CAPELLA MICROSYSTEMS LIGHT SENSOR DRIVER
+M:     Kevin Tsai <ktsai@capellamicro.com>
+S:     Maintained
+F:     drivers/iio/light/cm*
+F:     Documentation/devicetree/bindings/i2c/trivial-devices.txt
+
 CC2520 IEEE-802.15.4 RADIO DRIVER
 M:     Varka Bhadram <varkabhadram@gmail.com>
 L:     linux-wpan@vger.kernel.org
index 5a3237b..ae68c64 100644 (file)
@@ -48,6 +48,17 @@ config CM32181
         To compile this driver as a module, choose M here:
         the module will be called cm32181.
 
+config CM3232
+       depends on I2C
+       tristate "CM3232 ambient light sensor"
+       help
+        Say Y here if you use cm3232.
+        This option enables ambient light sensor using
+        Capella Microsystems cm3232 device driver.
+
+        To compile this driver as a module, choose M here:
+        the module will be called cm3232.
+
 config CM36651
        depends on I2C
        tristate "CM36651 driver"
index 74656c1..b12a516 100644 (file)
@@ -7,6 +7,7 @@ obj-$(CONFIG_ADJD_S311)         += adjd_s311.o
 obj-$(CONFIG_AL3320A)          += al3320a.o
 obj-$(CONFIG_APDS9300)         += apds9300.o
 obj-$(CONFIG_CM32181)          += cm32181.o
+obj-$(CONFIG_CM3232)           += cm3232.o
 obj-$(CONFIG_CM36651)          += cm36651.o
 obj-$(CONFIG_GP2AP020A00F)     += gp2ap020a00f.o
 obj-$(CONFIG_HID_SENSOR_ALS)   += hid-sensor-als.o
diff --git a/drivers/iio/light/cm3232.c b/drivers/iio/light/cm3232.c
new file mode 100644 (file)
index 0000000..90e3519
--- /dev/null
@@ -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");