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 <[email protected]>
---
.../devicetree/bindings/i2c/trivial-devices.txt | 1 +
MAINTAINERS | 6 +
drivers/iio/light/Kconfig | 11 +
drivers/iio/light/Makefile | 1 +
drivers/iio/light/cm3232.c | 403 +++++++++++++++++++++
5 files changed, 422 insertions(+)
create mode 100644 drivers/iio/light/cm3232.c
diff --git a/Documentation/devicetree/bindings/i2c/trivial-devices.txt b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
index 9f4e382..572a7c4 100644
--- a/Documentation/devicetree/bindings/i2c/trivial-devices.txt
+++ b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
@@ -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
diff --git a/MAINTAINERS b/MAINTAINERS
index ddb9ac8..06a613a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2378,6 +2378,12 @@ F: security/capability.c
F: security/commoncap.c
F: kernel/capability.c
+CAPELLA MICROSYSTEMS LIGHT SENSOR DRIVER
+M: Kevin Tsai <[email protected]>
+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 <[email protected]>
L: [email protected]
diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
index 5bea821..d2318e2 100644
--- a/drivers/iio/light/Kconfig
+++ b/drivers/iio/light/Kconfig
@@ -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 driver"
+ 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"
diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
index 47877a3..f2c8d55 100644
--- a/drivers/iio/light/Makefile
+++ b/drivers/iio/light/Makefile
@@ -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
index 0000000..fd98eeb
--- /dev/null
+++ b/drivers/iio/light/cm3232.c
@@ -0,0 +1,403 @@
+/*
+ * Copyright (C) 2014 Capella Microsystems Inc.
+ * Author: Kevin Tsai <[email protected]>
+ *
+ * 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 CM3232_REG_ADDR_CMD 0x00
+#define CM3232_REG_ADDR_ALS 0x50
+#define CM3232_REG_ADDR_ID 0x53
+
+/* CMD register */
+#define CM3232_CMD_ALS_DISABLE BIT(0)
+#define CM3232_CMD_ALS_HS BIT(1)
+
+#define CM3232_CMD_ALS_IT_SHIFT 2
+#define CM3232_CMD_ALS_IT_MASK (0x07 << CM3232_CMD_ALS_IT_SHIFT)
+#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_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 int CM3232_als_it_bits[] = { 0, 1, 2, 3, 4, 5};
+static const int CM3232_als_it_values[] = {
+ 100000, 200000, 400000, 800000, 1600000, 3200000};
+
+struct cm3232_als_info {
+ u32 id;
+ int calibscale;
+ int mlux_per_bit;
+ int mlux_per_bit_base_it;
+ const int *als_it_bits;
+ const int *als_it_values;
+ const int num_als_it;
+ int als_raw;
+};
+
+static struct cm3232_als_info cm3232_als_info_default = {
+ .id = 3232,
+ .calibscale = CM3232_CALIBSCALE_DEFAULT,
+ .mlux_per_bit = CM3232_MLUX_PER_BIT_DEFAULT,
+ .mlux_per_bit_base_it = CM3232_MLUX_PER_BIT_BASE_IT,
+ .als_it_bits = CM3232_als_it_bits,
+ .als_it_values = CM3232_als_it_values,
+ .num_als_it = ARRAY_SIZE(CM3232_als_it_bits),
+};
+
+struct cm3232_chip {
+ struct i2c_client *client;
+ struct mutex lock;
+ struct cm3232_als_info *als_info;
+ u8 regs_cmd;
+};
+
+static int cm3232_get_lux(struct cm3232_chip *chip);
+static int cm3232_read_als_it(struct cm3232_chip *chip, int *val2);
+
+/**
+ * cm3232_reg_init() - Initialize CM3232 registers
+ * @chip: pointer of struct cm3232.
+ *
+ * Initialize CM3232 ambient light sensor register to default values.
+ *
+ Return: 0 for success; otherwise for error code.
+ */
+static int cm3232_reg_init(struct cm3232_chip *chip)
+{
+ struct i2c_client *client = chip->client;
+ struct cm3232_als_info *als_info;
+ s32 ret;
+
+ /* Identify device */
+ ret = i2c_smbus_read_word_data(client, CM3232_REG_ADDR_ID);
+ if (ret < 0)
+ return ret;
+ if ((ret & 0xFF) != 0x32)
+ 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)
+ return ret;
+
+ /* Initialization */
+ als_info = chip->als_info = &cm3232_als_info_default;
+ chip->regs_cmd = CM3232_CMD_DEFAULT;
+
+ /* Configure register */
+ ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
+ chip->regs_cmd);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+/**
+ * cm3232_read_als_it() - Get sensor integration time (ms)
+ * @chip: pointer of struct cm3232
+ * @val2: pointer of int to load the als_it value.
+ *
+ * Report the current integration time in milliseconds.
+ *
+ * Return: IIO_VAL_INT_PLUS_MICRO for success, otherwise -EINVAL.
+ */
+static int cm3232_read_als_it(struct cm3232_chip *chip, int *val2)
+{
+ struct cm3232_als_info *als_info = chip->als_info;
+ 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 < als_info->num_als_it; i++) {
+ if (als_it == als_info->als_it_bits[i]) {
+ *val2 = als_info->als_it_values[i];
+ return IIO_VAL_INT_PLUS_MICRO;
+ }
+ }
+
+ return -EINVAL;
+}
+
+/**
+ * cm3232_write_als_it() - Write sensor integration time
+ * @chip: pointer of struct cm3232.
+ * @val: integration time in milliseconds.
+ *
+ * Convert integration time (ms) to sensor value.
+ *
+ * Return: i2c_smbus_write_word_data command return value.
+ */
+static int cm3232_write_als_it(struct cm3232_chip *chip, int val)
+{
+ struct i2c_client *client = chip->client;
+ struct cm3232_als_info *als_info = chip->als_info;
+ u16 als_it;
+ int ret, i;
+
+ for (i = 0; i < als_info->num_als_it; i++)
+ if (val <= als_info->als_it_values[i])
+ break;
+ if (i >= als_info->num_als_it)
+ i = als_info->num_als_it - 1;
+
+ als_it = als_info->als_it_bits[i];
+ als_it <<= CM3232_CMD_ALS_IT_SHIFT;
+
+ mutex_lock(&chip->lock);
+ chip->regs_cmd &= ~CM3232_CMD_ALS_IT_MASK;
+ chip->regs_cmd |= als_it;
+ ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
+ chip->regs_cmd);
+ mutex_unlock(&chip->lock);
+
+ return ret;
+}
+
+/**
+ * cm3232_get_lux() - report current lux value
+ * @chip: pointer of struct cm3232.
+ *
+ * Convert sensor raw data to lux. It depends on integration
+ * time and calibscale variable.
+ *
+ * Return: Positive value is lux, otherwise is 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 als_it;
+ u64 tmp;
+
+ /* Calculate mlux per bit based on als_it */
+ ret = cm3232_read_als_it(chip, &als_it);
+ if (ret < 0)
+ return -EINVAL;
+ tmp = (__force u64)als_info->mlux_per_bit;
+ tmp *= als_info->mlux_per_bit_base_it;
+ tmp = div_u64 (tmp, als_it);
+
+ /* Get als_raw */
+ als_info->als_raw = i2c_smbus_read_word_data(
+ client,
+ CM3232_REG_ADDR_ALS);
+ if (als_info->als_raw < 0)
+ return als_info->als_raw;
+
+ tmp *= als_info->als_raw;
+ tmp *= als_info->calibscale;
+ tmp = div_u64(tmp, CM3232_CALIBSCALE_RESOLUTION);
+ tmp = div_u64(tmp, CM3232_MLUX_PER_LUX);
+
+ if (tmp > 0xFFFF)
+ tmp = 0xFFFF;
+
+ return (int)tmp;
+}
+
+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:
+ *val = 0;
+ ret = cm3232_read_als_it(chip, val2);
+ return ret;
+ }
+
+ 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;
+ long ms;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_CALIBSCALE:
+ als_info->calibscale = val;
+ return val;
+ case IIO_CHAN_INFO_INT_TIME:
+ ms = val * 1000000 + val2;
+ return cm3232_write_als_it(chip, (int)ms);
+ }
+
+ 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 milliseconds.
+ *
+ * Return: string length.
+ */
+static ssize_t cm3232_get_it_available(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct cm3232_chip *chip = iio_priv(dev_to_iio_dev(dev));
+ struct cm3232_als_info *als_info = chip->als_info;
+ int i, len;
+
+ for (i = 0, len = 0; i < als_info->num_als_it; i++)
+ len += scnprintf(buf + len, PAGE_SIZE - len, "%u.%06u ",
+ als_info->als_it_values[i]/1000000,
+ als_info->als_it_values[i]%1000000);
+ 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) {
+ dev_err(&client->dev, "devm_iio_device_alloc failed\n");
+ return -ENOMEM;
+ }
+
+ chip = iio_priv(indio_dev);
+ i2c_set_clientdata(client, indio_dev);
+ chip->client = client;
+
+ mutex_init(&chip->lock);
+ indio_dev->dev.parent = &client->dev;
+ indio_dev->channels = cm3232_channels;
+ indio_dev->num_channels = ARRAY_SIZE(cm3232_channels);
+ indio_dev->info = &cm3232_info;
+ if (id && id->name)
+ indio_dev->name = id->name;
+ else
+ indio_dev->name = (char *)dev_name(&client->dev);
+ 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;
+ }
+
+ ret = iio_device_register(indio_dev);
+ return 0;
+}
+
+static int cm3232_remove(struct i2c_client *client)
+{
+ struct iio_dev *indio_dev = i2c_get_clientdata(client);
+
+ 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 <[email protected]>");
+MODULE_DESCRIPTION("CM3232 ambient light sensor driver");
+MODULE_LICENSE("GPL");
--
1.8.3.1
Kevin,
On Wed, Dec 31, 2014 at 04:10:30PM -0800, Kevin Tsai wrote:
> 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 <[email protected]>
> ---
> .../devicetree/bindings/i2c/trivial-devices.txt | 1 +
> MAINTAINERS | 6 +
> drivers/iio/light/Kconfig | 11 +
[...]
> +static int cm3232_get_lux(struct cm3232_chip *chip);
> +static int cm3232_read_als_it(struct cm3232_chip *chip, int *val2);
> +
> +/**
> + * cm3232_reg_init() - Initialize CM3232 registers
> + * @chip: pointer of struct cm3232.
> + *
> + * Initialize CM3232 ambient light sensor register to default values.
> + *
> + Return: 0 for success; otherwise for error code.
Is a '*' missing?
> + */
> +static int cm3232_reg_init(struct cm3232_chip *chip)
> +{
> + struct i2c_client *client = chip->client;
> + struct cm3232_als_info *als_info;
> + s32 ret;
> +
> + /* Identify device */
[...]
> +
> + /* Calculate mlux per bit based on als_it */
> + ret = cm3232_read_als_it(chip, &als_it);
> + if (ret < 0)
> + return -EINVAL;
> + tmp = (__force u64)als_info->mlux_per_bit;
> + tmp *= als_info->mlux_per_bit_base_it;
> + tmp = div_u64 (tmp, als_it);
^
no space after function
> +
> + /* Get als_raw */
> + als_info->als_raw = i2c_smbus_read_word_data(
> + client,
> + CM3232_REG_ADDR_ALS);
> + if (als_info->als_raw < 0)
> + return als_info->als_raw;
> +
> + tmp *= als_info->als_raw;
> + tmp *= als_info->calibscale;
> + tmp = div_u64(tmp, CM3232_CALIBSCALE_RESOLUTION);
> + tmp = div_u64(tmp, CM3232_MLUX_PER_LUX);
[...]
It builds clean and there are no checkpatch or sparse errors.
Overall it looks good.
--
- Jeremiah Mahler