On Thu, Jan 1, 2015 at 2:10 AM, Kevin Tsai <ktsai@xxxxxxxxxxxxxxxx> 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.
This looks good to me. Few comments inline.
>
> Signed-off-by: Kevin Tsai <ktsai@xxxxxxxxxxxxxxxx>
> ---
> .../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 <ktsai@xxxxxxxxxxxxxxxx>
> +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@xxxxxxxxx>
> L: linux-wpan@xxxxxxxxxxxxxxx
> 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"
Better name this: "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"
> 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 <ktsai@xxxxxxxxxxxxxxxx>
> + *
> + * 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.
> + *
Usually, here is the place to mention the I2C slave address.
> + */
> +
> +#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);
You could directly return i2c_smbus_write_byte_data(..).
> + 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)
Wouldn't make more sense to also add val here?
> +{
> + 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]) {
.. then make, *val = 0.
> + *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;
Here you could just return cm3232_read_als_it(...)
> + }
> +
> + 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");
There is no need for this error message. devm_iio_device_alloc will print
an error message in case of failure.
> + 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;
Directly return iio_device_register()
> +}
> +
> +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},
No need for space before ".
> + { }
> +};
> +
> +MODULE_DEVICE_TABLE(i2c, cm3232_id);
> +
> +static const struct of_device_id cm3232_of_match[] = {
> + { .compatible = "capella,cm3232" },
Same here. No need for space before "."
> + { }
> +};
> +
> +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@xxxxxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("CM3232 ambient light sensor driver");
> +MODULE_LICENSE("GPL");
> --
> 1.8.3.1
>
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