On 12/18/13 23:10, Kevin Tsai wrote:
> Add Capella Microsystem CM32181 Ambient Light Sensor IIO driver.
> This driver will convert raw data to lux value under open-air
> condition. Change the calibscale based on the cover material.
>
> Signed-off-by: Kevin Tsai <ktsai@xxxxxxxxxxxxxxxx>
Hi Kevin,
The device tree binding still needs documenting - probably in
Documentation/devicetree/bindings/i2c/trivial-devices.txt
That binding needs to be sent to devicetree@xxxxxxxxxxxxxxx.
The easiest option is probably going to be to do a v3 of this
patch with that included and send it to both linux-iio and devicetree
mailing lists.
There are a few more comments inline. Mainly little things like putting
function documentation into kernel-doc style and slight tweaks to code
ordering / error paths that make things a little bit cleaner.
Probably just a few minutes work to be ready to go.
Jonathan
> ---
> drivers/iio/light/Kconfig | 11 ++
> drivers/iio/light/Makefile | 1 +
> drivers/iio/light/cm32181.c | 354 ++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 366 insertions(+)
> create mode 100644 drivers/iio/light/cm32181.c
>
> diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
> index a022f27..d12b2a0 100644
> --- a/drivers/iio/light/Kconfig
> +++ b/drivers/iio/light/Kconfig
> @@ -27,6 +27,17 @@ config APDS9300
> To compile this driver as a module, choose M here: the
> module will be called apds9300.
>
> +config CM32181
> + depends on I2C
> + tristate "CM32181 driver"
> + help
> + Say Y here if you use cm32181.
> + This option enables ambient light sensor using
> + Capella cm32181 device driver.
> +
> + To compile this driver as a module, choose M here:
> + the module will be called cm32181.
> +
> config CM36651
> depends on I2C
> tristate "CM36651 driver"
> diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
> index daa327f..60e35ac 100644
> --- a/drivers/iio/light/Makefile
> +++ b/drivers/iio/light/Makefile
> @@ -5,6 +5,7 @@
> # When adding new entries keep the list in alphabetical order
> obj-$(CONFIG_ADJD_S311) += adjd_s311.o
> obj-$(CONFIG_APDS9300) += apds9300.o
> +obj-$(CONFIG_CM32181) += cm32181.o
> obj-$(CONFIG_CM36651) += cm36651.o
> obj-$(CONFIG_GP2AP020A00F) += gp2ap020a00f.o
> obj-$(CONFIG_HID_SENSOR_ALS) += hid-sensor-als.o
> diff --git a/drivers/iio/light/cm32181.c b/drivers/iio/light/cm32181.c
> new file mode 100644
> index 0000000..305789b
> --- /dev/null
> +++ b/drivers/iio/light/cm32181.c
> @@ -0,0 +1,354 @@
> +/*
> + * Copyright (C) 2013 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.
> + */
> +
> +#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_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 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;
> +};
> +
> +static int cm32181_reg_init(struct cm32181_chip *cm32181)
> +{
> + struct i2c_client *client = cm32181->client;
> + int i;
> + s32 ret;
> +
> + cm32181->conf_regs[CM32181_REG_ADDR_CMD] = CM32181_CMD_ALS_ENABLE |
> + CM32181_CMD_ALS_IT_DEFAULT | CM32181_CMD_ALS_SM_DEFAULT;
> +
> + 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;
> + }
> +
> + cm32181->calibscale = 1000;
> +
> + return 0;
> +}
> +
> +/*
> + * Get sensor integration time (ms).
> + * Return: IIO_VAL_INT for success, otherwise -EINVAL.
> + */
> +static int cm32181_read_als_it(struct cm32181_chip *cm32181, int *val)
> +{
> + 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 < sizeof(als_it_bits)/sizeof(als_it_bits[0]); i++) {
> + if (als_it == als_it_bits[i]) {
> + *val = als_it_value[i];
> + if (*val == 0)
> + return -EINVAL;
> + return IIO_VAL_INT;
> + }
> + }
> +
> + return -EINVAL;
> +}
> +
> +/*
> + * 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 = sizeof(als_it_value)/sizeof(als_it_value[0]);
> + for (i = 0; i < n; i++)
> + if (val <= als_it_value[i])
> + break;
> + if (i >= n)
Should be spaces around that -.
Please make sure to run scripts/checkpatch.pl which I would have
expected to catch this and any other similar cases..
> + 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;
> +}
> +
> +/*
Ideally any documentation will be in kernel-doc style
Documentation/kernel-doc-nano-HOWTO.txt
> + * Convert sensor data to lux.
> + * 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 (int)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;
Might as well return from here...
return IIO_VAL_INT;
instead of bothering with the break.
> + ret = IIO_VAL_INT;
> + break;
> + case IIO_CHAN_INFO_CALIBSCALE:
> + *val = cm32181->calibscale;
> + ret = IIO_VAL_INT;
> + break;
> + case IIO_CHAN_INFO_INT_TIME:
> + ret = cm32181_read_als_it(cm32181, val);
> + if (ret < 0)
> + return ret;
> + break;
> + default:
> + ret = -EINVAL;
> + }
> +
> + return ret;
> +}
> +
> +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;
> + ret = val;
> + break;
> + case IIO_CHAN_INFO_INT_TIME:
> + ret = cm32181_write_als_it(cm32181, val);
> + if (ret < 0)
> + return ret;
> + break;
> + default:
> + ret = -EINVAL;
> + }
> +
> + return ret;
> +}
> +
Function should have a prefix. Its just possible someone
will one day introduce a generic get_it_available
and hence cause a name clash.
hence
cm32181_get_it_available(...)
> +static ssize_t get_it_available(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + int i, n, len;
> +
> + n = sizeof(als_it_value)/sizeof(als_it_value[0]);
> + for (i = 0, len = 0; i < n; i++)
> + len += sprintf(buf + len, "%d ", als_it_value[i]);
> + return len + sprintf(buf + len, "\n");
> +}
> +
> +static const struct iio_chan_spec cm32181_channels[] = {
> + {
> + .type = IIO_LIGHT,
> + .indexed = 0,
> + .channel = 0,
> + .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, 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;
> + goto error_disable_reg;
> + }
> +
> + ret = iio_device_register(indio_dev);
> + if (ret) {
> + dev_err(&client->dev,
> + "%s: regist device failed\n",
> + __func__);
return ret
> + goto error_disable_reg;
> + }
> +
> + return 0;
> +
Don't bother with this - just return directly when the errors
occur. See above.
> +error_disable_reg:
> + return ret;
> +}
> +
As mentioned before, the staging-next tree includes
devm_iio_device_register and if you use that, then no
remove funciton will be needed.
> +static int cm32181_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 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,
> + .remove = cm32181_remove,
> +};
> +
> +module_i2c_driver(cm32181_driver);
> +
> +MODULE_AUTHOR("Kevin Tsai <ktsai@xxxxxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("CM32181 ambient light sensor driver");
> +MODULE_LICENSE("GPL");
>
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