Re: [PATCH v2 1/2] iio: cm36651: Add CM36651 proximity/light sensor driver

[Beomho Seo <beomho.seo@samsung.com>]

Hello Peter,
Thank you for your review.
I revised on your advice. v3 patch will be sent in the today.

Reply about your question below

I
> 
>> This patch add a new driver for Capella CM36651 proximity and RGB sensor.
> 
> moving in the right direction!
> couple of comments inline
> 
>> diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
>> index 0a25ae6..c965aeb 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 CM36651
>> +	depends on I2C
>> +	tristate "CM36651 driver"
>> +	help
>> +	  Say Y here if you use cm36651.
>> +	  This option enables proximity & RGB sensor using
>> +	  Capella cm36651 device driver.
>> +
>> +	  To compile this driver as a module, choose M here:
>> +	  the module will be called cm36651.
>> +
>>  config GP2AP020A00F
>>  	tristate "Sharp GP2AP020A00F Proximity/ALS sensor"
>>  	depends on I2C
>> diff --git a/drivers/iio/light/cm36651.c b/drivers/iio/light/cm36651.c
>> new file mode 100644
>> index 0000000..e1958ac
>> --- /dev/null
>> +++ b/drivers/iio/light/cm36651.c
>> @@ -0,0 +1,591 @@
>> +/*
>> + * Copyright (C) 2013 Samsung Electronics Co., Ltd.
>> + * Author: Beomho Seo <beomho.seo@samsung.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.
>> + */
>> +
>> +#include <linux/delay.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>
>> +
>> +/* Slave address 0x19 for PS of 7 bit addressing protocol for I2C */
>> +#define CM36651_I2C_ADDR_PS		0x19
>> +
>> +/* Ambient light sensor */
>> +#define CM36651_CS_CONF1		0x00
> 
> what does CS stand for?
> maybe ALS?
> 

In order to cm36651 manual, CS stands for COlor sensor(R, G, B and W). Manual uses abbreviation both CS and ALS. I follow register name and command in manual.

>> +#define CM36651_CS_CONF2		0x01
>> +#define CM36651_ALS_WH_M		0x02
>> +#define CM36651_ALS_WH_L		0x03
>> +#define CM36651_ALS_WL_M		0x04
>> +#define CM36651_ALS_WL_L		0x05
>> +#define CM36651_CS_CONF3		0x06
>> +#define CM36651_CS_REG_NUM		0x07
>> +
>> +/* Proximity sensor */
>> +#define CM36651_PS_CONF1		0x00
>> +#define CM36651_PS_THD		0x01
>> +#define CM36651_PS_CANC		0x02
>> +#define CM36651_PS_CONF2		0x03
>> +#define CM36651_PS_REG_NUM		0x04
>> +
>> +/* CS_CONF1 command code */
>> +#define CM36651_ALS_ENABLE		0x00
>> +#define CM36651_ALS_DISABLE		0x01
>> +#define CM36651_ALS_INT_EN		0x02
>> +#define CM36651_ALS_THRES		0x04
>> +
>> +/* CS_CONF2 command code */
>> +#define CM36651_CS_CONF2_DEFAULT_BIT	0x08
>> +
>> +/* CS_CONF3 channel integration time */
> 
> which unit?
> this could be made configurable via INT_TIME channel
> 
>> +#define CM36651_IT_80		0x00
>> +#define CM36651_W_IT_160		0x01
>> +#define CM36651_W_IT_320		0x02
>> +#define CM36651_W_IT_640		0x03
>> +#define CM36651_B_IT_160		0x04
>> +#define CM36651_B_IT_320		0x08
>> +#define CM36651_B_IT_640		0x0C
>> +#define CM36651_G_IT_160		0x10
>> +#define CM36651_G_IT_320		0x20
>> +#define CM36651_G_IT_640		0x30
>> +#define CM36651_R_IT_160		0x40
>> +#define CM36651_R_IT_320		0x80
>> +#define CM36651_R_IT_640		0xC0
>> +
>> +/* PS_CONF1 command code */
>> +#define CM36651_PS_ENABLE		0x00
>> +#define CM36651_PS_DISABLE		0x01
>> +#define CM36651_PS_INT_EN		0x02
>> +#define CM36651_PS_PERS_2		0x04
>> +#define CM36651_PS_PERS_3		0x08
>> +#define CM36651_PS_PERS_4		0x0C
>> +#define CM36651_PS_IT_2		0x10
>> +#define CM36651_PS_IT_3		0x20
>> +#define CM36651_PS_IT_4		0x30
>> +
>> +/* PS_THD command code */
>> +#define CM36651_PS_INITIAL_THD	0x09
>> +
>> +/* PS_CANC command code */
>> +#define CM36651_PS_CANC_DEFAULT	0x00
>> +
>> +/* PS_CONF2 command code */
>> +#define CM36651_PS_HYS_1		0x00
>> +#define CM36651_PS_HYS_2		0x01
>> +#define CM36651_PS_SMART_PERS_EN	0x02
>> +#define CM36651_PS_MS		0x10
>> +
>> +#define CM36651_SCAN_MODE_LIGHT	0
>> +#define CM36651_SCAN_MODE_PROX	1
>> +
>> +enum cm36651_operation_mode {
>> +	CM36651_LIGHT_EN,
>> +	CM36651_PROXIMITY_EN,
>> +	CM36651_PROXIMITY_EV_EN,
>> +};
>> +
>> +enum cm36651_light_channel_idx {
>> +	CM36651_LIGHT_CHANNEL_IDX_RED,
>> +	CM36651_LIGHT_CHANNEL_IDX_GREEN,
>> +	CM36651_LIGHT_CHANNEL_IDX_BLUE,
>> +	CM36651_LIGHT_CHANNEL_IDX_CLEAR,
>> +};
>> +
>> +enum cm36651_command {
>> +	CM36651_CMD_READ_RAW_LIGHT,
>> +	CM36651_CMD_READ_RAW_PROXIMITY,
>> +	CM36651_CMD_PROX_EV_EN,
>> +	CM36651_CMD_PROX_EV_DIS,
>> +};
>> +
>> +enum cm36651_proximity_event {
>> +	CM36651_CLOSE_PROXIMITY,
>> +	CM36651_FAR_PROXIMITY,
>> +};
>> +
>> +static u8 cm36651_als_reg[2] = {
> 
> const 
> 
>> +	CM36651_CS_CONF1,
>> +	CM36651_CS_CONF2,
>> +};
>> +
>> +static u8 cm36651_ps_reg[4] = {
> 
> const
> 
>> +	CM36651_PS_CONF1,
>> +	CM36651_PS_THD,
>> +	CM36651_PS_CANC,
>> +	CM36651_PS_CONF2,
>> +};
>> +
>> +struct cm36651_data {
>> +	const struct cm36651_platform_data *pdata;
>> +	struct i2c_client *client;
>> +	struct i2c_client *ps_client;
>> +	struct mutex lock;
>> +	struct regulator *vled_reg;
>> +	unsigned long flags;
>> +	u8 cs_ctrl_regs[2];
>> +	u8 ps_ctrl_regs[4];
>> +	u16 color[4];
>> +};
>> +
>> +static int cm36651_setup_reg(struct cm36651_data *cm36651)
>> +{
>> +	struct i2c_client *client = cm36651->client;
>> +	struct i2c_client *ps_client = cm36651->ps_client;
>> +	int i, ret;
>> +
>> +	/* ALS initialization */
>> +	cm36651->cs_ctrl_regs[CM36651_CS_CONF1] = CM36651_ALS_ENABLE
>> +							| CM36651_ALS_THRES;
>> +	cm36651->cs_ctrl_regs[CM36651_CS_CONF2] = CM36651_CS_CONF2_DEFAULT_BIT;
>> +
>> +	for (i = 0; i < 2; i++) {
> 
> use the CS_REG_NUM #defined
> 
>> +		ret = i2c_smbus_write_byte_data(client, cm36651_als_reg[i],
>> +						cm36651->cs_ctrl_regs[i]);
>> +		if (ret < 0)
>> +			goto err_setup_reg;
>> +	}
>> +
>> +	/* PS initialization */
>> +	cm36651->ps_ctrl_regs[CM36651_PS_CONF1] = CM36651_PS_ENABLE
>> +				   | CM36651_PS_PERS_4 | CM36651_PS_IT_4;
>> +	cm36651->ps_ctrl_regs[CM36651_PS_THD] = CM36651_PS_INITIAL_THD;
>> +	cm36651->ps_ctrl_regs[CM36651_PS_CANC] = CM36651_PS_CANC_DEFAULT;
>> +	cm36651->ps_ctrl_regs[CM36651_PS_CONF2] = CM36651_PS_HYS_2
>> +			      | CM36651_PS_SMART_PERS_EN | CM36651_PS_MS;
>> +
>> +	for (i = 0; i < 4; i++) {
> 
> use the PS_REG_NUM #defined
> 
>> +		ret = i2c_smbus_write_byte_data(ps_client, cm36651_ps_reg[i],
>> +						cm36651->ps_ctrl_regs[i]);
>> +		if (ret < 0)
>> +			goto err_setup_reg;
>> +	}
>> +
>> +	ret = i2c_smbus_read_byte(cm36651->ps_client);
>> +	if (ret < 0)
>> +		goto err_setup_reg;
>> +
>> +	/* Printing the initial proximity value with no contact */
>> +	dev_dbg(&client->dev, "Initial proximity value: %d\n", ret);
> 
> maybe drop the initial read? not needed when not in debug mode
> 
>> +
>> +	/* Device turn off */
>> +	ret = i2c_smbus_write_byte_data(client, CM36651_CS_CONF1,
>> +						CM36651_ALS_DISABLE);
>> +	if (ret < 0)
>> +		goto err_setup_reg;
>> +
>> +	ret = i2c_smbus_write_byte_data(cm36651->ps_client,
>> +				CM36651_PS_CONF1, CM36651_PS_DISABLE);
>> +	if (ret < 0)
>> +		goto err_setup_reg;
>> +
>> +	return 0;
>> +
>> +err_setup_reg:
>> +	dev_err(&client->dev, "Register setup failed: %d\n", ret);
>> +	return ret;
>> +}
>> +
>> +static int cm36651_read_output(struct cm36651_data *cm36651,
>> +				struct iio_chan_spec const *chan, int *val)
>> +{
>> +	struct i2c_client *client = cm36651->client;
>> +	int ret = -EINVAL;
>> +
>> +	switch (chan->scan_index) {
>> +	case CM36651_SCAN_MODE_LIGHT:
>> +		*val = i2c_smbus_read_word_data(client, chan->channel);
> 
> the CM36651 seems to be special here how data is returned; there seems to 
> be no dedicated register to pass the measurement?
> 

CM36651 aply slave address 0x18 for CS and 0x19 for PS of 7bit addressing protocol for I2C. CM36651 contains an 8 bit command register. All operation can be controlled by the command register(e.g. read sensor data)

>> +		if (val < 0)
>> +			goto read_err;
>> +
>> +		ret = i2c_smbus_write_byte_data(client, CM36651_CS_CONF1,
>> +							CM36651_ALS_DISABLE);
>> +		if (ret < 0)
>> +			goto write_err;
>> +
>> +		ret = IIO_VAL_INT;
>> +		break;
>> +	case CM36651_SCAN_MODE_PROX:
>> +		*val = i2c_smbus_read_byte(cm36651->ps_client);
>> +		if (val < 0)
>> +			goto read_err;
>> +
>> +		ret = i2c_smbus_write_byte_data(cm36651->ps_client,
>> +					CM36651_PS_CONF1, CM36651_PS_DISABLE);
>> +		if (ret < 0)
>> +			goto write_err;
>> +
>> +		ret = IIO_VAL_INT;
>> +		break;
>> +	}
>> +
>> +	return ret;
>> +
>> +read_err:
>> +	dev_err(&client->dev, "Register read failed\n");
>> +	return ret;
>> +
>> +write_err:
>> +	dev_err(&client->dev, "Register write failed\n");
>> +	return ret;
>> +}
>> +
>> +static irqreturn_t cm36651_irq_handler(int irq, void *data)
>> +{
>> +	struct iio_dev *indio_dev = data;
>> +	struct cm36651_data *cm36651 = iio_priv(indio_dev);
>> +	struct i2c_client *client = cm36651->client;
>> +	int ev_dir, val, ret;
>> +	u64 ev_code;
>> +
>> +	ret = i2c_smbus_read_byte(cm36651->ps_client);
>> +	if (ret < 0) {
>> +		dev_err(&client->dev,
>> +				"%s: Data read failed: %d\n", __func__, ret);
>> +		return IRQ_HANDLED;
>> +	}
>> +
>> +	if (ret < CM36651_PS_INITIAL_THD) {
>> +		ev_dir = IIO_EV_DIR_RISING;
>> +		val = CM36651_FAR_PROXIMITY;
>> +	} else {
>> +		ev_dir = IIO_EV_DIR_FALLING;
>> +		val = CM36651_CLOSE_PROXIMITY;
>> +	}
>> +
>> +	ev_code = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY,
>> +				CM36651_CMD_READ_RAW_PROXIMITY,
>> +				IIO_EV_TYPE_THRESH, ev_dir);
>> +
>> +	iio_push_event(indio_dev, ev_code, iio_get_time_ns());
>> +
>> +	return IRQ_HANDLED;
>> +}
>> +
>> +static int cm36651_set_operation_mode(struct cm36651_data *cm36651,
>> +						enum cm36651_command cmd)
>> +{
>> +	struct i2c_client *client = cm36651->client;
>> +	int ret = 0;
> 
> unknown cmd are silently not handled; 
> probably better to set ret = -EINVAL
> 
>> +	int i;
>> +
>> +	switch (cmd) {
>> +	case CM36651_CMD_READ_RAW_LIGHT:
>> +		ret = i2c_smbus_write_byte_data(client, CM36651_CS_CONF1,
>> +				cm36651->cs_ctrl_regs[CM36651_CS_CONF1]);
>> +		break;
>> +	case CM36651_CMD_READ_RAW_PROXIMITY:
>> +		ret = i2c_smbus_write_byte_data(cm36651->ps_client,
>> +		   CM36651_PS_CONF1, cm36651->ps_ctrl_regs[CM36651_PS_CONF1]);
>> +		break;
>> +	case CM36651_CMD_PROX_EV_EN:
>> +		if (test_bit(CM36651_PROXIMITY_EV_EN, &cm36651->flags)) {
>> +			dev_err(&client->dev,
>> +				"Already proximity event enable state\n");
>> +			return ret;
>> +		}
>> +		set_bit(CM36651_PROXIMITY_EV_EN, &cm36651->flags);
>> +
>> +		for (i = 0; i < 4; i++) {
> 
> REG_NUM
> 
>> +			ret = i2c_smbus_write_byte_data(cm36651->ps_client,
>> +				cm36651_ps_reg[i], cm36651->ps_ctrl_regs[i]);
>> +			if (ret < 0)
>> +				goto write_err;
>> +		}
>> +
>> +		enable_irq(client->irq);
>> +		break;
>> +	case CM36651_CMD_PROX_EV_DIS:
>> +		if (!test_bit(CM36651_PROXIMITY_EV_EN, &cm36651->flags)) {
>> +			dev_err(&client->dev,
>> +				"Already proximity event disable state\n");
>> +			return ret;
>> +		}
>> +		clear_bit(CM36651_PROXIMITY_EV_EN, &cm36651->flags);
>> +		disable_irq(client->irq);
>> +		ret = i2c_smbus_write_byte_data(cm36651->ps_client,
>> +					CM36651_PS_CONF1, CM36651_PS_DISABLE);
>> +		break;
>> +	}
>> +
>> +	if (ret < 0)
>> +		dev_err(&client->dev, "Write register failed\n");
>> +
>> +	return ret;
>> +
>> +write_err:
>> +	dev_err(&client->dev, "Proximity enable event is failed\n");
> 
> remove 'is'
> 
>> +	return ret;
>> +}
>> +
>> +static int cm36651_read_channel(struct cm36651_data *cm36651,
>> +				struct iio_chan_spec const *chan, int *val)
>> +{
>> +	struct i2c_client *client = cm36651->client;
>> +	enum cm36651_command cmd = 0;
>> +	int ret;
>> +
>> +	if (chan->scan_index == CM36651_SCAN_MODE_LIGHT)
>> +		cmd = CM36651_CMD_READ_RAW_LIGHT;
>> +	else /* CM36651_SCAN_MODE_PROX */
>> +		cmd = CM36651_CMD_READ_RAW_PROXIMITY;
> 
> chan->type could be used to distinguish between LIGHT and PROXIMITY, so no
> need for scan_index
> 
>> +
>> +	ret = cm36651_set_operation_mode(cm36651, cmd);
>> +	if (ret < 0) {
>> +		dev_err(&client->dev, "CM36651 set operation mode failed\n");
>> +		return ret;
>> +	}
>> +	/* Raw data integration time */
>> +	msleep(50);
> 
> shouldn't this depend on the integration time configured?
> same for ALS and PS?
> 
>> +	ret = cm36651_read_output(cm36651, chan, val);
>> +	if (ret < 0) {
>> +		dev_err(&client->dev, "CM36651 read output failed\n");
>> +		return ret;
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +static int cm36651_read_raw(struct iio_dev *indio_dev,
>> +			    struct iio_chan_spec const *chan,
>> +			    int *val, int *val2, long mask)
>> +{
>> +	struct cm36651_data *cm36651 = iio_priv(indio_dev);
>> +	int ret = -EINVAL;
>> +
>> +	mutex_lock(&cm36651->lock);
>> +
>> +	if (mask == IIO_CHAN_INFO_RAW)
>> +		ret = cm36651_read_channel(cm36651, chan, val);
>> +
>> +	mutex_unlock(&cm36651->lock);
>> +
>> +	return ret;
>> +}
>> +
>> +static int cm36651_read_thresh(struct iio_dev *indio_dev,
>> +					u64 event_code, int *val)
>> +{
>> +	struct cm36651_data *cm36651 = iio_priv(indio_dev);
>> +	int chan_type = IIO_EVENT_CODE_EXTRACT_CHAN_TYPE(event_code);
>> +	int event_type = IIO_EVENT_CODE_EXTRACT_TYPE(event_code);
>> +
>> +	if (event_type != IIO_EV_TYPE_THRESH ||	chan_type != IIO_PROXIMITY)
>> +		return -EINVAL;
>> +
>> +	*val = cm36651->ps_ctrl_regs[CM36651_PS_THD];
>> +
>> +	return 0;
>> +}
>> +
>> +static int cm36651_write_thresh(struct iio_dev *indio_dev,
>> +					u64 event_code, int val)
>> +{
>> +	struct cm36651_data *cm36651 = iio_priv(indio_dev);
>> +	struct i2c_client *client = cm36651->client;
>> +	int ret;
>> +
>> +	if (val < 3 || val > 255)
>> +		return -EINVAL;
>> +
>> +	cm36651->ps_ctrl_regs[CM36651_PS_THD] = val;
>> +	ret = i2c_smbus_write_byte_data(cm36651->ps_client, CM36651_PS_THD,
>> +					cm36651->ps_ctrl_regs[CM36651_PS_THD]);
>> +
>> +	if (ret < 0) {
>> +		dev_err(&client->dev, "PS register read faied: %d\n", ret);
> 
> that's a write; 'failed', maybe more specific: "PS threshold write failed"
> 
>> +		return ret;
>> +	}
>> +	dev_dbg(&client->dev, "New threshold is 0x%x\n",
>> +					cm36651->ps_ctrl_regs[CM36651_PS_THD]);
>> +
>> +	return 0;
>> +}
>> +
>> +static int cm36651_write_event_config(struct iio_dev *indio_dev,
>> +					u64 event_code, int state)
>> +{
>> +	struct cm36651_data *cm36651 = iio_priv(indio_dev);
>> +	enum cm36651_command cmd;
> 
> could avoid that local variable or move it down
> 
>> +	int chan_type = IIO_EVENT_CODE_EXTRACT_CHAN_TYPE(event_code);
>> +	int ret = -EINVAL;
>> +
>> +	mutex_lock(&cm36651->lock);
>> +
>> +	if (chan_type == IIO_PROXIMITY) {
>> +		cmd = state ? CM36651_CMD_PROX_EV_EN : CM36651_CMD_PROX_EV_DIS;
>> +		ret = cm36651_set_operation_mode(cm36651, cmd);
>> +	}
>> +
>> +	mutex_unlock(&cm36651->lock);
>> +
>> +	return ret;
>> +}
>> +
>> +static int cm36651_read_event_config(struct iio_dev *indio_dev, u64 event_code)
>> +{
>> +	struct cm36651_data *cm36651 = iio_priv(indio_dev);
>> +	int chan_type = IIO_EVENT_CODE_EXTRACT_CHAN_TYPE(event_code);
>> +	int event_en = -EINVAL;
>> +
>> +	mutex_lock(&cm36651->lock);
>> +
>> +	if (chan_type == IIO_PROXIMITY)
>> +		event_en = test_bit(CM36651_PROXIMITY_EV_EN, &cm36651->flags);
>> +
>> +	mutex_unlock(&cm36651->lock);
>> +
>> +	return event_en;
>> +}
>> +
>> +#define CM36651_LIGHT_CHANNEL(_color, _idx) {		\
>> +	.type = IIO_LIGHT,				\
>> +	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
>> +	.scan_type = IIO_ST('u', 16, 16, 0),		\
>> +	.scan_index = CM36651_SCAN_MODE_LIGHT,		\
> 
> no need scan_type and scan_index; driver does not support buffering
> 
>> +	.channel = _idx,
> 
> I'd rather use .address than .channel; there is just one light channel
> 				\
>> +	.modified = 1,					\
>> +	.channel2 = IIO_MOD_LIGHT_##_color,		\
>> +}
>> +
>> +static const struct iio_chan_spec cm36651_channels[] = {
>> +	{
>> +		.type = IIO_PROXIMITY,
>> +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
>> +		.scan_type = IIO_ST('u', 8, 8, 0),
>> +		.scan_index = CM36651_SCAN_MODE_PROX,
>> +		.event_mask = IIO_EV_BIT(IIO_EV_TYPE_THRESH, IIO_EV_DIR_EITHER)
>> +	},
>> +	CM36651_LIGHT_CHANNEL(RED, CM36651_LIGHT_CHANNEL_IDX_RED),
>> +	CM36651_LIGHT_CHANNEL(GREEN, CM36651_LIGHT_CHANNEL_IDX_GREEN),
>> +	CM36651_LIGHT_CHANNEL(BLUE, CM36651_LIGHT_CHANNEL_IDX_BLUE),
>> +	CM36651_LIGHT_CHANNEL(CLEAR, CM36651_LIGHT_CHANNEL_IDX_CLEAR),
>> +};
>> +
>> +static const struct iio_info cm36651_info = {
>> +	.driver_module		= THIS_MODULE,
>> +	.read_raw		= &cm36651_read_raw,
>> +	.read_event_value	= &cm36651_read_thresh,
>> +	.write_event_value	= &cm36651_write_thresh,
>> +	.read_event_config	= &cm36651_read_event_config,
>> +	.write_event_config	= &cm36651_write_event_config,
>> +};
>> +
>> +static int cm36651_probe(struct i2c_client *client,
>> +			     const struct i2c_device_id *id)
>> +{
>> +	struct cm36651_data *cm36651;
>> +	struct iio_dev *indio_dev;
>> +	unsigned long irqflag;
> 
> could avoid variable irqflag
> 
>> +	int ret;
>> +
>> +	dev_dbg(&client->dev, "cm36651 light/proxymity sensor probe\n");
> 
> proximity
> 
>> +
>> +	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*cm36651));
>> +	if (!indio_dev)
>> +		return -ENOMEM;
>> +
>> +	cm36651 = iio_priv(indio_dev);
>> +
>> +	cm36651->vled_reg = devm_regulator_get(&client->dev, "vled");
>> +	if (IS_ERR(cm36651->vled_reg)) {
>> +		dev_err(&client->dev, "get regulator vled failed\n");
>> +		return PTR_ERR(cm36651->vled_reg);
>> +	}
>> +
>> +	ret = regulator_enable(cm36651->vled_reg);
>> +	if (ret) {
>> +		dev_err(&client->dev, "enable regulator failed\n");
> 
> regulator vled
> 
>> +		return ret;
>> +	}
>> +
>> +	i2c_set_clientdata(client, indio_dev);
>> +
>> +	cm36651->client = client;
>> +	cm36651->ps_client = i2c_new_dummy(client->adapter,
>> +						CM36651_I2C_ADDR_PS);
>> +	mutex_init(&cm36651->lock);
>> +	indio_dev->dev.parent = &client->dev;
>> +	indio_dev->channels = cm36651_channels;
>> +	indio_dev->num_channels = ARRAY_SIZE(cm36651_channels);
>> +	indio_dev->info = &cm36651_info;
>> +	indio_dev->name = id->name;
>> +	indio_dev->modes = INDIO_DIRECT_MODE;
>> +
>> +	/* Check if the device is there or not */
>> +	ret = i2c_smbus_write_byte_data(cm36651->ps_client, CM36651_PS_CONF1,
>> +							   CM36651_PS_DISABLE);
>> +	if (ret < 0) {
>> +		dev_err(&client->dev, "PS register read faied: %d\n", ret);
> 
> "failed"
> isn't there a better way to check? setup_reg() would fail also if the 
> device is not there?!
> 
> regulator doesn't get disabled
> 
>> +		return ret;
>> +	}
>> +
>> +	ret = cm36651_setup_reg(cm36651);
> 
> ret not checked
> 
>> +
>> +	irqflag = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT;
>> +	ret = request_threaded_irq(client->irq, NULL, cm36651_irq_handler,
>> +				irqflag, "cm36651_proximity", indio_dev);
>> +	if (ret) {
>> +		dev_err(&client->dev, "%s: request irq failed\n", __func__);
> 
> regulator not disabled
> 
>> +		return ret;
>> +	}
>> +	disable_irq(client->irq);
>> +
>> +	ret = iio_device_register(indio_dev);
>> +	if (ret) {
>> +		regulator_disable(cm36651->vled_reg);
>> +		free_irq(client->irq, indio_dev);
>> +		return ret;
> 
> move 'return ret' down, save 'return 0'
> 
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int cm36651_remove(struct i2c_client *client)
>> +{
>> +	struct iio_dev *indio_dev = i2c_get_clientdata(client);
>> +	struct cm36651_data *cm36651 = iio_priv(indio_dev);
>> +
>> +	iio_device_unregister(indio_dev);
>> +	regulator_disable(cm36651->vled_reg);
>> +	free_irq(client->irq, indio_dev);
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct i2c_device_id cm36651_id[] = {
>> +	{ "cm36651", 0 },
>> +	{ }
>> +};
>> +
>> +MODULE_DEVICE_TABLE(i2c, cm36651_id);
>> +
>> +static const struct of_device_id cm36651_of_match[] = {
>> +	{ .compatible = "capella,cm36651" },
>> +	{ }
>> +};
>> +
>> +static struct i2c_driver cm36651_driver = {
>> +	.driver = {
>> +		.name	= "cm36651",
>> +		.of_match_table = of_match_ptr(cm36651_of_match),
>> +		.owner	= THIS_MODULE,
>> +	},
>> +	.probe		= cm36651_probe,
>> +	.remove		= cm36651_remove,
>> +	.id_table	= cm36651_id,
>> +};
>> +
>> +module_i2c_driver(cm36651_driver);
>> +
>> +MODULE_AUTHOR("Beomho Seo <beomho.seo@samsung.com>");
>> +MODULE_DESCRIPTION("CM36651 proximity/ambient light sensor driver");
>> +MODULE_LICENSE("GPL v2");
>>
> 


-- 
Best Regards,

Beomho Seo, Assistant Engineer
System S/W Lab., S/W Platform Team, Software Center
Samsung Electronics