Re: [PATCH v3 01/28] staging: iio: tsl2583: split out functionality of taos_chip_on()

[Jonathan Cameron <jic23@kernel.org>]

On 10/11/16 09:25, Brian Masney wrote:
> taos_chip_on() reads an eight member array called taos_config
> that contains the desired state of the chip's registers. Only four
> of the registers actually need to be written to. The four that do
> not need to be written to are for the {low,high} byte of the lower
> interrupt threshold and the {low,high} byte of the upper interrupt
> threshold. Interrupts are currently not supported by this driver
> so there is no need to write to these registers.
> 
> This patch removes the taos_config array and separates out the
> i2c calls that write to the CONTROL, TIMING, INTERRUPT and ANALOG
> registers. This is part of a larger refactor that was split up to
> make the code review easier.
> 
> Signed-off-by: Brian Masney <masneyb@onstation.org>
Looks good. Applied to the togreg branch of iio.git.

Thanks

Jonathan
> ---
>  drivers/staging/iio/light/tsl2583.c | 122 +++++++++++++++++-------------------
>  1 file changed, 58 insertions(+), 64 deletions(-)
> 
> diff --git a/drivers/staging/iio/light/tsl2583.c b/drivers/staging/iio/light/tsl2583.c
> index d74e33b..c196a42 100644
> --- a/drivers/staging/iio/light/tsl2583.c
> +++ b/drivers/staging/iio/light/tsl2583.c
> @@ -31,9 +31,6 @@
>  #include <linux/iio/iio.h>
>  #include <linux/iio/sysfs.h>
>  
> -/* Triton register offsets */
> -#define	TSL258X_REG_MAX		8
> -
>  /* Device Registers and Masks */
>  #define TSL258X_CNTRL			0x00
>  #define TSL258X_ALS_TIME		0X01
> @@ -55,6 +52,7 @@
>  
>  /* tsl2583 cntrl reg masks */
>  #define TSL258X_CNTL_ADC_ENBL	0x02
> +#define TSL258X_CNTL_PWR_OFF		0x00
>  #define TSL258X_CNTL_PWR_ON		0x01
>  
>  /* tsl2583 status reg masks */
> @@ -64,6 +62,8 @@
>  /* Lux calculation constants */
>  #define	TSL258X_LUX_CALC_OVER_FLOW		65535
>  
> +#define TSL2583_INTERRUPT_DISABLED	0x00
> +
>  #define TSL2583_CHIP_ID			0x90
>  #define TSL2583_CHIP_ID_MASK		0xf0
>  
> @@ -95,18 +95,8 @@ struct tsl2583_chip {
>  	int als_time_scale;
>  	int als_saturation;
>  	int taos_chip_status;
> -	u8 taos_config[8];
>  };
>  
> -/*
> - * Initial values for device - this values can/will be changed by driver.
> - * and applications as needed.
> - * These values are dynamic.
> - */
> -static const u8 taos_config[8] = {
> -		0x00, 0xee, 0x00, 0x03, 0x00, 0xFF, 0xFF, 0x00
> -}; /*	cntrl atime intC  Athl0 Athl1 Athh0 Athh1 gain */
> -
>  struct taos_lux {
>  	unsigned int ratio;
>  	unsigned int ch0;
> @@ -362,16 +352,26 @@ static int taos_als_calibrate(struct iio_dev *indio_dev)
>  	return (int)gain_trim_val;
>  }
>  
> +static int tsl2583_set_power_state(struct tsl2583_chip *chip, u8 state)
> +{
> +	int ret;
> +
> +	ret = i2c_smbus_write_byte_data(chip->client,
> +					TSL258X_CMD_REG | TSL258X_CNTRL, state);
> +	if (ret < 0)
> +		dev_err(&chip->client->dev, "%s failed to set the power state to %d\n",
> +			__func__, state);
> +
> +	return ret;
> +}
> +
>  /*
>   * Turn the device on.
>   * Configuration must be set before calling this function.
>   */
> -static int taos_chip_on(struct iio_dev *indio_dev)
> +static int tsl2583_chip_init_and_power_on(struct iio_dev *indio_dev)
>  {
> -	int i;
> -	int ret;
> -	u8 *uP;
> -	u8 utmp;
> +	int ret, val;
>  	int als_count;
>  	int als_time;
>  	struct tsl2583_chip *chip = iio_priv(indio_dev);
> @@ -383,6 +383,20 @@ static int taos_chip_on(struct iio_dev *indio_dev)
>  		return -EINVAL;
>  	}
>  
> +	/* Power on the device; ADC off. */
> +	ret = tsl2583_set_power_state(chip, TSL258X_CNTL_PWR_ON);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = i2c_smbus_write_byte_data(chip->client,
> +					TSL258X_CMD_REG | TSL258X_INTERRUPT,
> +					TSL2583_INTERRUPT_DISABLED);
> +	if (ret < 0) {
> +		dev_err(&chip->client->dev, "%s failed to disable interrupts\n",
> +			__func__);
> +		return ret;
> +	}
> +
>  	/* determine als integration register */
>  	als_count = (chip->taos_settings.als_time * 100 + 135) / 270;
>  	if (!als_count)
> @@ -390,62 +404,43 @@ static int taos_chip_on(struct iio_dev *indio_dev)
>  
>  	/* convert back to time (encompasses overrides) */
>  	als_time = (als_count * 27 + 5) / 10;
> -	chip->taos_config[TSL258X_ALS_TIME] = 256 - als_count;
> +
> +	val = 256 - als_count;
> +	ret = i2c_smbus_write_byte_data(chip->client,
> +					TSL258X_CMD_REG | TSL258X_ALS_TIME,
> +					val);
> +	if (ret < 0) {
> +		dev_err(&chip->client->dev, "%s failed to set the als time to %d\n",
> +			__func__, val);
> +		return ret;
> +	}
>  
>  	/* Set the gain based on taos_settings struct */
> -	chip->taos_config[TSL258X_GAIN] = chip->taos_settings.als_gain;
> +	ret = i2c_smbus_write_byte_data(chip->client,
> +					TSL258X_CMD_REG | TSL258X_GAIN,
> +					chip->taos_settings.als_gain);
> +	if (ret < 0) {
> +		dev_err(&chip->client->dev, "%s failed to set the gain to %d\n",
> +			__func__, chip->taos_settings.als_gain);
> +		return ret;
> +	}
>  
>  	/* set chip struct re scaling and saturation */
>  	chip->als_saturation = als_count * 922; /* 90% of full scale */
>  	chip->als_time_scale = (als_time + 25) / 50;
>  
> -	/* Power on the device; ADC off. */
> -	chip->taos_config[TSL258X_CNTRL] = TSL258X_CNTL_PWR_ON;
> -
> -	/*
> -	 * Use the following shadow copy for our delay before enabling ADC.
> -	 * Write all the registers.
> -	 */
> -	for (i = 0, uP = chip->taos_config; i < TSL258X_REG_MAX; i++) {
> -		ret = i2c_smbus_write_byte_data(chip->client,
> -						TSL258X_CMD_REG + i,
> -						*uP++);
> -		if (ret < 0) {
> -			dev_err(&chip->client->dev,
> -				"taos_chip_on failed on reg %d.\n", i);
> -			return ret;
> -		}
> -	}
> -
>  	usleep_range(3000, 3500);
> -	/*
> -	 * NOW enable the ADC
> -	 * initialize the desired mode of operation
> -	 */
> -	utmp = TSL258X_CNTL_PWR_ON | TSL258X_CNTL_ADC_ENBL;
> -	ret = i2c_smbus_write_byte_data(chip->client,
> -					TSL258X_CMD_REG | TSL258X_CNTRL,
> -					utmp);
> -	if (ret < 0) {
> -		dev_err(&chip->client->dev, "taos_chip_on failed on 2nd CTRL reg.\n");
> +
> +	ret = tsl2583_set_power_state(chip, TSL258X_CNTL_PWR_ON |
> +					    TSL258X_CNTL_ADC_ENBL);
> +	if (ret < 0)
>  		return ret;
> -	}
> +
>  	chip->taos_chip_status = TSL258X_CHIP_WORKING;
>  
>  	return ret;
>  }
>  
> -static int taos_chip_off(struct iio_dev *indio_dev)
> -{
> -	struct tsl2583_chip *chip = iio_priv(indio_dev);
> -
> -	/* turn device off */
> -	chip->taos_chip_status = TSL258X_CHIP_SUSPENDED;
> -	return i2c_smbus_write_byte_data(chip->client,
> -					TSL258X_CMD_REG | TSL258X_CNTRL,
> -					0x00);
> -}
> -
>  /* Sysfs Interface Functions */
>  
>  static ssize_t in_illuminance_input_target_show(struct device *dev,
> @@ -768,7 +763,6 @@ static int taos_probe(struct i2c_client *clientp,
>  
>  	mutex_init(&chip->als_mutex);
>  	chip->taos_chip_status = TSL258X_CHIP_UNKNOWN;
> -	memcpy(chip->taos_config, taos_config, sizeof(chip->taos_config));
>  
>  	ret = i2c_smbus_read_byte_data(clientp,
>  				       TSL258X_CMD_REG | TSL258X_CHIPID);
> @@ -808,7 +802,7 @@ static int taos_probe(struct i2c_client *clientp,
>  	taos_defaults(chip);
>  
>  	/* Make sure the chip is on */
> -	ret = taos_chip_on(indio_dev);
> +	ret = tsl2583_chip_init_and_power_on(indio_dev);
>  	if (ret < 0)
>  		return ret;
>  
> @@ -825,7 +819,7 @@ static int __maybe_unused taos_suspend(struct device *dev)
>  	mutex_lock(&chip->als_mutex);
>  
>  	if (chip->taos_chip_status == TSL258X_CHIP_WORKING) {
> -		ret = taos_chip_off(indio_dev);
> +		ret = tsl2583_set_power_state(chip, TSL258X_CNTL_PWR_OFF);
>  		chip->taos_chip_status = TSL258X_CHIP_SUSPENDED;
>  	}
>  
> @@ -842,7 +836,7 @@ static int __maybe_unused taos_resume(struct device *dev)
>  	mutex_lock(&chip->als_mutex);
>  
>  	if (chip->taos_chip_status == TSL258X_CHIP_SUSPENDED)
> -		ret = taos_chip_on(indio_dev);
> +		ret = tsl2583_chip_init_and_power_on(indio_dev);
>  
>  	mutex_unlock(&chip->als_mutex);
>  	return ret;
>