Re: [PATCH 1/3] leds: lm3532: Fix brightness control for i2c mode

[Jacek Anaszewski]

Hi Dan,

Thank you for the patch set. Please find my comments
in the code below.

On 8/1/19 5:14 PM, Dan Murphy wrote:
> Fix the brightness control for I2C mode.  Instead of
> changing the full scale current register update the ALS target
> register for the appropriate banks.
> 
> In addition clean up some code errors and random misspellings found
> during coding.
> 
> Tested on Droid4 as well as LM3532 EVM connected to a BeagleBoneBlack
> 
> Fixes: e37a7f8d77e1 ("leds: lm3532: Introduce the lm3532 LED driver")
> Reported-by: Pavel Machek <pavel@xxxxxx>
> Signed-off-by: Dan Murphy <dmurphy@xxxxxx>
> ---
>  drivers/leds/leds-lm3532.c | 78 ++++++++++++++++++++++++--------------
>  1 file changed, 50 insertions(+), 28 deletions(-)
> 
> diff --git a/drivers/leds/leds-lm3532.c b/drivers/leds/leds-lm3532.c
> index 646100724971..ff197adb2f22 100644
> --- a/drivers/leds/leds-lm3532.c
> +++ b/drivers/leds/leds-lm3532.c
> @@ -23,11 +23,11 @@
>  #define LM3532_REG_PWM_B_CFG	0x14
>  #define LM3532_REG_PWM_C_CFG	0x15
>  #define LM3532_REG_ZONE_CFG_A	0x16
> -#define LM3532_REG_CTRL_A_BRT	0x17
> +#define LM3532_REG_CTRL_A_FS_CURR	0x17
>  #define LM3532_REG_ZONE_CFG_B	0x18
> -#define LM3532_REG_CTRL_B_BRT	0x19
> +#define LM3532_REG_CTRL_B_FS_CURR	0x19
>  #define LM3532_REG_ZONE_CFG_C	0x1a
> -#define LM3532_REG_CTRL_C_BRT	0x1b
> +#define LM3532_REG_CTRL_C_FS_CURR	0x1b
>  #define LM3532_REG_ENABLE	0x1d
>  #define LM3532_ALS_CONFIG	0x23
>  #define LM3532_REG_ZN_0_HI	0x60
> @@ -38,9 +38,12 @@
>  #define LM3532_REG_ZN_2_LO	0x65
>  #define LM3532_REG_ZN_3_HI	0x66
>  #define LM3532_REG_ZN_3_LO	0x67
> +#define LM3532_REG_ZONE_TRGT_A	0x70
> +#define LM3532_REG_ZONE_TRGT_B	0x75
> +#define LM3532_REG_ZONE_TRGT_C	0x7a
>  #define LM3532_REG_MAX		0x7e
>  
> -/* Contorl Enable */
> +/* Control Enable */
>  #define LM3532_CTRL_A_ENABLE	BIT(0)
>  #define LM3532_CTRL_B_ENABLE	BIT(1)
>  #define LM3532_CTRL_C_ENABLE	BIT(2)
> @@ -63,6 +66,8 @@
>  #define LM3532_ZONE_2		BIT(3)
>  #define LM3532_ZONE_3		(BIT(2) | BIT(3))
>  #define LM3532_ZONE_4		BIT(4)
> +#define LM3532_BRT_CFG_MASK	(LM3532_I2C_CTRL | LM3532_LINEAR_MAP | \
> +				LM3532_ZONE_MASK)
>  
>  #define LM3532_ENABLE_ALS	BIT(3)
>  #define LM3532_ALS_SEL_SHIFT	6
> @@ -127,6 +132,7 @@ struct lm3532_led {
>  	int control_bank;
>  	int mode;
>  	int num_leds;
> +	int ctrl_brt_pointer;
>  	u32 led_strings[LM3532_MAX_CONTROL_BANKS];
>  	char label[LED_MAX_NAME_SIZE];
>  };
> @@ -161,18 +167,18 @@ struct lm3532_data {
>  };
>  
>  static const struct reg_default lm3532_reg_defs[] = {
> -	{LM3532_REG_OUTPUT_CFG, 0xe4},
> +	{LM3532_REG_OUTPUT_CFG, 0x24},
>  	{LM3532_REG_STARTSHUT_RAMP, 0xc0},
>  	{LM3532_REG_RT_RAMP, 0xc0},
>  	{LM3532_REG_PWM_A_CFG, 0x82},
>  	{LM3532_REG_PWM_B_CFG, 0x82},
>  	{LM3532_REG_PWM_C_CFG, 0x82},
>  	{LM3532_REG_ZONE_CFG_A, 0xf1},
> -	{LM3532_REG_CTRL_A_BRT, 0xf3},
> +	{LM3532_REG_CTRL_A_FS_CURR, 0x13},
>  	{LM3532_REG_ZONE_CFG_B, 0xf1},
> -	{LM3532_REG_CTRL_B_BRT, 0xf3},
> +	{LM3532_REG_CTRL_B_FS_CURR, 0x13},
>  	{LM3532_REG_ZONE_CFG_C, 0xf1},
> -	{LM3532_REG_CTRL_C_BRT, 0xf3},
> +	{LM3532_REG_CTRL_C_FS_CURR, 0x13},
>  	{LM3532_REG_ENABLE, 0xf8},
>  	{LM3532_ALS_CONFIG, 0x44},
>  	{LM3532_REG_ZN_0_HI, 0x35},
> @@ -302,7 +308,7 @@ static int lm3532_led_disable(struct lm3532_led *led_data)
>  	int ret;
>  
>  	ret = regmap_update_bits(led_data->priv->regmap, LM3532_REG_ENABLE,
> -					 ctrl_en_val, ~ctrl_en_val);
> +					 ctrl_en_val, 0);
>  	if (ret) {
>  		dev_err(led_data->priv->dev, "Failed to set ctrl:%d\n", ret);
>  		return ret;
> @@ -321,7 +327,7 @@ static int lm3532_brightness_set(struct led_classdev *led_cdev,
>  
>  	mutex_lock(&led->priv->lock);
>  
> -	if (led->mode == LM3532_BL_MODE_ALS) {
> +	if (led->mode == LM3532_ALS_CTRL) {
>  		if (brt_val > LED_OFF)
>  			ret = lm3532_led_enable(led);
>  		else
> @@ -339,11 +345,9 @@ static int lm3532_brightness_set(struct led_classdev *led_cdev,
>  	if (ret)
>  		goto unlock;
>  
> -	brightness_reg = LM3532_REG_CTRL_A_BRT + led->control_bank * 2;
> -	brt_val = brt_val / LM3532_BRT_VAL_ADJUST;
> -
> +	brightness_reg = LM3532_REG_ZONE_TRGT_A + led->control_bank * 5 +
> +			 (led->ctrl_brt_pointer >> 2);
>  	ret = regmap_write(led->priv->regmap, brightness_reg, brt_val);
> -
>  unlock:
>  	mutex_unlock(&led->priv->lock);
>  	return ret;
> @@ -356,8 +360,29 @@ static int lm3532_init_registers(struct lm3532_led *led)
>  	unsigned int output_cfg_val = 0;
>  	unsigned int output_cfg_shift = 0;
>  	unsigned int output_cfg_mask = 0;
> +	int brightness_config_reg;
> +	int brightness_config_val;
>  	int ret, i;
>  
> +	if (drvdata->enable_gpio)
> +		gpiod_direction_output(drvdata->enable_gpio, 1);
> +
> +	brightness_config_reg = LM3532_REG_ZONE_CFG_A + led->control_bank * 2;
> +	/* This could be hard coded to the default value but the control

Coding style issue:

        /*
         * This is the preferred style for multi-line comments


> +	 * brightness register may have changed during boot.
> +	 */> +	ret = regmap_read(drvdata->regmap, brightness_config_reg,
> +			  &led->ctrl_brt_pointer);
> +	if (ret)
> +		return ret;
> +
> +	led->ctrl_brt_pointer &= LM3532_ZONE_MASK;

Could you shed more light on this hardware peculiarity?
What kind of pointer is it?

> +	brightness_config_val = led->ctrl_brt_pointer | led->mode;
> +	ret = regmap_write(drvdata->regmap, brightness_config_reg,
> +			   brightness_config_val);
> +	if (ret)
> +		return ret;
> +
>  	for (i = 0; i < led->num_leds; i++) {
>  		output_cfg_shift = led->led_strings[i] * 2;
>  		output_cfg_val |= (led->control_bank << output_cfg_shift);
> @@ -382,7 +407,6 @@ static int lm3532_als_configure(struct lm3532_data *priv,
>  	struct lm3532_als_data *als = priv->als_data;
>  	u32 als_vmin, als_vmax, als_vstep;
>  	int zone_reg = LM3532_REG_ZN_0_HI;
> -	int brightnes_config_reg;
>  	int ret;
>  	int i;
>  
> @@ -411,14 +435,7 @@ static int lm3532_als_configure(struct lm3532_data *priv,
>  	als->config = (als->als_avrg_time | (LM3532_ENABLE_ALS) |
>  		(als->als_input_mode << LM3532_ALS_SEL_SHIFT));
>  
> -	ret = regmap_write(priv->regmap, LM3532_ALS_CONFIG, als->config);
> -	if (ret)
> -		return ret;
> -
> -	brightnes_config_reg = LM3532_REG_ZONE_CFG_A + led->control_bank * 2;
> -
> -	return regmap_update_bits(priv->regmap, brightnes_config_reg,
> -				  LM3532_I2C_CTRL, LM3532_ALS_CTRL);
> +	return regmap_write(priv->regmap, LM3532_ALS_CONFIG, als->config);
>  }
>  
>  static int lm3532_parse_als(struct lm3532_data *priv)
> @@ -542,12 +559,14 @@ static int lm3532_parse_node(struct lm3532_data *priv)
>  		}
>  
>  		if (led->mode == LM3532_BL_MODE_ALS) {
> +			led->mode = LM3532_ALS_CTRL;
>  			ret = lm3532_parse_als(priv);
>  			if (ret)
>  				dev_err(&priv->client->dev, "Failed to parse als\n");
>  			else
>  				lm3532_als_configure(priv, led);
> -		}
> +		} else
> +			led->mode = LM3532_I2C_CTRL;

Coding style issue: you need curly braces around the body of "else"
in this case as well.

>  
>  		led->num_leds = fwnode_property_count_u32(child, "led-sources");
>  		if (led->num_leds > LM3532_MAX_LED_STRINGS) {
> @@ -587,7 +606,13 @@ static int lm3532_parse_node(struct lm3532_data *priv)
>  			goto child_out;
>  		}
>  
> -		lm3532_init_registers(led);
> +		ret = lm3532_init_registers(led);
> +		if (ret) {
> +			dev_err(&priv->client->dev, "register init err: %d\n",
> +				ret);
> +			fwnode_handle_put(child);
> +			goto child_out;
> +		}
>  
>  		i++;
>  	}
> @@ -634,9 +659,6 @@ static int lm3532_probe(struct i2c_client *client,
>  		return ret;
>  	}
>  
> -	if (drvdata->enable_gpio)
> -		gpiod_direction_output(drvdata->enable_gpio, 1);
> -
>  	return ret;
>  }
>  
> 

-- 
Best regards,
Jacek Anaszewski