Re: [PATCH] leds-lm3530: set the value of max_brightness to 127

[Lars-Peter Clausen]

On 01/20/2012 06:34 PM, Kim, Milo wrote:
> Only 7 bits are used for the brightness. (register address : A0h)
> So the max_brightness property of lm3530 should be set to 127.
> 
> On initializing registers, maximum initial brightness is limited to 'max_brightness'.
> 
> Signed-off-by: Milo(Woogyom) Kim <milo.kim@xxxxxx>
> Reviewed-by: Lars-Peter Clausen <lars@xxxxxxxxxx>

Uhm, I might have suggested this, but I've definitely not yet reviewed this
patch. Please don't add tags for other people unless they have explicitly given
you that tag.

> ---
>  drivers/leds/leds-lm3530.c |    7 +++++++
>  1 files changed, 7 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/leds/leds-lm3530.c b/drivers/leds/leds-lm3530.c
> index 4d7ce76..dce6c2a 100644
> --- a/drivers/leds/leds-lm3530.c
> +++ b/drivers/leds/leds-lm3530.c
> @@ -80,6 +80,9 @@
>  #define LM3530_DEF_ZT_3			(0x66)
>  #define LM3530_DEF_ZT_4			(0x7F)
>  
> +/* 7 bits are used for the brightness : LM3530_BRT_CTRL_REG */
> +#define MAX_BRIGHTNESS			(127)
> +
>  struct lm3530_mode_map {
>  	const char *mode;
>  	enum lm3530_mode mode_val;
> @@ -184,6 +187,9 @@ static int lm3530_init_registers(struct lm3530_data *drvdata)
>  	else
>  		brightness = drvdata->brightness = pltfm->brt_val;
>  
> +	if (brightness > drvdata->led_dev.max_brightness)
> +		brightness = drvdata->led_dev.max_brightness;
> +
>  	reg_val[0] = gen_config;	/* LM3530_GEN_CONFIG */
>  	reg_val[1] = als_config;	/* LM3530_ALS_CONFIG */
>  	reg_val[2] = brt_ramp;		/* LM3530_BRT_RAMP_RATE */
> @@ -340,6 +346,7 @@ static int __devinit lm3530_probe(struct i2c_client *client,
>  	drvdata->enable = false;
>  	drvdata->led_dev.name = LM3530_LED_DEV;
>  	drvdata->led_dev.brightness_set = lm3530_brightness_set;
> +	drvdata->led_dev.max_brightness = MAX_BRIGHTNESS;
>  
>  	i2c_set_clientdata(client, drvdata);
>

You should also remove the division by two. max_brightness is supposed to be
the maximum value which the brightness value can be set to.

- Lars

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