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

From: Lars-Peter Clausen
Date: Fri Jan 20 2012 - 13:39:26 EST


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

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/