Re: [PATCH V2 1/2] backlight: qcom-wled: Fix FSC update issue for WLED5

From: Daniel Thompson <daniel.thompson@linaro.org>
To: Kiran Gunda <kgunda@codeaurora.org>
Cc: bjorn.andersson@linaro.org, jingoohan1@gmail.com,
	lee.jones@linaro.org, b.zolnierkie@samsung.com,
	dri-devel@lists.freedesktop.org, jacek.anaszewski@gmail.com,
	pavel@ucw.cz, robh+dt@kernel.org, mark.rutland@arm.com,
	linux-leds@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, Andy Gross <agross@kernel.org>,
	linux-arm-msm@vger.kernel.org, linux-fbdev@vger.kernel.org,
	phone-devel@vger.kernel.org
Subject: Re: [PATCH V2 1/2] backlight: qcom-wled: Fix FSC update issue for WLED5
Date: Fri, 26 Feb 2021 17:09:04 +0000	[thread overview]
Message-ID: <20210226170904.u5ysz6kg4tqbh3us@maple.lan> (raw)
In-Reply-To: <1614341544-5306-2-git-send-email-kgunda@codeaurora.org>

On Fri, Feb 26, 2021 at 05:42:23PM +0530, Kiran Gunda wrote:
> Currently, for WLED5, the FSC (Full scale current) setting is not
> updated properly due to driver toggling the wrong register after
> an FSC update.
> 
> On WLED5 we should only toggle the MOD_SYNC bit after a brightness
> update. For an FSC update we need to toggle the SYNC bits instead.
> 
> Fix it by adopting the common wled3_sync_toggle() for WLED5 and
> introducing new code to the brightness update path to compensate.
> 
> Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>

Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>

Daniel.

> ---
>  drivers/video/backlight/qcom-wled.c | 25 +++++++++++++++++++------
>  1 file changed, 19 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
> index 3bc7800..aef52b9 100644
> --- a/drivers/video/backlight/qcom-wled.c
> +++ b/drivers/video/backlight/qcom-wled.c
> @@ -348,7 +348,7 @@ static int wled3_sync_toggle(struct wled *wled)
>  	return rc;
>  }
>  
> -static int wled5_sync_toggle(struct wled *wled)
> +static int wled5_mod_sync_toggle(struct wled *wled)
>  {
>  	int rc;
>  	u8 val;
> @@ -445,10 +445,23 @@ static int wled_update_status(struct backlight_device *bl)
>  			goto unlock_mutex;
>  		}
>  
> -		rc = wled->wled_sync_toggle(wled);
> -		if (rc < 0) {
> -			dev_err(wled->dev, "wled sync failed rc:%d\n", rc);
> -			goto unlock_mutex;
> +		if (wled->version < 5) {
> +			rc = wled->wled_sync_toggle(wled);
> +			if (rc < 0) {
> +				dev_err(wled->dev, "wled sync failed rc:%d\n", rc);
> +				goto unlock_mutex;
> +			}
> +		} else {
> +			/*
> +			 * For WLED5 toggling the MOD_SYNC_BIT updates the
> +			 * brightness
> +			 */
> +			rc = wled5_mod_sync_toggle(wled);
> +			if (rc < 0) {
> +				dev_err(wled->dev, "wled mod sync failed rc:%d\n",
> +					rc);
> +				goto unlock_mutex;
> +			}
>  		}
>  	}
>  
> @@ -1459,7 +1472,7 @@ static int wled_configure(struct wled *wled)
>  		size = ARRAY_SIZE(wled5_opts);
>  		*cfg = wled5_config_defaults;
>  		wled->wled_set_brightness = wled5_set_brightness;
> -		wled->wled_sync_toggle = wled5_sync_toggle;
> +		wled->wled_sync_toggle = wled3_sync_toggle;
>  		wled->wled_cabc_config = wled5_cabc_config;
>  		wled->wled_ovp_delay = wled5_ovp_delay;
>  		wled->wled_auto_detection_required =
> -- 
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
>  a Linux Foundation Collaborative Project
> 