2021-03-18 12:42:52

by Kiran Gunda

Subject: [PATCH V5 1/2] backlight: qcom-wled: Fix FSC update issue for WLED5

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 <[email protected]>
Reviewed-by: Daniel Thompson <[email protected]>
---
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 fc8b443..e9fbe24 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

2021-03-22 17:36:52

by Lee Jones

Subject: Re: [PATCH V5 1/2] backlight: qcom-wled: Fix FSC update issue for WLED5

On Thu, 18 Mar 2021, 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 <[email protected]>
> Reviewed-by: Daniel Thompson <[email protected]>
> ---
> drivers/video/backlight/qcom-wled.c | 25 +++++++++++++++++++------
> 1 file changed, 19 insertions(+), 6 deletions(-)

Applied, thanks.

--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
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