This patch series has the following two WLED fixes
1. As per the current implementation, for WLED5, after
the FSC (Full Scale Current) update the driver is incorrectly
toggling the MOD_SYNC register instead of toggling the SYNC register.
The patch 1/2 fixes this by toggling the SYNC register after
FSC update.
2. Currently, the sync bits are set-then-cleared after FSC and brightness
update. As per hardware team recommendation the FSC and brightness sync
takes place from clear-then-set transition of the sync bits.
The patch 2/2 fies this issue.
Changes from V3:
1. Updated the patch description as per Daneil's suggestion.
2. Added Daniel's "Reviewed-by" tag for patch 2/2.
3. Updated the cover letter to use "set" and "clear" properly.
Changes from V2:
1. Added Daniel's "Reviewed-by" tag for patch 1/2.
2. Updated the patch 2/2 description with "set" and "clear"
terminology instead of "1" and "0".
3. Updated the cover letter with "set" and "clear" terminology
instead of "1" and "0".
Changes from V1:
1. Updated the cover letter.
2. Updated the description of the patches as per Daniel's suggestion.
Kiran Gunda (2):
backlight: qcom-wled: Fix FSC update issue for WLED5
backlight: qcom-wled: Correct the sync_toggle sequence
drivers/video/backlight/qcom-wled.c | 37 +++++++++++++++++++++++++------------
1 file changed, 25 insertions(+), 12 deletions(-)
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
As per the current implementation, after FSC (Full Scale Current)
and brightness update the sync bits are set-then-cleared.
But, the FSC and brightness sync takes place when the sync bits are
set (e.g. on a rising edge). So the hardware team recommends a
clear-then-set approach in order to guarantee such a transition
regardless of the previous register state.
Signed-off-by: Kiran Gunda <[email protected]>
Reviewed-by: Daniel Thompson <[email protected]>
---
drivers/video/backlight/qcom-wled.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
index aef52b9..19f83ac 100644
--- a/drivers/video/backlight/qcom-wled.c
+++ b/drivers/video/backlight/qcom-wled.c
@@ -337,13 +337,13 @@ static int wled3_sync_toggle(struct wled *wled)
rc = regmap_update_bits(wled->regmap,
wled->ctrl_addr + WLED3_SINK_REG_SYNC,
- mask, mask);
+ mask, WLED3_SINK_REG_SYNC_CLEAR);
if (rc < 0)
return rc;
rc = regmap_update_bits(wled->regmap,
wled->ctrl_addr + WLED3_SINK_REG_SYNC,
- mask, WLED3_SINK_REG_SYNC_CLEAR);
+ mask, mask);
return rc;
}
@@ -353,17 +353,17 @@ static int wled5_mod_sync_toggle(struct wled *wled)
int rc;
u8 val;
- val = (wled->cfg.mod_sel == MOD_A) ? WLED5_SINK_REG_SYNC_MOD_A_BIT :
- WLED5_SINK_REG_SYNC_MOD_B_BIT;
rc = regmap_update_bits(wled->regmap,
wled->sink_addr + WLED5_SINK_REG_MOD_SYNC_BIT,
- WLED5_SINK_REG_SYNC_MASK, val);
+ WLED5_SINK_REG_SYNC_MASK, 0);
if (rc < 0)
return rc;
+ val = (wled->cfg.mod_sel == MOD_A) ? WLED5_SINK_REG_SYNC_MOD_A_BIT :
+ WLED5_SINK_REG_SYNC_MOD_B_BIT;
return regmap_update_bits(wled->regmap,
wled->sink_addr + WLED5_SINK_REG_MOD_SYNC_BIT,
- WLED5_SINK_REG_SYNC_MASK, 0);
+ WLED5_SINK_REG_SYNC_MASK, val);
}
static int wled_ovp_fault_status(struct wled *wled, bool *fault_set)
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
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 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