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 transitioned from set-then-clear 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 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(-)
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 --- 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 =
As per the current implementation, after FSC (Full Scale Current) and brightness update the sync bits are transitioned from set-then-clear. But, the FSC and brightness sync takes place during a clear-then-set transition of the sync bits. 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 kgunda@codeaurora.org --- 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)
On Mon, Mar 01, 2021 at 02:58:36PM +0530, Kiran Gunda wrote:
As per the current implementation, after FSC (Full Scale Current) and brightness update the sync bits are transitioned from set-then-clear.
This does not makes sense since there are too many verbs. Set and clear are both verbs so in this context: "the code will set the bit and then the code will clear the bit".
Either:
s/transitioned from set-then-clear/set-then-cleared/.
Or:
s/transitioned from set-then-clear/using a set-then-clear approach/.
But, the FSC and brightness sync takes place during a clear-then-set transition of the sync bits.
Likewise this no longer makes sense and had also become misleading. Two changes of state, clear and then set, do not usually result in a single transition.
Either:
s/clear-then-set/0 to 1/
Alternatively, if you want to stick exclusively to the set/clear terminology then replace the whole quoted section with:
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 kgunda@codeaurora.org
With one of each of the changes proposed above: Reviewed-by: Daniel Thompson daniel.thompson@linaro.org
Daniel.
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;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
On 2021-03-01 15:32, Daniel Thompson wrote:
On Mon, Mar 01, 2021 at 02:58:36PM +0530, Kiran Gunda wrote:
As per the current implementation, after FSC (Full Scale Current) and brightness update the sync bits are transitioned from set-then-clear.
This does not makes sense since there are too many verbs. Set and clear are both verbs so in this context: "the code will set the bit and then the code will clear the bit".
Either:
s/transitioned from set-then-clear/set-then-cleared/.
Or:
s/transitioned from set-then-clear/using a set-then-clear approach/.
But, the FSC and brightness sync takes place during a clear-then-set transition of the sync bits.
Likewise this no longer makes sense and had also become misleading. Two changes of state, clear and then set, do not usually result in a single transition.
Either:
s/clear-then-set/0 to 1/
Alternatively, if you want to stick exclusively to the set/clear terminology then replace the whole quoted section with:
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 kgunda@codeaurora.org
With one of each of the changes proposed above: Reviewed-by: Daniel Thompson daniel.thompson@linaro.org
Daniel.
Apologies for the mistake. I have corrected and submitted the V4 series with the "reviewed-by" tag.
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;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
dri-devel@lists.freedesktop.org
-
Daniel Thompson -
kgunda＠codeaurora.org -
Kiran Gunda