On Fri, Feb 26, 2021 at 05:42:24PM +0530, Kiran Gunda wrote:
As per the current implementation, after FSC (Full Scale Current) and brightness update the sync bits are transitioned from 1 to 0.
This still seems to incorrectly describe the current behaviour.
Surely in most cases (i.e. every time except the first) the value of the sync bit is 0 when the function is called and we get both a 0 to 1 and then a 1 to 0 transition.
That is why I recommended set-then-clear terminology to describe the current behaviour. It is concise and correct.
Daniel.
But, the FSC and brightness sync takes place during a 0 to 1 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;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)
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