[PATCH v3 0/3] backlight: aw99706: DT parsing and blank state fixes

[PATCH v3 0/3] backlight: aw99706: DT parsing and blank state fixes

[Junjie Cao]

The driver reads its tuning properties under names the binding does not
define (patch 1), the validation paths accept values the binding forbids
(patch 2), and update_status() ignores the blank state, leaving bl_power
inoperative (patch 3).

v3:
- patch 2: reject 0 for awinic,sw-freq-hz (reserved-slot marker
  collided with it); add Fixes tag
- patch 3: add stable tag
v2: only patch 1/3 reached the lists (outbound mail failure):
    https://lore.kernel.org/all/20260803141310.1379194-2-junjie.cao@linux.dev/
v1: https://lore.kernel.org/all/20260701133918.33487-1-junjie.cao@linux.dev/

Junjie Cao (3):
  backlight: aw99706: Fix DT property names to match binding
  backlight: aw99706: Validate all DT property values consistently
  backlight: aw99706: Honor the core blank state in update_status()

 drivers/video/backlight/aw99706.c | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

-- 
2.43.0

[PATCH v3 1/3] backlight: aw99706: Fix DT property names to match binding

[Junjie Cao]

From: Junjie Cao <junjie.cao@linux.dev>

The driver reads four tuning properties without the unit suffixes that
the binding mandates: "awinic,sw-freq" instead of "awinic,sw-freq-hz",
"awinic,sw-ilmt" instead of "awinic,sw-ilmt-microamp", "awinic,iled-max"
instead of "awinic,iled-max-microamp", and "awinic,uvlo-thres" instead
of "awinic,uvlo-thres-microvolt".

As a result, device_property_read_u32() never finds these properties in
a binding-conformant device tree and silently falls back to the compiled-in
defaults for switching frequency, switching current limit, max LED current,
and UVLO threshold.

Fix by aligning the property name strings in aw99706_dt_props[] with the
binding. No value/range changes are needed since both sides already use
the same units and enumerations.

Fixes: 147b38a5ad06 ("backlight: aw99706: Add support for Awinic AW99706 backlight")
Cc: stable@vger.kernel.org
Signed-off-by: Junjie Cao <junjie.cao@linux.dev>
---
 drivers/video/backlight/aw99706.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/video/backlight/aw99706.c b/drivers/video/backlight/aw99706.c
index 18299faf06ad..e130f164303a 100644
--- a/drivers/video/backlight/aw99706.c
+++ b/drivers/video/backlight/aw99706.c
@@ -130,23 +130,23 @@ static const struct aw99706_dt_prop aw99706_dt_props[] = {
 		AW99706_CFG0_REG, AW99706_DIM_MODE_MASK, 1,
 	},
 	{
-		"awinic,sw-freq", aw99706_dt_property_lookup,
+		"awinic,sw-freq-hz", aw99706_dt_property_lookup,
 		aw99706_sw_freq_tbl, ARRAY_SIZE(aw99706_sw_freq_tbl),
 		AW99706_CFG1_REG, AW99706_SW_FREQ_MASK, 750000,
 	},
 	{
-		"awinic,sw-ilmt", aw99706_dt_property_lookup,
+		"awinic,sw-ilmt-microamp", aw99706_dt_property_lookup,
 		aw99706_sw_ilmt_tbl, ARRAY_SIZE(aw99706_sw_ilmt_tbl),
 		AW99706_CFG1_REG, AW99706_SW_ILMT_MASK, 3000000,
 	},
 	{
-		"awinic,iled-max", aw99706_dt_property_iled_max_convert,
+		"awinic,iled-max-microamp", aw99706_dt_property_iled_max_convert,
 		NULL, 0,
 		AW99706_CFG2_REG, AW99706_ILED_MAX_MASK, 20000,
 
 	},
 	{
-		"awinic,uvlo-thres", aw99706_dt_property_lookup,
+		"awinic,uvlo-thres-microvolt", aw99706_dt_property_lookup,
 		aw99706_ulvo_thres_tbl, ARRAY_SIZE(aw99706_ulvo_thres_tbl),
 		AW99706_CFG2_REG, AW99706_UVLOSEL_MASK, 2200000,
 	},
-- 
2.43.0

[PATCH v3 2/3] backlight: aw99706: Validate all DT property values consistently

[Junjie Cao]

From: Junjie Cao <junjie.cao@linux.dev>

The lookup helpers for dim-mode and ramp-ctl take a shortcut when
lookup_tbl is NULL: they accept any u32 value without range-checking
and return success unconditionally. Out-of-range values get silently
truncated by regmap_update_bits instead of triggering the dev_warn +
default-fallback path that the other properties use.

Add a field-width check for the NULL-table case so that values
exceeding the register field maximum are rejected the same way a
table-lookup miss is.

The switching frequency table has a second hole: reserved slots use 0
as their marker, so "awinic,sw-freq-hz = <0>" matches slot 0 and
programs a reserved encoding. Make the reserved marker U32_MAX and
skip such slots during lookup.

While here, also switch the error returns to -EINVAL for consistency.

Fixes: 147b38a5ad06 ("backlight: aw99706: Add support for Awinic AW99706 backlight")
Signed-off-by: Junjie Cao <junjie.cao@linux.dev>
---
 drivers/video/backlight/aw99706.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/video/backlight/aw99706.c b/drivers/video/backlight/aw99706.c
index e130f164303a..6ec49b6cb14c 100644
--- a/drivers/video/backlight/aw99706.c
+++ b/drivers/video/backlight/aw99706.c
@@ -60,7 +60,7 @@
 #define AW99706_MTPLDOSEL_REG			0x1E
 #define AW99706_MTPRUN_REG			0x1F
 
-#define RESV	0
+#define RESV	U32_MAX
 
 /* Boost switching frequency table, in Hz */
 static const u32 aw99706_sw_freq_tbl[] = {
@@ -94,17 +94,19 @@ static int aw99706_dt_property_lookup(const struct aw99706_dt_prop *prop,
 	int i;
 
 	if (!prop->lookup_tbl) {
+		if (dt_val > (prop->mask >> __ffs(prop->mask)))
+			return -EINVAL;
 		*val = dt_val;
 		return 0;
 	}
 
 	for (i = 0; i < prop->tbl_size; i++)
-		if (prop->lookup_tbl[i] == dt_val)
+		if (prop->lookup_tbl[i] != RESV && prop->lookup_tbl[i] == dt_val)
 			break;
 
 	*val = i;
 
-	return i == prop->tbl_size ? -1 : 0;
+	return i == prop->tbl_size ? -EINVAL : 0;
 }
 
 #define MIN_ILED_MAX	5000
@@ -116,11 +118,14 @@ aw99706_dt_property_iled_max_convert(const struct aw99706_dt_prop *prop,
 				     u32 dt_val, u8 *val)
 {
 	if (dt_val > MAX_ILED_MAX || dt_val < MIN_ILED_MAX)
-		return -1;
+		return -EINVAL;
+
+	if ((dt_val - MIN_ILED_MAX) % STEP_ILED_MAX)
+		return -EINVAL;
 
 	*val = (dt_val - MIN_ILED_MAX) / STEP_ILED_MAX;
 
-	return (dt_val - MIN_ILED_MAX) % STEP_ILED_MAX;
+	return 0;
 }
 
 static const struct aw99706_dt_prop aw99706_dt_props[] = {
-- 
2.43.0

[PATCH v3 3/3] backlight: aw99706: Honor the core blank state in update_status()

[Junjie Cao]

From: Junjie Cao <junjie.cao@linux.dev>

update_status() passes props.brightness straight to the hardware and
ignores the power/blank state tracked by the core. Writing 4 to the
bl_power sysfs attribute or blanking the framebuffer therefore leaves
the backlight lit.

Use backlight_get_brightness(), which returns 0 while the device is
blanked.

Fixes: 147b38a5ad06 ("backlight: aw99706: Add support for Awinic AW99706 backlight")
Cc: stable@vger.kernel.org
Signed-off-by: Junjie Cao <junjie.cao@linux.dev>
---
 drivers/video/backlight/aw99706.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/video/backlight/aw99706.c b/drivers/video/backlight/aw99706.c
index 6ec49b6cb14c..c4a66b59ecf1 100644
--- a/drivers/video/backlight/aw99706.c
+++ b/drivers/video/backlight/aw99706.c
@@ -340,7 +340,7 @@ static int aw99706_bl_update_status(struct backlight_device *bl)
 {
 	struct aw99706_device *aw = bl_get_data(bl);
 
-	return aw99706_update_brightness(aw, bl->props.brightness);
+	return aw99706_update_brightness(aw, backlight_get_brightness(bl));
 }
 
 static const struct backlight_ops aw99706_bl_ops = {
-- 
2.43.0

Re: [PATCH v3 1/3] backlight: aw99706: Fix DT property names to match binding

[Daniel Thompson]

On Tue, Aug 04, 2026 at 11:02:53AM +0800, Junjie Cao wrote:
> From: Junjie Cao <junjie.cao@linux.dev>
>
> The driver reads four tuning properties without the unit suffixes that
> the binding mandates: "awinic,sw-freq" instead of "awinic,sw-freq-hz",
> "awinic,sw-ilmt" instead of "awinic,sw-ilmt-microamp", "awinic,iled-max"
> instead of "awinic,iled-max-microamp", and "awinic,uvlo-thres" instead
> of "awinic,uvlo-thres-microvolt".
>
> As a result, device_property_read_u32() never finds these properties in
> a binding-conformant device tree and silently falls back to the compiled-in
> defaults for switching frequency, switching current limit, max LED current,
> and UVLO threshold.
>
> Fix by aligning the property name strings in aw99706_dt_props[] with the
> binding. No value/range changes are needed since both sides already use
> the same units and enumerations.
>
> Fixes: 147b38a5ad06 ("backlight: aw99706: Add support for Awinic AW99706 backlight")
> Cc: stable@vger.kernel.org
> Signed-off-by: Junjie Cao <junjie.cao@linux.dev>

There don't seem to be any usage of these properties in-tree so I think
it is probably OK to change the driver behaviour without fallbacks for
DTs with version skew!

Reviewed-by: Daniel Thompson (RISCstar) <danielt@kernel.org>


Daniel.

Re: [PATCH v3 2/3] backlight: aw99706: Validate all DT property values consistently

[Daniel Thompson]

On Tue, Aug 04, 2026 at 11:02:54AM +0800, Junjie Cao wrote:
> From: Junjie Cao <junjie.cao@linux.dev>
>
> The lookup helpers for dim-mode and ramp-ctl take a shortcut when
> lookup_tbl is NULL: they accept any u32 value without range-checking
> and return success unconditionally. Out-of-range values get silently
> truncated by regmap_update_bits instead of triggering the dev_warn +
> default-fallback path that the other properties use.
>
> Add a field-width check for the NULL-table case so that values
> exceeding the register field maximum are rejected the same way a
> table-lookup miss is.
>
> The switching frequency table has a second hole: reserved slots use 0
> as their marker, so "awinic,sw-freq-hz = <0>" matches slot 0 and
> programs a reserved encoding. Make the reserved marker U32_MAX and
> skip such slots during lookup.
>
> While here, also switch the error returns to -EINVAL for consistency.
>
> Fixes: 147b38a5ad06 ("backlight: aw99706: Add support for Awinic AW99706 backlight")
> Signed-off-by: Junjie Cao <junjie.cao@linux.dev>

Reviewed-by: Daniel Thompson (RISCstar) <danielt@kernel.org>


Daniel.

Re: [PATCH v3 3/3] backlight: aw99706: Honor the core blank state in update_status()

[Daniel Thompson]

On Tue, Aug 04, 2026 at 11:02:55AM +0800, Junjie Cao wrote:
> From: Junjie Cao <junjie.cao@linux.dev>
>
> update_status() passes props.brightness straight to the hardware and
> ignores the power/blank state tracked by the core. Writing 4 to the
> bl_power sysfs attribute or blanking the framebuffer therefore leaves
> the backlight lit.
>
> Use backlight_get_brightness(), which returns 0 while the device is
> blanked.
>
> Fixes: 147b38a5ad06 ("backlight: aw99706: Add support for Awinic AW99706 backlight")
> Cc: stable@vger.kernel.org
> Signed-off-by: Junjie Cao <junjie.cao@linux.dev>

Reviewed-by: Daniel Thompson (RISCstar) <danielt@kernel.org>


Daniel.