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backlight: aw99706: Validate all DT property values consistently

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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: 147b38a5ad ("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>
Link: https://patch.msgid.link/20260804030255.1934470-3-junjie.cao@intel.com
Signed-off-by: Lee Jones <lee@kernel.org>
This commit is contained in:
Junjie Cao 2026-08-04 11:02:54 +08:00 committed by Lee Jones
parent daf120e464
commit 3d142b19b0
1 changed files with 10 additions and 5 deletions
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15
drivers/video/backlight/aw99706.c
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@ -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[] = {