From: Mario Limonciello <mario.limoncie...@amd.com>
[WHY]
Userspace currently is offered a range from 0-0xFF but the PWM is
programmed from 0-0xFFFF. This can be limiting to some software
that wants to apply greater granularity.
[HOW]
Convert internally to firmware values only when mapping custom
brightness curves because these are in 0-0xFF range. Advertise full
PWM range to userspace.
Cc: Mario Limonciello <mario.limoncie...@amd.com>
Cc: Alex Deucher <alexander.deuc...@amd.com>
Cc: sta...@vger.kernel.org
Reviewed-by: Roman Li <roman...@amd.com>
Signed-off-by: Mario Limonciello <mario.limoncie...@amd.com>
Signed-off-by: Alex Hung <alex.h...@amd.com>
---
.../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 41 ++++++++++++-------
1 file changed, 27 insertions(+), 14 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 31df545f8c0f..19d38357f508 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -4721,9 +4721,23 @@ static int get_brightness_range(const struct
amdgpu_dm_backlight_caps *caps,
return 1;
}
+/* Rescale from [min..max] to [0..AMDGPU_MAX_BL_LEVEL] */
+static inline u32 scale_input_to_fw(int min, int max, u64 input)
+{
+ return DIV_ROUND_CLOSEST_ULL(input * AMDGPU_MAX_BL_LEVEL, max - min);
+}
+
+/* Rescale from [0..AMDGPU_MAX_BL_LEVEL] to [min..max] */
+static inline u32 scale_fw_to_input(int min, int max, u64 input)
+{
+ return min + DIV_ROUND_CLOSEST_ULL(input * (max - min),
AMDGPU_MAX_BL_LEVEL);
+}
+
static void convert_custom_brightness(const struct amdgpu_dm_backlight_caps
*caps,
- uint32_t *brightness)
+ unsigned int min, unsigned int max,
+ uint32_t *user_brightness)
{
+ u32 brightness = scale_input_to_fw(min, max, *user_brightness);
u8 prev_signal = 0, prev_lum = 0;
int i = 0;
@@ -4734,7 +4748,7 @@ static void convert_custom_brightness(const struct
amdgpu_dm_backlight_caps *cap
return;
/* choose start to run less interpolation steps */
- if (caps->luminance_data[caps->data_points/2].input_signal >
*brightness)
+ if (caps->luminance_data[caps->data_points/2].input_signal > brightness)
i = caps->data_points/2;
do {
u8 signal = caps->luminance_data[i].input_signal;
@@ -4745,17 +4759,18 @@ static void convert_custom_brightness(const struct
amdgpu_dm_backlight_caps *cap
* brightness < signal: interpolate between previous and
current luminance numerator
* brightness > signal: find next data point
*/
- if (*brightness > signal) {
+ if (brightness > signal) {
prev_signal = signal;
prev_lum = lum;
i++;
continue;
}
- if (*brightness < signal)
+ if (brightness < signal)
lum = prev_lum + DIV_ROUND_CLOSEST((lum - prev_lum) *
- (*brightness -
prev_signal),
+ (brightness -
prev_signal),
signal -
prev_signal);
- *brightness = DIV_ROUND_CLOSEST(lum * *brightness, 101);
+ *user_brightness = scale_fw_to_input(min, max,
+ DIV_ROUND_CLOSEST(lum *
brightness, 101));
return;
} while (i < caps->data_points);
}
@@ -4768,11 +4783,10 @@ static u32 convert_brightness_from_user(const struct
amdgpu_dm_backlight_caps *c
if (!get_brightness_range(caps, &min, &max))
return brightness;
- convert_custom_brightness(caps, &brightness);
+ convert_custom_brightness(caps, min, max, &brightness);
- // Rescale 0..255 to min..max
- return min + DIV_ROUND_CLOSEST((max - min) * brightness,
- AMDGPU_MAX_BL_LEVEL);
+ // Rescale 0..max to min..max
+ return min + DIV_ROUND_CLOSEST_ULL((u64)(max - min) * brightness, max);
}
static u32 convert_brightness_to_user(const struct amdgpu_dm_backlight_caps
*caps,
@@ -4785,8 +4799,8 @@ static u32 convert_brightness_to_user(const struct
amdgpu_dm_backlight_caps *cap
if (brightness < min)
return 0;
- // Rescale min..max to 0..255
- return DIV_ROUND_CLOSEST(AMDGPU_MAX_BL_LEVEL * (brightness - min),
+ // Rescale min..max to 0..max
+ return DIV_ROUND_CLOSEST_ULL((u64)max * (brightness - min),
max - min);
}
@@ -4936,11 +4950,10 @@ amdgpu_dm_register_backlight_device(struct
amdgpu_dm_connector *aconnector)
drm_dbg(drm, "Backlight caps: min: %d, max: %d, ac %d, dc
%d\n", min, max,
caps->ac_level, caps->dc_level);
} else
- props.brightness = AMDGPU_MAX_BL_LEVEL;
+ props.brightness = props.max_brightness = AMDGPU_MAX_BL_LEVEL;
if (caps->data_points && !(amdgpu_dc_debug_mask &
DC_DISABLE_CUSTOM_BRIGHTNESS_CURVE))
drm_info(drm, "Using custom brightness curve\n");
- props.max_brightness = AMDGPU_MAX_BL_LEVEL;
props.type = BACKLIGHT_RAW;
snprintf(bl_name, sizeof(bl_name), "amdgpu_bl%d",
--
2.43.0
