diff options
Diffstat (limited to 'drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c')
| -rw-r--r-- | drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 25 |
1 files changed, 25 insertions, 0 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 8d5daa96eeae..5e049b8f877d 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -4750,10 +4750,35 @@ static u32 convert_brightness_from_user(const struct amdgpu_dm_backlight_caps *c uint32_t brightness) { unsigned int min, max; + u8 prev_signal = 0, prev_lum = 0; if (!get_brightness_range(caps, &min, &max)) return brightness; + for (int i = 0; i < caps->data_points; i++) { + u8 signal, lum; + + signal = caps->luminance_data[i].input_signal; + lum = caps->luminance_data[i].luminance; + + /* + * brightness == signal: luminance is percent numerator + * brightness < signal: interpolate between previous and current luminance numerator + * brightness > signal: find next data point + */ + if (brightness < signal) + lum = prev_lum + DIV_ROUND_CLOSEST((lum - prev_lum) * + (brightness - prev_signal), + signal - prev_signal); + else if (brightness > signal) { + prev_signal = signal; + prev_lum = lum; + continue; + } + brightness = DIV_ROUND_CLOSEST(lum * brightness, 101); + break; + } + // Rescale 0..255 to min..max return min + DIV_ROUND_CLOSEST((max - min) * brightness, AMDGPU_MAX_BL_LEVEL); |