From: Iswara Nagulendran <[email protected]> [Why] ABM does not take effect when brightness is below twenty percent on VABC LCD panels.
[How] Create new VESA aux path for brightness translation functions. When VESA aux enabled use zero-anchored linear interpolation to translate instead of the legacy min max backlight mapping. Reviewed-by: Anthony Koo <[email protected]> Signed-off-by: Iswara Nagulendran <[email protected]> Signed-off-by: Roman Li <[email protected]> --- .../drm/amd/display/modules/power/power_abm.c | 215 ++++++++++++++++-- .../amd/display/modules/power/power_helpers.h | 9 + 2 files changed, 210 insertions(+), 14 deletions(-) diff --git a/drivers/gpu/drm/amd/display/modules/power/power_abm.c b/drivers/gpu/drm/amd/display/modules/power/power_abm.c index b26ceaba940d..5e86889eaa84 100644 --- a/drivers/gpu/drm/amd/display/modules/power/power_abm.c +++ b/drivers/gpu/drm/amd/display/modules/power/power_abm.c @@ -245,29 +245,80 @@ struct iram_table_v_2_2 { #define MOD_POWER_TO_CORE(mod_power)\ container_of(mod_power, struct core_power, mod_public) +/* Maximum brightness expressed in millipercent (100% * 1000). */ +#define BACKLIGHT_MILLIPERCENT_MAX (100 * 1000) + static uint16_t backlight_8_to_16(unsigned int backlight_8bit) { return (uint16_t)(backlight_8bit * 0x101); } +/* Caches the link's backlight control type on the panel's backlight + * properties so the brightness translation helpers can pick the correct + * mapping. + */ +void mod_power_set_backlight_control_type(struct core_power *core_power, + unsigned int inst, enum backlight_control_type backlight_control_type) +{ + if (core_power == NULL) + return; + + core_power->bl_prop[inst].backlight_control_type = backlight_control_type; +} + +/* Returns true when the panel uses the VESA AUX backlight control path, which + * requires zero-anchored linear brightness interpolation. + */ +static bool is_vesa_abc(struct core_power *core_power, unsigned int inst) +{ + if (core_power == NULL) + return false; + + return core_power->bl_prop[inst].backlight_control_type == + BACKLIGHT_CONTROL_VESA_AUX; +} + +/* Legacy millipercent→millinit conversion: scales linearly between + * [0%, 100%] → [min_brightness_millinits, max_brightness_millinits]. + */ +static unsigned int backlight_millipercent_to_millinit_legacy( + struct core_power *core_power, unsigned int millipercent, unsigned int inst) +{ + if (core_power == NULL) + return 0; + + return (unsigned int)div_u64((unsigned long long)millipercent * + core_power->bl_prop[inst].nits_range, + 100000) + + core_power->bl_prop[inst].min_brightness_millinits; +} + +/* Converts millipercent to millinit. + * For VESA AUX brightness control, uses simple linear interpolation with + * 0% = 0 nits and 100% = max_brightness_millinits. + * Otherwise, falls back to the legacy min→max nits range mapping. + */ unsigned int backlight_millipercent_to_millinit( struct core_power *core_power, unsigned int millipercent, unsigned int inst) { - unsigned int millinit = 0; - unsigned long long numerator = 0; + if (!is_vesa_abc(core_power, inst)) + return backlight_millipercent_to_millinit_legacy(core_power, millipercent, inst); if (core_power == NULL) return 0; - numerator = ((unsigned long long)millipercent) * - core_power->bl_prop[inst].nits_range; - millinit = ((unsigned int)div_u64(numerator, 100000)) + - core_power->bl_prop[inst].min_brightness_millinits; + if (millipercent >= BACKLIGHT_MILLIPERCENT_MAX) + return core_power->bl_prop[inst].max_brightness_millinits; - return millinit; + return (unsigned int)div_u64((unsigned long long)millipercent * + core_power->bl_prop[inst].max_brightness_millinits, + BACKLIGHT_MILLIPERCENT_MAX); } -static unsigned int backlight_millinit_to_millipercent( +/* Legacy millinit→millipercent conversion: scales linearly between + * [min_brightness_millinits, max_brightness_millinits] → [0%, 100%]. + */ +static unsigned int backlight_millinit_to_millipercent_legacy( struct core_power *core_power, unsigned int millinit, unsigned int inst) { unsigned int millipercent = 0; @@ -280,7 +331,7 @@ static unsigned int backlight_millinit_to_millipercent( return 0; if (millinit >= core_power->bl_prop[inst].max_brightness_millinits) - return (100 * 1000); + return BACKLIGHT_MILLIPERCENT_MAX; numerator = (((unsigned long long)millinit) - core_power->bl_prop[inst].min_brightness_millinits) * 100000; @@ -290,7 +341,31 @@ static unsigned int backlight_millinit_to_millipercent( return millipercent; } -static unsigned int backlight_pwm_to_millipercent( +/* Converts millinit to millipercent. + * For VESA AUX brightness control, uses simple linear interpolation with + * 0 nits = 0% and max_brightness_millinits = 100%. + * Otherwise, falls back to the legacy min→max nits range mapping. + */ +static unsigned int backlight_millinit_to_millipercent( + struct core_power *core_power, unsigned int millinit, unsigned int inst) +{ + if (!is_vesa_abc(core_power, inst)) + return backlight_millinit_to_millipercent_legacy(core_power, millinit, inst); + + if (core_power == NULL) + return 0; + + if (core_power->bl_prop[inst].max_brightness_millinits == 0) + return 0; + + if (millinit >= core_power->bl_prop[inst].max_brightness_millinits) + return BACKLIGHT_MILLIPERCENT_MAX; + + return (unsigned int)div_u64((unsigned long long)millinit * 100000, + core_power->bl_prop[inst].max_brightness_millinits); +} + +static unsigned int backlight_pwm_to_millipercent_legacy( struct core_power *core_power, unsigned int pwm, unsigned int inst) { unsigned int millipercent = 0; @@ -362,12 +437,37 @@ static unsigned int backlight_pwm_to_millipercent( } /* No interpolation, just take closest index */ - millipercent = 1000 * 100 * mid / max_index; + millipercent = BACKLIGHT_MILLIPERCENT_MAX * mid / max_index; return millipercent; } -static unsigned int backlight_pwm_to_millinit( +/* Converts PWM to millipercent. + * For VESA AUX brightness control, uses simple linear interpolation with + * 0 PWM = 0% and max_backlight_pwm = 100%. + * Otherwise, falls back to the legacy LUT based mapping. + */ +static unsigned int backlight_pwm_to_millipercent( + struct core_power *core_power, unsigned int pwm, unsigned int inst) +{ + if (!is_vesa_abc(core_power, inst)) + return backlight_pwm_to_millipercent_legacy(core_power, pwm, inst); + + if (core_power == NULL) + return 0; + + if (core_power->bl_prop[inst].max_backlight_pwm == 0) + return 0; + + if (pwm >= core_power->bl_prop[inst].max_backlight_pwm) + return BACKLIGHT_MILLIPERCENT_MAX; + + return (unsigned int)div_u64((unsigned long long)pwm * + BACKLIGHT_MILLIPERCENT_MAX, + core_power->bl_prop[inst].max_backlight_pwm); +} + +static unsigned int backlight_pwm_to_millinit_legacy( struct core_power *core_power, unsigned int pwm, unsigned int inst) { unsigned int millinit = 0; @@ -394,7 +494,32 @@ static unsigned int backlight_pwm_to_millinit( return millinit; } -unsigned int backlight_millipercent_to_pwm( +/* Converts PWM to millinit. + * For VESA AUX brightness control, uses simple linear interpolation with + * 0 PWM = 0 nits and max_backlight_pwm = max_brightness_millinits. + * Otherwise, falls back to the legacy min→max nits range mapping. + */ +static unsigned int backlight_pwm_to_millinit( + struct core_power *core_power, unsigned int pwm, unsigned int inst) +{ + if (!is_vesa_abc(core_power, inst)) + return backlight_pwm_to_millinit_legacy(core_power, pwm, inst); + + if (core_power == NULL) + return 0; + + if (core_power->bl_prop[inst].max_backlight_pwm == 0) + return 0; + + if (pwm >= core_power->bl_prop[inst].max_backlight_pwm) + return core_power->bl_prop[inst].max_brightness_millinits; + + return (unsigned int)div_u64((unsigned long long)pwm * + core_power->bl_prop[inst].max_brightness_millinits, + core_power->bl_prop[inst].max_backlight_pwm); +} + +static unsigned int backlight_millipercent_to_pwm_legacy( struct core_power *core_power, unsigned int millipercent, unsigned int inst) { unsigned int pwm = (unsigned int)-1; @@ -431,7 +556,32 @@ unsigned int backlight_millipercent_to_pwm( return pwm; } -static unsigned int backlight_millinit_to_pwm( +/* Converts millipercent to PWM. + * For VESA AUX brightness control, uses simple linear interpolation with + * 0% = 0 PWM and 100% = max_backlight_pwm. + * Otherwise, falls back to the legacy LUT based mapping. + */ +unsigned int backlight_millipercent_to_pwm( + struct core_power *core_power, unsigned int millipercent, unsigned int inst) +{ + if (!is_vesa_abc(core_power, inst)) + return backlight_millipercent_to_pwm_legacy(core_power, millipercent, inst); + + if (core_power == NULL) + return 0; + + if (millipercent >= BACKLIGHT_MILLIPERCENT_MAX) + return core_power->bl_prop[inst].max_backlight_pwm; + + return (unsigned int)div_u64((unsigned long long)millipercent * + core_power->bl_prop[inst].max_backlight_pwm, + BACKLIGHT_MILLIPERCENT_MAX); +} + +/* Legacy millinit→PWM conversion: scales linearly between + * [min_brightness_millinits, max_brightness_millinits] → [min_backlight_pwm, max_backlight_pwm]. + */ +static unsigned int backlight_millinit_to_pwm_legacy( struct core_power *core_power, unsigned int millinit, unsigned int inst) { unsigned int pwm = 0; @@ -460,6 +610,35 @@ static unsigned int backlight_millinit_to_pwm( return pwm; } +/* Converts millinit to PWM. + * For VESA AUX brightness control, uses simple linear interpolation with + * 0 nits = 0 PWM and max_brightness_millinits = max_backlight_pwm. + * Otherwise, falls back to the legacy min→max nits range mapping. + */ +static unsigned int backlight_millinit_to_pwm( + struct core_power *core_power, unsigned int millinit, unsigned int inst) +{ + if (!is_vesa_abc(core_power, inst)) + return backlight_millinit_to_pwm_legacy(core_power, millinit, inst); + + if (core_power == NULL) + return 0; + + if (core_power->bl_prop[inst].max_brightness_millinits == 0) + return 0; + + if (millinit >= core_power->bl_prop[inst].max_brightness_millinits) + return core_power->bl_prop[inst].max_backlight_pwm; + + /* millinit is bounded by max_brightness_millinits (up to ~10^7 for ~10000 nits). + * max_backlight_pwm is a 32-bit value. + * Worst-case product (~10^7 × UINT_MAX ≈ 4×10^16) fits within unsigned long long. + */ + return (unsigned int)div_u64((unsigned long long)millinit * + core_power->bl_prop[inst].max_backlight_pwm, + core_power->bl_prop[inst].max_brightness_millinits); +} + static bool validate_ext_backlight_caps( struct dm_acpi_atif_backlight_caps *ext_backlight_caps) { @@ -716,6 +895,14 @@ void mod_power_update_backlight_on_mode_change( { struct set_backlight_level_params backlight_level_params = { 0 }; + /* Cache the panel's backlight control type once at mode-change/init + * time. It is a stable per-panel property (decided in the OS shim + * from panel type + DPCD caps), so the brightness translation + * helpers can read it without it being passed on every call. + */ + mod_power_set_backlight_control_type(core_power, panel_inst, + link->backlight_control_type); + if ((link->dpcd_sink_ext_caps.bits.hdr_aux_backlight_control == 1 || link->dpcd_sink_ext_caps.bits.sdr_aux_backlight_control == 1) && link->backlight_control_type == BACKLIGHT_CONTROL_AMD_AUX) diff --git a/drivers/gpu/drm/amd/display/modules/power/power_helpers.h b/drivers/gpu/drm/amd/display/modules/power/power_helpers.h index 548c8ff6ddb4..68679fa10946 100644 --- a/drivers/gpu/drm/amd/display/modules/power/power_helpers.h +++ b/drivers/gpu/drm/amd/display/modules/power/power_helpers.h @@ -102,6 +102,13 @@ struct pwr_backlight_properties { unsigned int max_brightness_millinits; unsigned int nits_range; + /* Backlight control type of the associated link. Cached here so the + * brightness translation helpers can select the correct mapping + * (legacy vs. VESA AUX zero-anchored) without threading the type + * through every call. + */ + enum backlight_control_type backlight_control_type; + bool backlight_caps_valid; bool use_custom_backlight_caps; unsigned int custom_backlight_caps_config_no; @@ -190,6 +197,8 @@ void reset_replay_dsync_error_count(struct dc_link *link); void change_replay_to_psr(struct dc_link *link); void change_psr_to_replay(struct dc_link *link); void initialize_backlight_caps(struct core_power *core_power, unsigned int inst); +void mod_power_set_backlight_control_type(struct core_power *core_power, + unsigned int inst, enum backlight_control_type backlight_control_type); unsigned int backlight_millipercent_to_pwm( struct core_power *core_power, unsigned int millipercent, unsigned int inst); unsigned int backlight_millipercent_to_millinit( -- 2.34.1
