drm/amd/display: Expand dc to use 16.16 bit backlight

[Why] We want to increase precision for backlight setting.
But DC interface takes 8 bit backlight level value only.

[How] DMCU already takes 16 bit backlight level.
Expand the DC interface to take 16.16 bit value.
Max 32 bit backlight value (0xFFFF) will represent
max backlight (100%)

Signed-off-by: Anthony Koo <Anthony.Koo@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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 a3849e1615931cbb0ddd6ee6c6d42fe1592f2e9e..67b547c64a3eb00790ff2b453b1620326f746806 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -1580,8 +1580,14 @@ static int amdgpu_dm_backlight_update_status(struct backlight_device *bd)
         */
        if (bd->props.brightness < 1)
                return 1;
+
+       /* backlight_pwm_u16_16 parameter is in unsigned 32 bit, 16 bit integer
+        * and 16 bit fractional, where 1.0 is max backlight value.
+        * bd->props.brightness is 8 bit format and needs to be converted by
+        * scaling via copy lower byte to upper byte of 16 bit value.
+        */
        if (dc_link_set_backlight_level(dm->backlight_link,
-                       bd->props.brightness, 0, 0))
+                       (bd->props.brightness * 0x101), 0, 0))
                return 0;
        else
                return 1;

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link.c b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
index f4936f7c55451e32c983d75f0e7706448ee9b3b4..643407d18cce853996a08bbc796ca859c49cabbf 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
@@ -2141,14 +2141,16 @@ int dc_link_get_backlight_level(const struct dc_link *link)
 {
        struct abm *abm = link->ctx->dc->res_pool->abm;
 
-       if (abm == NULL || abm->funcs->get_current_backlight_8_bit == NULL)
+       if (abm == NULL || abm->funcs->get_current_backlight == NULL)
                return DC_ERROR_UNEXPECTED;
 
-       return (int) abm->funcs->get_current_backlight_8_bit(abm);
+       return (int) abm->funcs->get_current_backlight(abm);
 }
 
-bool dc_link_set_backlight_level(const struct dc_link *link, uint32_t level,
-               uint32_t frame_ramp, const struct dc_stream_state *stream)
+bool dc_link_set_backlight_level(const struct dc_link *link,
+               uint32_t backlight_pwm_u16_16,
+               uint32_t frame_ramp,
+               const struct dc_stream_state *stream)
 {
        struct dc  *core_dc = link->ctx->dc;
        struct abm *abm = core_dc->res_pool->abm;
@@ -2160,19 +2162,17 @@ bool dc_link_set_backlight_level(const struct dc_link *link, uint32_t level,
 
        if ((dmcu == NULL) ||
                (abm == NULL) ||
-               (abm->funcs->set_backlight_level == NULL))
+               (abm->funcs->set_backlight_level_pwm == NULL))
                return false;
 
-       if (stream) {
-               if (stream->bl_pwm_level == EDP_BACKLIGHT_RAMP_DISABLE_LEVEL)
-                       frame_ramp = 0;
-
-               ((struct dc_stream_state *)stream)->bl_pwm_level = level;
-       }
+       if (stream)
+               ((struct dc_stream_state *)stream)->bl_pwm_level =
+                               backlight_pwm_u16_16;
 
        use_smooth_brightness = dmcu->funcs->is_dmcu_initialized(dmcu);
 
-       DC_LOG_BACKLIGHT("New Backlight level: %d (0x%X)\n", level, level);
+       DC_LOG_BACKLIGHT("New Backlight level: %d (0x%X)\n",
+                       backlight_pwm_u16_16, backlight_pwm_u16_16);
 
        if (dc_is_embedded_signal(link->connector_signal)) {
                if (stream != NULL) {
@@ -2189,9 +2189,9 @@ bool dc_link_set_backlight_level(const struct dc_link *link, uint32_t level,
                                                1;
                        }
                }
-               abm->funcs->set_backlight_level(
+               abm->funcs->set_backlight_level_pwm(
                                abm,
-                               level,
+                               backlight_pwm_u16_16,
                                frame_ramp,
                                controller_id,
                                use_smooth_brightness);
@@ -2205,7 +2205,7 @@ bool dc_link_set_abm_disable(const struct dc_link *link)
        struct dc  *core_dc = link->ctx->dc;
        struct abm *abm = core_dc->res_pool->abm;
 
-       if ((abm == NULL) || (abm->funcs->set_backlight_level == NULL))
+       if ((abm == NULL) || (abm->funcs->set_backlight_level_pwm == NULL))
                return false;
 
        abm->funcs->set_abm_immediate_disable(abm);
@@ -2594,6 +2594,10 @@ void core_link_enable_stream(
                core_dc->hwss.unblank_stream(pipe_ctx,
                        &pipe_ctx->stream->sink->link->cur_link_settings);
 
+               dc_link_set_backlight_level(pipe_ctx->stream->sink->link,
+                               pipe_ctx->stream->bl_pwm_level,
+                               0,
+                               pipe_ctx->stream);
        }
 
 }

diff --git a/drivers/gpu/drm/amd/display/dc/dc_link.h b/drivers/gpu/drm/amd/display/dc/dc_link.h
index 3bfdccceb524427c40ac0a2b063710c2bb66bbe3..8738f27a87088d26a0bca47ebc9087f986037117 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dc_link.h
+++ b/drivers/gpu/drm/amd/display/dc/dc_link.h
@@ -138,9 +138,14 @@ static inline struct dc_link *dc_get_link_at_index(struct dc *dc, uint32_t link_
        return dc->links[link_index];
 }
 
-/* Set backlight level of an embedded panel (eDP, LVDS). */
-bool dc_link_set_backlight_level(const struct dc_link *dc_link, uint32_t level,
-               uint32_t frame_ramp, const struct dc_stream_state *stream);
+/* Set backlight level of an embedded panel (eDP, LVDS).
+ * backlight_pwm_u16_16 is unsigned 32 bit with 16 bit integer
+ * and 16 bit fractional, where 1.0 is max backlight value.
+ */
+bool dc_link_set_backlight_level(const struct dc_link *dc_link,
+               uint32_t backlight_pwm_u16_16,
+               uint32_t frame_ramp,
+               const struct dc_stream_state *stream);
 
 int dc_link_get_backlight_level(const struct dc_link *dc_link);
 

diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_abm.c b/drivers/gpu/drm/amd/display/dc/dce/dce_abm.c
index 29294db1a96b775013635d080725e392cda4766b..e9765bb38a8bc4d5692f78ed01a5b11e2b263351 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dce/dce_abm.c
+++ b/drivers/gpu/drm/amd/display/dc/dce/dce_abm.c
@@ -54,7 +54,7 @@
 #define MCP_DISABLE_ABM_IMMEDIATELY 255
 
 
-static unsigned int get_current_backlight_16_bit(struct dce_abm *abm_dce)
+static unsigned int calculate_16_bit_backlight_from_pwm(struct dce_abm *abm_dce)
 {
        uint64_t current_backlight;
        uint32_t round_result;
@@ -103,45 +103,21 @@ static unsigned int get_current_backlight_16_bit(struct dce_abm *abm_dce)
        return (uint32_t)(current_backlight);
 }
 
-static void driver_set_backlight_level(struct dce_abm *abm_dce, uint32_t level)
+static void driver_set_backlight_level(struct dce_abm *abm_dce,
+               uint32_t backlight_pwm_u16_16)
 {
-       uint32_t backlight_24bit;
-       uint32_t backlight_17bit;
        uint32_t backlight_16bit;
        uint32_t masked_pwm_period;
-       uint8_t rounding_bit;
        uint8_t bit_count;
        uint64_t active_duty_cycle;
        uint32_t pwm_period_bitcnt;
 
        /*
-        * 1. Convert 8-bit value to 17 bit U1.16 format
-        * (1 integer, 16 fractional bits)
-        */
-
-       /* 1.1 multiply 8 bit value by 0x10101 to get a 24 bit value,
-        * effectively multiplying value by 256/255
-        * eg. for a level of 0xEF, backlight_24bit = 0xEF * 0x10101 = 0xEFEFEF
-        */
-       backlight_24bit = level * 0x10101;
-
-       /* 1.2 The upper 16 bits of the 24 bit value is the fraction, lower 8
-        * used for rounding, take most significant bit of fraction for
-        * rounding, e.g. for 0xEFEFEF, rounding bit is 1
-        */
-       rounding_bit = (backlight_24bit >> 7) & 1;
-
-       /* 1.3 Add the upper 16 bits of the 24 bit value with the rounding bit
-        * resulting in a 17 bit value e.g. 0xEFF0 = (0xEFEFEF >> 8) + 1
-        */
-       backlight_17bit = (backlight_24bit >> 8) + rounding_bit;
-
-       /*
-        * 2. Find  16 bit backlight active duty cycle, where 0 <= backlight
+        * 1. Find  16 bit backlight active duty cycle, where 0 <= backlight
         * active duty cycle <= backlight period
         */
 
-       /* 2.1 Apply bitmask for backlight period value based on value of BITCNT
+       /* 1.1 Apply bitmask for backlight period value based on value of BITCNT
         */
        REG_GET_2(BL_PWM_PERIOD_CNTL,
                        BL_PWM_PERIOD_BITCNT, &pwm_period_bitcnt,
@@ -155,13 +131,13 @@ static void driver_set_backlight_level(struct dce_abm *abm_dce, uint32_t level)
        /* e.g. maskedPwmPeriod = 0x24 when bitCount is 6 */
        masked_pwm_period = masked_pwm_period & ((1 << bit_count) - 1);
 
-       /* 2.2 Calculate integer active duty cycle required upper 16 bits
+       /* 1.2 Calculate integer active duty cycle required upper 16 bits
         * contain integer component, lower 16 bits contain fractional component
         * of active duty cycle e.g. 0x21BDC0 = 0xEFF0 * 0x24
         */
-       active_duty_cycle = backlight_17bit * masked_pwm_period;
+       active_duty_cycle = backlight_pwm_u16_16 * masked_pwm_period;
 
-       /* 2.3 Calculate 16 bit active duty cycle from integer and fractional
+       /* 1.3 Calculate 16 bit active duty cycle from integer and fractional
         * components shift by bitCount then mask 16 bits and add rounding bit
         * from MSB of fraction e.g. 0x86F7 = ((0x21BDC0 >> 6) & 0xFFF) + 0
         */
@@ -170,23 +146,23 @@ static void driver_set_backlight_level(struct dce_abm *abm_dce, uint32_t level)
        backlight_16bit += (active_duty_cycle >> (bit_count - 1)) & 0x1;
 
        /*
-        * 3. Program register with updated value
+        * 2. Program register with updated value
         */
 
-       /* 3.1 Lock group 2 backlight registers */
+       /* 2.1 Lock group 2 backlight registers */
 
        REG_UPDATE_2(BL_PWM_GRP1_REG_LOCK,
                        BL_PWM_GRP1_IGNORE_MASTER_LOCK_EN, 1,
                        BL_PWM_GRP1_REG_LOCK, 1);
 
-       // 3.2 Write new active duty cycle
+       // 2.2 Write new active duty cycle
        REG_UPDATE(BL_PWM_CNTL, BL_ACTIVE_INT_FRAC_CNT, backlight_16bit);
 
-       /* 3.3 Unlock group 2 backlight registers */
+       /* 2.3 Unlock group 2 backlight registers */
        REG_UPDATE(BL_PWM_GRP1_REG_LOCK,
                        BL_PWM_GRP1_REG_LOCK, 0);
 
-       /* 5.4.4 Wait for pending bit to be cleared */
+       /* 3 Wait for pending bit to be cleared */
        REG_WAIT(BL_PWM_GRP1_REG_LOCK,
                        BL_PWM_GRP1_REG_UPDATE_PENDING, 0,
                        1, 10000);
@@ -194,16 +170,21 @@ static void driver_set_backlight_level(struct dce_abm *abm_dce, uint32_t level)
 
 static void dmcu_set_backlight_level(
        struct dce_abm *abm_dce,
-       uint32_t level,
+       uint32_t backlight_pwm_u16_16,
        uint32_t frame_ramp,
        uint32_t controller_id)
 {
-       unsigned int backlight_16_bit = (level * 0x10101) >> 8;
-       unsigned int backlight_17_bit = backlight_16_bit +
-                               (((backlight_16_bit & 0x80) >> 7) & 1);
+       unsigned int backlight_8_bit = 0;
        uint32_t rampingBoundary = 0xFFFF;
        uint32_t s2;
 
+       if (backlight_pwm_u16_16 & 0x10000)
+               // Check for max backlight condition
+               backlight_8_bit = 0xFF;
+       else
+               // Take MSB of fractional part since backlight is not max
+               backlight_8_bit = (backlight_pwm_u16_16 >> 8) & 0xFF;
+
        /* set ramping boundary */
        REG_WRITE(MASTER_COMM_DATA_REG1, rampingBoundary);
 
@@ -220,7 +201,7 @@ static void dmcu_set_backlight_level(
                        0, 1, 80000);
 
        /* setDMCUParam_BL */
-       REG_UPDATE(BL1_PWM_USER_LEVEL, BL1_PWM_USER_LEVEL, backlight_17_bit);
+       REG_UPDATE(BL1_PWM_USER_LEVEL, BL1_PWM_USER_LEVEL, backlight_pwm_u16_16);
 
        /* write ramp */
        if (controller_id == 0)
@@ -237,9 +218,9 @@ static void dmcu_set_backlight_level(
        s2 = REG_READ(BIOS_SCRATCH_2);
 
        s2 &= ~ATOM_S2_CURRENT_BL_LEVEL_MASK;
-       level &= (ATOM_S2_CURRENT_BL_LEVEL_MASK >>
+       backlight_8_bit &= (ATOM_S2_CURRENT_BL_LEVEL_MASK >>
                                ATOM_S2_CURRENT_BL_LEVEL_SHIFT);
-       s2 |= (level << ATOM_S2_CURRENT_BL_LEVEL_SHIFT);
+       s2 |= (backlight_8_bit << ATOM_S2_CURRENT_BL_LEVEL_SHIFT);
 
        REG_WRITE(BIOS_SCRATCH_2, s2);
 }
@@ -247,7 +228,7 @@ static void dmcu_set_backlight_level(
 static void dce_abm_init(struct abm *abm)
 {
        struct dce_abm *abm_dce = TO_DCE_ABM(abm);
-       unsigned int backlight = get_current_backlight_16_bit(abm_dce);
+       unsigned int backlight = calculate_16_bit_backlight_from_pwm(abm_dce);
 
        REG_WRITE(DC_ABM1_HG_SAMPLE_RATE, 0x103);
        REG_WRITE(DC_ABM1_HG_SAMPLE_RATE, 0x101);
@@ -284,12 +265,15 @@ static void dce_abm_init(struct abm *abm)
                        ABM1_BL_REG_READ_MISSED_FRAME_CLEAR, 1);
 }
 
-static unsigned int dce_abm_get_current_backlight_8_bit(struct abm *abm)
+static unsigned int dce_abm_get_current_backlight(struct abm *abm)
 {
        struct dce_abm *abm_dce = TO_DCE_ABM(abm);
        unsigned int backlight = REG_READ(BL1_PWM_CURRENT_ABM_LEVEL);
 
-       return (backlight >> 8);
+       /* return backlight in hardware format which is unsigned 17 bits, with
+        * 1 bit integer and 16 bit fractional
+        */
+       return backlight;
 }
 
 static bool dce_abm_set_level(struct abm *abm, uint32_t level)
@@ -396,9 +380,9 @@ static bool dce_abm_init_backlight(struct abm *abm)
        return true;
 }
 
-static bool dce_abm_set_backlight_level(
+static bool dce_abm_set_backlight_level_pwm(
                struct abm *abm,
-               unsigned int backlight_level,
+               unsigned int backlight_pwm_u16_16,
                unsigned int frame_ramp,
                unsigned int controller_id,
                bool use_smooth_brightness)
@@ -406,16 +390,16 @@ static bool dce_abm_set_backlight_level(
        struct dce_abm *abm_dce = TO_DCE_ABM(abm);
 
        DC_LOG_BACKLIGHT("New Backlight level: %d (0x%X)\n",
-                       backlight_level, backlight_level);
+                       backlight_pwm_u16_16, backlight_pwm_u16_16);
 
        /* If DMCU is in reset state, DMCU is uninitialized */
        if (use_smooth_brightness)
                dmcu_set_backlight_level(abm_dce,
-                               backlight_level,
+                               backlight_pwm_u16_16,
                                frame_ramp,
                                controller_id);
        else
-               driver_set_backlight_level(abm_dce, backlight_level);
+               driver_set_backlight_level(abm_dce, backlight_pwm_u16_16);
 
        return true;
 }
@@ -424,8 +408,8 @@ static const struct abm_funcs dce_funcs = {
        .abm_init = dce_abm_init,
        .set_abm_level = dce_abm_set_level,
        .init_backlight = dce_abm_init_backlight,
-       .set_backlight_level = dce_abm_set_backlight_level,
-       .get_current_backlight_8_bit = dce_abm_get_current_backlight_8_bit,
+       .set_backlight_level_pwm = dce_abm_set_backlight_level_pwm,
+       .get_current_backlight = dce_abm_get_current_backlight,
        .set_abm_immediate_disable = dce_abm_immediate_disable
 };
 

diff --git a/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c b/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c
index de3c3276db10269f74aa04758ed2a7b0ef6ccf04..de220778da8e03819e8b45762d470361e347d022 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c
+++ b/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c
@@ -1085,7 +1085,6 @@ void dce110_unblank_stream(struct pipe_ctx *pipe_ctx,
 
        if (link->local_sink && link->local_sink->sink_signal == SIGNAL_TYPE_EDP) {
                link->dc->hwss.edp_backlight_control(link, true);
-               stream->bl_pwm_level = EDP_BACKLIGHT_RAMP_DISABLE_LEVEL;
        }
 }
 void dce110_blank_stream(struct pipe_ctx *pipe_ctx)

diff --git a/drivers/gpu/drm/amd/display/dc/inc/hw/abm.h b/drivers/gpu/drm/amd/display/dc/inc/hw/abm.h
index a83a484946133d00311c8f1219ba2bcf17527805..458a641dc7965ea3cf8518072dd42c59f197a91f 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/inc/hw/abm.h
+++ b/drivers/gpu/drm/amd/display/dc/inc/hw/abm.h
@@ -47,12 +47,17 @@ struct abm_funcs {
        bool (*set_abm_level)(struct abm *abm, unsigned int abm_level);
        bool (*set_abm_immediate_disable)(struct abm *abm);
        bool (*init_backlight)(struct abm *abm);
-       bool (*set_backlight_level)(struct abm *abm,
-                       unsigned int backlight_level,
+
+       /* backlight_pwm_u16_16 is unsigned 32 bit,
+        * 16 bit integer + 16 fractional, where 1.0 is max backlight value.
+        */
+       bool (*set_backlight_level_pwm)(struct abm *abm,
+                       unsigned int backlight_pwm_u16_16,
                        unsigned int frame_ramp,
                        unsigned int controller_id,
                        bool use_smooth_brightness);
-       unsigned int (*get_current_backlight_8_bit)(struct abm *abm);
+
+       unsigned int (*get_current_backlight)(struct abm *abm);
 };
 
 #endif

diff --git a/drivers/gpu/drm/amd/display/dc/inc/hw_sequencer.h b/drivers/gpu/drm/amd/display/dc/inc/hw_sequencer.h
index 75de1d8d0c20ff72ceb6e41b84d62243f4df2c19..e5a85a0563b648abde4491afb47d95d0ba229d98 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/inc/hw_sequencer.h
+++ b/drivers/gpu/drm/amd/display/dc/inc/hw_sequencer.h
@@ -32,8 +32,6 @@
 #include "inc/hw/link_encoder.h"
 #include "core_status.h"
 
-#define EDP_BACKLIGHT_RAMP_DISABLE_LEVEL 0xFFFFFFFF
-
 enum pipe_gating_control {
        PIPE_GATING_CONTROL_DISABLE = 0,
        PIPE_GATING_CONTROL_ENABLE,