drm/amd/display: Add ABM driver implementation

[Why]
Moving ABM from DMCU to DMCUB.

[How]
Add ABM driver files and implementation.

Signed-off-by: Wyatt Wood <[e-mail]>
Reviewed-by: Nicholas Kazlauskas <[e-mail]>
Acked-by: Rodrigo Siqueira <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/display/dc/dce/Makefile

···
 DCE = dce_audio.o dce_stream_encoder.o dce_link_encoder.o dce_hwseq.o \
 dce_mem_input.o dce_clock_source.o dce_scl_filters.o dce_transform.o \
 dce_opp.o dce_dmcu.o dce_abm.o dce_ipp.o dce_aux.o \
-dce_i2c.o dce_i2c_hw.o dce_i2c_sw.o dmub_psr.o
+dce_i2c.o dce_i2c_hw.o dce_i2c_sw.o dmub_psr.o dmub_abm.o
 
 AMD_DAL_DCE = $(addprefix $(AMDDALPATH)/dc/dce/,$(DCE))
 

drivers/gpu/drm/amd/display/dc/dce/dce_abm.c

···
 	.set_backlight_level_pwm = dce_abm_set_backlight_level_pwm,
 	.get_current_backlight = dce_abm_get_current_backlight,
 	.get_target_backlight = dce_abm_get_target_backlight,
+	.load_abm_config = NULL,
 	.set_abm_immediate_disable = dce_abm_immediate_disable
 };
 

drivers/gpu/drm/amd/display/dc/dce/dmub_abm.c

···
+/*
+ * Copyright 2019 Advanced Micro Devices, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors: AMD
+ *
+ */
+
+#include "dmub_abm.h"
+#include "dce_abm.h"
+#include "dc.h"
+#include "dc_dmub_srv.h"
+#include "../../dmub/inc/dmub_srv.h"
+#include "core_types.h"
+#include "dm_services.h"
+#include "reg_helper.h"
+#include "fixed31_32.h"
+
+#include "atom.h"
+
+#define TO_DMUB_ABM(abm)\
+	container_of(abm, struct dce_abm, base)
+
+#define REG(reg) \
+	(dce_abm->regs->reg)
+
+#undef FN
+#define FN(reg_name, field_name) \
+	dce_abm->abm_shift->field_name, dce_abm->abm_mask->field_name
+
+#define CTX \
+	dce_abm->base.ctx
+
+#define DISABLE_ABM_IMMEDIATELY 255
+
+static bool dmub_abm_set_pipe(struct abm *abm, uint32_t otg_inst)
+{
+	union dmub_rb_cmd cmd;
+	struct dc_context *dc = abm->ctx;
+	uint32_t ramping_boundary = 0xFFFF;
+
+	cmd.abm_set_pipe.header.type = DMUB_CMD__ABM;
+	cmd.abm_set_pipe.header.sub_type = DMUB_CMD__ABM_SET_PIPE;
+	cmd.abm_set_pipe.abm_set_pipe_data.otg_inst = otg_inst;
+	cmd.abm_set_pipe.abm_set_pipe_data.ramping_boundary = ramping_boundary;
+	cmd.abm_set_pipe.header.payload_bytes = sizeof(struct dmub_cmd_abm_set_pipe_data);
+
+	dc_dmub_srv_cmd_queue(dc->dmub_srv, &cmd.abm_set_pipe.header);
+	dc_dmub_srv_cmd_execute(dc->dmub_srv);
+	dc_dmub_srv_wait_idle(dc->dmub_srv);
+
+	return true;
+}
+
+static unsigned int calculate_16_bit_backlight_from_pwm(struct dce_abm *dce_abm)
+{
+	uint64_t current_backlight;
+	uint32_t round_result;
+	uint32_t bl_period, bl_int_count;
+	uint32_t bl_pwm, fractional_duty_cycle_en;
+	uint32_t bl_period_mask, bl_pwm_mask;
+
+	REG_GET(BL_PWM_PERIOD_CNTL, BL_PWM_PERIOD, &bl_period);
+	REG_GET(BL_PWM_PERIOD_CNTL, BL_PWM_PERIOD_BITCNT, &bl_int_count);
+
+	REG_GET(BL_PWM_CNTL, BL_ACTIVE_INT_FRAC_CNT, &bl_pwm);
+	REG_GET(BL_PWM_CNTL, BL_PWM_FRACTIONAL_EN, &fractional_duty_cycle_en);
+
+	if (bl_int_count == 0)
+		bl_int_count = 16;
+
+	bl_period_mask = (1 << bl_int_count) - 1;
+	bl_period &= bl_period_mask;
+
+	bl_pwm_mask = bl_period_mask << (16 - bl_int_count);
+
+	if (fractional_duty_cycle_en == 0)
+		bl_pwm &= bl_pwm_mask;
+	else
+		bl_pwm &= 0xFFFF;
+
+	current_backlight = (uint64_t)bl_pwm << (1 + bl_int_count);
+
+	if (bl_period == 0)
+		bl_period = 0xFFFF;
+
+	current_backlight = div_u64(current_backlight, bl_period);
+	current_backlight = (current_backlight + 1) >> 1;
+
+	current_backlight = (uint64_t)(current_backlight) * bl_period;
+
+	round_result = (uint32_t)(current_backlight & 0xFFFFFFFF);
+
+	round_result = (round_result >> (bl_int_count-1)) & 1;
+
+	current_backlight >>= bl_int_count;
+	current_backlight += round_result;
+
+	return (uint32_t)(current_backlight);
+}
+
+static void dmcub_set_backlight_level(
+	struct dce_abm *dce_abm,
+	uint32_t backlight_pwm_u16_16,
+	uint32_t frame_ramp,
+	uint32_t otg_inst)
+{
+	union dmub_rb_cmd cmd;
+	struct dc_context *dc = dce_abm->base.ctx;
+	unsigned int backlight_8_bit = 0;
+	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;
+
+	dmub_abm_set_pipe(&dce_abm->base, otg_inst);
+
+	if (otg_inst == 0)
+		frame_ramp = 0;
+
+	cmd.abm_set_backlight.header.type = DMUB_CMD__ABM;
+	cmd.abm_set_backlight.header.sub_type = DMUB_CMD__ABM_SET_BACKLIGHT;
+	cmd.abm_set_backlight.abm_set_backlight_data.frame_ramp = frame_ramp;
+	cmd.abm_set_backlight.header.payload_bytes = sizeof(struct dmub_cmd_abm_set_backlight_data);
+
+	dc_dmub_srv_cmd_queue(dc->dmub_srv, &cmd.abm_set_backlight.header);
+	dc_dmub_srv_cmd_execute(dc->dmub_srv);
+	dc_dmub_srv_wait_idle(dc->dmub_srv);
+
+	// Update requested backlight level
+	s2 = REG_READ(BIOS_SCRATCH_2);
+
+	s2 &= ~ATOM_S2_CURRENT_BL_LEVEL_MASK;
+	backlight_8_bit &= (ATOM_S2_CURRENT_BL_LEVEL_MASK >>
+				ATOM_S2_CURRENT_BL_LEVEL_SHIFT);
+	s2 |= (backlight_8_bit << ATOM_S2_CURRENT_BL_LEVEL_SHIFT);
+
+	REG_WRITE(BIOS_SCRATCH_2, s2);
+}
+
+static void dmub_abm_init(struct abm *abm)
+{
+	struct dce_abm *dce_abm = TO_DMUB_ABM(abm);
+	unsigned int backlight = calculate_16_bit_backlight_from_pwm(dce_abm);
+
+	REG_WRITE(DC_ABM1_HG_SAMPLE_RATE, 0x103);
+	REG_WRITE(DC_ABM1_HG_SAMPLE_RATE, 0x101);
+	REG_WRITE(DC_ABM1_LS_SAMPLE_RATE, 0x103);
+	REG_WRITE(DC_ABM1_LS_SAMPLE_RATE, 0x101);
+	REG_WRITE(BL1_PWM_BL_UPDATE_SAMPLE_RATE, 0x101);
+
+	REG_SET_3(DC_ABM1_HG_MISC_CTRL, 0,
+			ABM1_HG_NUM_OF_BINS_SEL, 0,
+			ABM1_HG_VMAX_SEL, 1,
+			ABM1_HG_BIN_BITWIDTH_SIZE_SEL, 0);
+
+	REG_SET_3(DC_ABM1_IPCSC_COEFF_SEL, 0,
+			ABM1_IPCSC_COEFF_SEL_R, 2,
+			ABM1_IPCSC_COEFF_SEL_G, 4,
+			ABM1_IPCSC_COEFF_SEL_B, 2);
+
+	REG_UPDATE(BL1_PWM_CURRENT_ABM_LEVEL,
+			BL1_PWM_CURRENT_ABM_LEVEL, backlight);
+
+	REG_UPDATE(BL1_PWM_TARGET_ABM_LEVEL,
+			BL1_PWM_TARGET_ABM_LEVEL, backlight);
+
+	REG_UPDATE(BL1_PWM_USER_LEVEL,
+			BL1_PWM_USER_LEVEL, backlight);
+
+	REG_UPDATE_2(DC_ABM1_LS_MIN_MAX_PIXEL_VALUE_THRES,
+			ABM1_LS_MIN_PIXEL_VALUE_THRES, 0,
+			ABM1_LS_MAX_PIXEL_VALUE_THRES, 1000);
+
+	REG_SET_3(DC_ABM1_HGLS_REG_READ_PROGRESS, 0,
+			ABM1_HG_REG_READ_MISSED_FRAME_CLEAR, 1,
+			ABM1_LS_REG_READ_MISSED_FRAME_CLEAR, 1,
+			ABM1_BL_REG_READ_MISSED_FRAME_CLEAR, 1);
+}
+
+static unsigned int dmub_abm_get_current_backlight(struct abm *abm)
+{
+	struct dce_abm *dce_abm = TO_DMUB_ABM(abm);
+	unsigned int backlight = REG_READ(BL1_PWM_CURRENT_ABM_LEVEL);
+
+	/* return backlight in hardware format which is unsigned 17 bits, with
+	 * 1 bit integer and 16 bit fractional
+	 */
+	return backlight;
+}
+
+static unsigned int dmub_abm_get_target_backlight(struct abm *abm)
+{
+	struct dce_abm *dce_abm = TO_DMUB_ABM(abm);
+	unsigned int backlight = REG_READ(BL1_PWM_TARGET_ABM_LEVEL);
+
+	/* return backlight in hardware format which is unsigned 17 bits, with
+	 * 1 bit integer and 16 bit fractional
+	 */
+	return backlight;
+}
+
+static bool dmub_abm_set_level(struct abm *abm, uint32_t level)
+{
+	union dmub_rb_cmd cmd;
+	struct dc_context *dc = abm->ctx;
+
+	cmd.abm_set_level.header.type = DMUB_CMD__ABM;
+	cmd.abm_set_level.header.sub_type = DMUB_CMD__ABM_SET_LEVEL;
+	cmd.abm_set_level.abm_set_level_data.level = level;
+	cmd.abm_set_level.header.payload_bytes = sizeof(struct dmub_cmd_abm_set_level_data);
+
+	dc_dmub_srv_cmd_queue(dc->dmub_srv, &cmd.abm_set_level.header);
+	dc_dmub_srv_cmd_execute(dc->dmub_srv);
+	dc_dmub_srv_wait_idle(dc->dmub_srv);
+
+	return true;
+}
+
+static bool dmub_abm_immediate_disable(struct abm *abm)
+{
+	struct dce_abm *dce_abm = TO_DMUB_ABM(abm);
+
+	dmub_abm_set_pipe(abm, DISABLE_ABM_IMMEDIATELY);
+
+	abm->stored_backlight_registers.BL_PWM_CNTL =
+		REG_READ(BL_PWM_CNTL);
+	abm->stored_backlight_registers.BL_PWM_CNTL2 =
+		REG_READ(BL_PWM_CNTL2);
+	abm->stored_backlight_registers.BL_PWM_PERIOD_CNTL =
+		REG_READ(BL_PWM_PERIOD_CNTL);
+
+	REG_GET(LVTMA_PWRSEQ_REF_DIV, BL_PWM_REF_DIV,
+		&abm->stored_backlight_registers.LVTMA_PWRSEQ_REF_DIV_BL_PWM_REF_DIV);
+
+	return true;
+}
+
+static bool dmub_abm_init_backlight(struct abm *abm)
+{
+	struct dce_abm *dce_abm = TO_DMUB_ABM(abm);
+	uint32_t value;
+
+	/* It must not be 0, so we have to restore them
+	 * Bios bug w/a - period resets to zero,
+	 * restoring to cache values which is always correct
+	 */
+	REG_GET(BL_PWM_CNTL, BL_ACTIVE_INT_FRAC_CNT, &value);
+
+	if (value == 0 || value == 1) {
+		if (abm->stored_backlight_registers.BL_PWM_CNTL != 0) {
+			REG_WRITE(BL_PWM_CNTL,
+				abm->stored_backlight_registers.BL_PWM_CNTL);
+			REG_WRITE(BL_PWM_CNTL2,
+				abm->stored_backlight_registers.BL_PWM_CNTL2);
+			REG_WRITE(BL_PWM_PERIOD_CNTL,
+				abm->stored_backlight_registers.BL_PWM_PERIOD_CNTL);
+			REG_UPDATE(LVTMA_PWRSEQ_REF_DIV,
+				BL_PWM_REF_DIV,
+				abm->stored_backlight_registers.LVTMA_PWRSEQ_REF_DIV_BL_PWM_REF_DIV);
+		} else {
+			/* TODO: Note: This should not really happen since VBIOS
+			 * should have initialized PWM registers on boot.
+			 */
+			REG_WRITE(BL_PWM_CNTL, 0xC000FA00);
+			REG_WRITE(BL_PWM_PERIOD_CNTL, 0x000C0FA0);
+		}
+	} else {
+		abm->stored_backlight_registers.BL_PWM_CNTL =
+				REG_READ(BL_PWM_CNTL);
+		abm->stored_backlight_registers.BL_PWM_CNTL2 =
+				REG_READ(BL_PWM_CNTL2);
+		abm->stored_backlight_registers.BL_PWM_PERIOD_CNTL =
+				REG_READ(BL_PWM_PERIOD_CNTL);
+
+		REG_GET(LVTMA_PWRSEQ_REF_DIV, BL_PWM_REF_DIV,
+				&abm->stored_backlight_registers.LVTMA_PWRSEQ_REF_DIV_BL_PWM_REF_DIV);
+	}
+
+	// Have driver take backlight control
+	// TakeBacklightControl(true)
+	value = REG_READ(BIOS_SCRATCH_2);
+	value |= ATOM_S2_VRI_BRIGHT_ENABLE;
+	REG_WRITE(BIOS_SCRATCH_2, value);
+
+	// Enable the backlight output
+	REG_UPDATE(BL_PWM_CNTL, BL_PWM_EN, 1);
+
+	// Unlock group 2 backlight registers
+	REG_UPDATE(BL_PWM_GRP1_REG_LOCK,
+			BL_PWM_GRP1_REG_LOCK, 0);
+
+	return true;
+}
+
+static bool dmub_abm_set_backlight_level_pwm(
+		struct abm *abm,
+		unsigned int backlight_pwm_u16_16,
+		unsigned int frame_ramp,
+		unsigned int otg_inst,
+		bool use_smooth_brightness)
+{
+	struct dce_abm *dce_abm = TO_DMUB_ABM(abm);
+
+	dmcub_set_backlight_level(dce_abm,
+			backlight_pwm_u16_16,
+			frame_ramp,
+			otg_inst);
+
+	return true;
+}
+
+static void dmub_abm_enable_fractional_pwm(struct dc_context *dc)
+{
+	union dmub_rb_cmd cmd;
+	uint32_t fractional_pwm = (dc->dc->config.disable_fractional_pwm == false) ? 1 : 0;
+
+	cmd.abm_set_pwm_frac.header.type = DMUB_CMD__ABM;
+	cmd.abm_set_pwm_frac.header.sub_type = DMUB_CMD__ABM_SET_PWM_FRAC;
+	cmd.abm_set_pwm_frac.abm_set_pwm_frac_data.fractional_pwm = fractional_pwm;
+	cmd.abm_set_pwm_frac.header.payload_bytes = sizeof(struct dmub_cmd_abm_set_pwm_frac_data);
+
+	dc_dmub_srv_cmd_queue(dc->dmub_srv, &cmd.abm_set_pwm_frac.header);
+	dc_dmub_srv_cmd_execute(dc->dmub_srv);
+	dc_dmub_srv_wait_idle(dc->dmub_srv);
+}
+
+static bool dmub_abm_load_config(struct abm *abm,
+	unsigned int start_offset,
+	const char *src,
+	unsigned int bytes)
+{
+	return true;
+}
+
+static const struct abm_funcs abm_funcs = {
+	.abm_init = dmub_abm_init,
+	.set_abm_level = dmub_abm_set_level,
+	.init_backlight = dmub_abm_init_backlight,
+	.set_pipe = dmub_abm_set_pipe,
+	.set_backlight_level_pwm = dmub_abm_set_backlight_level_pwm,
+	.get_current_backlight = dmub_abm_get_current_backlight,
+	.get_target_backlight = dmub_abm_get_target_backlight,
+	.set_abm_immediate_disable = dmub_abm_immediate_disable,
+	.load_abm_config = dmub_abm_load_config,
+};
+
+static void dmub_abm_construct(
+	struct dce_abm *abm_dce,
+	struct dc_context *ctx,
+	const struct dce_abm_registers *regs,
+	const struct dce_abm_shift *abm_shift,
+	const struct dce_abm_mask *abm_mask)
+{
+	struct abm *base = &abm_dce->base;
+
+	base->ctx = ctx;
+	base->funcs = &abm_funcs;
+	base->stored_backlight_registers.BL_PWM_CNTL = 0;
+	base->stored_backlight_registers.BL_PWM_CNTL2 = 0;
+	base->stored_backlight_registers.BL_PWM_PERIOD_CNTL = 0;
+	base->stored_backlight_registers.LVTMA_PWRSEQ_REF_DIV_BL_PWM_REF_DIV = 0;
+	base->dmcu_is_running = false;
+
+	abm_dce->regs = regs;
+	abm_dce->abm_shift = abm_shift;
+	abm_dce->abm_mask = abm_mask;
+
+	dmub_abm_enable_fractional_pwm(ctx);
+}
+
+struct abm *dmub_abm_create(
+	struct dc_context *ctx,
+	const struct dce_abm_registers *regs,
+	const struct dce_abm_shift *abm_shift,
+	const struct dce_abm_mask *abm_mask)
+{
+	struct dce_abm *abm_dce = kzalloc(sizeof(*abm_dce), GFP_KERNEL);
+
+	if (abm_dce == NULL) {
+		BREAK_TO_DEBUGGER();
+		return NULL;
+	}
+
+	dmub_abm_construct(abm_dce, ctx, regs, abm_shift, abm_mask);
+
+	return &abm_dce->base;
+}
+
+void dmub_abm_destroy(struct abm **abm)
+{
+	struct dce_abm *abm_dce = TO_DMUB_ABM(*abm);
+
+	kfree(abm_dce);
+	*abm = NULL;
+}

drivers/gpu/drm/amd/display/dc/dce/dmub_abm.h

···
+/*
+ * Copyright 2019 Advanced Micro Devices, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors: AMD
+ *
+ */
+
+#ifndef __DMUB_ABM_H__
+#define __DMUB_ABM_H__
+
+#include "abm.h"
+#include "dce_abm.h"
+
+struct abm *dmub_abm_create(
+	struct dc_context *ctx,
+	const struct dce_abm_registers *regs,
+	const struct dce_abm_shift *abm_shift,
+	const struct dce_abm_mask *abm_mask);
+
+void dmub_abm_destroy(struct abm **abm);
+
+#endif

drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c

···
 #include "vm_helper.h"
 #include "dcn20/dcn20_vmid.h"
 #include "dce/dmub_psr.h"
+#include "dce/dmub_abm.h"
 
 #define SOC_BOUNDING_BOX_VALID false
 #define DC_LOGGER_INIT(logger)
···
 		pool->base.dp_clock_source = NULL;
 	}
 
-
-	if (pool->base.abm != NULL)
-		dce_abm_destroy(&pool->base.abm);
+	if (pool->base.abm != NULL) {
+		if (pool->base.abm->ctx->dc->debug.disable_dmcu)
+			dmub_abm_destroy(&pool->base.abm);
+		else
+			dce_abm_destroy(&pool->base.abm);
+	}
 
 	if (pool->base.dmcu != NULL)
 		dce_dmcu_destroy(&pool->base.dmcu);
···
 		goto create_fail;
 	}
 
-	pool->base.dmcu = dcn21_dmcu_create(ctx,
-			&dmcu_regs,
-			&dmcu_shift,
-			&dmcu_mask);
-	if (pool->base.dmcu == NULL) {
-		dm_error("DC: failed to create dmcu!\n");
-		BREAK_TO_DEBUGGER();
-		goto create_fail;
+	if (!dc->debug.disable_dmcu) {
+		pool->base.dmcu = dcn21_dmcu_create(ctx,
+				&dmcu_regs,
+				&dmcu_shift,
+				&dmcu_mask);
+		if (pool->base.dmcu == NULL) {
+			dm_error("DC: failed to create dmcu!\n");
+			BREAK_TO_DEBUGGER();
+			goto create_fail;
+		}
 	}
 
 	if (dc->debug.disable_dmcu) {
···
 		}
 	}
 
-	pool->base.abm = dce_abm_create(ctx,
+	if (dc->debug.disable_dmcu)
+		pool->base.abm = dmub_abm_create(ctx,
 			&abm_regs,
 			&abm_shift,
 			&abm_mask);
-	if (pool->base.abm == NULL) {
-		dm_error("DC: failed to create abm!\n");
-		BREAK_TO_DEBUGGER();
-		goto create_fail;
-	}
+	else
+		pool->base.abm = dce_abm_create(ctx,
+			&abm_regs,
+			&abm_shift,
+			&abm_mask);
 
 	pool->base.pp_smu = dcn21_pp_smu_create(ctx);
 

drivers/gpu/drm/amd/display/dc/inc/hw/abm.h

···
 
 	unsigned int (*get_current_backlight)(struct abm *abm);
 	unsigned int (*get_target_backlight)(struct abm *abm);
+	bool (*load_abm_config)(struct abm *abm,
+			unsigned int start_offset,
+			const char *src,
+			unsigned int bytes);
 };
 
 #endif

drivers/gpu/drm/amd/display/dmub/inc/dmub_cmd.h

···
 	struct dmub_cmd_abm_set_pwm_frac_data abm_set_pwm_frac_data;
 };
 
+struct dmub_cmd_abm_init_config_data {
+	union dmub_addr src;
+	uint16_t bytes;
+};
+
+struct dmub_rb_cmd_abm_init_config {
+	struct dmub_cmd_header header;
+	struct dmub_cmd_abm_init_config_data abm_init_config_data;
+};
+
 union dmub_rb_cmd {
 	struct dmub_rb_cmd_read_modify_write read_modify_write;
 	struct dmub_rb_cmd_reg_field_update_sequence reg_field_update_seq;
···
 	struct dmub_rb_cmd_abm_set_level abm_set_level;
 	struct dmub_rb_cmd_abm_set_ambient_level abm_set_ambient_level;
 	struct dmub_rb_cmd_abm_set_pwm_frac abm_set_pwm_frac;
+	struct dmub_rb_cmd_abm_init_config abm_init_config;
 };
 
 #pragma pack(pop)

drivers/gpu/drm/amd/display/modules/power/power_helpers.c

···
 
 #include "power_helpers.h"
 #include "dc/inc/hw/dmcu.h"
+#include "dc/inc/hw/abm.h"
+#include "dc.h"
+#include "core_types.h"
 
 #define DIV_ROUNDUP(a, b) (((a)+((b)/2))/(b))
 
···
 {
 	unsigned char ram_table[IRAM_SIZE];
 	bool result = false;
+	struct abm *abm = dmcu->ctx->dc->res_pool->abm;
 
-	if (dmcu == NULL)
+	if (dmcu == NULL && abm == NULL)
 		return false;
 
-	if (!dmcu->funcs->is_dmcu_initialized(dmcu))
+	if (dmcu && !dmcu->funcs->is_dmcu_initialized(dmcu))
 		return true;
 
 	memset(&ram_table, 0, sizeof(ram_table));
 
-	if (dmcu->dmcu_version.abm_version == 0x24) {
+	// In the case where abm is implemented on dmcub,
+	// dmcu object will be null.
+	// ABM 2.4 and up are implemented on dmcub
+	if (dmcu == NULL) {
 		fill_iram_v_2_3((struct iram_table_v_2_2 *)ram_table, params);
-		result = dmcu->funcs->load_iram(
-				dmcu, 0, (char *)(&ram_table), IRAM_RESERVE_AREA_START_V2_2);
+		result = abm->funcs->load_abm_config(
+			abm, 0, (char *)(&ram_table), IRAM_RESERVE_AREA_START_V2_2);
+	} else if (dmcu->dmcu_version.abm_version == 0x24) {
+		fill_iram_v_2_3((struct iram_table_v_2_2 *)ram_table, params);
+			result = dmcu->funcs->load_iram(
+					dmcu, 0, (char *)(&ram_table), IRAM_RESERVE_AREA_START_V2_2);
 	} else if (dmcu->dmcu_version.abm_version == 0x23) {
 		fill_iram_v_2_3((struct iram_table_v_2_2 *)ram_table, params);