drm/amd/display: ABM pause toggle

[why]
Allow ABM states to be transferred across display
adapters for smooth display transitions.

[how]
We call DMUB to pause and get ABM states. We
transfer data to other gpu, and deliver data and
ask ABM to un-pause.

Reviewed-by: Harry Vanzylldejong <harry.vanzylldejong@amd.com>
Acked-by: Alan Liu <haoping.liu@amd.com>
Signed-off-by: Reza Amini <reza.amini@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

3 files changed, 80 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/display/dc/dce/dmub_abm.c b/drivers/gpu/drm/amd/display/dc/dce/dmub_abm.c
index 2fb9572ce25d..d3e6544022b7 100644
--- a/drivers/gpu/drm/amd/display/dc/dce/dmub_abm.c
+++ b/drivers/gpu/drm/amd/display/dc/dce/dmub_abm.c
@@ -27,6 +27,7 @@
 #include "dmub_abm_lcd.h"
 #include "dc.h"
 #include "core_types.h"
+#include "dmub_cmd.h"
 
 #define TO_DMUB_ABM(abm)\
 	container_of(abm, struct dce_abm, base)
@@ -118,6 +119,32 @@ static bool dmub_abm_set_pause_ex(struct abm *abm, bool pause, unsigned int pane
 	return ret;
 }
 
+/*****************************************************************************
+ *  dmub_abm_save_restore_ex() - calls dmub_abm_save_restore for preserving DMUB's
+ *                              Varibright states for LCD only. OLED is TBD
+ *  @abm: used to check get dc context
+ *  @panel_inst: panel instance index
+ *  @pData: contains command to pause/un-pause abm and abm parameters
+ *
+ *
+ ***************************************************************************/
+static bool dmub_abm_save_restore_ex(
+		struct abm *abm,
+		unsigned int panel_inst,
+		struct abm_save_restore *pData)
+{
+	bool ret = false;
+	unsigned int feature_support;
+	struct dc_context *dc = abm->ctx;
+
+	feature_support = abm_feature_support(abm, panel_inst);
+
+	if (feature_support == ABM_LCD_SUPPORT)
+		ret = dmub_abm_save_restore(dc, panel_inst, pData);
+
+	return ret;
+}
+
 static bool dmub_abm_set_pipe_ex(struct abm *abm, uint32_t otg_inst, uint32_t option, uint32_t panel_inst)
 {
 	bool ret = false;
@@ -155,6 +182,7 @@ static const struct abm_funcs abm_funcs = {
 	.get_target_backlight = dmub_abm_get_target_backlight_ex,
 	.init_abm_config = dmub_abm_init_config_ex,
 	.set_abm_pause = dmub_abm_set_pause_ex,
+	.save_restore = dmub_abm_save_restore_ex,
 	.set_pipe_ex = dmub_abm_set_pipe_ex,
 	.set_backlight_level_pwm = dmub_abm_set_backlight_level_pwm_ex,
 };
diff --git a/drivers/gpu/drm/amd/display/dc/dce/dmub_abm_lcd.c b/drivers/gpu/drm/amd/display/dc/dce/dmub_abm_lcd.c
index 39da73eba86e..592a8f7a1c6d 100644
--- a/drivers/gpu/drm/amd/display/dc/dce/dmub_abm_lcd.c
+++ b/drivers/gpu/drm/amd/display/dc/dce/dmub_abm_lcd.c
@@ -208,6 +208,52 @@ bool dmub_abm_set_pause(struct abm *abm, bool pause, unsigned int panel_inst, un
 	return true;
 }
 
+
+/*****************************************************************************
+ *  dmub_abm_save_restore() - dmub interface for abm save+pause and restore+
+ *                           un-pause
+ *  @dc: dc context
+ *  @panel_inst: panel instance index
+ *  @pData: contains command to pause/un-pause abm and exchange abm parameters
+ *
+ *  When called Pause will get abm data and store in pData, and un-pause will
+ *  set/apply abm data stored in pData.
+ *
+ *****************************************************************************/
+bool dmub_abm_save_restore(
+		struct dc_context *dc,
+		unsigned int panel_inst,
+		struct abm_save_restore *pData)
+{
+	union dmub_rb_cmd cmd;
+	uint8_t panel_mask = 0x01 << panel_inst;
+	unsigned int bytes = sizeof(struct abm_save_restore);
+
+	// TODO: Optimize by only reading back final 4 bytes
+	dmub_flush_buffer_mem(&dc->dmub_srv->dmub->scratch_mem_fb);
+
+	// Copy iramtable into cw7
+	memcpy(dc->dmub_srv->dmub->scratch_mem_fb.cpu_addr, (void *)pData, bytes);
+
+	memset(&cmd, 0, sizeof(cmd));
+	cmd.abm_save_restore.header.type = DMUB_CMD__ABM;
+	cmd.abm_save_restore.header.sub_type = DMUB_CMD__ABM_SAVE_RESTORE;
+
+	cmd.abm_save_restore.abm_init_config_data.src.quad_part = dc->dmub_srv->dmub->scratch_mem_fb.gpu_addr;
+	cmd.abm_save_restore.abm_init_config_data.bytes = bytes;
+	cmd.abm_save_restore.abm_init_config_data.version = DMUB_CMD_ABM_CONTROL_VERSION_1;
+	cmd.abm_save_restore.abm_init_config_data.panel_mask = panel_mask;
+
+	cmd.abm_save_restore.header.payload_bytes = sizeof(struct dmub_rb_cmd_abm_save_restore);
+
+	dm_execute_dmub_cmd(dc, &cmd, DM_DMUB_WAIT_TYPE_WAIT);
+
+	// Copy iramtable data into local structure
+	memcpy((void *)pData, dc->dmub_srv->dmub->scratch_mem_fb.cpu_addr, bytes);
+
+	return true;
+}
+
 bool dmub_abm_set_pipe(struct abm *abm, uint32_t otg_inst, uint32_t option, uint32_t panel_inst)
 {
 	union dmub_rb_cmd cmd;
diff --git a/drivers/gpu/drm/amd/display/dc/dce/dmub_abm_lcd.h b/drivers/gpu/drm/amd/display/dc/dce/dmub_abm_lcd.h
index 00b4e268768e..853564d7f471 100644
--- a/drivers/gpu/drm/amd/display/dc/dce/dmub_abm_lcd.h
+++ b/drivers/gpu/drm/amd/display/dc/dce/dmub_abm_lcd.h
@@ -28,6 +28,8 @@
 
 #include "abm.h"
 
+struct abm_save_restore;
+
 void dmub_abm_init(struct abm *abm, uint32_t backlight);
 bool dmub_abm_set_level(struct abm *abm, uint32_t level, uint8_t panel_mask);
 unsigned int dmub_abm_get_current_backlight(struct abm *abm);
@@ -38,6 +40,10 @@ void dmub_abm_init_config(struct abm *abm,
 	unsigned int inst);
 
 bool dmub_abm_set_pause(struct abm *abm, bool pause, unsigned int panel_inst, unsigned int stream_inst);
+bool dmub_abm_save_restore(
+		struct dc_context *dc,
+		unsigned int panel_inst,
+		struct abm_save_restore *pData);
 bool dmub_abm_set_pipe(struct abm *abm, uint32_t otg_inst, uint32_t option, uint32_t panel_inst);
 bool dmub_abm_set_backlight_level(struct abm *abm,
 		unsigned int backlight_pwm_u16_16,