[PATCH v3] drm/amdgpu: Disable ABM when AC mode

[Ryan Lin]

Disable ABM feature when the system is running on AC mode to get the more
perfect contrast of the display.

v2: remove "UPSTREAM" from the subject.

v3: adv->pm.ac_power updating by amd gpu_acpi_event_handler.

Signed-off-by: Ryan Lin <tsung-hua.lin at amd.com>

---
 drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c      |  3 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c    |  1 +
 drivers/gpu/drm/amd/display/dc/dce/dmub_abm.c | 61 +++++++++++--------
 drivers/gpu/drm/amd/include/amd_acpi.h        |  1 +
 4 files changed, 41 insertions(+), 25 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c
index 4811b0faafd9a..6ac331ee4255d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c
@@ -822,7 +822,8 @@ static int amdgpu_acpi_event(struct notifier_block *nb,
 	struct amdgpu_device *adev = container_of(nb, struct amdgpu_device, acpi_nb);
 	struct acpi_bus_event *entry = (struct acpi_bus_event *)data;
 
-	if (strcmp(entry->device_class, ACPI_AC_CLASS) == 0) {
+	if (strcmp(entry->device_class, ACPI_AC_CLASS) == 0 ||
+	    strcmp(entry->device_class, ACPI_BATTERY_CLASS) == 0) {
 		if (power_supply_is_system_supplied() > 0)
 			DRM_DEBUG_DRIVER("pm: AC\n");
 		else
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index abfcc1304ba0c..3a0afe7602727 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -3454,6 +3454,7 @@ int amdgpu_device_init(struct amdgpu_device *adev,
 
 	adev->gfx.gfx_off_req_count = 1;
 	adev->pm.ac_power = power_supply_is_system_supplied() > 0;
+	adev->pm.old_ac_power = true;
 
 	atomic_set(&adev->throttling_logging_enabled, 1);
 	/*
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 54a1408c8015c..090bd23410b45 100644
--- a/drivers/gpu/drm/amd/display/dc/dce/dmub_abm.c
+++ b/drivers/gpu/drm/amd/display/dc/dce/dmub_abm.c
@@ -22,7 +22,8 @@
  * Authors: AMD
  *
  */
-
+#include <linux/power_supply.h>
+#include "amdgpu.h"
 #include "dmub_abm.h"
 #include "dce_abm.h"
 #include "dc.h"
@@ -50,7 +51,7 @@
 
 #define DISABLE_ABM_IMMEDIATELY 255
 
-
+extern uint amdgpu_dm_abm_level;
 
 static void dmub_abm_enable_fractional_pwm(struct dc_context *dc)
 {
@@ -117,28 +118,6 @@ static void dmub_abm_init(struct abm *abm, uint32_t backlight)
 	dmub_abm_enable_fractional_pwm(abm->ctx);
 }
 
-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;
@@ -147,6 +126,10 @@ static bool dmub_abm_set_level(struct abm *abm, uint32_t level)
 	int i;
 	int edp_num;
 	uint8_t panel_mask = 0;
+	struct amdgpu_device *dev = dc->driver_context;
+
+	if (dev->pm.ac_power)
+		level = 0;
 
 	get_edp_links(dc->dc, edp_links, &edp_num);
 
@@ -170,6 +153,36 @@ static bool dmub_abm_set_level(struct abm *abm, uint32_t level)
 	return true;
 }
 
+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);
+	struct dc_context *dc = abm->ctx;
+	struct amdgpu_device *adev = dc->driver_context;
+
+	if (adev->pm.ac_power != adev->pm.old_ac_power) {
+		dmub_abm_set_level(abm, amdgpu_dm_abm_level);
+		adev->pm.ac_power = power_supply_is_system_supplied() > 0;
+		adev->pm.old_ac_power = adev->pm.ac_power;
+	}
+
+	/* 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_init_config(struct abm *abm,
 	const char *src,
 	unsigned int bytes,
diff --git a/drivers/gpu/drm/amd/include/amd_acpi.h b/drivers/gpu/drm/amd/include/amd_acpi.h
index 2d089d30518f3..5a62e580668e4 100644
--- a/drivers/gpu/drm/amd/include/amd_acpi.h
+++ b/drivers/gpu/drm/amd/include/amd_acpi.h
@@ -25,6 +25,7 @@
 #define AMD_ACPI_H
 
 #define ACPI_AC_CLASS           "ac_adapter"
+#define ACPI_BATTERY_CLASS  "battery"
 
 struct atif_verify_interface {
 	u16 size;		/* structure size in bytes (includes size field) */
-- 
2.25.1