drm/amd: Add DM DMCU support

DMCU (Display Microcontroller Unit) is a GPU chip involved in
eDP features like Adaptive Backlight Modulation and Panel Self
Refresh.

DC is already fully equipped to initialize DMCU as long as the
firmware is loaded.

At the moment only the raven firmware is available.

A single .bin file is loaded by the kernel's loading mechanism
and split into two ucodes according to the header.

DMCU is optional, so if the firmware is not found, no error or
warning is raised.

Signed-off-by: David Francis <David.Francis@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -30,6 +30,7 @@
 #include "vid.h"
 #include "amdgpu.h"
 #include "amdgpu_display.h"
+#include "amdgpu_ucode.h"
 #include "atom.h"
 #include "amdgpu_dm.h"
 #include "amdgpu_pm.h"
@@ -50,6 +51,7 @@
 #include <linux/version.h>
 #include <linux/types.h>
 #include <linux/pm_runtime.h>
+#include <linux/firmware.h>
 
 #include <drm/drmP.h>
 #include <drm/drm_atomic.h>
@@ -71,6 +73,9 @@
 
 #include "modules/inc/mod_freesync.h"
 
+#define FIRMWARE_RAVEN_DMCU		"amdgpu/raven_dmcu.bin"
+MODULE_FIRMWARE(FIRMWARE_RAVEN_DMCU);
+
 /* basic init/fini API */
 static int amdgpu_dm_init(struct amdgpu_device *adev);
 static void amdgpu_dm_fini(struct amdgpu_device *adev);
@@ -514,13 +519,97 @@ static void amdgpu_dm_fini(struct amdgpu_device *adev)
 	return;
 }
 
-static int dm_sw_init(void *handle)
+static int load_dmcu_fw(struct amdgpu_device *adev)
 {
+	const char *fw_name_dmcu;
+	int r;
+	const struct dmcu_firmware_header_v1_0 *hdr;
+
+	switch(adev->asic_type) {
+	case CHIP_BONAIRE:
+	case CHIP_HAWAII:
+	case CHIP_KAVERI:
+	case CHIP_KABINI:
+	case CHIP_MULLINS:
+	case CHIP_TONGA:
+	case CHIP_FIJI:
+	case CHIP_CARRIZO:
+	case CHIP_STONEY:
+	case CHIP_POLARIS11:
+	case CHIP_POLARIS10:
+	case CHIP_POLARIS12:
+	case CHIP_VEGAM:
+	case CHIP_VEGA10:
+	case CHIP_VEGA12:
+	case CHIP_VEGA20:
+		return 0;
+	case CHIP_RAVEN:
+		fw_name_dmcu = FIRMWARE_RAVEN_DMCU;
+		break;
+	default:
+		DRM_ERROR("Unsupported ASIC type: 0x%X\n", adev->asic_type);
+		return -1;
+	}
+
+	if (adev->firmware.load_type != AMDGPU_FW_LOAD_PSP) {
+		DRM_DEBUG_KMS("dm: DMCU firmware not supported on direct or SMU loading\n");
+		return 0;
+	}
+
+	r = request_firmware_direct(&adev->dm.fw_dmcu, fw_name_dmcu, adev->dev);
+	if (r == -ENOENT) {
+		/* DMCU firmware is not necessary, so don't raise a fuss if it's missing */
+		DRM_DEBUG_KMS("dm: DMCU firmware not found\n");
+		adev->dm.fw_dmcu = NULL;
+		return 0;
+	}
+	if (r) {
+		dev_err(adev->dev, "amdgpu_dm: Can't load firmware \"%s\"\n",
+			fw_name_dmcu);
+		return r;
+	}
+
+	r = amdgpu_ucode_validate(adev->dm.fw_dmcu);
+	if (r) {
+		dev_err(adev->dev, "amdgpu_dm: Can't validate firmware \"%s\"\n",
+			fw_name_dmcu);
+		release_firmware(adev->dm.fw_dmcu);
+		adev->dm.fw_dmcu = NULL;
+		return r;
+	}
+
+	hdr = (const struct dmcu_firmware_header_v1_0 *)adev->dm.fw_dmcu->data;
+	adev->firmware.ucode[AMDGPU_UCODE_ID_DMCU_ERAM].ucode_id = AMDGPU_UCODE_ID_DMCU_ERAM;
+	adev->firmware.ucode[AMDGPU_UCODE_ID_DMCU_ERAM].fw = adev->dm.fw_dmcu;
+	adev->firmware.fw_size +=
+		ALIGN(le32_to_cpu(hdr->header.ucode_size_bytes) - le32_to_cpu(hdr->intv_size_bytes), PAGE_SIZE);
+
+	adev->firmware.ucode[AMDGPU_UCODE_ID_DMCU_INTV].ucode_id = AMDGPU_UCODE_ID_DMCU_INTV;
+	adev->firmware.ucode[AMDGPU_UCODE_ID_DMCU_INTV].fw = adev->dm.fw_dmcu;
+	adev->firmware.fw_size +=
+		ALIGN(le32_to_cpu(hdr->intv_size_bytes), PAGE_SIZE);
+
+	DRM_DEBUG_KMS("PSP loading DMCU firmware\n");
+
 	return 0;
 }
 
+static int dm_sw_init(void *handle)
+{
+	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
+
+	return load_dmcu_fw(adev);
+}
+
 static int dm_sw_fini(void *handle)
 {
+	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
+
+	if(adev->dm.fw_dmcu) {
+		release_firmware(adev->dm.fw_dmcu);
+		adev->dm.fw_dmcu = NULL;
+	}
+
 	return 0;
 }
 

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h

@@ -129,6 +129,8 @@ struct amdgpu_display_manager {
 	struct drm_atomic_state *cached_state;
 
 	struct dm_comressor_info compressor;
+
+	const struct firmware *fw_dmcu;
 };
 
 struct amdgpu_dm_connector {