drm/panfrost: add support for vendor quirk

The T820, G31 & G52 GPUs integrated by Amlogic in the respective GXM,
G12A/SM1 & G12B SoCs needs a quirk in the PWR registers after each reset.

This adds a callback in the device compatible struct of permit this.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
[Steven: Fix typo in commit log]
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200916150147.25753-2-narmstrong@baylibre.com

drivers/gpu/drm/panfrost/panfrost_device.h

@@ -70,6 +70,9 @@ struct panfrost_compatible {
 	int num_pm_domains;
 	/* Only required if num_pm_domains > 1. */
 	const char * const *pm_domain_names;
+
+	/* Vendor implementation quirks callback */
+	void (*vendor_quirk)(struct panfrost_device *pfdev);
 };
 
 struct panfrost_device {

drivers/gpu/drm/panfrost/panfrost_gpu.c

@@ -136,6 +136,10 @@ static void panfrost_gpu_init_quirks(struct panfrost_device *pfdev)
 
 	if (quirks)
 		gpu_write(pfdev, GPU_JM_CONFIG, quirks);
+
+	/* Here goes platform specific quirks */
+	if (pfdev->comp->vendor_quirk)
+		pfdev->comp->vendor_quirk(pfdev);
 }
 
 #define MAX_HW_REVS 6