drm/panthor: Add arch-specific panthor_hw binding

This patch adds the framework for binding to a specific panthor_hw
structure based on the architecture major value parsed from the GPU_ID
register. This is in preparation of enabling architecture-specific
behaviours based on GPU_ID. As such, it also splits the GPU_ID register
read operation into its own helper function.

This framework allows a single panthor_hw structure to be shared across
multiple architectures should there be minimal changes between them via
the arch_min and arch_max field of the panthor_hw_entry structure,
instead of duplicating the structure across multiple architectures.

Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Karunika Choo <karunika.choo@arm.com>
Link: https://patch.msgid.link/20251125125548.3282320-2-karunika.choo@arm.com
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>

3 files changed, 74 insertions, 1 deletions

diff --git a/drivers/gpu/drm/panthor/panthor_device.h b/drivers/gpu/drm/panthor/panthor_device.h
index f32c1868bf6d..f0b143732ea0 100644
--- a/drivers/gpu/drm/panthor/panthor_device.h
+++ b/drivers/gpu/drm/panthor/panthor_device.h
@@ -24,6 +24,7 @@ struct panthor_device;
 struct panthor_gpu;
 struct panthor_group_pool;
 struct panthor_heap_pool;
+struct panthor_hw;
 struct panthor_job;
 struct panthor_mmu;
 struct panthor_fw;
@@ -134,6 +135,9 @@ struct panthor_device {
 	/** @csif_info: Command stream interface information. */
 	struct drm_panthor_csif_info csif_info;
 
+	/** @hw: GPU-specific data. */
+	struct panthor_hw *hw;
+
 	/** @gpu: GPU management data. */
 	struct panthor_gpu *gpu;
 
diff --git a/drivers/gpu/drm/panthor/panthor_hw.c b/drivers/gpu/drm/panthor/panthor_hw.c
index c44033a0bba8..5b5a82e15f86 100644
--- a/drivers/gpu/drm/panthor/panthor_hw.c
+++ b/drivers/gpu/drm/panthor/panthor_hw.c
@@ -10,6 +10,28 @@
 #define GPU_PROD_ID_MAKE(arch_major, prod_major) \
 	(((arch_major) << 24) | (prod_major))
 
+/** struct panthor_hw_entry - HW arch major to panthor_hw binding entry */
+struct panthor_hw_entry {
+	/** @arch_min: Minimum supported architecture major value (inclusive) */
+	u8 arch_min;
+
+	/** @arch_max: Maximum supported architecture major value (inclusive) */
+	u8 arch_max;
+
+	/** @hwdev: Pointer to panthor_hw structure */
+	struct panthor_hw *hwdev;
+};
+
+static struct panthor_hw panthor_hw_arch_v10 = {};
+
+static struct panthor_hw_entry panthor_hw_match[] = {
+	{
+		.arch_min = 10,
+		.arch_max = 13,
+		.hwdev = &panthor_hw_arch_v10,
+	},
+};
+
 static char *get_gpu_model_name(struct panthor_device *ptdev)
 {
 	const u32 gpu_id = ptdev->gpu_info.gpu_id;
@@ -64,7 +86,6 @@ static void panthor_gpu_info_init(struct panthor_device *ptdev)
 {
 	unsigned int i;
 
-	ptdev->gpu_info.gpu_id = gpu_read(ptdev, GPU_ID);
 	ptdev->gpu_info.csf_id = gpu_read(ptdev, GPU_CSF_ID);
 	ptdev->gpu_info.gpu_rev = gpu_read(ptdev, GPU_REVID);
 	ptdev->gpu_info.core_features = gpu_read(ptdev, GPU_CORE_FEATURES);
@@ -119,8 +140,50 @@ static void panthor_hw_info_init(struct panthor_device *ptdev)
 		 ptdev->gpu_info.tiler_present);
 }
 
+static int panthor_hw_bind_device(struct panthor_device *ptdev)
+{
+	struct panthor_hw *hdev = NULL;
+	const u32 arch_major = GPU_ARCH_MAJOR(ptdev->gpu_info.gpu_id);
+	int i = 0;
+
+	for (i = 0; i < ARRAY_SIZE(panthor_hw_match); i++) {
+		struct panthor_hw_entry *entry = &panthor_hw_match[i];
+
+		if (arch_major >= entry->arch_min && arch_major <= entry->arch_max) {
+			hdev = entry->hwdev;
+			break;
+		}
+	}
+
+	if (!hdev)
+		return -EOPNOTSUPP;
+
+	ptdev->hw = hdev;
+
+	return 0;
+}
+
+static int panthor_hw_gpu_id_init(struct panthor_device *ptdev)
+{
+	ptdev->gpu_info.gpu_id = gpu_read(ptdev, GPU_ID);
+	if (!ptdev->gpu_info.gpu_id)
+		return -ENXIO;
+
+	return 0;
+}
+
 int panthor_hw_init(struct panthor_device *ptdev)
 {
+	int ret = 0;
+
+	ret = panthor_hw_gpu_id_init(ptdev);
+	if (ret)
+		return ret;
+
+	ret = panthor_hw_bind_device(ptdev);
+	if (ret)
+		return ret;
+
 	panthor_hw_info_init(ptdev);
 
 	return 0;
diff --git a/drivers/gpu/drm/panthor/panthor_hw.h b/drivers/gpu/drm/panthor/panthor_hw.h
index 0af6acc6aa6a..39752de3e7ad 100644
--- a/drivers/gpu/drm/panthor/panthor_hw.h
+++ b/drivers/gpu/drm/panthor/panthor_hw.h
@@ -6,6 +6,12 @@
 
 struct panthor_device;
 
+/**
+ * struct panthor_hw - GPU specific register mapping and functions
+ */
+struct panthor_hw {
+};
+
 int panthor_hw_init(struct panthor_device *ptdev);
 
 #endif /* __PANTHOR_HW_H__ */