drm/panthor: add custom ASN_HASH support for mt8196

Add panthor_soc_data to control custom ASN_HASH. Add compatible string
for "mediatek,mt8196-mali" and enable custom ASN_HASH for the soc.

Without custom ASN_HASH, FW fails to boot

  panthor 48000000.gpu: [drm] *ERROR* Unhandled Page fault in AS0 at VA 0x0000000000000000
  panthor 48000000.gpu: [drm] *ERROR* Failed to boot MCU (status=fatal)
  panthor 48000000.gpu: probe with driver panthor failed with error -110

With custom ASN_HASH, panthor probes fine and userspace boots to ui just
fine as well

  panthor 48000000.gpu: [drm] clock rate = 0
  panthor 48000000.gpu: EM: created perf domain
  panthor 48000000.gpu: [drm] Mali-G925-Immortalis id 0xd830 major 0x0 minor 0x1 status 0x5
  panthor 48000000.gpu: [drm] Features: L2:0x8130306 Tiler:0x809 Mem:0x301 MMU:0x2830 AS:0xff
  panthor 48000000.gpu: [drm] shader_present=0xee0077 l2_present=0x1 tiler_present=0x1
  panthor 48000000.gpu: [drm] Firmware protected mode entry not be supported, ignoring
  panthor 48000000.gpu: [drm] Firmware git sha: 27713280172c742d467a4b7d11180930094092ec
  panthor 48000000.gpu: [drm] CSF FW using interface v3.13.0, Features 0x10 Instrumentation features 0x71
  [drm] Initialized panthor 1.5.0 for 48000000.gpu on minor 1

Note that the clock and the regulator drivers are not upstreamed yet.
They might as well take a different form when upstreamed.

Signed-off-by: Chia-I Wu <olvaffe@gmail.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://lore.kernel.org/r/20250913002155.1163908-3-olvaffe@gmail.com

drivers/gpu/drm/panthor/panthor_device.c

@@ -172,6 +172,8 @@ int panthor_device_init(struct panthor_device *ptdev)
 	struct page *p;
 	int ret;
 
+	ptdev->soc_data = of_device_get_match_data(ptdev->base.dev);
+
 	init_completion(&ptdev->unplug.done);
 	ret = drmm_mutex_init(&ptdev->base, &ptdev->unplug.lock);
 	if (ret)

drivers/gpu/drm/panthor/panthor_device.h

@@ -31,6 +31,17 @@ struct panthor_perfcnt;
 struct panthor_vm;
 struct panthor_vm_pool;
 
+/**
+ * struct panthor_soc_data - Panthor SoC Data
+ */
+struct panthor_soc_data {
+	/** @asn_hash_enable: True if GPU_L2_CONFIG_ASN_HASH_ENABLE must be set. */
+	bool asn_hash_enable;
+
+	/** @asn_hash: ASN_HASH values when asn_hash_enable is true. */
+	u32 asn_hash[3];
+};
+
 /**
  * enum panthor_device_pm_state - PM state
  */
@@ -93,6 +104,9 @@ struct panthor_device {
 	/** @base: Base drm_device. */
 	struct drm_device base;
 
+	/** @soc_data: Optional SoC data. */
+	const struct panthor_soc_data *soc_data;
+
 	/** @phys_addr: Physical address of the iomem region. */
 	phys_addr_t phys_addr;
 

drivers/gpu/drm/panthor/panthor_drv.c

@@ -1682,7 +1682,13 @@ static struct attribute *panthor_attrs[] = {
 
 ATTRIBUTE_GROUPS(panthor);
 
+static const struct panthor_soc_data soc_data_mediatek_mt8196 = {
+	.asn_hash_enable = true,
+	.asn_hash = { 0xb, 0xe, 0x0, },
+};
+
 static const struct of_device_id dt_match[] = {
+	{ .compatible = "mediatek,mt8196-mali", .data = &soc_data_mediatek_mt8196, },
 	{ .compatible = "rockchip,rk3588-mali" },
 	{ .compatible = "arm,mali-valhall-csf" },
 	{}

drivers/gpu/drm/panthor/panthor_gpu.c

@@ -52,6 +52,28 @@ static void panthor_gpu_coherency_set(struct panthor_device *ptdev)
 		ptdev->coherent ? GPU_COHERENCY_PROT_BIT(ACE_LITE) : GPU_COHERENCY_NONE);
 }
 
+static void panthor_gpu_l2_config_set(struct panthor_device *ptdev)
+{
+	const struct panthor_soc_data *data = ptdev->soc_data;
+	u32 l2_config;
+	u32 i;
+
+	if (!data || !data->asn_hash_enable)
+		return;
+
+	if (GPU_ARCH_MAJOR(ptdev->gpu_info.gpu_id) < 11) {
+		drm_err(&ptdev->base, "Custom ASN hash not supported by the device");
+		return;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(data->asn_hash); i++)
+		gpu_write(ptdev, GPU_ASN_HASH(i), data->asn_hash[i]);
+
+	l2_config = gpu_read(ptdev, GPU_L2_CONFIG);
+	l2_config |= GPU_L2_CONFIG_ASN_HASH_ENABLE;
+	gpu_write(ptdev, GPU_L2_CONFIG, l2_config);
+}
+
 static void panthor_gpu_irq_handler(struct panthor_device *ptdev, u32 status)
 {
 	gpu_write(ptdev, GPU_INT_CLEAR, status);
@@ -241,8 +263,9 @@ int panthor_gpu_l2_power_on(struct panthor_device *ptdev)
 			      hweight64(ptdev->gpu_info.shader_present));
 	}
 
-	/* Set the desired coherency mode before the power up of L2 */
+	/* Set the desired coherency mode and L2 config before the power up of L2 */
 	panthor_gpu_coherency_set(ptdev);
+	panthor_gpu_l2_config_set(ptdev);
 
 	return panthor_gpu_power_on(ptdev, L2, 1, 20000);
 }

drivers/gpu/drm/panthor/panthor_regs.h

@@ -64,6 +64,8 @@
 
 #define GPU_FAULT_STATUS				0x3C
 #define GPU_FAULT_ADDR					0x40
+#define GPU_L2_CONFIG					0x48
+#define   GPU_L2_CONFIG_ASN_HASH_ENABLE			BIT(24)
 
 #define GPU_PWR_KEY					0x50
 #define  GPU_PWR_KEY_UNLOCK				0x2968A819
@@ -110,6 +112,8 @@
 
 #define GPU_REVID					0x280
 
+#define GPU_ASN_HASH(n)					(0x2C0 + ((n) * 4))
+
 #define GPU_COHERENCY_FEATURES				0x300
 #define GPU_COHERENCY_PROT_BIT(name)			BIT(GPU_COHERENCY_  ## name)