[PATCH v3 2/8] drm/panthor: Add architecture-specific function operations

[Karunika Choo <karunika.choo@arm.com>]

Introduce architecture-specific function pointers to support
architecture-dependent behaviours. This patch adds the following
function pointers and updates their usage accordingly:

- soft_reset
- l2_power_on
- l2_power_off

Signed-off-by: Karunika Choo <karunika.choo@arm.com>
---
v3:
 * Reverted includes changes to align with the include behaviour of the
   rest of the driver while enabling the definition of static inline
   function pointer accessors.
 * Moved the function pointer accessors from panthor_device.h to
   panthor_hw.h
v2:
 * Updated includes for panthor_hw.h to allow static inline function
   pointer accessor functions instead of MACROs.
 * updated l2_power_off function signature to void instead of returning
   int as we have no way of handling a failure in this case.
---
 drivers/gpu/drm/panthor/panthor_device.c |  4 +--
 drivers/gpu/drm/panthor/panthor_device.h |  1 -
 drivers/gpu/drm/panthor/panthor_fw.c     |  5 ++--
 drivers/gpu/drm/panthor/panthor_gpu.c    | 12 ++++++--
 drivers/gpu/drm/panthor/panthor_gpu.h    |  1 +
 drivers/gpu/drm/panthor/panthor_hw.c     |  9 +++++-
 drivers/gpu/drm/panthor/panthor_hw.h     | 35 +++++++++++++++++++++++-
 7 files changed, 57 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/panthor/panthor_device.c b/drivers/gpu/drm/panthor/panthor_device.c
index 81df49880bd8..847dea458682 100644
--- a/drivers/gpu/drm/panthor/panthor_device.c
+++ b/drivers/gpu/drm/panthor/panthor_device.c
@@ -141,8 +141,8 @@ static void panthor_device_reset_work(struct work_struct *work)
 	panthor_sched_pre_reset(ptdev);
 	panthor_fw_pre_reset(ptdev, true);
 	panthor_mmu_pre_reset(ptdev);
-	panthor_gpu_soft_reset(ptdev);
-	panthor_gpu_l2_power_on(ptdev);
+	panthor_hw_soft_reset(ptdev);
+	panthor_hw_l2_power_on(ptdev);
 	panthor_mmu_post_reset(ptdev);
 	ret = panthor_fw_post_reset(ptdev);
 	atomic_set(&ptdev->reset.pending, 0);
diff --git a/drivers/gpu/drm/panthor/panthor_device.h b/drivers/gpu/drm/panthor/panthor_device.h
index 1457c1255f1f..f8e37a24d081 100644
--- a/drivers/gpu/drm/panthor/panthor_device.h
+++ b/drivers/gpu/drm/panthor/panthor_device.h
@@ -26,7 +26,6 @@ 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;
diff --git a/drivers/gpu/drm/panthor/panthor_fw.c b/drivers/gpu/drm/panthor/panthor_fw.c
index 9bf06e55eaee..e6c39c70d348 100644
--- a/drivers/gpu/drm/panthor/panthor_fw.c
+++ b/drivers/gpu/drm/panthor/panthor_fw.c
@@ -21,6 +21,7 @@
 #include "panthor_fw.h"
 #include "panthor_gem.h"
 #include "panthor_gpu.h"
+#include "panthor_hw.h"
 #include "panthor_mmu.h"
 #include "panthor_regs.h"
 #include "panthor_sched.h"
@@ -1184,7 +1185,7 @@ void panthor_fw_unplug(struct panthor_device *ptdev)
 	ptdev->fw->vm = NULL;

 	if (!IS_ENABLED(CONFIG_PM) || pm_runtime_active(ptdev->base.dev))
-		panthor_gpu_power_off(ptdev, L2, ptdev->gpu_info.l2_present, 20000);
+		panthor_hw_l2_power_off(ptdev);
 }

 /**
@@ -1363,7 +1364,7 @@ int panthor_fw_init(struct panthor_device *ptdev)
 		return ret;
 	}

-	ret = panthor_gpu_l2_power_on(ptdev);
+	ret = panthor_hw_l2_power_on(ptdev);
 	if (ret)
 		return ret;

diff --git a/drivers/gpu/drm/panthor/panthor_gpu.c b/drivers/gpu/drm/panthor/panthor_gpu.c
index db69449a5be0..63ed8c461796 100644
--- a/drivers/gpu/drm/panthor/panthor_gpu.c
+++ b/drivers/gpu/drm/panthor/panthor_gpu.c
@@ -18,6 +18,7 @@

 #include "panthor_device.h"
 #include "panthor_gpu.h"
+#include "panthor_hw.h"
 #include "panthor_regs.h"

 /**
@@ -218,6 +219,11 @@ int panthor_gpu_block_power_on(struct panthor_device *ptdev,
 	return 0;
 }

+void panthor_gpu_l2_power_off(struct panthor_device *ptdev)
+{
+	panthor_gpu_power_off(ptdev, L2, ptdev->gpu_info.l2_present, 20000);
+}
+
 /**
  * panthor_gpu_l2_power_on() - Power-on the L2-cache
  * @ptdev: Device.
@@ -344,9 +350,9 @@ void panthor_gpu_suspend(struct panthor_device *ptdev)
 {
 	/* On a fast reset, simply power down the L2. */
 	if (!ptdev->reset.fast)
-		panthor_gpu_soft_reset(ptdev);
+		panthor_hw_soft_reset(ptdev);
 	else
-		panthor_gpu_power_off(ptdev, L2, 1, 20000);
+		panthor_hw_l2_power_off(ptdev);

 	panthor_gpu_irq_suspend(&ptdev->gpu->irq);
 }
@@ -361,6 +367,6 @@ void panthor_gpu_suspend(struct panthor_device *ptdev)
 void panthor_gpu_resume(struct panthor_device *ptdev)
 {
 	panthor_gpu_irq_resume(&ptdev->gpu->irq, GPU_INTERRUPTS_MASK);
-	panthor_gpu_l2_power_on(ptdev);
+	panthor_hw_l2_power_on(ptdev);
 }

diff --git a/drivers/gpu/drm/panthor/panthor_gpu.h b/drivers/gpu/drm/panthor/panthor_gpu.h
index 7c17a8c06858..12e66f48ced1 100644
--- a/drivers/gpu/drm/panthor/panthor_gpu.h
+++ b/drivers/gpu/drm/panthor/panthor_gpu.h
@@ -46,6 +46,7 @@ int panthor_gpu_block_power_off(struct panthor_device *ptdev,
 				   type ## _PWRTRANS, \
 				   mask, timeout_us)

+void panthor_gpu_l2_power_off(struct panthor_device *ptdev);
 int panthor_gpu_l2_power_on(struct panthor_device *ptdev);
 int panthor_gpu_flush_caches(struct panthor_device *ptdev,
 			     u32 l2, u32 lsc, u32 other);
diff --git a/drivers/gpu/drm/panthor/panthor_hw.c b/drivers/gpu/drm/panthor/panthor_hw.c
index b6e7401327c3..ed0ebd53f4ba 100644
--- a/drivers/gpu/drm/panthor/panthor_hw.c
+++ b/drivers/gpu/drm/panthor/panthor_hw.c
@@ -2,6 +2,7 @@
 /* Copyright 2025 ARM Limited. All rights reserved. */

 #include "panthor_device.h"
+#include "panthor_gpu.h"
 #include "panthor_hw.h"
 #include "panthor_regs.h"

@@ -20,7 +21,13 @@ struct panthor_hw_entry {
 	struct panthor_hw *hwdev;
 };

-static struct panthor_hw panthor_hw_arch_v10 = {};
+static struct panthor_hw panthor_hw_arch_v10 = {
+	.ops = {
+		.soft_reset = panthor_gpu_soft_reset,
+		.l2_power_off = panthor_gpu_l2_power_off,
+		.l2_power_on = panthor_gpu_l2_power_on,
+	},
+};

 static struct panthor_hw_entry panthor_hw_match[] = {
 	{
diff --git a/drivers/gpu/drm/panthor/panthor_hw.h b/drivers/gpu/drm/panthor/panthor_hw.h
index 39752de3e7ad..64616caa6f05 100644
--- a/drivers/gpu/drm/panthor/panthor_hw.h
+++ b/drivers/gpu/drm/panthor/panthor_hw.h
@@ -4,14 +4,47 @@
 #ifndef __PANTHOR_HW_H__
 #define __PANTHOR_HW_H__

-struct panthor_device;
+#include "panthor_device.h"
+
+/**
+ * struct panthor_hw_ops - HW operations that are specific to a GPU
+ */
+struct panthor_hw_ops {
+	/** @soft_reset: Soft reset function pointer */
+	int (*soft_reset)(struct panthor_device *ptdev);
+
+	/** @l2_power_off: L2 power off function pointer */
+	void (*l2_power_off)(struct panthor_device *ptdev);
+
+	/** @l2_power_on: L2 power on function pointer */
+	int (*l2_power_on)(struct panthor_device *ptdev);
+};

 /**
  * struct panthor_hw - GPU specific register mapping and functions
  */
 struct panthor_hw {
+	/** @features: Bitmap containing panthor_hw_feature */
+
+	/** @ops: Panthor HW specific operations */
+	struct panthor_hw_ops ops;
 };

 int panthor_hw_init(struct panthor_device *ptdev);

+static inline int panthor_hw_soft_reset(struct panthor_device *ptdev)
+{
+	return ptdev->hw->ops.soft_reset(ptdev);
+}
+
+static inline int panthor_hw_l2_power_on(struct panthor_device *ptdev)
+{
+	return ptdev->hw->ops.l2_power_on(ptdev);
+}
+
+static inline void panthor_hw_l2_power_off(struct panthor_device *ptdev)
+{
+	ptdev->hw->ops.l2_power_off(ptdev);
+}
+
 #endif /* __PANTHOR_HW_H__ */
--
2.49.0