[PATCH v2 3/8] drm/panthor: Replace cross-component register accesses with helpers

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

Stop reaching into other components' registers directly and route those
operations through the component that owns them.

Move the timestamp/coherency helpers into panthor_gpu, add a doorbell
helper, and update call sites accordingly. This keeps register knowledge
local to each block and avoids spreading cross-component register
accesses across the driver.

This is a preparatory cleanup for using per-component iomem bases.

v2:
- Fix incorrect spelling of timestamp helpers
- Fix unintended trailing backslash

Signed-off-by: Karunika Choo <karunika.choo@arm.com>
---
 drivers/gpu/drm/panthor/panthor_device.c | 27 ----------------
 drivers/gpu/drm/panthor/panthor_drv.c    |  7 ++---
 drivers/gpu/drm/panthor/panthor_fw.c     | 13 +++++---
 drivers/gpu/drm/panthor/panthor_fw.h     |  1 +
 drivers/gpu/drm/panthor/panthor_gpu.c    | 40 ++++++++++++++++++++++++
 drivers/gpu/drm/panthor/panthor_gpu.h    |  6 ++++
 drivers/gpu/drm/panthor/panthor_pwr.c    |  2 +-
 drivers/gpu/drm/panthor/panthor_sched.c  |  2 +-
 8 files changed, 61 insertions(+), 37 deletions(-)

diff --git a/drivers/gpu/drm/panthor/panthor_device.c b/drivers/gpu/drm/panthor/panthor_device.c
index f876b13492ae..bd417d6ae8c0 100644
--- a/drivers/gpu/drm/panthor/panthor_device.c
+++ b/drivers/gpu/drm/panthor/panthor_device.c
@@ -22,38 +22,11 @@
 #include "panthor_fw_regs.h"
 #include "panthor_gem.h"
 #include "panthor_gpu.h"
-#include "panthor_gpu_regs.h"
 #include "panthor_hw.h"
 #include "panthor_mmu.h"
 #include "panthor_pwr.h"
 #include "panthor_sched.h"
 
-static int panthor_gpu_coherency_init(struct panthor_device *ptdev)
-{
-	BUILD_BUG_ON(GPU_COHERENCY_NONE != DRM_PANTHOR_GPU_COHERENCY_NONE);
-	BUILD_BUG_ON(GPU_COHERENCY_ACE_LITE != DRM_PANTHOR_GPU_COHERENCY_ACE_LITE);
-	BUILD_BUG_ON(GPU_COHERENCY_ACE != DRM_PANTHOR_GPU_COHERENCY_ACE);
-
-	/* Start with no coherency, and update it if the device is flagged coherent. */
-	ptdev->gpu_info.selected_coherency = GPU_COHERENCY_NONE;
-	ptdev->coherent = device_get_dma_attr(ptdev->base.dev) == DEV_DMA_COHERENT;
-
-	if (!ptdev->coherent)
-		return 0;
-
-	/* Check if the ACE-Lite coherency protocol is actually supported by the GPU.
-	 * ACE protocol has never been supported for command stream frontend GPUs.
-	 */
-	if ((gpu_read(ptdev->iomem, GPU_COHERENCY_FEATURES) &
-		      GPU_COHERENCY_PROT_BIT(ACE_LITE))) {
-		ptdev->gpu_info.selected_coherency = GPU_COHERENCY_ACE_LITE;
-		return 0;
-	}
-
-	drm_err(&ptdev->base, "Coherency not supported by the device");
-	return -ENOTSUPP;
-}
-
 static int panthor_clk_init(struct panthor_device *ptdev)
 {
 	ptdev->clks.core = devm_clk_get(ptdev->base.dev, NULL);
diff --git a/drivers/gpu/drm/panthor/panthor_drv.c b/drivers/gpu/drm/panthor/panthor_drv.c
index e63210b01e6e..66996c9147c2 100644
--- a/drivers/gpu/drm/panthor/panthor_drv.c
+++ b/drivers/gpu/drm/panthor/panthor_drv.c
@@ -34,7 +34,6 @@
 #include "panthor_fw.h"
 #include "panthor_gem.h"
 #include "panthor_gpu.h"
-#include "panthor_gpu_regs.h"
 #include "panthor_heap.h"
 #include "panthor_mmu.h"
 #include "panthor_sched.h"
@@ -839,7 +838,7 @@ static int panthor_query_timestamp_info(struct panthor_device *ptdev,
 	}
 
 	if (flags & DRM_PANTHOR_TIMESTAMP_GPU_OFFSET)
-		arg->timestamp_offset = gpu_read64(ptdev->iomem, GPU_TIMESTAMP_OFFSET);
+		arg->timestamp_offset = panthor_gpu_get_timestamp_offset(ptdev);
 	else
 		arg->timestamp_offset = 0;
 
@@ -854,7 +853,7 @@ static int panthor_query_timestamp_info(struct panthor_device *ptdev,
 		query_start_time = 0;
 
 	if (flags & DRM_PANTHOR_TIMESTAMP_GPU)
-		arg->current_timestamp = gpu_read64_counter(ptdev->iomem, GPU_TIMESTAMP);
+		arg->current_timestamp = panthor_gpu_get_timestamp(ptdev);
 	else
 		arg->current_timestamp = 0;
 
@@ -870,7 +869,7 @@ static int panthor_query_timestamp_info(struct panthor_device *ptdev,
 	}
 
 	if (flags & DRM_PANTHOR_TIMESTAMP_GPU_CYCLE_COUNT)
-		arg->cycle_count = gpu_read64_counter(ptdev->iomem, GPU_CYCLE_COUNT);
+		arg->cycle_count = panthor_gpu_get_cycle_count(ptdev);
 	else
 		arg->cycle_count = 0;
 
diff --git a/drivers/gpu/drm/panthor/panthor_fw.c b/drivers/gpu/drm/panthor/panthor_fw.c
index 4704275b9c8f..4a0c23e987b6 100644
--- a/drivers/gpu/drm/panthor/panthor_fw.c
+++ b/drivers/gpu/drm/panthor/panthor_fw.c
@@ -1054,7 +1054,7 @@ static void panthor_fw_init_global_iface(struct panthor_device *ptdev)
 			       GLB_CFG_POWEROFF_TIMER |
 			       GLB_CFG_PROGRESS_TIMER);
 
-	gpu_write(ptdev->iomem, CSF_DOORBELL(CSF_GLB_DOORBELL_ID), 1);
+	panthor_fw_ring_doorbell(ptdev, CSF_GLB_DOORBELL_ID);
 
 	/* Kick the watchdog. */
 	mod_delayed_work(ptdev->reset.wq, &ptdev->fw->watchdog.ping_work,
@@ -1156,7 +1156,7 @@ static void panthor_fw_halt_mcu(struct panthor_device *ptdev)
 	else
 		panthor_fw_update_reqs(glb_iface, req, GLB_HALT, GLB_HALT);
 
-	gpu_write(ptdev->iomem, CSF_DOORBELL(CSF_GLB_DOORBELL_ID), 1);
+	panthor_fw_ring_doorbell(ptdev, CSF_GLB_DOORBELL_ID);
 }
 
 static bool panthor_fw_wait_mcu_halted(struct panthor_device *ptdev)
@@ -1400,6 +1400,11 @@ int panthor_fw_csg_wait_acks(struct panthor_device *ptdev, u32 csg_slot,
 	return ret;
 }
 
+void panthor_fw_ring_doorbell(struct panthor_device *ptdev, u32 doorbell_id)
+{
+	gpu_write(ptdev->iomem, CSF_DOORBELL(doorbell_id), 1);
+}
+
 /**
  * panthor_fw_ring_csg_doorbells() - Ring command stream group doorbells.
  * @ptdev: Device.
@@ -1414,7 +1419,7 @@ void panthor_fw_ring_csg_doorbells(struct panthor_device *ptdev, u32 csg_mask)
 	struct panthor_fw_global_iface *glb_iface = panthor_fw_get_glb_iface(ptdev);
 
 	panthor_fw_toggle_reqs(glb_iface, doorbell_req, doorbell_ack, csg_mask);
-	gpu_write(ptdev->iomem, CSF_DOORBELL(CSF_GLB_DOORBELL_ID), 1);
+	panthor_fw_ring_doorbell(ptdev, CSF_GLB_DOORBELL_ID);
 }
 
 static void panthor_fw_ping_work(struct work_struct *work)
@@ -1429,7 +1434,7 @@ static void panthor_fw_ping_work(struct work_struct *work)
 		return;
 
 	panthor_fw_toggle_reqs(glb_iface, req, ack, GLB_PING);
-	gpu_write(ptdev->iomem, CSF_DOORBELL(CSF_GLB_DOORBELL_ID), 1);
+	panthor_fw_ring_doorbell(ptdev, CSF_GLB_DOORBELL_ID);
 
 	ret = panthor_fw_glb_wait_acks(ptdev, GLB_PING, &acked, 100);
 	if (ret) {
diff --git a/drivers/gpu/drm/panthor/panthor_fw.h b/drivers/gpu/drm/panthor/panthor_fw.h
index fbdc21469ba3..a99a9b6f4825 100644
--- a/drivers/gpu/drm/panthor/panthor_fw.h
+++ b/drivers/gpu/drm/panthor/panthor_fw.h
@@ -500,6 +500,7 @@ int panthor_fw_csg_wait_acks(struct panthor_device *ptdev, u32 csg_id, u32 req_m
 int panthor_fw_glb_wait_acks(struct panthor_device *ptdev, u32 req_mask, u32 *acked,
 			     u32 timeout_ms);
 
+void panthor_fw_ring_doorbell(struct panthor_device *ptdev, u32 doorbell_id);
 void panthor_fw_ring_csg_doorbells(struct panthor_device *ptdev, u32 csg_slot);
 
 struct panthor_kernel_bo *
diff --git a/drivers/gpu/drm/panthor/panthor_gpu.c b/drivers/gpu/drm/panthor/panthor_gpu.c
index fecc30747acf..747ac332be64 100644
--- a/drivers/gpu/drm/panthor/panthor_gpu.c
+++ b/drivers/gpu/drm/panthor/panthor_gpu.c
@@ -427,3 +427,43 @@ void panthor_gpu_resume(struct panthor_device *ptdev)
 	panthor_hw_l2_power_on(ptdev);
 }
 
+u64 panthor_gpu_get_timestamp(struct panthor_device *ptdev)
+{
+	return gpu_read64_counter(ptdev->iomem, GPU_TIMESTAMP);
+}
+
+u64 panthor_gpu_get_timestamp_offset(struct panthor_device *ptdev)
+{
+	return gpu_read64(ptdev->iomem, GPU_TIMESTAMP_OFFSET);
+}
+
+u64 panthor_gpu_get_cycle_count(struct panthor_device *ptdev)
+{
+	return gpu_read64_counter(ptdev->iomem, GPU_CYCLE_COUNT);
+}
+
+int panthor_gpu_coherency_init(struct panthor_device *ptdev)
+{
+	BUILD_BUG_ON(GPU_COHERENCY_NONE != DRM_PANTHOR_GPU_COHERENCY_NONE);
+	BUILD_BUG_ON(GPU_COHERENCY_ACE_LITE != DRM_PANTHOR_GPU_COHERENCY_ACE_LITE);
+	BUILD_BUG_ON(GPU_COHERENCY_ACE != DRM_PANTHOR_GPU_COHERENCY_ACE);
+
+	/* Start with no coherency, and update it if the device is flagged coherent. */
+	ptdev->gpu_info.selected_coherency = GPU_COHERENCY_NONE;
+	ptdev->coherent = device_get_dma_attr(ptdev->base.dev) == DEV_DMA_COHERENT;
+
+	if (!ptdev->coherent)
+		return 0;
+
+	/* Check if the ACE-Lite coherency protocol is actually supported by the GPU.
+	 * ACE protocol has never been supported for command stream frontend GPUs.
+	 */
+	if ((gpu_read(ptdev->iomem, GPU_COHERENCY_FEATURES) &
+		      GPU_COHERENCY_PROT_BIT(ACE_LITE))) {
+		ptdev->gpu_info.selected_coherency = GPU_COHERENCY_ACE_LITE;
+		return 0;
+	}
+
+	drm_err(&ptdev->base, "Coherency not supported by the device");
+	return -ENOTSUPP;
+}
diff --git a/drivers/gpu/drm/panthor/panthor_gpu.h b/drivers/gpu/drm/panthor/panthor_gpu.h
index 12c263a39928..f615feb05609 100644
--- a/drivers/gpu/drm/panthor/panthor_gpu.h
+++ b/drivers/gpu/drm/panthor/panthor_gpu.h
@@ -54,4 +54,10 @@ int panthor_gpu_soft_reset(struct panthor_device *ptdev);
 void panthor_gpu_power_changed_off(struct panthor_device *ptdev);
 int panthor_gpu_power_changed_on(struct panthor_device *ptdev);
 
+u64 panthor_gpu_get_timestamp(struct panthor_device *ptdev);
+u64 panthor_gpu_get_timestamp_offset(struct panthor_device *ptdev);
+u64 panthor_gpu_get_cycle_count(struct panthor_device *ptdev);
+
+int panthor_gpu_coherency_init(struct panthor_device *ptdev);
+
 #endif
diff --git a/drivers/gpu/drm/panthor/panthor_pwr.c b/drivers/gpu/drm/panthor/panthor_pwr.c
index 306592ff2227..aafb0c5c7d23 100644
--- a/drivers/gpu/drm/panthor/panthor_pwr.c
+++ b/drivers/gpu/drm/panthor/panthor_pwr.c
@@ -199,7 +199,7 @@ static int panthor_pwr_domain_wait_transition(struct panthor_device *ptdev, u32
 
 static void panthor_pwr_debug_info_show(struct panthor_device *ptdev)
 {
-	drm_info(&ptdev->base, "GPU_FEATURES:    0x%016llx", gpu_read64(ptdev->iomem, GPU_FEATURES));
+	drm_info(&ptdev->base, "GPU_FEATURES:    0x%016llx", ptdev->gpu_info.gpu_features);
 	drm_info(&ptdev->base, "PWR_STATUS:      0x%016llx", gpu_read64(ptdev->iomem, PWR_STATUS));
 	drm_info(&ptdev->base, "L2_PRESENT:      0x%016llx", gpu_read64(ptdev->iomem, PWR_L2_PRESENT));
 	drm_info(&ptdev->base, "L2_PWRTRANS:     0x%016llx", gpu_read64(ptdev->iomem, PWR_L2_PWRTRANS));
diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/panthor/panthor_sched.c
index 70b8a22b3ed7..60e7b4e20a13 100644
--- a/drivers/gpu/drm/panthor/panthor_sched.c
+++ b/drivers/gpu/drm/panthor/panthor_sched.c
@@ -3373,7 +3373,7 @@ queue_run_job(struct drm_sched_job *sched_job)
 		if (resume_tick)
 			sched_resume_tick(ptdev);
 
-		gpu_write(ptdev->iomem, CSF_DOORBELL(queue->doorbell_id), 1);
+		panthor_fw_ring_doorbell(ptdev, queue->doorbell_id);
 		if (!sched->pm.has_ref &&
 		    !(group->blocked_queues & BIT(job->queue_idx))) {
 			pm_runtime_get(ptdev->base.dev);
-- 
2.43.0