drm/panthor: Use a local iomem base for firmware control registers

Add an MCU_CONTROL-local iomem pointer to struct panthor_fw and use it
for firmware control and status register accesses.

Job interrupt accesses continue to go through the IRQ-local base, while
doorbell writes stay on the device-wide mapping because they live
outside the MCU control window. This keeps firmware register accesses
scoped to the component that owns them.

No functional change intended.

v3:
- Pick up R-bs from Liviu and Steve
v2:
- Pick up Ack from Boris.

Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Acked-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Karunika Choo <karunika.choo@arm.com>
Tested-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>
Link: https://patch.msgid.link/20260427155934.416502-8-karunika.choo@arm.com

diff --git a/drivers/gpu/drm/panthor/panthor_fw.c b/drivers/gpu/drm/panthor/panthor_fw.c
index 73ef07a37e22ee7e49adc899eb65463cc89bdc02..986151681b246be1a3d72b953008e479d86f8011 100644 (file)
--- a/drivers/gpu/drm/panthor/panthor_fw.c
+++ b/drivers/gpu/drm/panthor/panthor_fw.c
@@ -234,6 +234,9 @@ struct panthor_fw_iface {
  * struct panthor_fw - Firmware management
  */
 struct panthor_fw {
+       /** @iomem: CPU mapping of MCU_CONTROL iomem region */
+       void __iomem *iomem;
+
        /** @vm: MCU VM. */
        struct panthor_vm *vm;
 
@@ -1069,7 +1072,7 @@ static void panthor_job_irq_handler(struct panthor_device *ptdev, u32 status)
        if (tracepoint_enabled(gpu_job_irq))
                start = ktime_get_ns();
 
-       gpu_write(ptdev->iomem, JOB_INT_CLEAR, status);
+       gpu_write(ptdev->fw->irq.iomem, INT_CLEAR, status);
 
        if (!ptdev->fw->booted && (status & JOB_INT_GLOBAL_IF))
                ptdev->fw->booted = true;
@@ -1092,18 +1095,19 @@ PANTHOR_IRQ_HANDLER(job, panthor_job_irq_handler);
 
 static int panthor_fw_start(struct panthor_device *ptdev)
 {
+       struct panthor_fw *fw = ptdev->fw;
        bool timedout = false;
 
        ptdev->fw->booted = false;
        panthor_job_irq_enable_events(&ptdev->fw->irq, ~0);
        panthor_job_irq_resume(&ptdev->fw->irq);
-       gpu_write(ptdev->iomem, MCU_CONTROL, MCU_CONTROL_AUTO);
+       gpu_write(fw->iomem, MCU_CONTROL, MCU_CONTROL_AUTO);
 
        if (!wait_event_timeout(ptdev->fw->req_waitqueue,
                                ptdev->fw->booted,
                                msecs_to_jiffies(1000))) {
                if (!ptdev->fw->booted &&
-                   !(gpu_read(ptdev->iomem, JOB_INT_STAT) & JOB_INT_GLOBAL_IF))
+                   !(gpu_read(fw->irq.iomem, INT_STAT) & JOB_INT_GLOBAL_IF))
                        timedout = true;
        }
 
@@ -1114,7 +1118,7 @@ static int panthor_fw_start(struct panthor_device *ptdev)
                        [MCU_STATUS_HALT] = "halt",
                        [MCU_STATUS_FATAL] = "fatal",
                };
-               u32 status = gpu_read(ptdev->iomem, MCU_STATUS);
+               u32 status = gpu_read(fw->iomem, MCU_STATUS);
 
                drm_err(&ptdev->base, "Failed to boot MCU (status=%s)",
                        status < ARRAY_SIZE(status_str) ? status_str[status] : "unknown");
@@ -1126,10 +1130,11 @@ static int panthor_fw_start(struct panthor_device *ptdev)
 
 static void panthor_fw_stop(struct panthor_device *ptdev)
 {
+       struct panthor_fw *fw = ptdev->fw;
        u32 status;
 
-       gpu_write(ptdev->iomem, MCU_CONTROL, MCU_CONTROL_DISABLE);
-       if (gpu_read_poll_timeout(ptdev->iomem, MCU_STATUS, status,
+       gpu_write(fw->iomem, MCU_CONTROL, MCU_CONTROL_DISABLE);
+       if (gpu_read_poll_timeout(fw->iomem, MCU_STATUS, status,
                                  status == MCU_STATUS_DISABLED, 10, 100000))
                drm_err(&ptdev->base, "Failed to stop MCU");
 }
@@ -1139,7 +1144,7 @@ static bool panthor_fw_mcu_halted(struct panthor_device *ptdev)
        struct panthor_fw_global_iface *glb_iface = panthor_fw_get_glb_iface(ptdev);
        bool halted;
 
-       halted = gpu_read(ptdev->iomem, MCU_STATUS) == MCU_STATUS_HALT;
+       halted = gpu_read(ptdev->fw->iomem, MCU_STATUS) == MCU_STATUS_HALT;
 
        if (panthor_fw_has_glb_state(ptdev))
                halted &= (GLB_STATE_GET(glb_iface->output->ack) == GLB_STATE_HALT);
@@ -1461,6 +1466,7 @@ int panthor_fw_init(struct panthor_device *ptdev)
        if (!fw)
                return -ENOMEM;
 
+       fw->iomem = ptdev->iomem + MCU_CONTROL_BASE;
        ptdev->fw = fw;
        init_waitqueue_head(&fw->req_waitqueue);
        INIT_LIST_HEAD(&fw->sections);

diff --git a/drivers/gpu/drm/panthor/panthor_fw_regs.h b/drivers/gpu/drm/panthor/panthor_fw_regs.h
index eeb41aff249bd08a7db6fcb4761755ce2efa23c7..b2e59cfc22b005f2f041e8793e07f51421539589 100644 (file)
--- a/drivers/gpu/drm/panthor/panthor_fw_regs.h
+++ b/drivers/gpu/drm/panthor/panthor_fw_regs.h
@@ -4,23 +4,20 @@
 #ifndef __PANTHOR_FW_REGS_H__
 #define __PANTHOR_FW_REGS_H__
 
-#define MCU_CONTROL                                    0x700
+#define MCU_CONTROL_BASE                               0x700
+
+#define MCU_CONTROL                                    0x0
 #define   MCU_CONTROL_ENABLE                           1
 #define   MCU_CONTROL_AUTO                             2
 #define   MCU_CONTROL_DISABLE                          0
 
-#define MCU_STATUS                                     0x704
+#define MCU_STATUS                                     0x4
 #define   MCU_STATUS_DISABLED                          0
 #define   MCU_STATUS_ENABLED                           1
 #define   MCU_STATUS_HALT                              2
 #define   MCU_STATUS_FATAL                             3
 
 #define JOB_INT_BASE                                   0x1000
-
-#define JOB_INT_RAWSTAT                                        0x1000
-#define JOB_INT_CLEAR                                  0x1004
-#define JOB_INT_MASK                                   0x1008
-#define JOB_INT_STAT                                   0x100c
 #define   JOB_INT_GLOBAL_IF                            BIT(31)
 #define   JOB_INT_CSG_IF(x)                            BIT(x)