refactor(core): extract framebuffer queue for reuse

[no changelog]

core/embed/io/display/fb_queue/fb_queue.c

@@ -0,0 +1,99 @@
+#ifdef KERNEL_MODE
+
+#include <trezor_rtl.h>
+
+#include <sys/irq.h>
+
+#include "fb_queue.h"
+
+// Initializes the queue and make it empty
+// Clear peeked flag
+void fb_queue_reset(fb_queue_t* queue) {
+  memset(queue, 0, sizeof(fb_queue_t));
+  for (int i = 0; i < FRAME_BUFFER_COUNT; i++) {
+    queue->entries[i].index = -1;
+  }
+}
+
+// Inserts a new element to the tail of the queue
+bool fb_queue_put(fb_queue_t* queue, int16_t index) {
+  irq_key_t irq_key = irq_lock();
+
+  // check if the queue is full
+  if (queue->entries[queue->wix].index != -1) {
+    irq_unlock(irq_key);
+    return false;
+  }
+
+  queue->entries[queue->wix].index = index;
+  queue->wix = (queue->wix + 1) % FRAME_BUFFER_COUNT;
+
+  irq_unlock(irq_key);
+
+  return true;
+}
+
+// Removes an element from the queue head, returns -1 if the queue is empty
+// Clear peeked flag
+int16_t fb_queue_take(fb_queue_t* queue) {
+  irq_key_t irq_key = irq_lock();
+
+  if (queue->entries[queue->rix].index == -1) {
+    irq_unlock(irq_key);
+    return -1;
+  }
+
+  queue->peaked = false;
+  int16_t index = queue->entries[queue->rix].index;
+  queue->entries[queue->rix].index = -1;
+  queue->rix = (queue->rix + 1) % FRAME_BUFFER_COUNT;
+
+  irq_unlock(irq_key);
+  return index;
+}
+// Returns true if the queue is empty
+bool fb_queue_empty(fb_queue_t* queue) {
+  irq_key_t irq_key = irq_lock();
+
+  if (queue->entries[queue->rix].index == -1) {
+    irq_unlock(irq_key);
+    return true;
+  }
+
+  irq_unlock(irq_key);
+  return false;
+}
+
+// Waits until the queue is not empty
+void fb_queue_wait(fb_queue_t* queue) {
+  while (fb_queue_empty(queue))
+    ;
+}
+
+// Returns the head of the queue (or -1 if the queue is empty)
+// Set peeked flag if the queue is not empty
+int16_t fb_queue_peek(fb_queue_t* queue) {
+  irq_key_t irq_key = irq_lock();
+
+  if (queue->entries[queue->rix].index == -1) {
+    irq_unlock(irq_key);
+    return -1;
+  }
+
+  int16_t index = queue->entries[queue->rix].index;
+  queue->peaked = true;
+
+  irq_unlock(irq_key);
+
+  return index;
+}
+
+// Return if the head was already peeked
+bool fb_queue_peeked(fb_queue_t* queue) {
+  irq_key_t key = irq_lock();
+  bool peeked = queue->peaked;
+  irq_unlock(key);
+  return peeked;
+}
+
+#endif

core/embed/io/display/fb_queue/fb_queue.h

@@ -0,0 +1,71 @@
+/*
+ * This file is part of the Trezor project, https://trezor.io/
+ *
+ * Copyright (c) SatoshiLabs
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <trezor_types.h>
+
+// Number of frame buffers used (1 or 2)
+// If 1 buffer is selected, some animations may not
+// be so smooth but the memory usage is lower.
+#define FRAME_BUFFER_COUNT 2
+
+// Each frame buffer can be in one of the following states:
+typedef struct {
+  int16_t index;
+} fb_queue_entry;
+
+typedef struct {
+  // Queue entries
+  fb_queue_entry entries[FRAME_BUFFER_COUNT];
+
+  // Read index
+  // (accessed & updated in the context of the interrupt handlers
+  uint8_t rix;
+  // Write index
+  // (accessed & updated in context of the main thread)
+  uint8_t wix;
+
+  // Flag indicating that the head of the queue has been peaked
+  bool peaked;
+
+} fb_queue_t;
+
+// Initializes the queue and make it empty
+// Clear peeked flag
+void fb_queue_reset(fb_queue_t* queue);
+
+// Inserts a new element to the tail of the queue
+bool fb_queue_put(fb_queue_t* queue, int16_t index);
+
+// Removes an element from the queue head, returns -1 if the queue is empty
+// Clear peeked flag
+int16_t fb_queue_take(fb_queue_t* queue);
+// Returns true if the queue is empty
+bool fb_queue_empty(fb_queue_t* queue);
+
+// Waits until the queue is not empty
+void fb_queue_wait(fb_queue_t* queue);
+
+// Returns the head of the queue (or -1 if the queue is empty)
+// Set peeked flag if the queue is not empty
+int16_t fb_queue_peek(fb_queue_t* queue);
+
+// Return if the head was already peeked
+bool fb_queue_peeked(fb_queue_t* queue);

core/embed/io/display/st-7789/display_driver.c

@@ -56,6 +56,10 @@ void display_init(display_content_mode_t mode) {
 
   memset(drv, 0, sizeof(display_driver_t));
 
+#ifdef FRAMEBUFFER
+  display_fb_init();
+#endif
+
   if (mode == DISPLAY_RESET_CONTENT) {
     display_io_init_gpio();
     display_io_init_fmc();
@@ -149,7 +153,7 @@ int display_set_orientation(int angle) {
       drv->orientation_angle = angle;
 
 #ifdef FRAMEBUFFER
-      display_physical_fb_clear();
+      display_fb_clear();
 #endif
 
       display_panel_set_window(0, 0, INTERNAL_FB_WIDTH - 1,

core/embed/io/display/st-7789/display_fb.c

@@ -63,7 +63,7 @@ _Static_assert(FRAME_BUFFER_COUNT == 1 || FRAME_BUFFER_COUNT == 2);
                  PHYSICAL_FRAME_BUFFER_ALIGNMENT)
 
 // Physical frame buffers in internal SRAM memory.
-// Both frame buffers layes in the fixed addresses that
+// Both frame buffers layers in the fixed addresses that
 // are shared between bootloaders and the firmware.
 static
     __attribute__((section(".fb1"), aligned(PHYSICAL_FRAME_BUFFER_ALIGNMENT)))
@@ -91,6 +91,21 @@ void display_set_unpriv_access(bool unpriv) {
 }
 #endif  // USE_TRUSTZONE
 
+void display_fb_init(void) {
+  display_driver_t *drv = &g_display_driver;
+
+  if (drv->initialized) {
+    return;
+  }
+
+  fb_queue_reset(&drv->empty_frames);
+  fb_queue_reset(&drv->ready_frames);
+
+  for (int16_t i = 0; i < FRAME_BUFFER_COUNT; i++) {
+    fb_queue_put(&drv->empty_frames, i);
+  }
+}
+
 // Returns the pointer to the physical frame buffer (0.. FRAME_BUFFER_COUNT-1)
 // Returns NULL if the framebuffer index is out of range.
 static uint8_t *get_fb_ptr(uint32_t index) {
@@ -105,7 +120,7 @@ static uint8_t *get_fb_ptr(uint32_t index) {
   }
 }
 
-void display_physical_fb_clear(void) {
+void display_fb_clear(void) {
   for (int i = 0; i < FRAME_BUFFER_COUNT; i++) {
     mpu_set_active_fb(get_fb_ptr(i), PHYSICAL_FRAME_BUFFER_SIZE);
     memset(get_fb_ptr(i), 0, PHYSICAL_FRAME_BUFFER_SIZE);
@@ -120,13 +135,7 @@ void display_physical_fb_clear(void) {
 static void bg_copy_callback(void) {
   display_driver_t *drv = &g_display_driver;
 
-  if (drv->queue.rix >= FRAME_BUFFER_COUNT) {
-    // This is an invalid state and we should never get here
-    return;
-  }
-
-  drv->queue.entry[drv->queue.rix] = FB_STATE_EMPTY;
-  drv->queue.rix = (drv->queue.rix + 1) % FRAME_BUFFER_COUNT;
+  fb_queue_put(&drv->empty_frames, fb_queue_take(&drv->ready_frames));
 }
 
 // Interrupt routing handling TE signal
@@ -135,37 +144,15 @@ static void display_te_interrupt_handler(void) {
 
   __HAL_GPIO_EXTI_CLEAR_FLAG(DISPLAY_TE_PIN);
 
-  if (drv->queue.rix >= FRAME_BUFFER_COUNT) {
-    // This is an invalid state and we should never get here
-    return;
-  }
+  if (!fb_queue_peeked(&drv->ready_frames)) {
+    int16_t fb_idx = fb_queue_peek(&drv->ready_frames);
 
-  switch (drv->queue.entry[drv->queue.rix]) {
-    case FB_STATE_EMPTY:
-    case FB_STATE_PREPARING:
-      // No new frame queued
-      break;
-
-    case FB_STATE_COPYING:
-      // Currently we are copying a data to the display.
-      // We need to wait for the next TE interrupt.
-      break;
-
-    case FB_STATE_READY:
-      // Now it's proper time to copy the data to the display
-      drv->queue.entry[drv->queue.rix] = FB_STATE_COPYING;
+    if (fb_idx >= 0) {
       display_panel_set_window(0, 0, DISPLAY_RESX - 1, DISPLAY_RESY - 1);
-      bg_copy_start_const_out_8(get_fb_ptr(drv->queue.rix),
+      bg_copy_start_const_out_8(get_fb_ptr(fb_idx),
                                 (uint8_t *)DISPLAY_DATA_ADDRESS,
                                 PHYSICAL_FRAME_BUFFER_SIZE, bg_copy_callback);
-
-      // NOTE: when copying is done, this queue slot is marked empty
-      // (see bg_copy_callback())
-      break;
-
-    default:
-      // This is an invalid state and we should never get here
-      break;
+    }
   }
 }
 
@@ -187,17 +174,10 @@ bool display_get_frame_buffer(display_fb_info_t *fb) {
     return false;
   }
 
-  frame_buffer_state_t state;
+  fb_queue_wait(&drv->empty_frames);
+  uint8_t fb_idx = fb_queue_peek(&drv->empty_frames);
 
-  // We have to wait if the buffer was passed for copying
-  // to the interrupt handler
-  do {
-    state = drv->queue.entry[drv->queue.wix];
-  } while (state == FB_STATE_READY || state == FB_STATE_COPYING);
-
-  drv->queue.entry[drv->queue.wix] = FB_STATE_PREPARING;
-
-  fb->ptr = get_fb_ptr(drv->queue.wix);
+  fb->ptr = get_fb_ptr(fb_idx);
   fb->stride = DISPLAY_RESX * sizeof(uint16_t);
   // Enable access to the frame buffer from the unprivileged code
   mpu_set_active_fb(fb->ptr, PHYSICAL_FRAME_BUFFER_SIZE);
@@ -205,6 +185,7 @@ bool display_get_frame_buffer(display_fb_info_t *fb) {
   return true;
 }
 
+#ifdef BOARDLOADER
 // Copies the frame buffer with the given index to the display
 static void copy_fb_to_display(uint8_t index) {
   uint16_t *fb = (uint16_t *)get_fb_ptr(index);
@@ -228,6 +209,7 @@ static void wait_for_te_signal(void) {
   while (GPIO_PIN_RESET == HAL_GPIO_ReadPin(DISPLAY_TE_PORT, DISPLAY_TE_PIN)) {
   }
 }
+#endif
 
 void display_refresh(void) {
   display_driver_t *drv = &g_display_driver;
@@ -236,7 +218,7 @@ void display_refresh(void) {
     return;
   }
 
-  if (drv->queue.entry[drv->queue.wix] != FB_STATE_PREPARING) {
+  if (!fb_queue_peeked(&drv->empty_frames)) {
     // No refresh needed as the frame buffer is not in
     // the state to be copied to the display
     return;
@@ -246,35 +228,16 @@ void display_refresh(void) {
   mpu_set_active_fb(NULL, 0);
 
 #ifndef BOARDLOADER
-  if (is_mode_exception()) {
-    // Disable scheduling of any new background copying
-    NVIC_DisableIRQ(DISPLAY_TE_INTERRUPT_NUM);
-    // Wait for next TE signal. During this time the
-    // display might be updated in the background
-    wait_for_te_signal();
-    // Stop any background copying even if it is not finished yet
-    bg_copy_abort();
-    // Copy the frame buffer to the display manually
-    copy_fb_to_display(drv->queue.wix);
-    // Reset the buffer queue so we can eventually continue
-    // safely in thread mode
-    drv->queue.wix = 0;
-    drv->queue.rix = 0;
-    for (int i = 0; i < FRAME_BUFFER_COUNT; i++) {
-      drv->queue.entry[i] = FB_STATE_EMPTY;
-    }
-    // Enable normal processing again
-    NVIC_EnableIRQ(DISPLAY_TE_INTERRUPT_NUM);
-  } else {
   // Mark the buffer ready to switch to
-    drv->queue.entry[drv->queue.wix] = FB_STATE_READY;
-    drv->queue.wix = (drv->queue.wix + 1) % FRAME_BUFFER_COUNT;
-  }
+  fb_queue_put(&drv->ready_frames, fb_queue_take(&drv->empty_frames));
 
 #else  // BOARDLOADER
   wait_for_te_signal();
-  copy_fb_to_display(drv->queue.wix);
-  drv->queue.entry[drv->queue.wix] = FB_STATE_EMPTY;
+  int16_t fb_idx = fb_queue_take(&drv->empty_frames);
+  if (fb_idx >= 0) {
+    copy_fb_to_display(fb_idx);
+    fb_queue_put(&drv->empty_frames, fb_idx);
+  }
 #endif
 }
 
@@ -293,14 +256,7 @@ void display_ensure_refreshed(void) {
     //  so we can be sure there's not scheduled or pending
     // background copying
     do {
-      copy_pending = false;
-      for (int i = 0; i < FRAME_BUFFER_COUNT; i++) {
-        frame_buffer_state_t state = drv->queue.entry[i];
-        if (state == FB_STATE_READY || state == FB_STATE_COPYING) {
-          copy_pending = true;
-          break;
-        }
-      }
+      copy_pending = !fb_queue_empty(&drv->ready_frames);
       __WFI();
     } while (copy_pending);
 

core/embed/io/display/st-7789/display_fb.h

@@ -24,8 +24,10 @@
 
 #ifdef FRAMEBUFFER
 
+void display_fb_init(void);
+
 // Clears both physical frame buffers
-void display_physical_fb_clear(void);
+void display_fb_clear(void);
 
 void display_ensure_refreshed(void);
 

core/embed/io/display/st-7789/display_internal.h

@@ -6,37 +6,7 @@
 
 #ifdef FRAMEBUFFER
 
-// Number of frame buffers used (1 or 2)
-// If 1 buffer is selected, some animations may not
-// be so smooth but the memory usage is lower.
-#define FRAME_BUFFER_COUNT 2
-
-// Each frame buffer can be in one of the following states:
-typedef enum {
-  // The frame buffer is empty and can be written to
-  FB_STATE_EMPTY = 0,
-  // The frame buffer pass passed to application
-  FB_STATE_PREPARING = 1,
-  // The frame buffer was written to and is ready
-  // to be copied to the display
-  FB_STATE_READY = 2,
-  // The frame buffer is currently being copied to
-  // the display
-  FB_STATE_COPYING = 3,
-
-} frame_buffer_state_t;
-
-typedef struct {
-  // Queue entries
-  volatile frame_buffer_state_t entry[FRAME_BUFFER_COUNT];
-  // Read index
-  // (accessed & updated in the context of the interrupt handlers
-  uint8_t rix;
-  // Write index
-  // (accessed & updated in context of the main thread)
-  uint8_t wix;
-
-} frame_buffer_queue_t;
+#include "../fb_queue/fb_queue.h"
 
 #endif  // FRAMEBUFFER
 
@@ -49,7 +19,8 @@ typedef struct {
   // Framebuffer queue
   // (accessed & updated in the context of the main thread
   // and the interrupt context)
-  volatile frame_buffer_queue_t queue;
+  fb_queue_t empty_frames;
+  fb_queue_t ready_frames;
 #endif
 
   // Current display orientation (0, 90, 180, 270)

core/site_scons/models/T3T1/trezor_t3t1_revE.py

@@ -47,6 +47,7 @@ def configure(
     sources += ["embed/io/display/st-7789/display_io.c"]
     sources += ["embed/io/display/st-7789/display_panel.c"]
     sources += ["embed/io/display/st-7789/panels/lx154a2482.c"]
+    sources += ["embed/io/display/fb_queue/fb_queue.c"]
     paths += ["embed/io/display/inc"]
 
     sources += ["embed/io/display/backlight/stm32/backlight_pwm.c"]