From 83c2a7f54ee63c2e1f5283886fb781353513a396 Mon Sep 17 00:00:00 2001
From: rongyichang <rongyichang@xiaomi.com>
Date: Thu, 8 Aug 2024 15:51:09 +0800
Subject: [PATCH] drivers/fb: add panbuffer clear ioctl

Some devices need to clear the fb panbuf when waking up from sleep
to avoid outputting residual buffers from before sleeping

Signed-off-by: rongyichang <rongyichang@xiaomi.com>
---
 drivers/video/fb.c       | 41 ++++++++++++++++++++++++++++++++++++++++
 include/nuttx/video/fb.h | 10 +++++++---
 2 files changed, 48 insertions(+), 3 deletions(-)

diff --git a/drivers/video/fb.c b/drivers/video/fb.c
index 739bff0e28..200093808e 100644
--- a/drivers/video/fb.c
+++ b/drivers/video/fb.c
@@ -110,6 +110,8 @@ static FAR struct circbuf_s *fb_get_panbuf(FAR struct fb_chardev_s *fb,
 static int     fb_add_paninfo(FAR struct fb_chardev_s *fb,
                               FAR const union fb_paninfo_u *info,
                               int overlay);
+static int     fb_clear_paninfo(FAR struct fb_chardev_s *fb,
+                                int overlay);
 static int     fb_open(FAR struct file *filep);
 static int     fb_close(FAR struct file *filep);
 static ssize_t fb_read(FAR struct file *filep, FAR char *buffer,
@@ -217,6 +219,39 @@ static int fb_add_paninfo(FAR struct fb_chardev_s *fb,
   return ret <= 0 ? -ENOSPC : OK;
 }
 
+/****************************************************************************
+ * Name: fb_clear_paninfo
+ ****************************************************************************/
+
+static int fb_clear_paninfo(FAR struct fb_chardev_s *fb,
+                            int overlay)
+{
+  FAR struct circbuf_s *panbuf;
+  irqstate_t flags;
+
+  DEBUGASSERT(fb != NULL);
+
+  panbuf = fb_get_panbuf(fb, overlay);
+  if (panbuf == NULL)
+    {
+      return -EINVAL;
+    }
+
+  /* Disable the interrupt when writing to the queue to
+   * prevent it from being modified by the interrupted
+   * thread during the writing process.
+   */
+
+  flags = enter_critical_section();
+
+  circbuf_reset(panbuf);
+
+  /* Re-enable interrupts */
+
+  leave_critical_section(flags);
+  return OK;
+}
+
 /****************************************************************************
  * Name: fb_open
  ****************************************************************************/
@@ -861,6 +896,12 @@ static int fb_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
         }
         break;
 
+      case FBIOPAN_CLEAR:
+        {
+          ret = fb_clear_paninfo(fb, (int)arg);
+        }
+        break;
+
       case FBIOSET_VSYNCOFFSET:
         {
           fb->vsyncoffset = USEC2TICK(arg);
diff --git a/include/nuttx/video/fb.h b/include/nuttx/video/fb.h
index 054d001d12..c582ee2307 100644
--- a/include/nuttx/video/fb.h
+++ b/include/nuttx/video/fb.h
@@ -301,15 +301,19 @@
                                                * Argument: read-only struct
                                                *           fb_planeinfo_s* */
 
-#define FBIOSET_VSYNCOFFSET   _FBIOC(0x0019)  /* Set VSync offset in usec
+#define FBIOPAN_CLEAR         _FBIOC(0x0019)  /* Pan clear */
+                                              /* Argument: read-only
+                                               *           unsigned long */
+
+#define FBIOSET_VSYNCOFFSET   _FBIOC(0x001a)  /* Set VSync offset in usec
                                                * Argument:             int */
 
 /* Linux Support ************************************************************/
 
-#define FBIOGET_VSCREENINFO   _FBIOC(0x001a)  /* Get video variable info */
+#define FBIOGET_VSCREENINFO   _FBIOC(0x001b)  /* Get video variable info */
                                               /* Argument: writable struct
                                                *           fb_var_screeninfo */
-#define FBIOGET_FSCREENINFO   _FBIOC(0x001b)  /* Get video fix info */
+#define FBIOGET_FSCREENINFO   _FBIOC(0x001c)  /* Get video fix info */
                                               /* Argument: writable struct
                                                *           fb_fix_screeninfo */