dm: video: Add basic ANSI escape sequence support

[u-boot] / drivers / video / vidconsole-uclass.c

diff --git a/drivers/video/vidconsole-uclass.c b/drivers/video/vidconsole-uclass.c
index e081d5a0eeb3e9473a9e67c98453645bf07d0f87..37eb2a0ef46da513f6565b9706545a9ec9a6be15 100644 (file)
--- a/drivers/video/vidconsole-uclass.c
+++ b/drivers/video/vidconsole-uclass.c
@@ -9,6 +9,7 @@
  */
 
 #include <common.h>
+#include <linux/ctype.h>
 #include <dm.h>
 #include <video.h>
 #include <video_console.h>
@@ -107,12 +108,119 @@ static void vidconsole_newline(struct udevice *dev)
        video_sync(dev->parent);
 }
 
+static char *parsenum(char *s, int *num)
+{
+       char *end;
+       *num = simple_strtol(s, &end, 10);
+       return end;
+}
+
+/*
+ * Process a character while accumulating an escape string.  Chars are
+ * accumulated into escape_buf until the end of escape sequence is
+ * found, at which point the sequence is parsed and processed.
+ */
+static void vidconsole_escape_char(struct udevice *dev, char ch)
+{
+       struct vidconsole_priv *priv = dev_get_uclass_priv(dev);
+
+       if (!IS_ENABLED(CONFIG_VIDEO_ANSI))
+               goto error;
+
+       /* Sanity checking for bogus ESC sequences: */
+       if (priv->escape_len >= sizeof(priv->escape_buf))
+               goto error;
+       if (priv->escape_len == 0 && ch != '[')
+               goto error;
+
+       priv->escape_buf[priv->escape_len++] = ch;
+
+       /*
+        * Escape sequences are terminated by a letter, so keep
+        * accumulating until we get one:
+        */
+       if (!isalpha(ch))
+               return;
+
+       /*
+        * clear escape mode first, otherwise things will get highly
+        * surprising if you hit any debug prints that come back to
+        * this console.
+        */
+       priv->escape = 0;
+
+       switch (ch) {
+       case 'H':
+       case 'f': {
+               int row, col;
+               char *s = priv->escape_buf;
+
+               /*
+                * Set cursor position: [%d;%df or [%d;%dH
+                */
+               s++;    /* [ */
+               s = parsenum(s, &row);
+               s++;    /* ; */
+               s = parsenum(s, &col);
+
+               priv->ycur = row * priv->y_charsize;
+               priv->xcur_frac = priv->xstart_frac +
+                       VID_TO_POS(col * priv->x_charsize);
+
+               break;
+       }
+       case 'J': {
+               int mode;
+
+               /*
+                * Clear part/all screen:
+                *   [J or [0J - clear screen from cursor down
+                *   [1J       - clear screen from cursor up
+                *   [2J       - clear entire screen
+                *
+                * TODO we really only handle entire-screen case, others
+                * probably require some additions to video-uclass (and
+                * are not really needed yet by efi_console)
+                */
+               parsenum(priv->escape_buf + 1, &mode);
+
+               if (mode == 2) {
+                       video_clear(dev->parent);
+                       video_sync(dev->parent);
+                       priv->ycur = 0;
+                       priv->xcur_frac = priv->xstart_frac;
+               } else {
+                       debug("unsupported clear mode: %d\n", mode);
+               }
+               break;
+       }
+       default:
+               debug("unrecognized escape sequence: %*s\n",
+                     priv->escape_len, priv->escape_buf);
+       }
+
+       return;
+
+error:
+       /* something went wrong, just revert to normal mode: */
+       priv->escape = 0;
+}
+
 int vidconsole_put_char(struct udevice *dev, char ch)
 {
        struct vidconsole_priv *priv = dev_get_uclass_priv(dev);
        int ret;
 
+       if (priv->escape) {
+               vidconsole_escape_char(dev, ch);
+               return 0;
+       }
+
        switch (ch) {
+       case '\x1b':
+               priv->escape_len = 0;
+               priv->escape = 1;
+               break;
        case '\a':
                /* beep */
                break;