video: Add font functions to the vidconsole API

Support for fonts currently depends on the type of vidconsole in use. Add
two new methods to enumerate fonts and to set the font.

Fix a few other method comments while we are here.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/include/video_console.h b/include/video_console.h
index d755eb7..9d2c0f2 100644
--- a/include/video_console.h
+++ b/include/video_console.h
@@ -63,6 +63,15 @@
 };
 
 /**
+ * struct vidfont_info - information about a font
+ *
+ * @name: Font name, e.g. nimbus_sans_l_regular
+ */
+struct vidfont_info {
+	const char *name;
+};
+
+/**
  * struct vidconsole_ops - Video console operations
  *
  * These operations work on either an absolute console position (measured
@@ -111,6 +120,9 @@
 	/**
 	 * entry_start() - Indicate that text entry is starting afresh
 	 *
+	 * @dev:	Device to adjust
+	 * Returns: 0 on success, -ve on error
+	 *
 	 * Consoles which use proportional fonts need to track the position of
 	 * each character output so that backspace will return to the correct
 	 * place. This method signals to the console driver that a new entry
@@ -123,6 +135,9 @@
 	/**
 	 * backspace() - Handle erasing the last character
 	 *
+	 * @dev:	Device to adjust
+	 * Returns: 0 on success, -ve on error
+	 *
 	 * With proportional fonts the vidconsole uclass cannot itself erase
 	 * the previous character. This optional method will be called when
 	 * a backspace is needed. The driver should erase the previous
@@ -133,12 +148,54 @@
 	 * characters.
 	 */
 	int (*backspace)(struct udevice *dev);
+
+	/**
+	 * get_font() - Obtain information about a font (optional)
+	 *
+	 * @dev:	Device to check
+	 * @seq:	Font number to query (0=first, 1=second, etc.)
+	 * @info:	Returns font information on success
+	 * Returns: 0 on success, -ENOENT if no such font
+	 */
+	int (*get_font)(struct udevice *dev, int seq,
+			struct vidfont_info *info);
+
+	/**
+	 * select_font() - Select a particular font by name / size
+	 *
+	 * @dev:	Device to adjust
+	 * @name:	Font name to use (NULL to use default)
+	 * @size:	Font size to use (0 to use default)
+	 * Returns: 0 on success, -ENOENT if no such font
+	 */
+	int (*select_font)(struct udevice *dev, const char *name, uint size);
 };
 
 /* Get a pointer to the driver operations for a video console device */
 #define vidconsole_get_ops(dev)  ((struct vidconsole_ops *)(dev)->driver->ops)
 
 /**
+ * vidconsole_get_font() - Obtain information about a font
+ *
+ * @dev:	Device to check
+ * @seq:	Font number to query (0=first, 1=second, etc.)
+ * @info:	Returns font information on success
+ * Returns: 0 on success, -ENOENT if no such font, -ENOSYS if there is no such
+ * method
+ */
+int vidconsole_get_font(struct udevice *dev, int seq,
+			struct vidfont_info *info);
+
+/**
+ * vidconsole_select_font() - Select a particular font by name / size
+ *
+ * @dev:	Device to adjust
+ * @name:	Font name to use (NULL to use default)
+ * @size:	Font size to use (0 to use default)
+ */
+int vidconsole_select_font(struct udevice *dev, const char *name, uint size);
+
+/**
  * vidconsole_putc_xy() - write a single character to a position
  *
  * @dev:	Device to write to
@@ -234,27 +291,21 @@
 /**
  * vidconsole_list_fonts() - List the available fonts
  *
- * This shows a list on the console
- */
-void vidconsole_list_fonts(void);
-
-/**
- * vidconsole_select_font() - Select a font to use
+ * @dev: vidconsole device to check
  *
- * @dev: vidconsole device
- * @name: Font name
- * @size: Size of the font (norminal pixel height) or 0 for default
+ * This shows a list of fonts known by this vidconsole. The list is displayed on
+ * the console (not necessarily @dev but probably)
  */
-int vidconsole_select_font(struct udevice *dev, const char *name, uint size);
+void vidconsole_list_fonts(struct udevice *dev);
 
 /**
- * vidconsole_get_font() - get the current font name and size
+ * vidconsole_get_font_size() - get the current font name and size
  *
  * @dev: vidconsole device
  * @sizep: Place to put the font size (nominal height in pixels)
  * Returns: Current font name
  */
-const char *vidconsole_get_font(struct udevice *dev, uint *sizep);
+const char *vidconsole_get_font_size(struct udevice *dev, uint *sizep);
 
 #ifdef CONFIG_VIDEO_COPY
 /**