dm: video: Add a uclass for the text console

The existing LCD/video interface suffers from conflating the bitmap display
with text output on that display. As a result the implementation is more
complex than it needs to me.

We can support multiple text console drivers. Create a separate uclass to
support this, with its own API.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Anatolij Gustschin <agust@denx.de>

1 files changed, 136 insertions, 0 deletions

diff --git a/include/video_console.h b/include/video_console.h
new file mode 100644
index 0000000000..c0fc79273a
--- /dev/null
+++ b/include/video_console.h
@@ -0,0 +1,136 @@
+/*
+ * Copyright (c) 2015 Google, Inc
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef __video_console_h
+#define __video_console_h
+
+/**
+ * struct vidconsole_priv - uclass-private data about a console device
+ *
+ * @sdev:	stdio device, acting as an output sink
+ * @curr_col:	Current text column (0=left)
+ * @curr_row:	Current row (0=top)
+ * @rows:	Number of text rows
+ * @cols:	Number of text columns
+ */
+struct vidconsole_priv {
+	struct stdio_dev sdev;
+	int curr_col;
+	int curr_row;
+	int rows;
+	int cols;
+};
+
+/**
+ * struct vidconsole_ops - Video console operations
+ *
+ * These operations work on either an absolute console position (measured
+ * in pixels) or a text row number (measured in rows, where each row consists
+ * of an entire line of text - typically 16 pixels).
+ */
+struct vidconsole_ops {
+	/**
+	 * putc_xy() - write a single character to a position
+	 *
+	 * @dev:	Device to write to
+	 * @x:		Pixel X position (0=left-most pixel)
+	 * @y:		Pixel Y position (0=top-most pixel)
+	 * @ch:		Character to write
+	 * @return 0 if OK, -ve on error
+	 */
+	int (*putc_xy)(struct udevice *dev, uint x, uint y, char ch);
+
+	/**
+	 * move_rows() - Move text rows from one place to another
+	 *
+	 * @dev:	Device to adjust
+	 * @rowdst:	Destination text row (0=top)
+	 * @rowsrc:	Source start text row
+	 * @count:	Number of text rows to move
+	 * @return 0 if OK, -ve on error
+	 */
+	int (*move_rows)(struct udevice *dev, uint rowdst, uint rowsrc,
+			  uint count);
+
+	/**
+	 * set_row() - Set the colour of a text row
+	 *
+	 * Every pixel contained within the text row is adjusted
+	 *
+	 * @dev:	Device to adjust
+	 * @row:	Text row to adjust (0=top)
+	 * @clr:	Raw colour (pixel value) to write to each pixel
+	 * @return 0 if OK, -ve on error
+	 */
+	int (*set_row)(struct udevice *dev, uint row, int clr);
+};
+
+/* Get a pointer to the driver operations for a video console device */
+#define vidconsole_get_ops(dev)  ((struct vidconsole_ops *)(dev)->driver->ops)
+
+/**
+ * vidconsole_putc_xy() - write a single character to a position
+ *
+ * @dev:	Device to write to
+ * @x:		Pixel X position (0=left-most pixel)
+ * @y:		Pixel Y position (0=top-most pixel)
+ * @ch:		Character to write
+ * @return 0 if OK, -ve on error
+ */
+int vidconsole_putc_xy(struct udevice *dev, uint x, uint y, char ch);
+
+/**
+ * vidconsole_move_rows() - Move text rows from one place to another
+ *
+ * @dev:	Device to adjust
+ * @rowdst:	Destination text row (0=top)
+ * @rowsrc:	Source start text row
+ * @count:	Number of text rows to move
+ * @return 0 if OK, -ve on error
+ */
+int vidconsole_move_rows(struct udevice *dev, uint rowdst, uint rowsrc,
+			 uint count);
+
+/**
+ * vidconsole_set_row() - Set the colour of a text row
+ *
+ * Every pixel contained within the text row is adjusted
+ *
+ * @dev:	Device to adjust
+ * @row:	Text row to adjust (0=top)
+ * @clr:	Raw colour (pixel value) to write to each pixel
+ * @return 0 if OK, -ve on error
+ */
+int vidconsole_set_row(struct udevice *dev, uint row, int clr);
+
+/**
+ * vidconsole_put_char() - Output a character to the current console position
+ *
+ * Outputs a character to the console and advances the cursor. This function
+ * handles wrapping to new lines and scrolling the console. Special
+ * characters are handled also: \n, \r, \b and \t.
+ *
+ * The device always starts with the cursor at position 0,0 (top left). It
+ * can be adjusted manually using vidconsole_position_cursor().
+ *
+ * @dev:	Device to adjust
+ * @ch:		Character to write
+ * @return 0 if OK, -ve on error
+ */
+int vidconsole_put_char(struct udevice *dev, char ch);
+
+/**
+ * vidconsole_position_cursor() - Move the text cursor
+ *
+ * @dev:	Device to adjust
+ * @col:	New cursor text column
+ * @row:	New cursor text row
+ * @return 0 if OK, -ve on error
+ */
+void vidconsole_position_cursor(struct udevice *dev, unsigned col,
+				unsigned row);
+
+#endif