sandbox: Add SDL library for LCD, keyboard, audio

SDL (Simple DirectMedia Layer - see www.libsdl.org) is a library which
provides simple graphics and sound features. It works under X11 and also
with a simple frame buffer interface. It is ideally suited to sandbox
U-Boot since it fits nicely with the low-level feature set required by
U-Boot. For example, U-Boot has its own font drawing routines, its own
keyboard processing and just needs raw sound output.

We can use SDL to provide emulation of these basic functions for sandbox.
This significantly expands the testing that is possible with sandbox.

Add a basic SDL library which we will use in future commits.

Tested-by: Che-Liang Chiou <clchiou@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>

1 files changed, 118 insertions, 0 deletions

diff --git a/arch/sandbox/include/asm/sdl.h b/arch/sandbox/include/asm/sdl.h
new file mode 100644
index 0000000000..6edec1acfa
--- /dev/null
+++ b/arch/sandbox/include/asm/sdl.h
@@ -0,0 +1,118 @@
+/*
+ * Copyright (c) 2013 Google, Inc
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef __SANDBOX_SDL_H
+#define __SANDBOX_SDL_H
+
+#include <errno.h>
+
+#ifdef CONFIG_SANDBOX_SDL
+
+/**
+ * sandbox_sdl_init_display() - Set up SDL video ready for use
+ *
+ * @width:	Window width in pixels
+ * @height	Window height in pixels
+ * @log2_bpp:	Log to base 2 of the number of bits per pixel. So a 32bpp
+ *		display will pass 5, since 2*5 = 32
+ * @return 0 if OK, -ENODEV if no device, -EIO if SDL failed to initialize
+ *		and -EPERM if the video failed to come up.
+ */
+int sandbox_sdl_init_display(int width, int height, int log2_bpp);
+
+/**
+ * sandbox_sdl_sync() - Sync current U-Boot LCD frame buffer to SDL
+ *
+ * This must be called periodically to update the screen for SDL so that the
+ * user can see it.
+ *
+ * @lcd_base: Base of frame buffer
+ * @return 0 if screen was updated, -ENODEV is there is no screen.
+ */
+int sandbox_sdl_sync(void *lcd_base);
+
+/**
+ * sandbox_sdl_scan_keys() - scan for pressed keys
+ *
+ * Works out which keys are pressed and returns a list
+ *
+ * @key:	Array to receive keycodes
+ * @max_keys:	Size of array
+ * @return number of keycodes found, 0 if none, -ENODEV if no keyboard
+ */
+int sandbox_sdl_scan_keys(int key[], int max_keys);
+
+/**
+ * sandbox_sdl_key_pressed() - check if a particular key is pressed
+ *
+ * @keycode:	Keycode to check (KEY_... - see include/linux/input.h
+ * @return 0 if pressed, -ENOENT if not pressed. -ENODEV if keybord not
+ * available,
+ */
+int sandbox_sdl_key_pressed(int keycode);
+
+/**
+ * sandbox_sdl_sound_start() - start playing a sound
+ *
+ * @frequency:	Frequency of sounds in Hertz
+ * @return 0 if OK, -ENODEV if no sound is available
+ */
+int sandbox_sdl_sound_start(uint frequency);
+
+/**
+ * sandbox_sdl_sound_stop() - stop playing a sound
+ *
+ * @return 0 if OK, -ENODEV if no sound is available
+ */
+int sandbox_sdl_sound_stop(void);
+
+/**
+ * sandbox_sdl_sound_init() - set up the sound system
+ *
+ * @return 0 if OK, -ENODEV if no sound is available
+ */
+int sandbox_sdl_sound_init(void);
+
+#else
+static inline int sandbox_sdl_init_display(int width, int height,
+					    int log2_bpp)
+{
+	return -ENODEV;
+}
+
+static inline int sandbox_sdl_sync(void *lcd_base)
+{
+	return -ENODEV;
+}
+
+static inline int sandbox_sdl_scan_keys(int key[], int max_keys)
+{
+	return -ENODEV;
+}
+
+static inline int sandbox_sdl_key_pressed(int keycode)
+{
+	return -ENODEV;
+}
+
+static inline int sandbox_sdl_sound_start(uint frequency)
+{
+	return -ENODEV;
+}
+
+static inline int sandbox_sdl_sound_stop(void)
+{
+	return -ENODEV;
+}
+
+static inline int sandbox_sdl_sound_init(void)
+{
+	return -ENODEV;
+}
+
+#endif
+
+#endif