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>

4 files changed, 467 insertions, 0 deletions

diff --git a/arch/sandbox/config.mk b/arch/sandbox/config.mk
index 668aa71..e094ae2 100644
--- a/arch/sandbox/config.mk
+++ b/arch/sandbox/config.mk
@@ -5,6 +5,11 @@ PLATFORM_CPPFLAGS += -DCONFIG_SANDBOX -D__SANDBOX__ -U_FORTIFY_SOURCE
 PLATFORM_CPPFLAGS += -DCONFIG_ARCH_MAP_SYSMEM -DCONFIG_SYS_GENERIC_BOARD
 PLATFORM_LIBS += -lrt
 
+ifdef CONFIG_SANDBOX_SDL
+PLATFORM_LIBS += $(shell sdl-config --libs)
+PLATFORM_CPPFLAGS += $(shell sdl-config --cflags)
+endif
+
 # Support generic board on sandbox
 __HAVE_ARCH_GENERIC_BOARD := y
 
diff --git a/arch/sandbox/cpu/Makefile b/arch/sandbox/cpu/Makefile
index 63deded..7d4410c 100644
--- a/arch/sandbox/cpu/Makefile
+++ b/arch/sandbox/cpu/Makefile
@@ -8,6 +8,7 @@
 #
 
 obj-y	:= cpu.o os.o start.o state.o
+obj-$(CONFIG_SANDBOX_SDL)	+= sdl.o
 
 # os.c is build in the system environment, so needs standard includes
 # CFLAGS_REMOVE_os.o cannot be used to drop header include path
@@ -17,3 +18,5 @@ cmd_cc_os.o = $(CC) $(filter-out -nostdinc, \
 
 $(obj)/os.o: $(src)/os.c FORCE
 	$(call if_changed_dep,cc_os.o)
+$(obj)/sdl.o: $(src)/sdl.c FORCE
+	$(call if_changed_dep,cc_os.o)
diff --git a/arch/sandbox/cpu/sdl.c b/arch/sandbox/cpu/sdl.c
new file mode 100644
index 0000000..18dc7ed
--- /dev/null
+++ b/arch/sandbox/cpu/sdl.c
@@ -0,0 +1,341 @@
+/*
+ * Copyright (c) 2013 Google, Inc
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <errno.h>
+#include <linux/input.h>
+#include <SDL/SDL.h>
+#include <sound.h>
+#include <asm/state.h>
+
+static struct sdl_info {
+	SDL_Surface *screen;
+	int width;
+	int height;
+	int depth;
+	int pitch;
+	uint frequency;
+	uint audio_pos;
+	uint audio_size;
+	uint8_t *audio_data;
+	bool audio_active;
+	bool inited;
+} sdl;
+
+static void sandbox_sdl_poll_events(void)
+{
+	/*
+	 * We don't want to include common.h in this file since it uses
+	 * system headers. So add a declation here.
+	 */
+	extern void reset_cpu(unsigned long addr);
+	SDL_Event event;
+
+	while (SDL_PollEvent(&event)) {
+		switch (event.type) {
+		case SDL_QUIT:
+			puts("LCD window closed - quitting\n");
+			reset_cpu(1);
+			break;
+		}
+	}
+}
+
+static int sandbox_sdl_ensure_init(void)
+{
+	if (!sdl.inited) {
+		if (SDL_Init(0) < 0) {
+			printf("Unable to initialize SDL: %s\n",
+			       SDL_GetError());
+			return -EIO;
+		}
+
+		atexit(SDL_Quit);
+
+		sdl.inited = true;
+	}
+	return 0;
+}
+
+int sandbox_sdl_init_display(int width, int height, int log2_bpp)
+{
+	struct sandbox_state *state = state_get_current();
+	int err;
+
+	if (!width || !state->show_lcd)
+		return 0;
+	err = sandbox_sdl_ensure_init();
+	if (err)
+		return err;
+	if (SDL_InitSubSystem(SDL_INIT_VIDEO) < 0) {
+		printf("Unable to initialize SDL LCD: %s\n", SDL_GetError());
+		return -EPERM;
+	}
+	SDL_WM_SetCaption("U-Boot", "U-Boot");
+
+	sdl.width = width;
+	sdl.height = height;
+	sdl.depth = 1 << log2_bpp;
+	sdl.pitch = sdl.width * sdl.depth / 8;
+	sdl.screen = SDL_SetVideoMode(width, height, 0, 0);
+	sandbox_sdl_poll_events();
+
+	return 0;
+}
+
+int sandbox_sdl_sync(void *lcd_base)
+{
+	SDL_Surface *frame;
+
+	frame = SDL_CreateRGBSurfaceFrom(lcd_base, sdl.width, sdl.height,
+			sdl.depth, sdl.pitch,
+			0x1f << 11, 0x3f << 5, 0x1f << 0, 0);
+	SDL_BlitSurface(frame, NULL, sdl.screen, NULL);
+	SDL_FreeSurface(frame);
+	SDL_UpdateRect(sdl.screen, 0, 0, 0, 0);
+	sandbox_sdl_poll_events();
+
+	return 0;
+}
+
+#define NONE (-1)
+#define NUM_SDL_CODES	(SDLK_UNDO + 1)
+
+static int16_t sdl_to_keycode[NUM_SDL_CODES] = {
+	/* 0 */
+	NONE, NONE, NONE, NONE, NONE,
+	NONE, NONE, NONE, KEY_BACKSPACE, KEY_TAB,
+	NONE, NONE, NONE, KEY_ENTER, NONE,
+	NONE, NONE, NONE, NONE, KEY_POWER,	/* use PAUSE as POWER */
+
+	/* 20 */
+	NONE, NONE, NONE, NONE, NONE,
+	NONE, NONE, KEY_ESC, NONE, NONE,
+	NONE, NONE, KEY_SPACE, NONE, NONE,
+	NONE, NONE, NONE, NONE, NONE,
+
+	/* 40 */
+	NONE, NONE, NONE, NONE, KEY_COMMA,
+	KEY_MINUS, KEY_DOT, KEY_SLASH, KEY_0, KEY_1,
+	KEY_2, KEY_3, KEY_4, KEY_5, KEY_6,
+	KEY_7, KEY_8, KEY_9, NONE, KEY_SEMICOLON,
+
+	/* 60 */
+	NONE, KEY_EQUAL, NONE, NONE, NONE,
+	NONE, NONE, NONE, NONE, NONE,
+	NONE, NONE, NONE, NONE, NONE,
+	NONE, NONE, NONE, NONE, NONE,
+
+	/* 80 */
+	NONE, NONE, NONE, NONE, NONE,
+	NONE, NONE, NONE, NONE, NONE,
+	NONE, NONE, KEY_BACKSLASH, NONE, NONE,
+	NONE, KEY_GRAVE, KEY_A, KEY_B, KEY_C,
+
+	/* 100 */
+	KEY_D, KEY_E, KEY_F, KEY_G, KEY_H,
+	KEY_I, KEY_J, KEY_K, KEY_L, KEY_M,
+	KEY_N, KEY_O, KEY_P, KEY_Q, KEY_R,
+	KEY_S, KEY_T, KEY_U, KEY_V, KEY_W,
+
+	/* 120 */
+	KEY_X, KEY_Y, KEY_Z, NONE, NONE,
+	NONE, NONE, KEY_DELETE, NONE, NONE,
+	NONE, NONE, NONE, NONE, NONE,
+	NONE, NONE, NONE, NONE, NONE,
+
+	/* 140 */
+	NONE, NONE, NONE, NONE, NONE,
+	NONE, NONE, NONE, NONE, NONE,
+	NONE, NONE, NONE, NONE, NONE,
+	NONE, NONE, NONE, NONE, NONE,
+
+	/* 160 */
+	NONE, NONE, NONE, NONE, NONE,
+	NONE, NONE, NONE, NONE, NONE,
+	NONE, NONE, NONE, NONE, NONE,
+	NONE, NONE, NONE, NONE, NONE,
+
+	/* 180 */
+	NONE, NONE, NONE, NONE, NONE,
+	NONE, NONE, NONE, NONE, NONE,
+	NONE, NONE, NONE, NONE, NONE,
+	NONE, NONE, NONE, NONE, NONE,
+
+	/* 200 */
+	NONE, NONE, NONE, NONE, NONE,
+	NONE, NONE, NONE, NONE, NONE,
+	NONE, NONE, NONE, NONE, NONE,
+	NONE, NONE, NONE, NONE, NONE,
+
+	/* 220 */
+	NONE, NONE, NONE, NONE, NONE,
+	NONE, NONE, NONE, NONE, NONE,
+	NONE, NONE, NONE, NONE, NONE,
+	NONE, NONE, NONE, NONE, NONE,
+
+	/* 240 */
+	NONE, NONE, NONE, NONE, NONE,
+	NONE, NONE, NONE, NONE, NONE,
+	NONE, NONE, NONE, NONE, NONE,
+	NONE, KEY_KP0, KEY_KP1, KEY_KP2, KEY_KP3,
+
+	/* 260 */
+	KEY_KP4, KEY_KP5, KEY_KP6, KEY_KP7, KEY_KP8,
+	KEY_KP9, KEY_KPDOT, KEY_KPSLASH, KEY_KPASTERISK, KEY_KPMINUS,
+	KEY_KPPLUS, KEY_KPENTER, KEY_KPEQUAL, KEY_UP, KEY_DOWN,
+	KEY_RIGHT, KEY_LEFT, KEY_INSERT, KEY_HOME, KEY_END,
+
+	/* 280 */
+	KEY_PAGEUP, KEY_PAGEDOWN, KEY_F1, KEY_F2, KEY_F3,
+	KEY_F4, KEY_F5, KEY_F6, KEY_F7, KEY_F8,
+	KEY_F9, KEY_F10, KEY_F11, KEY_F12, NONE,
+	NONE, NONE, NONE, NONE, NONE,
+
+	/* 300 */
+	KEY_NUMLOCK, KEY_CAPSLOCK, KEY_SCROLLLOCK, KEY_RIGHTSHIFT,
+		KEY_LEFTSHIFT,
+	KEY_RIGHTCTRL, KEY_LEFTCTRL, KEY_RIGHTALT, KEY_LEFTALT, KEY_RIGHTMETA,
+	KEY_LEFTMETA, NONE, KEY_FN, NONE, KEY_COMPOSE,
+	NONE, KEY_PRINT, KEY_SYSRQ, KEY_PAUSE, NONE,
+
+	/* 320 */
+	NONE, NONE, NONE,
+};
+
+int sandbox_sdl_scan_keys(int key[], int max_keys)
+{
+	Uint8 *keystate;
+	int i, count;
+
+	sandbox_sdl_poll_events();
+	keystate = SDL_GetKeyState(NULL);
+	for (i = count = 0; i < NUM_SDL_CODES; i++) {
+		if (count >= max_keys)
+			break;
+		else if (keystate[i])
+			key[count++] = sdl_to_keycode[i];
+	}
+
+	return count;
+}
+
+int sandbox_sdl_key_pressed(int keycode)
+{
+	int key[8];	/* allow up to 8 keys to be pressed at once */
+	int count;
+	int i;
+
+	count = sandbox_sdl_scan_keys(key, sizeof(key) / sizeof(key[0]));
+	for (i = 0; i < count; i++) {
+		if (key[i] == keycode)
+			return 0;
+	}
+
+	return -ENOENT;
+}
+
+void sandbox_sdl_fill_audio(void *udata, Uint8 *stream, int len)
+{
+	int avail;
+
+	avail = sdl.audio_size - sdl.audio_pos;
+	if (avail < len)
+		len = avail;
+
+	SDL_MixAudio(stream, sdl.audio_data + sdl.audio_pos, len,
+		     SDL_MIX_MAXVOLUME);
+	sdl.audio_pos += len;
+
+	/* Loop if we are at the end */
+	if (sdl.audio_pos == sdl.audio_size)
+		sdl.audio_pos = 0;
+}
+
+int sandbox_sdl_sound_init(void)
+{
+	SDL_AudioSpec wanted;
+
+	if (sandbox_sdl_ensure_init())
+		return -1;
+
+	if (sdl.audio_active)
+		return 0;
+
+	/*
+	 * At present all sandbox sounds crash. This is probably due to
+	 * symbol name conflicts with U-Boot. We can remove the malloc()
+	 * probles with:
+	 *
+	 * #define USE_DL_PREFIX
+	 *
+	 * and get this:
+	 *
+	 * Assertion 'e->pollfd->fd == e->fd' failed at pulse/mainloop.c:676,
+	 *		function dispatch_pollfds(). Aborting.
+	 *
+	 * The right solution is probably to make U-Boot's names private or
+	 * link os.c and sdl.c against their libraries before liking with
+	 * U-Boot. TBD. For now sound is disabled.
+	 */
+	printf("(Warning: sandbox sound disabled)\n");
+	return 0;
+
+	/* Set the audio format */
+	wanted.freq = 22050;
+	wanted.format = AUDIO_S16;
+	wanted.channels = 1;    /* 1 = mono, 2 = stereo */
+	wanted.samples = 1024;  /* Good low-latency value for callback */
+	wanted.callback = sandbox_sdl_fill_audio;
+	wanted.userdata = NULL;
+
+	sdl.audio_size = sizeof(uint16_t) * wanted.freq;
+	sdl.audio_data = malloc(sdl.audio_size);
+	if (!sdl.audio_data) {
+		printf("%s: Out of memory\n", __func__);
+		return -1;
+	}
+	sdl.audio_pos = 0;
+
+	if (SDL_InitSubSystem(SDL_INIT_AUDIO) < 0) {
+		printf("Unable to initialize SDL audio: %s\n", SDL_GetError());
+		goto err;
+	}
+
+	/* Open the audio device, forcing the desired format */
+	if (SDL_OpenAudio(&wanted, NULL) < 0) {
+		printf("Couldn't open audio: %s\n", SDL_GetError());
+		goto err;
+	}
+	sdl.audio_active = true;
+
+	return 0;
+
+err:
+	free(sdl.audio_data);
+	return -1;
+}
+
+int sandbox_sdl_sound_start(uint frequency)
+{
+	if (!sdl.audio_active)
+		return -1;
+	sdl.frequency = frequency;
+	sound_create_square_wave((unsigned short *)sdl.audio_data,
+				 sdl.audio_size, frequency);
+	sdl.audio_pos = 0;
+	SDL_PauseAudio(0);
+
+	return 0;
+}
+
+int sandbox_sdl_sound_stop(void)
+{
+	if (!sdl.audio_active)
+		return -1;
+	SDL_PauseAudio(1);
+
+	return 0;
+}
diff --git a/arch/sandbox/include/asm/sdl.h b/arch/sandbox/include/asm/sdl.h
new file mode 100644
index 0000000..6edec1a
--- /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