driver: SDL based display emulation driver

This driver introduces an emulated LCD display for the native POSIX board. The emulated display driver makes use of SDL2 to render the displays frame buffer into a dedicated desktop window. Signed-off-by: Jan Van Winkel <[email protected]>
zephyrproject-rtos · Dec 1, 2018 · 384c4c7 · 384c4c7
1 parent 1d3e0ea
commit 384c4c7
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Showing 12 changed files with 521 additions and 7 deletions.
diff --git a/boards/posix/native_posix/CMakeLists.txt b/boards/posix/native_posix/CMakeLists.txt
@@ -12,6 +12,15 @@ zephyr_library_sources(
 	cmdline.c
 	)
 
+if(CONFIG_HAS_SDL)
+	find_package(PkgConfig REQUIRED)
+	pkg_search_module(SDL2 REQUIRED sdl2)
+	zephyr_include_directories(${SDL2_INCLUDE_DIRS})
+	zephyr_link_libraries(${SDL2_LIBRARIES})
+	zephyr_compile_options(${SDL2_CFLAGS_OTHER})
+	zephyr_library_sources(sdl_events.c)
+endif()
+
 zephyr_ld_options(
   -lm
 )

diff --git a/boards/posix/native_posix/Kconfig b/boards/posix/native_posix/Kconfig
@@ -15,4 +15,9 @@ config NATIVE_POSIX_SLOWDOWN_TO_REAL_TIME
 	  case the zephyr kernel and application cannot tell the difference unless they
 	  interact with some other driver/device which runs at real time.
 
+config HAS_SDL
+	bool
+	help
+	  This option specifies that the target board has SDL support
+
 endif
diff --git a/boards/posix/native_posix/Kconfig.defconfig b/boards/posix/native_posix/Kconfig.defconfig
@@ -72,4 +72,11 @@ config UART_CONSOLE
 
 endif #CONSOLE
 
+if DISPLAY
+
+config SDL_DISPLAY
+	default y
+
+endif # DISPLAY
+
 endif # BOARD_NATIVE_POSIX
diff --git a/boards/posix/native_posix/doc/board.rst b/boards/posix/native_posix/doc/board.rst
@@ -519,6 +519,23 @@ The following peripherals are currently provided with this board:
   must be powered down and support Bluetooth Low Energy (i.e. support the
   Bluetooth specification version 4.0 or greater).
 
+**Display driver**:
+  A display driver is provided that creates a window on the host machine to
+  render display content.
+
+  This driver requires a 32-bit version of the `SDL2`_ library on the host
+  machine and ``pkg-config`` settings to correctly pickup the SDL2 install path
+  and compiler flags.
+
+  On a Ubuntu 18.04 host system, for example, install the ``pkg-config`` and
+  ``libsdl2-dev:i386`` packages, and configure the pkg-config search path with
+  these commands::
+
+    $ sudo apt-get install pkg-config libsdl2-dev:i386
+    $ export PKG_CONFIG_PATH=/usr/lib/i386-linux-gnu/pkgconfig
+
+.. _SDL2:
+   https://www.libsdl.org/download-2.0.php
 
 UART
 *****

diff --git a/boards/posix/native_posix/hw_models_top.c b/boards/posix/native_posix/hw_models_top.c
@@ -12,12 +12,16 @@
 #include <stdint.h>
 #include <signal.h>
 #include <stddef.h>
+#include <stdlib.h>
+#include <pthread.h>
 #include "hw_models_top.h"
 #include "timer_model.h"
 #include "irq_ctrl.h"
 #include "posix_board_if.h"
 #include "posix_soc_if.h"
 #include "posix_arch_internal.h"
+#include "sdl_events.h"
+#include <misc/util.h>
 
 
 static u64_t simu_time; /* The actual time as known by the HW models */
@@ -26,21 +30,33 @@ static u64_t end_of_time = NEVER; /* When will this device stop */
 /* List of HW model timers: */
 extern u64_t hw_timer_timer; /* When should this timer_model be called */
 extern u64_t irq_ctrl_timer;
-
-static enum { HWTIMER = 0, IRQCNT, NUMBER_OF_TIMERS, NONE }
-	next_timer_index = NONE;
+#ifdef CONFIG_HAS_SDL
+extern u64_t sdl_event_timer;
+#endif
+
+static enum {
+	HWTIMER = 0,
+	IRQCNT,
+#ifdef CONFIG_HAS_SDL
+	SDLEVENTTIMER,
+#endif
+	NUMBER_OF_TIMERS,
+	NONE
+} next_timer_index = NONE;
 
 static u64_t *Timer_list[NUMBER_OF_TIMERS] = {
 	&hw_timer_timer,
-	&irq_ctrl_timer
+	&irq_ctrl_timer,
+#ifdef CONFIG_HAS_SDL
+	&sdl_event_timer,
+#endif
 };
 
 static u64_t next_timer_time;
 
 /* Have we received a SIGTERM or SIGINT */
 static volatile sig_atomic_t signaled_end;
 
-
 /**
  * Handler for SIGTERM and SIGINT
  */
@@ -95,7 +111,6 @@ static void hwm_sleep_until_next_timer(void)
 	if (signaled_end || (simu_time > end_of_time)) {
 		posix_print_trace("\nStopped at %.3Lfs\n",
 				((long double)simu_time)/1.0e6);
-
 		posix_exit(0);
 	}
 }
@@ -134,6 +149,11 @@ void hwm_main_loop(void)
 		case IRQCNT:
 			hw_irq_ctrl_timer_triggered();
 			break;
+#ifdef CONFIG_HAS_SDL
+		case SDLEVENTTIMER:
+			sdl_handle_events();
+			break;
+#endif
 		default:
 			/* LCOV_EXCL_START */
 			posix_print_error_and_exit(

diff --git a/boards/posix/native_posix/sdl_events.c b/boards/posix/native_posix/sdl_events.c
@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2018 Jan Van Winkel <[email protected]>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <SDL.h>
+#include "posix_board_if.h"
+#include "posix_trace.h"
+#include "posix_arch_internal.h"
+#include "soc.h"
+#include "hw_models_top.h"
+
+u64_t sdl_event_timer;
+
+static void sdl_handle_window_event(const SDL_Event *event)
+{
+	SDL_Window *window;
+	SDL_Renderer *renderer;
+
+	switch (event->window.event) {
+	case SDL_WINDOWEVENT_EXPOSED:
+
+		window = SDL_GetWindowFromID(event->window.windowID);
+		if (window == NULL) {
+			return;
+		}
+
+		renderer = SDL_GetRenderer(window);
+		if (renderer == NULL) {
+			return;
+		}
+		SDL_RenderPresent(renderer);
+		break;
+	default:
+		break;
+	}
+}
+
+void sdl_handle_events(void)
+{
+	SDL_Event event;
+
+	sdl_event_timer = hwm_get_time() + 10000;
+
+	while (SDL_PollEvent(&event)) {
+		switch (event.type) {
+		case SDL_WINDOWEVENT:
+			sdl_handle_window_event(&event);
+			break;
+		case SDL_QUIT:
+			posix_exit(0);
+			break;
+		default:
+			break;
+		}
+	}
+
+}
+
+static void sdl_init(void)
+{
+	if (SDL_Init(SDL_INIT_VIDEO) != 0) {
+		posix_print_error_and_exit("Error on SDL_Init (%s)\n",
+				SDL_GetError());
+	}
+}
+
+static void sdl_cleanup(void)
+{
+	SDL_Quit();
+}
+
+NATIVE_TASK(sdl_init, PRE_BOOT_2, 1);
+NATIVE_TASK(sdl_cleanup, ON_EXIT, 2);
diff --git a/boards/posix/native_posix/sdl_events.h b/boards/posix/native_posix/sdl_events.h
@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) 2018 Jan Van Winkel <[email protected]>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+#ifndef ZEPHYR_BOARD_POSIX_NATIVE_POSIX_SDL_EVENTS_H
+#define ZEPHYR_BOARD_POSIX_NATIVE_POSIX_SDL_EVENTS_H
+
+#include <zephyr/types.h>
+
+void sdl_handle_events(void);
+
+#endif /* ZEPHYR_BOARD_POSIX_NATIVE_POSIX_SDL_EVENTS_H */
+
diff --git a/drivers/display/CMakeLists.txt b/drivers/display/CMakeLists.txt
@@ -10,3 +10,6 @@ zephyr_sources_ifdef(CONFIG_ILI9340_LCD_ADAFRUIT_1480
 )
 zephyr_sources_ifdef(CONFIG_SSD1306 ssd1306.c)
 zephyr_sources_ifdef(CONFIG_SSD1673 ssd1673.c)
+
+zephyr_sources_ifdef(CONFIG_SDL_DISPLAY display_sdl.c)
+
diff --git a/drivers/display/Kconfig b/drivers/display/Kconfig
@@ -20,8 +20,8 @@ source "subsys/logging/Kconfig.template.log_config"
 source "drivers/display/Kconfig.grove"
 
 source "drivers/display/Kconfig.microbit"
-
 source "drivers/display/Kconfig.ili9340"
+source "drivers/display/Kconfig.sdl"
 
 source "drivers/display/Kconfig.ssd1306"
 

diff --git a/drivers/display/Kconfig.sdl b/drivers/display/Kconfig.sdl
@@ -0,0 +1,30 @@
+# Kconfig - SDL based emulated display configuration options
+
+#
+# Copyright (c) 2018 Jan Van Winkel <[email protected]>
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+menuconfig SDL_DISPLAY
+	bool "SDL based emulated display"
+	depends on BOARD_NATIVE_POSIX
+	select HAS_SDL
+	help
+	  Enable SDL based emulated display compliant with display driver API.
+
+if SDL_DISPLAY
+
+config SDL_DISPLAY_DEV_NAME
+	string "SDL display device name"
+	default "SDL_DISPLAY"
+
+config SDL_DISPLAY_X_RES
+	int "X resolution for SDL display"
+	default 320
+
+config SDL_DISPLAY_Y_RES
+	int "Y resolution for SDL display"
+	default 240
+
+endif #SDL_DISPLAY