Merge pull request #1703 from sgjava/master

Make arm-linux use dynamic buffer everywhere

> @olikraus was there something else you were waiting on besides ifdef change?

thats it :-)

csrc/u8g2.h

@@ -1376,6 +1376,11 @@ void u8g2_SetBufferCurrTileRow(u8g2_t *u8g2, uint8_t row) U8G2_NOINLINE;
 void u8g2_FirstPage(u8g2_t *u8g2);
 uint8_t u8g2_NextPage(u8g2_t *u8g2);
 
+// Add ability to set buffer pointer
+#ifdef __ARM_LINUX__
+#define U8G2_USE_DYNAMIC_ALLOC
+#endif
+
 #ifdef U8G2_USE_DYNAMIC_ALLOC
 #define u8g2_SetBufferPtr(u8g2, buf) ((u8g2)->tile_buf_ptr = (buf));
 #define u8g2_GetBufferSize(u8g2) ((u8g2)->u8x8.display_info->tile_width * 8 * (u8g2)->tile_buf_height)

sys/arm-linux/examples/c-examples/u8g2_sw_i2c_thread/Makefile

@@ -0,0 +1,61 @@
+
+# Chosse proper compiler for your PI
+# NanoPi:             arm-linux-gnueabi-gcc
+# Raspberry Pi Zero:  arm-linux-gnueabi-gcc
+
+# Raspberry Pi 2:     arm-linux-gnueabihf-gcc
+# OrangePi Zero:      arm-linux-gnueabihf-gcc
+# NanoPi NEO:         arm-linux-gnueabihf-gcc
+# NanoPi NEO Plus 2:  arm-linux-gnueabihf-gcc
+
+# C-SKY Linux:  csky-linux-gcc
+
+CC=arm-linux-gnueabi-gcc
+
+# IP Address of your PI
+PI=pi@raspberrypi.local
+
+TARGET=u8g2_sw_i2c_thread
+IDIR= -I ../../../drivers -I ../../../../../csrc -I ../../../port
+SRCDIR=../../../../../csrc
+OBJDIR=../../../obj
+OUTDIR=../../../bin
+LDIR= -L ../../../lib
+LIBS=  -lm -lpthread
+
+CFLAGS= $(IDIR) -W -Wall -D __ARM_LINUX__
+
+OBJ+=u8g2_sw_i2c_thread.o\
+	../../../port/u8g2port.o\
+	../../../drivers/gpio.o\
+	../../../drivers/spi.o\
+	../../../drivers/i2c.o\
+
+OBJ+=$(patsubst $(SRCDIR)/%.c,$(OBJDIR)/%.o, $(wildcard $(SRCDIR)/*.c))
+
+all: directories $(TARGET) 
+
+directories:
+	@mkdir -p $(OBJDIR)
+	@mkdir -p $(OUTDIR)
+
+$(TARGET):$(OBJ)
+	@echo Generating $(TARGET) ...
+	@$(CC) -o $(OUTDIR)/$@ $(OBJ) $(LDIR) $(LIBS)
+
+$(OBJDIR)/%.o: $(SRCDIR)/%.c
+	$(CC) -c -o $@ $< $(CFLAGS) $(LDIR) $(LIBS)
+
+clean:
+	@echo RM -rf $(OBJDIR)/
+	@rm -rf $(OBJ)
+	@rm -rf $(OBJDIR)
+	
+	@echo RM -rf $(OUTDIR)/
+	@rm -rf $(OUTDIR)
+
+upload:
+	scp $(OUTDIR)/$(TARGET) $(PI):~/
+
+run:
+	ssh $(PI)

sys/arm-linux/examples/c-examples/u8g2_sw_i2c_thread/u8g2_sw_i2c_thread.c

@@ -0,0 +1,81 @@
+/*
+ * Run three displays drawing random lines. This proves you can use U8g2 to run
+ * multiple displays in a thread safe way.
+ */
+
+#include "u8g2port.h"
+#include <pthread.h>
+#include <string.h>
+#include <errno.h>
+
+// Encapsulate each thread's info
+struct display {
+	uint8_t gpio_chip;
+	uint8_t scl;
+	uint8_t sda;
+	uint8_t res;
+	unsigned long delay;
+};
+
+typedef struct display display_t;
+
+/*
+ * Draw random lines with 50 ms delay.
+ */
+void* do_display(void *arg) {
+	display_t disp = *((display_t*) arg);
+	pthread_t id = pthread_self();
+	uint8_t h, w, y1, y2;
+
+	printf("Thread %lu start\n", id);
+	u8g2_t u8g2;
+	// Initialization
+	u8g2_Setup_ssd1306_i2c_128x32_univision_f(&u8g2, U8G2_R0, u8x8_byte_sw_i2c,
+			u8x8_arm_linux_gpio_and_delay);
+	init_i2c_sw(&u8g2, disp.gpio_chip, disp.scl, disp.sda, disp.res,
+			disp.delay);
+	u8g2_InitDisplay(&u8g2);
+	h = u8g2_GetDisplayHeight(&u8g2);
+	w = u8g2_GetDisplayWidth(&u8g2);
+	u8g2_SetPowerSave(&u8g2, 0);
+	u8g2_SetFont(&u8g2, u8g2_font_ncenB08_tr);
+	for (int i = 1; i < 200; ++i) {
+		u8g2_ClearBuffer(&u8g2);
+		y1 = rand() % h;
+		y2 = rand() % h;
+		u8g2_DrawLine(&u8g2, 0, y1, w - 1, y2);
+		u8g2_SendBuffer(&u8g2);
+		sleep_ms(50);
+	}
+	u8g2_SetPowerSave(&u8g2, 1);
+	// Close and deallocate GPIO resources
+	done_user_data(&u8g2);
+	printf("Thread %lu end\n", id);
+	return NULL;
+}
+
+int main(void) {
+
+	pthread_t id_1;
+	pthread_t id_2;
+	pthread_t id_3;
+
+	void *retval_1;
+	void *retval_2;
+	void *retval_3;
+
+	display_t display_1 = { 0, 14, 13, U8X8_PIN_NONE, 0 };
+	display_t display_2 = { 0, 15, 16, U8X8_PIN_NONE, 0 };
+	display_t display_3 = { 0, 198, 199, U8X8_PIN_NONE, 0 };
+
+	pthread_create(&id_1, NULL, &do_display, &display_1);
+	pthread_create(&id_2, NULL, &do_display, &display_2);
+	pthread_create(&id_3, NULL, &do_display, &display_3);
+
+	pthread_join(id_1, (void**) &retval_1);
+	pthread_join(id_2, (void**) &retval_2);
+	pthread_join(id_3, (void**) &retval_3);
+	printf("Done\n");
+
+	return 0;
+}

sys/arm-linux/port/U8g2lib.h

@@ -142,7 +142,8 @@ public:
 	}
 	void initSpiHw(uint8_t gpio_chip, uint8_t bus, uint8_t dc, uint8_t res,
 			uint8_t cs, unsigned int spi_mode, uint32_t max_speed) {
-		init_spi_hw_advanced(&u8g2, gpio_chip, bus, dc, res, cs, spi_mode, max_speed);
+		init_spi_hw_advanced(&u8g2, gpio_chip, bus, dc, res, cs, spi_mode,
+				max_speed);
 	}
 	void initSpiHw(uint8_t gpio_chip, uint8_t bus, uint8_t dc, uint8_t res,
 			uint8_t cs) {
@@ -209,15 +210,10 @@ public:
 	}
 
 	bool begin(void) {
-		/* note: call to u8x8_utf8_init is not required here, this is done in the setup procedures before */
-#ifndef U8G2_USE_DYNAMIC_ALLOC
 		initDisplay();
 		clearDisplay();
 		setPowerSave(0);
 		return 1;
-#else
-      return 0;
-      #endif
 	}
 
 	void beginSimple(void) {

sys/arm-linux/port/u8g2port.c

@@ -1,7 +1,9 @@
 /*
- * This code should support multiple displays since GPIO pin handles have been
+ * This code supports multiple displays since GPIO pin handles have been
  * moved into user_data_struct. I2C and SPI handles are global since they can be
  * shared by multiple devices (think I2C with different address sharing bus).
+ *
+ * So far I have tested this with 3 software I2C displays. See examples.
  */
 
 #include "u8g2port.h"
@@ -46,8 +48,12 @@ void sleep_ns(unsigned long nanoseconds) {
  * Allocate user_data_struct, set common values and set user_ptr.
  */
 user_data_t* init_user_data(u8g2_t *u8g2) {
-	// Dynamically allocate u8x8_buffer_struct
+	// Dynamically allocate user data_struct
 	user_data_t *user_data = (user_data_t*) malloc(sizeof(user_data_t));
+	// Dynamically allocate internal buffer
+	user_data->int_buf = (uint8_t*)malloc(u8g2_GetBufferSize(u8g2));
+	// We need a unique buffer for each display in order to be thread friendly
+	u8g2_SetBufferPtr(u8g2, user_data->int_buf);
 	for (int i = 0; i < U8X8_PIN_CNT; ++i) {
 		user_data->pins[i] = NULL;
 	}
@@ -122,12 +128,16 @@ void init_spi_sw(u8g2_t *u8g2, uint8_t gpio_chip, uint8_t dc, uint8_t res,
 void done_user_data(u8g2_t *u8g2) {
 	user_data_t *user_data = u8g2_GetUserPtr(u8g2);
 	if (user_data != NULL) {
+		// Close all GPIO pins
 		for (int i = 0; i < U8X8_PIN_CNT; ++i) {
 			if (user_data->pins[i] != NULL) {
 				gpio_close(user_data->pins[i]);
 				gpio_free(user_data->pins[i]);
 			}
 		}
+		// Free internal buffer
+		free(user_data->int_buf);
+		// Free user data struct
 		free(user_data);
 		u8g2_SetUserPtr(u8g2, NULL);
 	}

sys/arm-linux/port/u8g2port.h

@@ -28,7 +28,7 @@ struct user_data_struct {
 	uint8_t bus;
 	// Index into buffer
 	uint8_t index;
-	// Display buffer, I2C should send 32 bytes max and SPI 128 bytes max
+	// Callback buffer, I2C should send 32 bytes max and SPI 128 bytes max
 	uint8_t buffer[128];
 	// Nanosecond delay for U8X8_MSG_DELAY_I2C
 	unsigned long delay;
@@ -36,6 +36,8 @@ struct user_data_struct {
 	unsigned int spi_mode;
 	// SPI max speed
 	uint32_t max_speed;
+	// Internal buffer
+	uint8_t *int_buf;
 };
 
 typedef struct user_data_struct user_data_t;