More comments for the UEXT SSD1306 SPI board file

boards/base/Olimex-SAM7EX256-GE8/board_SSD1306_i2c.h

@@ -0,0 +1,146 @@
+/*
+ * This file is subject to the terms of the GFX License. If a copy of
+ * the license was not distributed with this file, you can obtain one at:
+ *
+ *              http://ugfx.org/license.html
+ */
+
+#ifndef _GDISP_LLD_BOARD_H
+#define _GDISP_LLD_BOARD_H
+
+#include "board_uext.h"
+
+/*
+ * NOTE: This board file is for an SSD1306 running in I2C mode
+ * 		 You will need to use a different board file for an SSD1306 running in SPI mode
+ */
+
+#define I2C_ADDRESS				(0x78/2)			// SSD1306 supports either 0x78 or 0x7A (including the write bit)
+#define I2C_RATE				400000				// 400kHz is I2C FAST mode
+
+// The various methods of driving the I2C interface
+#define I2C_METHOD_CHIBIOS		3
+
+// The various supported CPU's
+#define CPU_AT91				1
+
+// What methods are we using in this file
+#define I2C_METHOD			I2C_METHOD_CHIBIOS
+#define CPU_METHOD			CPU_AT91
+
+// If using SPI_METHOD_CHIBIOS the CPU specific i2cconfig structure must be defined for your CPU
+#if CPU_METHOD == CPU_AT91
+	#define I2C_CONFIG_REGISTER		((((MCK/I2C_RATE/2 - 3)>>8)<<16)|(((MCK/I2C_RATE/2 - 3)&0xFF)<<8)|(((MCK/I2C_RATE/2 - 3)&0xFF)<<0))			// For AT91SAM7:	8bit, CPOL=1, NCPHA = 0, ClockPhase=0, SCLK = 48Mhz/8 = 6MHz
+	#if I2C_METHOD == I2C_METHOD_CHIBIOS
+		// ChibiOS - Yuck! This structure is different on each platform.
+		//			 This is the one for the AT91
+		static const I2CConfig i2cconfig = {
+			I2C_CONFIG_REGISTER
+		};
+	#endif
+#else
+	#error "SSD1306: Unsupported CPU"
+#endif
+
+
+
+//---------------------------------------------------------------------
+
+/*
+ * Pin connection for the display to the UEXT connector:
+ *
+ * DISPLAY VCC					UEXT PIN 1 (3.3V)
+ * DISPLAY GND					UEXT PIN 2 (GND)
+ * DISPLAY SCL					UEXT PIN 5 (SCL)
+ * DISPLAY SDA					UEXT PIN 6 (SDA)
+ */
+
+#if I2C_METHOD == I2C_METHOD_CHIBIOS
+
+	/* ChibiOS can't send a separate data prefix byte in the same transaction as the real data.
+	 * Nor does it support an address prefix to the data (such as an EEPROM would use).
+	 * Instead we tell the driver to put it into the RAM buffer at the beginning of each page (Yuck!).
+	 *
+	 * Prefix bytes:
+	 * 0x40 means all following bytes in this transaction go into the GDRAM.
+	 * 0x00 means the following byte (singular) is a command byte.
+	 */
+	#define SSD1306_PAGE_PREFIX		0x40
+
+	#define I2C_INIT()
+
+	#define I2C_GETBUS() {											\
+		i2cAcquireBus(UEXT_I2C);									\
+		i2cStart(UEXT_I2C, &i2cconfig);								\
+	}
+
+	#define I2C_RELEASEBUS() {										\
+		i2cStop(UEXT_I2C);											\
+		i2cReleaseBus(UEXT_I2C);									\
+	}
+
+	#define I2C_WAITCOMPLETE()
+	#define I2C_WRITECMDBYTE(cmd)			{						\
+		uint8_t	data[2];											\
+		data[0] = 0;												\
+		data[1] = cmd;												\
+		i2cMasterTransmitTimeout (UEXT_I2C, I2C_ADDRESS, data, 2, 0, 0, TIME_INFINITE);	\
+	}
+	#define I2C_WRITEBYTES(pdata, len)		i2cMasterTransmitTimeout (UEXT_I2C, I2C_ADDRESS, pdata, length, 0, 0, TIME_INFINITE)
+
+#else
+	#error "SSD1306 board file: Unsupported I2C method"
+#endif
+
+static inline void init_board(GDisplay *g) {
+	(void) g;
+
+	I2C_INIT();
+}
+
+static inline void post_init_board(GDisplay *g) {
+	(void) g;
+}
+
+static inline void setpin_reset(GDisplay *g, bool_t state) {
+	(void) g;
+	(void) state;
+}
+
+static inline void set_backlight(GDisplay *g, uint8_t percent) {
+	(void) g;
+	(void) percent;
+}
+
+static inline void acquire_bus(GDisplay *g) {
+	(void) g;
+
+	I2C_GETBUS();
+}
+
+static inline void release_bus(GDisplay *g) {
+	(void) g;
+
+	I2C_WAITCOMPLETE();
+	I2C_RELEASEBUS();
+}
+
+static inline void write_cmd(GDisplay *g, uint8_t cmd) {
+	(void) g;
+
+	I2C_WAITCOMPLETE();
+
+	// Command mode please
+	I2C_WRITECMDBYTE(cmd);
+}
+
+static inline void write_data(GDisplay *g, uint8_t* data, uint16_t length) {
+	(void) g;
+
+	I2C_WAITCOMPLETE();
+
+	// Data mode please
+	I2C_WRITEBYTES(data, length);
+}
+
+#endif /* _GDISP_LLD_BOARD_H */

boards/base/Olimex-SAM7EX256-GE8/board_SSD1306_spi.h

@@ -10,6 +10,10 @@
 
 #include "board_uext.h"
 
+/*
+ * NOTE: This board file is for an SSD1306 running in SPI mode
+ * 		 You will need to use a different board file for an SSD1306 running in I2C mode
+ */
 // The various methods of driving the SPI interface
 #define SPI_METHOD_PIO		1
 #define SPI_METHOD_AT91		2
@@ -28,6 +32,16 @@
 
 //---------------------------------------------------------------------
 
+/*
+ * Pin connection for the display to the UEXT connector:
+ *
+ * DISPLAY VCC					UEXT PIN 1 (3.3V)
+ * DISPLAY GND					UEXT PIN 2 (GND)
+ * DISPLAY SCL					UEXT PIN 9 (SCK)
+ * DISPLAY SDA					UEXT PIN 8 (MOSI)
+ * DISPLAY RST					UEXT PIN 5 (SCL)
+ * DISPLAY D/C					UEXT PIN 6 (SDA)
+ */
 #define PORT_RESET		UEXT_PORT_PIN5
 #define PIN_RESET		UEXT_PORTPIN_PIN5
 #define PORT_DC			UEXT_PORT_PIN6
@@ -42,7 +56,7 @@
 	#define PinSet(port,pin)			palSetPad((port), (pin))
 	#define PinClear(port,pin)			palClearPad((port), (pin))
 #else
-	#error "TLS8204 board file: Unsupported PIO method"
+	#error "SSD1306 board file: Unsupported PIO method"
 #endif
 
 #if SPI_METHOD == SPI_METHOD_PIO
@@ -144,7 +158,7 @@
 	#define SPI_WRITEBYTES(pdata, len)		spiSend(UEXT_SPI, len, pdata)
 
 #else
-	#error "TLS8204 board file: Unsupported SPI method"
+	#error "SSD1306 board file: Unsupported SPI method"
 #endif
 
 static inline void init_board(GDisplay *g) {