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Here we are! MetaWatch support in Oswald!

Nils Faerber authored on 27/04/2013 20:22:32
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metawatch/sharp_mem_lcd.c
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+// taken and adapted from
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+// Programming Sharp’s Memory LCDs
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+// by Ken Green
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+
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+// LCD commands - Note: the bits are reversed per the memory LCD data
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+// sheets because of the order the bits are shifted out in the SPI
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+// port.
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+#define MLCD_WR 0x80		//MLCD write line command
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+#define MLCD_CM 0x20		//MLCD clear memory command
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+#define MLCD_NO 0x00		//MLCD NOP command (used to switch VCOM)
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+
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+//LCD resolution
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+#define MLCD_XRES 96		//pixels per horizontal line
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+#define MLCD_YRES 96		//pixels per vertical line
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+#define MLCD_BYTES_LINE MLCD_XRES / 8 //number of bytes in a line
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+#define MLCD_BUF_SIZE MLCD_YRES * MLCD_BYTES_LINE
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+
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+//defines the VCOM bit in the command word that goes to the LCD
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+#define VCOM_HI 0x40
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+#define VCOM_LO 0x00
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+
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+static char *frmbufter; //current address of buffer to be displayed
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+static char locbuf[MLCD_BYTES_LINE + 3];	// local line buffer
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+static char linenum;				// current line number being transmitted
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+
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+//there are 3 stages in transmitting a buffer:
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+//stage 0: first line (has command in it)
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+//stage 1: 2nd through last line (no command)
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+//stage 2: null byte trailer
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+static int stage = 0;
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+
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+//current state of vcom. This should alternate
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+//between VCOM _ HI and VCOM _ LO on a 1-30 second
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+//period.
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+extern char vcom;
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+
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+////////////////////////////////////////////////////////////////
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+//
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+// This routine transmits the contents of the pixel memory in
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+// a frame buffer to the memory LCD. It uses DMA to transfer
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+// each individual line. The address of the frame buffer to
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+// transfer is in the global variable show _ frm.
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+//
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+//
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+// NOTE: this routine also acts as the interrupt handler for SPI interrupts.
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+//
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+//
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+// INPUTS:
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+// The SPI and DMA units must have been previously initialized
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+// show _ frm:
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+// pointer to the buffer to be displayed
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+//
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+////////////////////////////////////////////////////////////////
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+void show _ frame(char *show _ frm) {
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+int i;
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+unsigned long sts;
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+
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+	switch(stage) {
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+		case 0:
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+			// stage 0: sending the first line. The command is
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+			// included in this line
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+			set_scs(HIGH);	//set SCS high
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+			frmbufptr = show_frm;	//init pointer to frame buffer
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+			linebuf = locbuf; //init pointer to line buffer
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+			linenum = 1; //init line address
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+
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+			//first line of data is preceeded by a write command
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+			*linebuf++ = MLCD _ WR | vcom; //command (note: no need to swap)
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+			*linebuf++ = swap(linenum++); //line number (address)
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+
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+			for (i=0; i<MLCD_BYTES_LINE; i++)
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+				*linebuf++ = swap(*frmbufptr++); //swap the order of the bits
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+			*linebuf++ = 0; //trailer
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+
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+			//Setup the SPI DMA controller (starting addr, size)
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+			TransferSetup(locbuf, linebuf - locbuf);
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+			//Start the xfer
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+			TransferStart;
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+			stage = 1; //set to next stage
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+			break;
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+
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+		case 1: //Sending a line (other than the first line). At this
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+			//point the DMA transfer for the previous line is done
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+			//and the channel disabled.
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+			linebuf = locbuf; //init pointer to line buffer
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+			*linebuf++ = swap(linenum++); //line number
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+			for (i=0; i<MLCD_BYTES_LINE; i++)
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+				*linebuf++ = swap(*frmbufptr++); //swap the order of the bits
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+			*linebuf++ = 0; //trailer
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+			//set up DMA control
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+			TransferSetup(locbuf, linebuf - locbuf);
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+			//Start the xfer
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+			TransferStart;
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+			if (linenum > MLCD_YRES)
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+				stage = 2; //all lines sent, go to next stage
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+			break;
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+		case 2:
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+			// All lines sent, send a fi nal null byte trailer. The DMA
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+			//transfer of the last line is fi nished and the channel
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+			//disabled. All that is left is to write a trailing null
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+			//byte. It’s not worth using DMA to transfer 1 byte, so
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+			//it’s done by directing writing to the SPI port.
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+			//Write the last (null) byte
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+			Write_to_SPI(0);
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+			//Since there is no interrupt on transmit buffer empty, loop
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+			//here until the byte is sent, then drop SCS.
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+			i = 0;
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+			while (SPI_BSY); //wait until done
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+			set_scs(LOW);
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+			stage = 0; //go back to stage 0 - sending out first line
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+	}
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+}
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+