/*
 * Almost all of this Pirelli LCD black magic has been lifted from OsmocomBB.
 */

#include <sys/types.h>
#include "types.h"

#define	GPIO_OUT_REG	(*(volatile u16 *)0xFFFE4802)
#define	nCS4_ADDR0	(*(volatile u16 *)0x02800000)
#define	nCS4_ADDR2	(*(volatile u16 *)0x02800002)

#define	DELAY_1MS	13000

fb_spca_write(addr, data)
{
	GPIO_OUT_REG &= 0xFF7F;
	nCS4_ADDR0 = addr;
	nCS4_ADDR2 = data;
}

void
cmd_spca(argbulk)
	char *argbulk;
{
	char *argv[3];
	u_long addr, data;

	if (parse_args(argbulk, 2, 2, argv, 0) < 0)
		return;
	if (parse_hexarg(argv[0], 4, &addr) < 0) {
		printf("ERROR: arg1 must be a valid 16-bit hex value\n");
		return;
	}
	if (parse_hexarg(argv[1], 4, &data) < 0) {
		printf("ERROR: arg2 must be a valid 16-bit hex value\n");
		return;
	}
	fb_spca_write(addr, data);
}

void
cmd_spcainit()
{
	/*
	 * Apparently we have to give it a reset pulse, then immediately
	 * do the black magic register write sequence.
	 */
	GPIO_OUT_REG = 0x0000;
	GPIO_OUT_REG = 0x0012;
	/*
	 * The non-understandable voodoo that follows has been copied from
	 * OsmocomBB, and more recently has been updated to use true ms
	 * delays instead of bogo-ms.  OBB's original code used their
	 * delay_ms() function, but the latter implements a delay in
	 * bogo-milliseconds instead of true ms, with 1 bogo-ms equal to
	 * 400 us in actual physical time.
	 */
	fb_spca_write(0x7e, 0x00);	/* internal register access */
	wait_ARM_cycles(DELAY_1MS * 4);	/* 10 bogo-ms = 4 ms */
	fb_spca_write(0x7a, 0x00);	/* keep CPU in reset state */
	wait_ARM_cycles(DELAY_1MS * 4);	/* 10 bogo-ms = 4 ms */
	fb_spca_write(0x7f, 0x00);	/* select main page */
	wait_ARM_cycles(DELAY_1MS * 2);	/* 5 bogo-ms = 2 ms */
	fb_spca_write(0x72, 0x07);	/* don't reshape timing, 16 bit mode */
	fb_spca_write(0x14, 0x03);
	fb_spca_write(0x7f, 0x00);	/* select main page */
	wait_ARM_cycles(DELAY_1MS * 2);	/* 5 bogo-ms = 2 ms */
	fb_spca_write(0x06, 0xff);
	fb_spca_write(0x7f, 0x09);
	fb_spca_write(0x19, 0x08);	/* backlight: 0x08 is on, 0x0c is off */
	fb_spca_write(0x23, 0x18);
}

enum s6b33b1x_cmdflag { CMD, DATA, END };

struct s6b33b1x_cmdlist {
	enum s6b33b1x_cmdflag is_cmd:8;	/* 1: is a command, 0: is data, 2: end marker! */
	u_char data;			/* 8 bit to send to LC display */
};

static const struct s6b33b1x_cmdlist
s6b33b1x_initdata[] = {
	{ CMD,  0x26 }, /* CMD   DCDC and AMP ON/OFF set */
	{ DATA, 0x00 }, /* DATA: everything off */
	{ CMD,  0x02 }, /* CMD   Oscillation Mode Set */
	{ DATA, 0x00 }, /* DATA: oscillator off */
	{ CMD,  0x2c }, /* CMD   Standby Mode off */
	{ CMD,  0x50 }, /* CMD   Display off */
	{ CMD,  0x02 }, /* CMD   Oscillation Mode Set */
	{ DATA, 0x01 }, /* DATA: oscillator on */
	{ CMD,  0x26 }, /* CMD   DCDC and AMP ON/OFF set */
	{ DATA, 0x01 }, /* DATA: Booster 1 on */
	{ CMD,  0x26 }, /* CMD   DCDC and AMP ON/OFF set */
	{ DATA, 0x09 }, /* DATA: Booster 1 on, OP-AMP on */
	{ CMD,  0x26 }, /* CMD   DCDC and AMP ON/OFF set */
	{ DATA, 0x0b }, /* DATA: Booster 1 + 2 on, OP-AMP on */
	{ CMD,  0x26 }, /* CMD   DCDC and AMP ON/OFF set */
	{ DATA, 0x0f }, /* DATA: Booster 1 + 2 + 3 on, OP-AMP on */
	{ CMD,  0x20 }, /* CMD   DC-DC Select */
	{ DATA, 0x01 }, /* DATA: step up x1.5 */
	{ CMD,  0x24 }, /* CMD   DCDC Clock Division Set */
	{ DATA, 0x0a }, /* DATA: fPCK = fOSC/6 */
	{ CMD,  0x2a }, /* CMD   Contrast Control */
	{ DATA, 0x2d }, /* DATA: default contrast */
	{ CMD,  0x30 }, /* CMD   Adressing mode set */
	{ DATA, 0x0b }, /* DATA: 65536 color mode */
	{ CMD,  0x10 }, /* CMD   Driver output mode set */
	{ DATA, 0x03 }, /* DATA: Display duty: 1/132 */
	{ CMD,  0x34 }, /* CMD   N-line inversion set */
	{ DATA, 0x88 }, /* DATA: inversion on, one frame, every 8 blocks */
	{ CMD,  0x40 }, /* CMD   Entry mode set */
	{ DATA, 0x00 }, /* DATA: Y address counter mode */
	{ CMD,  0x28 }, /* CMD   Temperature Compensation set */
	{ DATA, 0x01 }, /* DATA: slope -0.05%/degC */
	{ CMD,  0x32 }, /* CMD   ROW vector mode set */
	{ DATA, 0x01 }, /* DATA: every 2 subgroup */
	{ CMD,  0x51 }, /* CMD   Display on */
	{ END,  0x00 }, /* MARKER: end of list */
};

static void
fb_s6b33b1x_send_cmdlist(p)
	struct s6b33b1x_cmdlist *p;
{
	while(p->is_cmd != END) {
		nCS4_ADDR0 = p->data;
		p++;
	}
}

void
cmd_lcdinit()
{
	GPIO_OUT_REG |= 0x0080;
	fb_s6b33b1x_send_cmdlist(s6b33b1x_initdata);
}

set_lcd_addr_region(xstart, xend, ystart, yend)
{
	GPIO_OUT_REG |= 0x0080;
	nCS4_ADDR0 = 0x42;
	nCS4_ADDR0 = ystart + 4;
	nCS4_ADDR0 = yend + 4;
	nCS4_ADDR0 = 0x43;
	nCS4_ADDR0 = xstart;
	nCS4_ADDR0 = xend;
}

void
cmd_lcdfill(argbulk)
	char *argbulk;
{
	int argc;
	char *argv[6];
	u_long pixval;
	int xstart, xend, ystart, yend;
	int npix;

	if (parse_args(argbulk, 1, 5, argv, &argc) < 0)
		return;
	if (parse_hexarg(argv[0], 4, &pixval) < 0) {
		printf("ERROR: arg1 must be a valid 16-bit hex value\n");
		return;
	}
	switch (argc) {
	case 1:
		xstart = ystart = 0;
		xend = yend = 127;
		break;
	case 5:
		xstart = atoi(argv[1]);
		if (xstart < 0 || xstart > 127) {
range_err:		printf("ERROR: coordinate arg out of range\n");
			return;
		}
		xend = atoi(argv[2]);
		if (xend < 0 || xend > 127)
			goto range_err;
		ystart = atoi(argv[3]);
		if (ystart < 0 || ystart > 127)
			goto range_err;
		yend = atoi(argv[4]);
		if (yend < 0 || yend > 127)
			goto range_err;
		if (xend < xstart || yend < ystart) {
			printf("ERROR: negative range\n");
			return;
		}
		break;
	default:
		printf("ERROR: wrong number of arguments\n");
		return;
	}
	set_lcd_addr_region(xstart, xend, ystart, yend);
	npix = (xend + 1 - xstart) * (yend + 1 - ystart);
	while (npix--)
		nCS4_ADDR2 = pixval;
}

void
cmd_lcdtest()
{
	int i, j, k, p;

	/*
	 * The result of this command should be 8 vertical bars
	 * in the natural RGB order.
	 */
	set_lcd_addr_region(10, 89, 10, 89);
	for (i = 0; i < 80; i++) {
		for (j = 0; j < 8; j++) {
			p = 0;
			if (j & 4)
				p |= 0xF800;
			if (j & 2)
				p |= 0x07E0;
			if (j & 1)
				p |= 0x001F;
			for (k = 0; k < 10; k++)
				nCS4_ADDR2 = p;
		}
	}
}

void
cmd_blit(argbulk)
	char *argbulk;
{
	int argc;
	char *argv[6];
	u16 imgbuf[16384];
	size_t img_file_size;
	int xstart, ystart, width, height;
	int npix, i;

	if (parse_args(argbulk, 1, 5, argv, &argc) < 0)
		return;
	if (tiffs_read_into_ram(argv[0], imgbuf, 32768, &img_file_size) < 0)
		return;
	switch (argc) {
	case 1:
		xstart = ystart = 0;
		width = height = 128;
		break;
	case 3:
		xstart = ystart = 0;
		goto widthheight;
	case 5:
		xstart = atoi(argv[3]);
		if (xstart < 0 || xstart > 127) {
range_err:		printf("ERROR: coordinate arg out of range\n");
			return;
		}
		ystart = atoi(argv[4]);
		if (ystart < 0 || ystart > 127)
			goto range_err;
		/* FALL THRU */
	widthheight:
		width = atoi(argv[1]);
		if (width < 1 || width > 128)
			goto range_err;
		height = atoi(argv[2]);
		if (height < 1 || height > 128)
			goto range_err;
		if (xstart + width > 128)
			goto range_err;
		if (ystart + height > 128)
			goto range_err;
		break;
	default:
		printf("ERROR: wrong number of arguments\n");
		return;
	}
	npix = width * height;
	if (img_file_size != npix * 2) {
		printf("ERROR: image file size (%u bytes) does not match WxH\n",
			img_file_size);
		return;
	}
	set_lcd_addr_region(xstart, xstart + width - 1,
				ystart, ystart + height - 1);
	/* the artwork images in Pirelli's FFS appear to be inverted */
	for (i = 0; i < npix; i++)
		nCS4_ADDR2 = ~imgbuf[i];
}