/*
 * ubb-la.c - UBB logic analyzer
 *
 * Written 2013 by Werner Almesberger
 * Copyright 2013 Werner Almesberger
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <assert.h>
#include <sys/mman.h>

#include <ubb/ubb.h>
#include <ubb/regs4740.h>
#include <ubb/mmcclk.h>
#include <ubb/physmem.h>


#define	DMA	5


/* ----- Enable/disable interrupts ----------------------------------------- */


static uint32_t old_icmr;


static void disable_interrupts(void)
{
	old_icmr = ICMR;
	ICMSR = 0xffffffff;
}


static void enable_interrupts(void)
{
	ICMCR = ~old_icmr;
}


/* ----- DMA control ------------------------------------------------------- */


static uint32_t old_dmac;


static void dma_stop(void)
{
        DCS(DMA) =
            DCS_TT |                    /* Transfer terminated */
            DCS_HLT;                    /* DMA halt */
        DCS(DMA) = 0;                   /* reset DMA channel */
}


static void dma_init(void)
{
	old_dmac = DMAC;

	DMAC = DMAC_DMAE; /* activate the DMA controller (in case it's off) */
	dma_stop();

	DCM(DMA) =
	    DCM_DAI |	/* destination address increment */
	    (DCM_TSZ_32BYTE << DCM_TSZ_SHIFT);
			/* transfer size is 32 bytes */
        DRT(DMA) = DRT_MSC_RX;	/* MSC receive-fifo-full transfer request */
}


static void dma_cleanup(void)
{
	DMAC = old_dmac;
	dma_stop();
}


static void dma_setup(unsigned long buf, int nibbles)
{
	assert(!(nibbles & 63));

	DCS(DMA) = DCS_NDES;			/* no-descriptor transfer */
	DSA(DMA) = REG_PADDR(MSC_RXFIFO);	/* source */
	DTA(DMA) = buf;				/* destination */
	DTC(DMA) = nibbles >> 6;		/* 32 bytes per transfer */
}


static void wait_dma_done(void)
{
	while (!(DCS(DMA) & DCS_TT));
}


/* ----- MMC control ------------------------------------------------------- */


static void xfer(unsigned long buf, int nibbles)
{
	dma_init();
	dma_setup(buf, nibbles);

	MSC_STRPCL = MSC_STRPCRL_START_CLOCK;	/* start the bus clock */
	MSC_RESTO = MSC_RESTO_MASK;		/* maximum response time-out */
	MSC_RDTO = MSC_RDTO_MASK;
	MSC_BLKLEN = nibbles >> 1;

	MSC_CMDAT =
	    MSC_CMDAT_BUS_WIDTH_4 << MSC_CMDAT_BUS_WIDTH_SHIFT |
	    MSC_CMDAT_DMA_EN |		/* DMA */
	    MSC_CMDAT_DATA_EN |		/* with data transfer */
	    MSC_CMDAT_RESPONSE_FORMAT_NONE; /* no response required */

	MSC_STRPCL = MSC_STRPCRL_START_OP;

	while (MSC_STAT & MSC_STAT_DATA_FIFO_EMPTY);

	IN(UBB_CMD);

	disable_interrupts();

	while (!(PDPIN & UBB_DAT1));

//	sleep(1);		/* @@@ wait here for trigger */

	DCS(DMA) =
	    DCS_NDES |          /* no descriptor */
	    DCS_CTE;            /* enable channel */

	enable_interrupts();

	wait_dma_done();

printf("MSC_STAT = %08x\n", MSC_STAT);

	dma_cleanup();

}


static void do_buf(int nibbles)
{
	uint8_t *buf = physmem_malloc(4095);
	struct physmem_vec vec;
	int n, i;
	uint8_t v, last = 0xff;
	int count = 0;

	if (mlockall(MCL_CURRENT | MCL_FUTURE)) {
		perror("mlockall");
		exit(1);
	}

	memset(buf, 0, 4095);
	physmem_flush(buf, 4095);

	n = physmem_xlat((void *) buf, nibbles >> 1, &vec, 1);
	if (n != 1) {
		fprintf(stderr, "physmem_xlat_vec: expected 1, got %d\n", n);
		exit(1);
	}
	xfer(vec.addr, nibbles);

	for (i = 0; i != nibbles; i++) {
		v = (buf[i >> 1] >> (4*(~i & 1))) & 0xf;
		if (v == last) {
			count++;
		} else {
			switch (count) {
			case 0:
				break;
			case 1:
				printf("%X", last);
				break;
			default:
				printf("%X{%d}", last, count);
				break;
			}
			last = v;
			count = 1;
		}
	}
	if (count == 1)
		printf("%X\n", last);
	else
		printf("%X{%d}\n", last, count);
}


static void frequency(struct mmcclk *clk, int hz)
{
	struct mmcclk mmc;

	mmcclk_first(&mmc, 0);
	*clk = mmc;
	while (mmcclk_next(&mmc))
		if (fabs(clk->bus_clk_hz-hz) > fabs(mmc.bus_clk_hz-hz))
			*clk = mmc;
}


int main(int argc, char **argv)
{
	struct mmcclk clk;

	ubb_open(UBB_ALL);
	PDFUNS = UBB_DAT0 | UBB_DAT1 | UBB_DAT2 | UBB_DAT3;
	PDFUNS = UBB_CLK;
	OUT(UBB_CMD);
	CLR(UBB_CMD);
	PDFUNC = UBB_CMD;

	frequency(&clk, atoi(argv[1]));
	printf("bus %g MHz (MSC %g MHz)\n", clk.bus_clk_hz/1e6,
	    clk.sys_clk_hz/(clk.clkdiv+1.0)/1e6);
	mmcclk_start(&clk);

	do_buf(6400);

	mmcclk_stop();
	ubb_close(UBB_ALL);

	return 0;
}