/*
 * (C) Copyright 2015 - 2016, Xilinx, Inc,
 * Michal Simek <michal.simek@xilinx.com>
 * Siva Durga Prasad <siva.durga.paladugu@xilinx.com>
 *
 * SPDX-License-Identifier:	GPL-2.0
 */

#include <console.h>
#include <common.h>
#include <zynqmppl.h>
#include <linux/sizes.h>

#define DUMMY_WORD	0xffffffff

/* Xilinx binary format header */
static const u32 bin_format[] = {
	DUMMY_WORD, /* Dummy words */
	DUMMY_WORD,
	DUMMY_WORD,
	DUMMY_WORD,
	DUMMY_WORD,
	DUMMY_WORD,
	DUMMY_WORD,
	DUMMY_WORD,
	DUMMY_WORD,
	DUMMY_WORD,
	DUMMY_WORD,
	DUMMY_WORD,
	DUMMY_WORD,
	DUMMY_WORD,
	DUMMY_WORD,
	DUMMY_WORD,
	0x000000bb, /* Sync word */
	0x11220044, /* Sync word */
	DUMMY_WORD,
	DUMMY_WORD,
	0xaa995566, /* Sync word */
};

#define SWAP_NO		1
#define SWAP_DONE	2

/*
 * Load the whole word from unaligned buffer
 * Keep in your mind that it is byte loading on little-endian system
 */
static u32 load_word(const void *buf, u32 swap)
{
	u32 word = 0;
	u8 *bitc = (u8 *)buf;
	int p;

	if (swap == SWAP_NO) {
		for (p = 0; p < 4; p++) {
			word <<= 8;
			word |= bitc[p];
		}
	} else {
		for (p = 3; p >= 0; p--) {
			word <<= 8;
			word |= bitc[p];
		}
	}

	return word;
}

static u32 check_header(const void *buf)
{
	u32 i, pattern;
	int swap = SWAP_NO;
	u32 *test = (u32 *)buf;

	debug("%s: Let's check bitstream header\n", __func__);

	/* Checking that passing bin is not a bitstream */
	for (i = 0; i < ARRAY_SIZE(bin_format); i++) {
		pattern = load_word(&test[i], swap);

		/*
		 * Bitstreams in binary format are swapped
		 * compare to regular bistream.
		 * Do not swap dummy word but if swap is done assume
		 * that parsing buffer is binary format
		 */
		if ((__swab32(pattern) != DUMMY_WORD) &&
		    (__swab32(pattern) == bin_format[i])) {
			swap = SWAP_DONE;
			debug("%s: data swapped - let's swap\n", __func__);
		}

		debug("%s: %d/%px: pattern %x/%x bin_format\n", __func__, i,
		      &test[i], pattern, bin_format[i]);
	}
	debug("%s: Found bitstream header at %px %s swapinng\n", __func__,
	      buf, swap == SWAP_NO ? "without" : "with");

	return swap;
}

static void *check_data(u8 *buf, size_t bsize, u32 *swap)
{
	u32 word, p = 0; /* possition */

	/* Because buf doesn't need to be aligned let's read it by chars */
	for (p = 0; p < bsize; p++) {
		word = load_word(&buf[p], SWAP_NO);
		debug("%s: word %x %x/%px\n", __func__, word, p, &buf[p]);

		/* Find the first bitstream dummy word */
		if (word == DUMMY_WORD) {
			debug("%s: Found dummy word at position %x/%px\n",
			      __func__, p, &buf[p]);
			*swap = check_header(&buf[p]);
			if (*swap) {
				/* FIXME add full bitstream checking here */
				return &buf[p];
			}
		}
		/* Loop can be huge - support CTRL + C */
		if (ctrlc())
			return NULL;
	}
	return NULL;
}

static ulong zynqmp_align_dma_buffer(u32 *buf, u32 len, u32 swap)
{
	u32 *new_buf;
	u32 i;

	if ((ulong)buf != ALIGN((ulong)buf, ARCH_DMA_MINALIGN)) {
		new_buf = (u32 *)ALIGN((ulong)buf, ARCH_DMA_MINALIGN);

		/*
		 * This might be dangerous but permits to flash if
		 * ARCH_DMA_MINALIGN is greater than header size
		 */
		if (new_buf > (u32 *)buf) {
			debug("%s: Aligned buffer is after buffer start\n",
			      __func__);
			new_buf -= ARCH_DMA_MINALIGN;
		}
		printf("%s: Align buffer at %px to %px(swap %d)\n", __func__,
		       buf, new_buf, swap);

		for (i = 0; i < (len/4); i++)
			new_buf[i] = load_word(&buf[i], swap);

		buf = new_buf;
	} else if (swap != SWAP_DONE) {
		/* For bitstream which are aligned */
		u32 *new_buf = (u32 *)buf;

		printf("%s: Bitstream is not swapped(%d) - swap it\n", __func__,
		       swap);

		for (i = 0; i < (len/4); i++)
			new_buf[i] = load_word(&buf[i], swap);
	}

	return (ulong)buf;
}

static int zynqmp_validate_bitstream(xilinx_desc *desc, const void *buf,
				   size_t bsize, u32 blocksize, u32 *swap)
{
	ulong *buf_start;
	ulong diff;

	buf_start = check_data((u8 *)buf, blocksize, swap);

	if (!buf_start)
		return FPGA_FAIL;

	/* Check if data is postpone from start */
	diff = (ulong)buf_start - (ulong)buf;
	if (diff) {
		printf("%s: Bitstream is not validated yet (diff %lx)\n",
		       __func__, diff);
		return FPGA_FAIL;
	}

	if ((ulong)buf < SZ_1M) {
		printf("%s: Bitstream has to be placed up to 1MB (%px)\n",
		       __func__, buf);
		return FPGA_FAIL;
	}

	return 0;
}

static int invoke_smc(ulong id, ulong reg0, ulong reg1, ulong reg2)
{
	struct pt_regs regs;
	regs.regs[0] = id;
	regs.regs[1] = reg0;
	regs.regs[2] = reg1;
	regs.regs[3] = reg2;

	smc_call(&regs);

	return regs.regs[0];
}

static int zynqmp_load(xilinx_desc *desc, const void *buf, size_t bsize,
		     bitstream_type bstype)
{
	u32 swap;
	ulong bin_buf, flags;
	int ret;

	if (zynqmp_validate_bitstream(desc, buf, bsize, bsize, &swap))
		return FPGA_FAIL;

	bin_buf = zynqmp_align_dma_buffer((u32 *)buf, bsize, swap);

	debug("%s called!\n", __func__);
	flush_dcache_range(bin_buf, bin_buf + bsize);

	if (bsize % 4)
		bsize = bsize / 4 + 1;
	else
		bsize = bsize / 4;

	flags = (u32)bsize | ((u64)bstype << 32);

	ret = invoke_smc(ZYNQMP_SIP_SVC_PM_FPGA_LOAD, bin_buf, flags, 0);
	if (ret)
		debug("PL FPGA LOAD fail\n");

	return ret;
}

struct xilinx_fpga_op zynqmp_op = {
	.load = zynqmp_load,
};