/*
 * U-boot - string.c Contains library routines.
 *
 * Copyright (c) 2005-2008 Analog Devices Inc.
 *
 * (C) Copyright 2000-2004
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 * SPDX-License-Identifier:     GPL-2.0+
 */

#include <common.h>
#include <config.h>
#include <asm/blackfin.h>
#include <asm/io.h>
#include <asm/dma.h>

char *strcpy(char *dest, const char *src)
{
        char *xdest = dest;
        char temp = 0;

        __asm__ __volatile__ (
                "1:\t%2 = B [%1++] (Z);\n\t"
                "B [%0++] = %2;\n\t"
                "CC = %2;\n\t"
                "if cc jump 1b (bp);\n"
                : "=a"(dest), "=a"(src), "=d"(temp)
                : "0"(dest), "1"(src), "2"(temp)
                : "memory");

        return xdest;
}

char *strncpy(char *dest, const char *src, size_t n)
{
        char *xdest = dest;
        char temp = 0;

        if (n == 0)
                return xdest;

        __asm__ __volatile__ (
                "1:\t%3 = B [%1++] (Z);\n\t"
                "B [%0++] = %3;\n\t"
                "CC = %3;\n\t"
                "if ! cc jump 2f;\n\t"
                "%2 += -1;\n\t"
                "CC = %2 == 0;\n\t"
                "if ! cc jump 1b (bp);\n"
                "2:\n"
                : "=a"(dest), "=a"(src), "=da"(n), "=d"(temp)
                : "0"(dest), "1"(src), "2"(n), "3"(temp)
                : "memory");

        return xdest;
}

int strcmp(const char *cs, const char *ct)
{
        char __res1, __res2;

        __asm__ (
                "1:\t%2 = B[%0++] (Z);\n\t"     /* get *cs */
                "%3 = B[%1++] (Z);\n\t" /* get *ct */
                "CC = %2 == %3;\n\t"    /* compare a byte */
                "if ! cc jump 2f;\n\t"  /* not equal, break out */
                "CC = %2;\n\t"  /* at end of cs? */
                "if cc jump 1b (bp);\n\t"       /* no, keep going */
                "jump.s 3f;\n"  /* strings are equal */
                "2:\t%2 = %2 - %3;\n"   /* *cs - *ct */
                "3:\n"
                : "=a"(cs), "=a"(ct), "=d"(__res1), "=d"(__res2)
                : "0"(cs), "1"(ct));

        return __res1;
}

int strncmp(const char *cs, const char *ct, size_t count)
{
        char __res1, __res2;

        if (!count)
                return 0;

        __asm__(
                "1:\t%3 = B[%0++] (Z);\n\t"     /* get *cs */
                "%4 = B[%1++] (Z);\n\t" /* get *ct */
                "CC = %3 == %4;\n\t"    /* compare a byte */
                "if ! cc jump 3f;\n\t"  /* not equal, break out */
                "CC = %3;\n\t"  /* at end of cs? */
                "if ! cc jump 4f;\n\t"  /* yes, all done */
                "%2 += -1;\n\t" /* no, adjust count */
                "CC = %2 == 0;\n\t" "if ! cc jump 1b;\n"        /* more to do, keep going */
                "2:\t%3 = 0;\n\t"       /* strings are equal */
                "jump.s    4f;\n" "3:\t%3 = %3 - %4;\n" /* *cs - *ct */
                "4:"
                : "=a"(cs), "=a"(ct), "=da"(count), "=d"(__res1), "=d"(__res2)
                : "0"(cs), "1"(ct), "2"(count));

        return __res1;
}

#ifdef MDMA1_D0_NEXT_DESC_PTR
# define MDMA_D0_NEXT_DESC_PTR MDMA1_D0_NEXT_DESC_PTR
# define MDMA_S0_NEXT_DESC_PTR MDMA1_S0_NEXT_DESC_PTR
#endif

static void dma_calc_size(unsigned long ldst, unsigned long lsrc, size_t count,
                        unsigned long *dshift, unsigned long *bpos)
{
        unsigned long limit;

#ifdef MSIZE
        /* The max memory DMA memory transfer size is 32 bytes. */
        limit = 5;
        *dshift = MSIZE_P;
#else
        /* The max memory DMA memory transfer size is 4 bytes. */
        limit = 2;
        *dshift = WDSIZE_P;
#endif

        *bpos = min(limit, ffs(ldst | lsrc | count)) - 1;
}

/* This version misbehaves for count values of 0 and 2^16+.
 * Perhaps we should detect that ?  Nowhere do we actually
 * use dma memcpy for those types of lengths though ...
 */
void dma_memcpy_nocache(void *dst, const void *src, size_t count)
{
        struct dma_register *mdma_d0 = (void *)MDMA_D0_NEXT_DESC_PTR;
        struct dma_register *mdma_s0 = (void *)MDMA_S0_NEXT_DESC_PTR;
        unsigned long ldst = (unsigned long)dst;
        unsigned long lsrc = (unsigned long)src;
        unsigned long dshift, bpos;
        uint32_t dsize, mod;

        /* Disable DMA in case it's still running (older u-boot's did not
         * always turn them off).  Do it before the if statement below so
         * we can be cheap and not do a SSYNC() due to the forced abort.
         */
        bfin_write(&mdma_d0->config, 0);
        bfin_write(&mdma_s0->config, 0);
        bfin_write(&mdma_d0->status, DMA_RUN | DMA_DONE | DMA_ERR);

        /* Scratchpad cannot be a DMA source or destination */
        if ((lsrc >= L1_SRAM_SCRATCH && lsrc < L1_SRAM_SCRATCH_END) ||
            (ldst >= L1_SRAM_SCRATCH && ldst < L1_SRAM_SCRATCH_END))
                hang();

        dma_calc_size(ldst, lsrc, count, &dshift, &bpos);
        dsize = bpos << dshift;
        count >>= bpos;
        mod = 1 << bpos;

#ifdef PSIZE
        /* The max memory DMA peripheral transfer size is 4 bytes. */
        dsize |= min(2, bpos) << PSIZE_P;
#endif

        /* Copy sram functions from sdram to sram */
        /* Setup destination start address */
        bfin_write(&mdma_d0->start_addr, ldst);
        /* Setup destination xcount */
        bfin_write(&mdma_d0->x_count, count);
        /* Setup destination xmodify */
        bfin_write(&mdma_d0->x_modify, mod);

        /* Setup Source start address */
        bfin_write(&mdma_s0->start_addr, lsrc);
        /* Setup Source xcount */
        bfin_write(&mdma_s0->x_count, count);
        /* Setup Source xmodify */
        bfin_write(&mdma_s0->x_modify, mod);

        /* Enable source DMA */
        bfin_write(&mdma_s0->config, dsize | DMAEN);
        bfin_write(&mdma_d0->config, dsize | DMAEN | WNR | DI_EN);
        SSYNC();

        while (!(bfin_read(&mdma_d0->status) & DMA_DONE))
                continue;

        bfin_write(&mdma_d0->status, DMA_RUN | DMA_DONE | DMA_ERR);
        bfin_write(&mdma_d0->config, 0);
        bfin_write(&mdma_s0->config, 0);
}
/* We should do a dcache invalidate on the destination after the dma, but since
 * we lack such hardware capability, we'll flush/invalidate the destination
 * before the dma and bank on the idea that u-boot is single threaded.
 */
void *dma_memcpy(void *dst, const void *src, size_t count)
{
        if (dcache_status()) {
                blackfin_dcache_flush_range(src, src + count);
                blackfin_dcache_flush_invalidate_range(dst, dst + count);
        }

        dma_memcpy_nocache(dst, src, count);

        if (icache_status())
                blackfin_icache_flush_range(dst, dst + count);

        return dst;
}

/*
 * memcpy - Copy one area of memory to another
 * @dest: Where to copy to
 * @src: Where to copy from
 * @count: The size of the area.
 *
 * We need to have this wrapper in memcpy() as common code may call memcpy()
 * to load up L1 regions.  Consider loading an ELF which has sections with
 * LMA's pointing to L1.  The common code ELF loader will simply use memcpy()
 * to move the ELF's sections into the right place.  We need to catch that
 * here and redirect to dma_memcpy().
 */
extern void *memcpy_ASM(void *dst, const void *src, size_t count);
void *memcpy(void *dst, const void *src, size_t count)
{
        if (!count)
                return dst;

#ifdef CONFIG_CMD_KGDB
        if (src >= (void *)SYSMMR_BASE) {
                if (count == 2 && (unsigned long)src % 2 == 0) {
                        u16 mmr = bfin_read16(src);
                        memcpy(dst, &mmr, sizeof(mmr));
                        return dst;
                }
                if (count == 4 && (unsigned long)src % 4 == 0) {
                        u32 mmr = bfin_read32(src);
                        memcpy(dst, &mmr, sizeof(mmr));
                        return dst;
                }
                /* Failed for some reason */
                memset(dst, 0xad, count);
                return dst;
        }
        if (dst >= (void *)SYSMMR_BASE) {
                if (count == 2 && (unsigned long)dst % 2 == 0) {
                        u16 mmr;
                        memcpy(&mmr, src, sizeof(mmr));
                        bfin_write16(dst, mmr);
                        return dst;
                }
                if (count == 4 && (unsigned long)dst % 4 == 0) {
                        u32 mmr;
                        memcpy(&mmr, src, sizeof(mmr));
                        bfin_write32(dst, mmr);
                        return dst;
                }
                /* Failed for some reason */
                memset(dst, 0xad, count);
                return dst;
        }
#endif

        /* if L1 is the source or dst, use DMA */
        if (addr_bfin_on_chip_mem(dst) || addr_bfin_on_chip_mem(src))
                return dma_memcpy(dst, src, count);
        else
                /* No L1 is involved, so just call regular memcpy */
                return memcpy_ASM(dst, src, count);
}