/*
 * Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
 *
 * Based on code:
 *      Copyright (C) 2005-2009 Samsung Electronics
 *      Kyungmin Park <kyungmin.park@samsung.com>
 *
 * SPDX-License-Identifier:     GPL-2.0+
 */

#include <common.h>
#include <asm/io.h>
#include <linux/mtd/onenand_regs.h>
#include <onenand_uboot.h>

/*
 * Device geometry:
 * - 2048b page, 128k erase block.
 * - 4096b page, 256k erase block.
 */
enum onenand_spl_pagesize {
        PAGE_2K = 2048,
        PAGE_4K = 4096,
};

static unsigned int density_mask;

#define ONENAND_PAGES_PER_BLOCK                 64
#define onenand_sector_address(page)            (page << 2)
#define onenand_buffer_address()                ((1 << 3) << 8)

static inline int onenand_block_address(int block)
{
        /* Device Flash Core select, NAND Flash Block Address */
        if (block & density_mask)
                return ONENAND_DDP_CHIP1 | (block ^ density_mask);

        return block;
}

static inline int onenand_bufferram_address(int block)
{
        /* Device BufferRAM Select */
        if (block & density_mask)
                return ONENAND_DDP_CHIP1;

        return ONENAND_DDP_CHIP0;
}

static inline uint16_t onenand_readw(uint32_t addr)
{
        return readw(CONFIG_SYS_ONENAND_BASE + addr);
}

static inline void onenand_writew(uint16_t value, uint32_t addr)
{
        writew(value, CONFIG_SYS_ONENAND_BASE + addr);
}

static enum onenand_spl_pagesize onenand_spl_get_geometry(void)
{
        unsigned int dev_id, density, size;

        if (!onenand_readw(ONENAND_REG_TECHNOLOGY)) {
                dev_id = onenand_readw(ONENAND_REG_DEVICE_ID);
                density = dev_id >> ONENAND_DEVICE_DENSITY_SHIFT;
                density &= ONENAND_DEVICE_DENSITY_MASK;

                if (density < ONENAND_DEVICE_DENSITY_4Gb)
                        return PAGE_2K;

                if (dev_id & ONENAND_DEVICE_IS_DDP) {
                        size = onenand_readw(ONENAND_REG_DATA_BUFFER_SIZE);
                        density_mask = 1 << (18 + density - ffs(size));
                        return PAGE_2K;
                }
        }

        return PAGE_4K;
}

static int onenand_spl_read_page(uint32_t block, uint32_t page, uint32_t *buf,
                                        enum onenand_spl_pagesize pagesize)
{
        const uint32_t addr = CONFIG_SYS_ONENAND_BASE + ONENAND_DATARAM;
        uint32_t offset;

        onenand_writew(onenand_block_address(block),
                        ONENAND_REG_START_ADDRESS1);

        onenand_writew(onenand_bufferram_address(block),
                        ONENAND_REG_START_ADDRESS2);

        onenand_writew(onenand_sector_address(page),
                        ONENAND_REG_START_ADDRESS8);

        onenand_writew(onenand_buffer_address(),
                        ONENAND_REG_START_BUFFER);

        onenand_writew(ONENAND_INT_CLEAR, ONENAND_REG_INTERRUPT);

        onenand_writew(ONENAND_CMD_READ, ONENAND_REG_COMMAND);

        while (!(onenand_readw(ONENAND_REG_INTERRUPT) & ONENAND_INT_READ))
                continue;

        /* Check for invalid block mark */
        if (page < 2 && (onenand_readw(ONENAND_SPARERAM) != 0xffff))
                return 1;

        for (offset = 0; offset < pagesize; offset += 4)
                buf[offset / 4] = readl(addr + offset);

        return 0;
}

#ifdef CONFIG_SPL_UBI
/* Temporary storage for non page aligned and non page sized reads. */
static u8 scratch_buf[PAGE_4K];

/**
 * onenand_spl_read_block - Read data from physical eraseblock into a buffer
 * @block:      Number of the physical eraseblock
 * @offset:     Data offset from the start of @peb
 * @len:        Data size to read
 * @dst:        Address of the destination buffer
 *
 * Notes:
 *      @offset + @len are not allowed to be larger than a physical
 *      erase block. No sanity check done for simplicity reasons.
 */
int onenand_spl_read_block(int block, int offset, int len, void *dst)
{
        int page, read;
        static int psize;

        if (!psize)
                psize = onenand_spl_get_geometry();

        /* Calculate the page number */
        page = offset / psize;
        /* Offset to the start of a flash page */
        offset = offset % psize;

        while (len) {
                /*
                 * Non page aligned reads go to the scratch buffer.
                 * Page aligned reads go directly to the destination.
                 */
                if (offset || len < psize) {
                        onenand_spl_read_page(block, page,
                                              (uint32_t *)scratch_buf, psize);
                        read = min(len, psize - offset);
                        memcpy(dst, scratch_buf + offset, read);
                        offset = 0;
                } else {
                        onenand_spl_read_page(block, page, dst, psize);
                        read = psize;
                }
                page++;
                len -= read;
                dst += read;
        }
        return 0;
}
#endif

void onenand_spl_load_image(uint32_t offs, uint32_t size, void *dst)
{
        uint32_t *addr = (uint32_t *)dst;
        uint32_t to_page;
        uint32_t block;
        uint32_t page, rpage;
        enum onenand_spl_pagesize pagesize;
        int ret;

        pagesize = onenand_spl_get_geometry();

        /*
         * The page can be either 2k or 4k, avoid using DIV_ROUND_UP to avoid
         * pulling further unwanted functions into the SPL.
         */
        if (pagesize == 2048) {
                page = offs / 2048;
                to_page = page + DIV_ROUND_UP(size, 2048);
        } else {
                page = offs / 4096;
                to_page = page + DIV_ROUND_UP(size, 4096);
        }

        for (; page <= to_page; page++) {
                block = page / ONENAND_PAGES_PER_BLOCK;
                rpage = page & (ONENAND_PAGES_PER_BLOCK - 1);
                ret = onenand_spl_read_page(block, rpage, addr, pagesize);
                if (ret)
                        page += ONENAND_PAGES_PER_BLOCK - 1;
                else
                        addr += pagesize / 4;
        }
}