/*
 * Copyright (C) 2014       Panasonic Corporation
 * Copyright (C) 2014-2015  Masahiro Yamada <yamada.masahiro@socionext.com>
 *
 * SPDX-License-Identifier:     GPL-2.0+
 */

#include <common.h>
#include <asm/io.h>
#include <asm/unaligned.h>
#include <linux/mtd/rawnand.h>
#include "denali.h"

#define DENALI_MAP01            (1 << 26)       /* read/write pages in PIO */
#define DENALI_MAP10            (2 << 26)       /* high-level control plane */

#define INDEX_CTRL_REG          0x0
#define INDEX_DATA_REG          0x10

#define SPARE_ACCESS            0x41
#define MAIN_ACCESS             0x42
#define PIPELINE_ACCESS         0x2000

#define BANK(x) ((x) << 24)

static void __iomem *denali_flash_mem =
                        (void __iomem *)CONFIG_SYS_NAND_DATA_BASE;
static void __iomem *denali_flash_reg =
                        (void __iomem *)CONFIG_SYS_NAND_REGS_BASE;

static const int flash_bank;
static int page_size, oob_size, pages_per_block;

static void index_addr(uint32_t address, uint32_t data)
{
        writel(address, denali_flash_mem + INDEX_CTRL_REG);
        writel(data, denali_flash_mem + INDEX_DATA_REG);
}

static int wait_for_irq(uint32_t irq_mask)
{
        unsigned long timeout = 1000000;
        uint32_t intr_status;

        do {
                intr_status = readl(denali_flash_reg + INTR_STATUS(flash_bank));

                if (intr_status & INTR__ECC_UNCOR_ERR) {
                        debug("Uncorrected ECC detected\n");
                        return -EBADMSG;
                }

                if (intr_status & irq_mask)
                        break;

                udelay(1);
                timeout--;
        } while (timeout);

        if (!timeout) {
                debug("Timeout with interrupt status %08x\n", intr_status);
                return -EIO;
        }

        return 0;
}

static void read_data_from_flash_mem(uint8_t *buf, int len)
{
        int i;
        uint32_t *buf32;

        /* transfer the data from the flash */
        buf32 = (uint32_t *)buf;

        /*
         * Let's take care of unaligned access although it rarely happens.
         * Avoid put_unaligned() for the normal use cases since it leads to
         * a bit performance regression.
         */
        if ((unsigned long)buf32 % 4) {
                for (i = 0; i < len / 4; i++)
                        put_unaligned(readl(denali_flash_mem + INDEX_DATA_REG),
                                      buf32++);
        } else {
                for (i = 0; i < len / 4; i++)
                        *buf32++ = readl(denali_flash_mem + INDEX_DATA_REG);
        }

        if (len % 4) {
                u32 tmp;

                tmp = cpu_to_le32(readl(denali_flash_mem + INDEX_DATA_REG));
                buf = (uint8_t *)buf32;
                for (i = 0; i < len % 4; i++) {
                        *buf++ = tmp;
                        tmp >>= 8;
                }
        }
}

int denali_send_pipeline_cmd(int page, int ecc_en, int access_type)
{
        uint32_t addr, cmd;
        static uint32_t page_count = 1;

        writel(ecc_en, denali_flash_reg + ECC_ENABLE);

        /* clear all bits of intr_status. */
        writel(0xffff, denali_flash_reg + INTR_STATUS(flash_bank));

        addr = BANK(flash_bank) | page;

        /* setup the acccess type */
        cmd = DENALI_MAP10 | addr;
        index_addr(cmd, access_type);

        /* setup the pipeline command */
        index_addr(cmd, PIPELINE_ACCESS | page_count);

        cmd = DENALI_MAP01 | addr;
        writel(cmd, denali_flash_mem + INDEX_CTRL_REG);

        return wait_for_irq(INTR__LOAD_COMP);
}

static int nand_read_oob(void *buf, int page)
{
        int ret;

        ret = denali_send_pipeline_cmd(page, 0, SPARE_ACCESS);
        if (ret < 0)
                return ret;

        read_data_from_flash_mem(buf, oob_size);

        return 0;
}

static int nand_read_page(void *buf, int page)
{
        int ret;

        ret = denali_send_pipeline_cmd(page, 1, MAIN_ACCESS);
        if (ret < 0)
                return ret;

        read_data_from_flash_mem(buf, page_size);

        return 0;
}

static int nand_block_isbad(void *buf, int block)
{
        int ret;

        ret = nand_read_oob(buf, block * pages_per_block);
        if (ret < 0)
                return ret;

        return *((uint8_t *)buf + CONFIG_SYS_NAND_BAD_BLOCK_POS) != 0xff;
}

/* nand_init() - initialize data to make nand usable by SPL */
void nand_init(void)
{
        /* access to main area */
        writel(0, denali_flash_reg + TRANSFER_SPARE_REG);

        /*
         * These registers are expected to be already set by the hardware
         * or earlier boot code.  So we read these values out.
         */
        page_size = readl(denali_flash_reg + DEVICE_MAIN_AREA_SIZE);
        oob_size = readl(denali_flash_reg + DEVICE_SPARE_AREA_SIZE);
        pages_per_block = readl(denali_flash_reg + PAGES_PER_BLOCK);
}

int nand_spl_load_image(uint32_t offs, unsigned int size, void *dst)
{
        int block, page, column, readlen;
        int ret;
        int force_bad_block_check = 1;

        page = offs / page_size;
        column = offs % page_size;

        block = page / pages_per_block;
        page = page % pages_per_block;

        while (size) {
                if (force_bad_block_check || page == 0) {
                        ret = nand_block_isbad(dst, block);
                        if (ret < 0)
                                return ret;

                        if (ret) {
                                block++;
                                continue;
                        }
                }

                force_bad_block_check = 0;

                ret = nand_read_page(dst, block * pages_per_block + page);
                if (ret < 0)
                        return ret;

                readlen = min(page_size - column, (int)size);

                if (unlikely(column)) {
                        /* Partial page read */
                        memmove(dst, dst + column, readlen);
                        column = 0;
                }

                size -= readlen;
                dst += readlen;
                page++;
                if (page == pages_per_block) {
                        block++;
                        page = 0;
                }
        }

        return 0;
}

void nand_deselect(void) {}