/*
 *   Octeon Bootbus flash setup
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2007, 2008 Cavium Networks
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/semaphore.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/mtd/partitions.h>

#include <asm/octeon/octeon.h>

static struct map_info flash_map;
static struct mtd_info *mymtd;
static const char *part_probe_types[] = {
        "cmdlinepart",
#ifdef CONFIG_MTD_REDBOOT_PARTS
        "RedBoot",
#endif
        NULL
};

static map_word octeon_flash_map_read(struct map_info *map, unsigned long ofs)
{
        map_word r;

        down(&octeon_bootbus_sem);
        r = inline_map_read(map, ofs);
        up(&octeon_bootbus_sem);

        return r;
}

static void octeon_flash_map_write(struct map_info *map, const map_word datum,
                                   unsigned long ofs)
{
        down(&octeon_bootbus_sem);
        inline_map_write(map, datum, ofs);
        up(&octeon_bootbus_sem);
}

static void octeon_flash_map_copy_from(struct map_info *map, void *to,
                                       unsigned long from, ssize_t len)
{
        down(&octeon_bootbus_sem);
        inline_map_copy_from(map, to, from, len);
        up(&octeon_bootbus_sem);
}

static void octeon_flash_map_copy_to(struct map_info *map, unsigned long to,
                                     const void *from, ssize_t len)
{
        down(&octeon_bootbus_sem);
        inline_map_copy_to(map, to, from, len);
        up(&octeon_bootbus_sem);
}

/*
 * Module/ driver initialization.
 *
 * Returns Zero on success
 */
static int octeon_flash_probe(struct platform_device *pdev)
{
        union cvmx_mio_boot_reg_cfgx region_cfg;
        u32 cs;
        int r;
        struct device_node *np = pdev->dev.of_node;

        r = of_property_read_u32(np, "reg", &cs);
        if (r)
                return r;

        /*
         * Read the bootbus region 0 setup to determine the base
         * address of the flash.
         */
        region_cfg.u64 = cvmx_read_csr(CVMX_MIO_BOOT_REG_CFGX(cs));
        if (region_cfg.s.en) {
                /*
                 * The bootloader always takes the flash and sets its
                 * address so the entire flash fits below
                 * 0x1fc00000. This way the flash aliases to
                 * 0x1fc00000 for booting. Software can access the
                 * full flash at the true address, while core boot can
                 * access 4MB.
                 */
                /* Use this name so old part lines work */
                flash_map.name = "phys_mapped_flash";
                flash_map.phys = region_cfg.s.base << 16;
                flash_map.size = 0x1fc00000 - flash_map.phys;
                /* 8-bit bus (0 + 1) or 16-bit bus (1 + 1) */
                flash_map.bankwidth = region_cfg.s.width + 1;
                flash_map.virt = ioremap(flash_map.phys, flash_map.size);
                pr_notice("Bootbus flash: Setting flash for %luMB flash at "
                          "0x%08llx\n", flash_map.size >> 20, flash_map.phys);
                WARN_ON(!map_bankwidth_supported(flash_map.bankwidth));
                flash_map.read = octeon_flash_map_read;
                flash_map.write = octeon_flash_map_write;
                flash_map.copy_from = octeon_flash_map_copy_from;
                flash_map.copy_to = octeon_flash_map_copy_to;
                mymtd = do_map_probe("cfi_probe", &flash_map);
                if (mymtd) {
                        mymtd->owner = THIS_MODULE;
                        mtd_device_parse_register(mymtd, part_probe_types,
                                                  NULL, NULL, 0);
                } else {
                        pr_err("Failed to register MTD device for flash\n");
                }
        }
        return 0;
}

static const struct of_device_id of_flash_match[] = {
        {
                .compatible     = "cfi-flash",
        },
        { },
};
MODULE_DEVICE_TABLE(of, of_flash_match);

static struct platform_driver of_flash_driver = {
        .driver = {
                .name = "octeon-of-flash",
                .of_match_table = of_flash_match,
        },
        .probe          = octeon_flash_probe,
};

static int octeon_flash_init(void)
{
        return platform_driver_register(&of_flash_driver);
}
late_initcall(octeon_flash_init);

MODULE_LICENSE("GPL");