/*
 * Ceiva flash memory driver.
 * Copyright (C) 2002 Rob Scott <rscott@mtrob.fdns.net>
 *
 * Note: this driver supports jedec compatible devices. Modification
 * for CFI compatible devices should be straight forward: change
 * jedec_probe to cfi_probe.
 *
 * Based on: sa1100-flash.c, which has the following copyright:
 * Flash memory access on SA11x0 based devices
 *
 * (C) 2000 Nicolas Pitre <nico@fluxnic.net>
 *
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>

#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
#include <linux/mtd/partitions.h>
#include <linux/mtd/concat.h>

#include <mach/hardware.h>
#include <asm/mach-types.h>
#include <asm/io.h>
#include <asm/sizes.h>

/*
 * This isn't complete yet, so...
 */
#define CONFIG_MTD_CEIVA_STATICMAP

#ifdef CONFIG_MTD_CEIVA_STATICMAP
/*
 * See include/linux/mtd/partitions.h for definition of the mtd_partition
 * structure.
 *
 * Please note:
 *  1. The flash size given should be the largest flash size that can
 *     be accomodated.
 *
 *  2. The bus width must defined in clps_setup_flash.
 *
 * The MTD layer will detect flash chip aliasing and reduce the size of
 * the map accordingly.
 *
 */

#ifdef CONFIG_ARCH_CEIVA
/* Flash / Partition sizing */
/* For the 28F8003, we use the block mapping to calcuate the sizes */
#define MAX_SIZE_KiB                  (16 + 8 + 8 + 96 + (7*128))
#define BOOT_PARTITION_SIZE_KiB       (16)
#define PARAMS_PARTITION_SIZE_KiB     (8)
#define KERNEL_PARTITION_SIZE_KiB     (4*128)
/* Use both remaing portion of first flash, and all of second flash */
#define ROOT_PARTITION_SIZE_KiB       (3*128) + (8*128)

static struct mtd_partition ceiva_partitions[] = {
        {
                .name = "Ceiva BOOT partition",
                .size   = BOOT_PARTITION_SIZE_KiB*1024,
                .offset = 0,

        },{
                .name = "Ceiva parameters partition",
                .size   = PARAMS_PARTITION_SIZE_KiB*1024,
                .offset = (16 + 8) * 1024,
        },{
                .name = "Ceiva kernel partition",
                .size = (KERNEL_PARTITION_SIZE_KiB)*1024,
                .offset = 0x20000,

        },{
                .name = "Ceiva root filesystem partition",
                .offset = MTDPART_OFS_APPEND,
                .size = (ROOT_PARTITION_SIZE_KiB)*1024,
        }
};
#endif

static int __init clps_static_partitions(struct mtd_partition **parts)
{
        int nb_parts = 0;

#ifdef CONFIG_ARCH_CEIVA
        if (machine_is_ceiva()) {
                *parts       = ceiva_partitions;
                nb_parts     = ARRAY_SIZE(ceiva_partitions);
        }
#endif
        return nb_parts;
}
#endif

struct clps_info {
        unsigned long base;
        unsigned long size;
        int width;
        void *vbase;
        struct map_info *map;
        struct mtd_info *mtd;
        struct resource *res;
};

#define NR_SUBMTD 4

static struct clps_info info[NR_SUBMTD];

static int __init clps_setup_mtd(struct clps_info *clps, int nr, struct mtd_info **rmtd)
{
        struct mtd_info *subdev[nr];
        struct map_info *maps;
        int i, found = 0, ret = 0;

        /*
         * Allocate the map_info structs in one go.
         */
        maps = kzalloc(sizeof(struct map_info) * nr, GFP_KERNEL);
        if (!maps)
                return -ENOMEM;
        /*
         * Claim and then map the memory regions.
         */
        for (i = 0; i < nr; i++) {
                if (clps[i].base == (unsigned long)-1)
                        break;

                clps[i].res = request_mem_region(clps[i].base, clps[i].size, "clps flash");
                if (!clps[i].res) {
                        ret = -EBUSY;
                        break;
                }

                clps[i].map = maps + i;

                clps[i].map->name = "clps flash";
                clps[i].map->phys = clps[i].base;

                clps[i].vbase = ioremap(clps[i].base, clps[i].size);
                if (!clps[i].vbase) {
                        ret = -ENOMEM;
                        break;
                }

                clps[i].map->virt = (void __iomem *)clps[i].vbase;
                clps[i].map->bankwidth = clps[i].width;
                clps[i].map->size = clps[i].size;

                simple_map_init(&clps[i].map);

                clps[i].mtd = do_map_probe("jedec_probe", clps[i].map);
                if (clps[i].mtd == NULL) {
                        ret = -ENXIO;
                        break;
                }
                clps[i].mtd->owner = THIS_MODULE;
                subdev[i] = clps[i].mtd;

                printk(KERN_INFO "clps flash: JEDEC device at 0x%08lx, %dMiB, "
                        "%d-bit\n", clps[i].base, clps[i].mtd->size >> 20,
                        clps[i].width * 8);
                found += 1;
        }

        /*
         * ENXIO is special.  It means we didn't find a chip when
         * we probed.  We need to tear down the mapping, free the
         * resource and mark it as such.
         */
        if (ret == -ENXIO) {
                iounmap(clps[i].vbase);
                clps[i].vbase = NULL;
                release_resource(clps[i].res);
                clps[i].res = NULL;
        }

        /*
         * If we found one device, don't bother with concat support.
         * If we found multiple devices, use concat if we have it
         * available, otherwise fail.
         */
        if (ret == 0 || ret == -ENXIO) {
                if (found == 1) {
                        *rmtd = subdev[0];
                        ret = 0;
                } else if (found > 1) {
                        /*
                         * We detected multiple devices.  Concatenate
                         * them together.
                         */
#ifdef CONFIG_MTD_CONCAT
                        *rmtd = mtd_concat_create(subdev, found,
                                                  "clps flash");
                        if (*rmtd == NULL)
                                ret = -ENXIO;
#else
                        printk(KERN_ERR "clps flash: multiple devices "
                               "found but MTD concat support disabled.\n");
                        ret = -ENXIO;
#endif
                }
        }

        /*
         * If we failed, clean up.
         */
        if (ret) {
                do {
                        if (clps[i].mtd)
                                map_destroy(clps[i].mtd);
                        if (clps[i].vbase)
                                iounmap(clps[i].vbase);
                        if (clps[i].res)
                                release_resource(clps[i].res);
                } while (i--);

                kfree(maps);
        }

        return ret;
}

static void __exit clps_destroy_mtd(struct clps_info *clps, struct mtd_info *mtd)
{
        int i;

        del_mtd_partitions(mtd);

        if (mtd != clps[0].mtd)
                mtd_concat_destroy(mtd);

        for (i = NR_SUBMTD; i >= 0; i--) {
                if (clps[i].mtd)
                        map_destroy(clps[i].mtd);
                if (clps[i].vbase)
                        iounmap(clps[i].vbase);
                if (clps[i].res)
                        release_resource(clps[i].res);
        }
        kfree(clps[0].map);
}

/*
 * We define the memory space, size, and width for the flash memory
 * space here.
 */

static int __init clps_setup_flash(void)
{
        int nr = 0;

#ifdef CONFIG_ARCH_CEIVA
        if (machine_is_ceiva()) {
                info[0].base = CS0_PHYS_BASE;
                info[0].size = SZ_32M;
                info[0].width = CEIVA_FLASH_WIDTH;
                info[1].base = CS1_PHYS_BASE;
                info[1].size = SZ_32M;
                info[1].width = CEIVA_FLASH_WIDTH;
                nr = 2;
        }
#endif
        return nr;
}

static struct mtd_partition *parsed_parts;
static const char *probes[] = { "cmdlinepart", "RedBoot", NULL };

static void __init clps_locate_partitions(struct mtd_info *mtd)
{
        const char *part_type = NULL;
        int nr_parts = 0;
        do {
                /*
                 * Partition selection stuff.
                 */
                nr_parts = parse_mtd_partitions(mtd, probes, &parsed_parts, 0);
                if (nr_parts > 0) {
                        part_type = "command line";
                        break;
                }
#ifdef CONFIG_MTD_CEIVA_STATICMAP
                nr_parts = clps_static_partitions(&parsed_parts);
                if (nr_parts > 0) {
                        part_type = "static";
                        break;
                }
                printk("found: %d partitions\n", nr_parts);
#endif
        } while (0);

        if (nr_parts == 0) {
                printk(KERN_NOTICE "clps flash: no partition info "
                        "available, registering whole flash\n");
                add_mtd_device(mtd);
        } else {
                printk(KERN_NOTICE "clps flash: using %s partition "
                        "definition\n", part_type);
                add_mtd_partitions(mtd, parsed_parts, nr_parts);
        }

        /* Always succeeds. */
}

static void __exit clps_destroy_partitions(void)
{
        kfree(parsed_parts);
}

static struct mtd_info *mymtd;

static int __init clps_mtd_init(void)
{
        int ret;
        int nr;

        nr = clps_setup_flash();
        if (nr < 0)
                return nr;

        ret = clps_setup_mtd(info, nr, &mymtd);
        if (ret)
                return ret;

        clps_locate_partitions(mymtd);

        return 0;
}

static void __exit clps_mtd_cleanup(void)
{
        clps_destroy_mtd(info, mymtd);
        clps_destroy_partitions();
}

module_init(clps_mtd_init);
module_exit(clps_mtd_cleanup);

MODULE_AUTHOR("Rob Scott");
MODULE_DESCRIPTION("Cirrus Logic JEDEC map driver");
MODULE_LICENSE("GPL");