/*
 * Copyright 2011, Netlogic Microsystems.
 * Copyright 2004, Matt Porter <mporter@kernel.crashing.org>
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2.  This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/ioport.h>
#include <linux/resource.h>
#include <linux/spi/flash.h>

#include <linux/mtd/mtd.h>
#include <linux/mtd/physmap.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/partitions.h>

#include <asm/netlogic/haldefs.h>
#include <asm/netlogic/xlr/iomap.h>
#include <asm/netlogic/xlr/flash.h>
#include <asm/netlogic/xlr/bridge.h>
#include <asm/netlogic/xlr/gpio.h>
#include <asm/netlogic/xlr/xlr.h>

/*
 * Default NOR partition layout
 */
static struct mtd_partition xlr_nor_parts[] = {
        {
                .name = "User FS",
                .offset = 0x800000,
                .size   = MTDPART_SIZ_FULL,
        }
};

/*
 * Default NAND partition layout
 */
static struct mtd_partition xlr_nand_parts[] = {
        {
                .name   = "Root Filesystem",
                .offset = 64 * 64 * 2048,
                .size   = 432 * 64 * 2048,
        },
        {
                .name   = "Home Filesystem",
                .offset = MTDPART_OFS_APPEND,
                .size   = MTDPART_SIZ_FULL,
        },
};

/* Use PHYSMAP flash for NOR */
struct physmap_flash_data xlr_nor_data = {
        .width          = 2,
        .parts          = xlr_nor_parts,
        .nr_parts       = ARRAY_SIZE(xlr_nor_parts),
};

static struct resource xlr_nor_res[] = {
        {
                .flags  = IORESOURCE_MEM,
        },
};

static struct platform_device xlr_nor_dev = {
        .name   = "physmap-flash",
        .dev    = {
                .platform_data  = &xlr_nor_data,
        },
        .num_resources  = ARRAY_SIZE(xlr_nor_res),
        .resource       = xlr_nor_res,
};

const char *xlr_part_probes[] = { "cmdlinepart", NULL };

/*
 * Use "gen_nand" driver for NAND flash
 *
 * There seems to be no way to store a private pointer containing
 * platform specific info in gen_nand drivier. We will use a global
 * struct for now, since we currently have only one NAND chip per board.
 */
struct xlr_nand_flash_priv {
        int cs;
        uint64_t flash_mmio;
};

static struct xlr_nand_flash_priv nand_priv;

static void xlr_nand_ctrl(struct mtd_info *mtd, int cmd,
                unsigned int ctrl)
{
        if (ctrl & NAND_CLE)
                nlm_write_reg(nand_priv.flash_mmio,
                        FLASH_NAND_CLE(nand_priv.cs), cmd);
        else if (ctrl & NAND_ALE)
                nlm_write_reg(nand_priv.flash_mmio,
                        FLASH_NAND_ALE(nand_priv.cs), cmd);
}

struct platform_nand_data xlr_nand_data = {
        .chip = {
                .nr_chips       = 1,
                .nr_partitions  = ARRAY_SIZE(xlr_nand_parts),
                .chip_delay     = 50,
                .partitions     = xlr_nand_parts,
                .part_probe_types = xlr_part_probes,
        },
        .ctrl = {
                .cmd_ctrl       = xlr_nand_ctrl,
        },
};

static struct resource xlr_nand_res[] = {
        {
                .flags          = IORESOURCE_MEM,
        },
};

static struct platform_device xlr_nand_dev = {
        .name           = "gen_nand",
        .id             = -1,
        .num_resources  = ARRAY_SIZE(xlr_nand_res),
        .resource       = xlr_nand_res,
        .dev            = {
                .platform_data  = &xlr_nand_data,
        }
};

/*
 * XLR/XLS supports upto 8 devices on its FLASH interface. The value in
 * FLASH_BAR (on the MEM/IO bridge) gives the base for mapping all the
 * flash devices.
 * Under this, each flash device has an offset and size given by the
 * CSBASE_ADDR and CSBASE_MASK registers for the device.
 *
 * The CSBASE_ registers are expected to be setup by the bootloader.
 */
static void setup_flash_resource(uint64_t flash_mmio,
        uint64_t flash_map_base, int cs, struct resource *res)
{
        u32 base, mask;

        base = nlm_read_reg(flash_mmio, FLASH_CSBASE_ADDR(cs));
        mask = nlm_read_reg(flash_mmio, FLASH_CSADDR_MASK(cs));

        res->start = flash_map_base + ((unsigned long)base << 16);
        res->end = res->start + (mask + 1) * 64 * 1024;
}

static int __init xlr_flash_init(void)
{
        uint64_t gpio_mmio, flash_mmio, flash_map_base;
        u32 gpio_resetcfg, flash_bar;
        int cs, boot_nand, boot_nor;

        /* Flash address bits 39:24 is in bridge flash BAR */
        flash_bar = nlm_read_reg(nlm_io_base, BRIDGE_FLASH_BAR);
        flash_map_base = (flash_bar & 0xffff0000) << 8;

        gpio_mmio = nlm_mmio_base(NETLOGIC_IO_GPIO_OFFSET);
        flash_mmio = nlm_mmio_base(NETLOGIC_IO_FLASH_OFFSET);

        /* Get the chip reset config */
        gpio_resetcfg = nlm_read_reg(gpio_mmio, GPIO_PWRON_RESET_CFG_REG);

        /* Check for boot flash type */
        boot_nor = boot_nand = 0;
        if (nlm_chip_is_xls()) {
                /* On XLS, check boot from NAND bit (GPIO reset reg bit 16) */
                if (gpio_resetcfg & (1 << 16))
                        boot_nand = 1;

                /* check boot from PCMCIA, (GPIO reset reg bit 15 */
                if ((gpio_resetcfg & (1 << 15)) == 0)
                        boot_nor = 1;   /* not set, booted from NOR */
        } else { /* XLR */
                /* check boot from PCMCIA (bit 16 in GPIO reset on XLR) */
                if ((gpio_resetcfg & (1 << 16)) == 0)
                        boot_nor = 1;   /* not set, booted from NOR */
        }

        /* boot flash at chip select 0 */
        cs = 0;

        if (boot_nand) {
                nand_priv.cs = cs;
                nand_priv.flash_mmio = flash_mmio;
                setup_flash_resource(flash_mmio, flash_map_base, cs,
                         xlr_nand_res);

                /* Initialize NAND flash at CS 0 */
                nlm_write_reg(flash_mmio, FLASH_CSDEV_PARM(cs),
                                FLASH_NAND_CSDEV_PARAM);
                nlm_write_reg(flash_mmio, FLASH_CSTIME_PARMA(cs),
                                FLASH_NAND_CSTIME_PARAMA);
                nlm_write_reg(flash_mmio, FLASH_CSTIME_PARMB(cs),
                                FLASH_NAND_CSTIME_PARAMB);

                pr_info("ChipSelect %d: NAND Flash %pR\n", cs, xlr_nand_res);
                return platform_device_register(&xlr_nand_dev);
        }

        if (boot_nor) {
                setup_flash_resource(flash_mmio, flash_map_base, cs,
                        xlr_nor_res);
                pr_info("ChipSelect %d: NOR Flash %pR\n", cs, xlr_nor_res);
                return platform_device_register(&xlr_nor_dev);
        }
        return 0;
}

arch_initcall(xlr_flash_init);