/*
 * GPMC support functions
 *
 * Copyright (C) 2005-2006 Nokia Corporation
 *
 * Author: Juha Yrjola
 *
 * Copyright (C) 2009 Texas Instruments
 * Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#undef DEBUG

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/ioport.h>
#include <linux/spinlock.h>
#include <linux/io.h>
#include <linux/module.h>

#include <asm/mach-types.h>
#include <plat/gpmc.h>

#include <plat/sdrc.h>

/* GPMC register offsets */
#define GPMC_REVISION           0x00
#define GPMC_SYSCONFIG          0x10
#define GPMC_SYSSTATUS          0x14
#define GPMC_IRQSTATUS          0x18
#define GPMC_IRQENABLE          0x1c
#define GPMC_TIMEOUT_CONTROL    0x40
#define GPMC_ERR_ADDRESS        0x44
#define GPMC_ERR_TYPE           0x48
#define GPMC_CONFIG             0x50
#define GPMC_STATUS             0x54
#define GPMC_PREFETCH_CONFIG1   0x1e0
#define GPMC_PREFETCH_CONFIG2   0x1e4
#define GPMC_PREFETCH_CONTROL   0x1ec
#define GPMC_PREFETCH_STATUS    0x1f0
#define GPMC_ECC_CONFIG         0x1f4
#define GPMC_ECC_CONTROL        0x1f8
#define GPMC_ECC_SIZE_CONFIG    0x1fc
#define GPMC_ECC1_RESULT        0x200

#define GPMC_CS0_OFFSET         0x60
#define GPMC_CS_SIZE            0x30

#define GPMC_MEM_START          0x00000000
#define GPMC_MEM_END            0x3FFFFFFF
#define BOOT_ROM_SPACE          0x100000        /* 1MB */

#define GPMC_CHUNK_SHIFT        24              /* 16 MB */
#define GPMC_SECTION_SHIFT      28              /* 128 MB */

#define PREFETCH_FIFOTHRESHOLD  (0x40 << 8)
#define CS_NUM_SHIFT            24
#define ENABLE_PREFETCH         (0x1 << 7)
#define DMA_MPU_MODE            2

/* Structure to save gpmc cs context */
struct gpmc_cs_config {
        u32 config1;
        u32 config2;
        u32 config3;
        u32 config4;
        u32 config5;
        u32 config6;
        u32 config7;
        int is_valid;
};

/*
 * Structure to save/restore gpmc context
 * to support core off on OMAP3
 */
struct omap3_gpmc_regs {
        u32 sysconfig;
        u32 irqenable;
        u32 timeout_ctrl;
        u32 config;
        u32 prefetch_config1;
        u32 prefetch_config2;
        u32 prefetch_control;
        struct gpmc_cs_config cs_context[GPMC_CS_NUM];
};

static struct resource  gpmc_mem_root;
static struct resource  gpmc_cs_mem[GPMC_CS_NUM];
static DEFINE_SPINLOCK(gpmc_mem_lock);
static unsigned int gpmc_cs_map;        /* flag for cs which are initialized */
static int gpmc_ecc_used = -EINVAL;     /* cs using ecc engine */

static void __iomem *gpmc_base;

static struct clk *gpmc_l3_clk;

static void gpmc_write_reg(int idx, u32 val)
{
        __raw_writel(val, gpmc_base + idx);
}

static u32 gpmc_read_reg(int idx)
{
        return __raw_readl(gpmc_base + idx);
}

static void gpmc_cs_write_byte(int cs, int idx, u8 val)
{
        void __iomem *reg_addr;

        reg_addr = gpmc_base + GPMC_CS0_OFFSET + (cs * GPMC_CS_SIZE) + idx;
        __raw_writeb(val, reg_addr);
}

static u8 gpmc_cs_read_byte(int cs, int idx)
{
        void __iomem *reg_addr;

        reg_addr = gpmc_base + GPMC_CS0_OFFSET + (cs * GPMC_CS_SIZE) + idx;
        return __raw_readb(reg_addr);
}

void gpmc_cs_write_reg(int cs, int idx, u32 val)
{
        void __iomem *reg_addr;

        reg_addr = gpmc_base + GPMC_CS0_OFFSET + (cs * GPMC_CS_SIZE) + idx;
        __raw_writel(val, reg_addr);
}

u32 gpmc_cs_read_reg(int cs, int idx)
{
        void __iomem *reg_addr;

        reg_addr = gpmc_base + GPMC_CS0_OFFSET + (cs * GPMC_CS_SIZE) + idx;
        return __raw_readl(reg_addr);
}

/* TODO: Add support for gpmc_fck to clock framework and use it */
unsigned long gpmc_get_fclk_period(void)
{
        unsigned long rate = clk_get_rate(gpmc_l3_clk);

        if (rate == 0) {
                printk(KERN_WARNING "gpmc_l3_clk not enabled\n");
                return 0;
        }

        rate /= 1000;
        rate = 1000000000 / rate;       /* In picoseconds */

        return rate;
}

unsigned int gpmc_ns_to_ticks(unsigned int time_ns)
{
        unsigned long tick_ps;

        /* Calculate in picosecs to yield more exact results */
        tick_ps = gpmc_get_fclk_period();

        return (time_ns * 1000 + tick_ps - 1) / tick_ps;
}

unsigned int gpmc_ps_to_ticks(unsigned int time_ps)
{
        unsigned long tick_ps;

        /* Calculate in picosecs to yield more exact results */
        tick_ps = gpmc_get_fclk_period();

        return (time_ps + tick_ps - 1) / tick_ps;
}

unsigned int gpmc_ticks_to_ns(unsigned int ticks)
{
        return ticks * gpmc_get_fclk_period() / 1000;
}

unsigned int gpmc_round_ns_to_ticks(unsigned int time_ns)
{
        unsigned long ticks = gpmc_ns_to_ticks(time_ns);

        return ticks * gpmc_get_fclk_period() / 1000;
}

#ifdef DEBUG
static int set_gpmc_timing_reg(int cs, int reg, int st_bit, int end_bit,
                               int time, const char *name)
#else
static int set_gpmc_timing_reg(int cs, int reg, int st_bit, int end_bit,
                               int time)
#endif
{
        u32 l;
        int ticks, mask, nr_bits;

        if (time == 0)
                ticks = 0;
        else
                ticks = gpmc_ns_to_ticks(time);
        nr_bits = end_bit - st_bit + 1;
        if (ticks >= 1 << nr_bits) {
#ifdef DEBUG
                printk(KERN_INFO "GPMC CS%d: %-10s* %3d ns, %3d ticks >= %d\n",
                                cs, name, time, ticks, 1 << nr_bits);
#endif
                return -1;
        }

        mask = (1 << nr_bits) - 1;
        l = gpmc_cs_read_reg(cs, reg);
#ifdef DEBUG
        printk(KERN_INFO
                "GPMC CS%d: %-10s: %3d ticks, %3lu ns (was %3i ticks) %3d ns\n",
               cs, name, ticks, gpmc_get_fclk_period() * ticks / 1000,
                        (l >> st_bit) & mask, time);
#endif
        l &= ~(mask << st_bit);
        l |= ticks << st_bit;
        gpmc_cs_write_reg(cs, reg, l);

        return 0;
}

#ifdef DEBUG
#define GPMC_SET_ONE(reg, st, end, field) \
        if (set_gpmc_timing_reg(cs, (reg), (st), (end),         \
                        t->field, #field) < 0)                  \
                return -1
#else
#define GPMC_SET_ONE(reg, st, end, field) \
        if (set_gpmc_timing_reg(cs, (reg), (st), (end), t->field) < 0) \
                return -1
#endif

int gpmc_cs_calc_divider(int cs, unsigned int sync_clk)
{
        int div;
        u32 l;

        l = sync_clk + (gpmc_get_fclk_period() - 1);
        div = l / gpmc_get_fclk_period();
        if (div > 4)
                return -1;
        if (div <= 0)
                div = 1;

        return div;
}

int gpmc_cs_set_timings(int cs, const struct gpmc_timings *t)
{
        int div;
        u32 l;

        div = gpmc_cs_calc_divider(cs, t->sync_clk);
        if (div < 0)
                return -1;

        GPMC_SET_ONE(GPMC_CS_CONFIG2,  0,  3, cs_on);
        GPMC_SET_ONE(GPMC_CS_CONFIG2,  8, 12, cs_rd_off);
        GPMC_SET_ONE(GPMC_CS_CONFIG2, 16, 20, cs_wr_off);

        GPMC_SET_ONE(GPMC_CS_CONFIG3,  0,  3, adv_on);
        GPMC_SET_ONE(GPMC_CS_CONFIG3,  8, 12, adv_rd_off);
        GPMC_SET_ONE(GPMC_CS_CONFIG3, 16, 20, adv_wr_off);

        GPMC_SET_ONE(GPMC_CS_CONFIG4,  0,  3, oe_on);
        GPMC_SET_ONE(GPMC_CS_CONFIG4,  8, 12, oe_off);
        GPMC_SET_ONE(GPMC_CS_CONFIG4, 16, 19, we_on);
        GPMC_SET_ONE(GPMC_CS_CONFIG4, 24, 28, we_off);

        GPMC_SET_ONE(GPMC_CS_CONFIG5,  0,  4, rd_cycle);
        GPMC_SET_ONE(GPMC_CS_CONFIG5,  8, 12, wr_cycle);
        GPMC_SET_ONE(GPMC_CS_CONFIG5, 16, 20, access);

        GPMC_SET_ONE(GPMC_CS_CONFIG5, 24, 27, page_burst_access);

        if (cpu_is_omap34xx()) {
                GPMC_SET_ONE(GPMC_CS_CONFIG6, 16, 19, wr_data_mux_bus);
                GPMC_SET_ONE(GPMC_CS_CONFIG6, 24, 28, wr_access);
        }

        /* caller is expected to have initialized CONFIG1 to cover
         * at least sync vs async
         */
        l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG1);
        if (l & (GPMC_CONFIG1_READTYPE_SYNC | GPMC_CONFIG1_WRITETYPE_SYNC)) {
#ifdef DEBUG
                printk(KERN_INFO "GPMC CS%d CLK period is %lu ns (div %d)\n",
                                cs, (div * gpmc_get_fclk_period()) / 1000, div);
#endif
                l &= ~0x03;
                l |= (div - 1);
                gpmc_cs_write_reg(cs, GPMC_CS_CONFIG1, l);
        }

        return 0;
}

static void gpmc_cs_enable_mem(int cs, u32 base, u32 size)
{
        u32 l;
        u32 mask;

        mask = (1 << GPMC_SECTION_SHIFT) - size;
        l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG7);
        l &= ~0x3f;
        l = (base >> GPMC_CHUNK_SHIFT) & 0x3f;
        l &= ~(0x0f << 8);
        l |= ((mask >> GPMC_CHUNK_SHIFT) & 0x0f) << 8;
        l |= GPMC_CONFIG7_CSVALID;
        gpmc_cs_write_reg(cs, GPMC_CS_CONFIG7, l);
}

static void gpmc_cs_disable_mem(int cs)
{
        u32 l;

        l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG7);
        l &= ~GPMC_CONFIG7_CSVALID;
        gpmc_cs_write_reg(cs, GPMC_CS_CONFIG7, l);
}

static void gpmc_cs_get_memconf(int cs, u32 *base, u32 *size)
{
        u32 l;
        u32 mask;

        l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG7);
        *base = (l & 0x3f) << GPMC_CHUNK_SHIFT;
        mask = (l >> 8) & 0x0f;
        *size = (1 << GPMC_SECTION_SHIFT) - (mask << GPMC_CHUNK_SHIFT);
}

static int gpmc_cs_mem_enabled(int cs)
{
        u32 l;

        l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG7);
        return l & GPMC_CONFIG7_CSVALID;
}

int gpmc_cs_set_reserved(int cs, int reserved)
{
        if (cs > GPMC_CS_NUM)
                return -ENODEV;

        gpmc_cs_map &= ~(1 << cs);
        gpmc_cs_map |= (reserved ? 1 : 0) << cs;

        return 0;
}

int gpmc_cs_reserved(int cs)
{
        if (cs > GPMC_CS_NUM)
                return -ENODEV;

        return gpmc_cs_map & (1 << cs);
}

static unsigned long gpmc_mem_align(unsigned long size)
{
        int order;

        size = (size - 1) >> (GPMC_CHUNK_SHIFT - 1);
        order = GPMC_CHUNK_SHIFT - 1;
        do {
                size >>= 1;
                order++;
        } while (size);
        size = 1 << order;
        return size;
}

static int gpmc_cs_insert_mem(int cs, unsigned long base, unsigned long size)
{
        struct resource *res = &gpmc_cs_mem[cs];
        int r;

        size = gpmc_mem_align(size);
        spin_lock(&gpmc_mem_lock);
        res->start = base;
        res->end = base + size - 1;
        r = request_resource(&gpmc_mem_root, res);
        spin_unlock(&gpmc_mem_lock);

        return r;
}

int gpmc_cs_request(int cs, unsigned long size, unsigned long *base)
{
        struct resource *res = &gpmc_cs_mem[cs];
        int r = -1;

        if (cs > GPMC_CS_NUM)
                return -ENODEV;

        size = gpmc_mem_align(size);
        if (size > (1 << GPMC_SECTION_SHIFT))
                return -ENOMEM;

        spin_lock(&gpmc_mem_lock);
        if (gpmc_cs_reserved(cs)) {
                r = -EBUSY;
                goto out;
        }
        if (gpmc_cs_mem_enabled(cs))
                r = adjust_resource(res, res->start & ~(size - 1), size);
        if (r < 0)
                r = allocate_resource(&gpmc_mem_root, res, size, 0, ~0,
                                      size, NULL, NULL);
        if (r < 0)
                goto out;

        gpmc_cs_enable_mem(cs, res->start, resource_size(res));
        *base = res->start;
        gpmc_cs_set_reserved(cs, 1);
out:
        spin_unlock(&gpmc_mem_lock);
        return r;
}
EXPORT_SYMBOL(gpmc_cs_request);

void gpmc_cs_free(int cs)
{
        spin_lock(&gpmc_mem_lock);
        if (cs >= GPMC_CS_NUM || cs < 0 || !gpmc_cs_reserved(cs)) {
                printk(KERN_ERR "Trying to free non-reserved GPMC CS%d\n", cs);
                BUG();
                spin_unlock(&gpmc_mem_lock);
                return;
        }
        gpmc_cs_disable_mem(cs);
        release_resource(&gpmc_cs_mem[cs]);
        gpmc_cs_set_reserved(cs, 0);
        spin_unlock(&gpmc_mem_lock);
}
EXPORT_SYMBOL(gpmc_cs_free);

/**
 * gpmc_read_status - read access request to get the different gpmc status
 * @cmd: command type
 * @return status
 */
int gpmc_read_status(int cmd)
{
        int     status = -EINVAL;
        u32     regval = 0;

        switch (cmd) {
        case GPMC_GET_IRQ_STATUS:
                status = gpmc_read_reg(GPMC_IRQSTATUS);
                break;

        case GPMC_PREFETCH_FIFO_CNT:
                regval = gpmc_read_reg(GPMC_PREFETCH_STATUS);
                status = GPMC_PREFETCH_STATUS_FIFO_CNT(regval);
                break;

        case GPMC_PREFETCH_COUNT:
                regval = gpmc_read_reg(GPMC_PREFETCH_STATUS);
                status = GPMC_PREFETCH_STATUS_COUNT(regval);
                break;

        case GPMC_STATUS_BUFFER:
                regval = gpmc_read_reg(GPMC_STATUS);
                /* 1 : buffer is available to write */
                status = regval & GPMC_STATUS_BUFF_EMPTY;
                break;

        default:
                printk(KERN_ERR "gpmc_read_status: Not supported\n");
        }
        return status;
}
EXPORT_SYMBOL(gpmc_read_status);

/**
 * gpmc_cs_configure - write request to configure gpmc
 * @cs: chip select number
 * @cmd: command type
 * @wval: value to write
 * @return status of the operation
 */
int gpmc_cs_configure(int cs, int cmd, int wval)
{
        int err = 0;
        u32 regval = 0;

        switch (cmd) {
        case GPMC_SET_IRQ_STATUS:
                gpmc_write_reg(GPMC_IRQSTATUS, wval);
                break;

        case GPMC_CONFIG_WP:
                regval = gpmc_read_reg(GPMC_CONFIG);
                if (wval)
                        regval &= ~GPMC_CONFIG_WRITEPROTECT; /* WP is ON */
                else
                        regval |= GPMC_CONFIG_WRITEPROTECT;  /* WP is OFF */
                gpmc_write_reg(GPMC_CONFIG, regval);
                break;

        case GPMC_CONFIG_RDY_BSY:
                regval  = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG1);
                if (wval)
                        regval |= WR_RD_PIN_MONITORING;
                else
                        regval &= ~WR_RD_PIN_MONITORING;
                gpmc_cs_write_reg(cs, GPMC_CS_CONFIG1, regval);
                break;

        case GPMC_CONFIG_DEV_SIZE:
                regval  = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG1);
                regval |= GPMC_CONFIG1_DEVICESIZE(wval);
                gpmc_cs_write_reg(cs, GPMC_CS_CONFIG1, regval);
                break;

        case GPMC_CONFIG_DEV_TYPE:
                regval  = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG1);
                regval |= GPMC_CONFIG1_DEVICETYPE(wval);
                if (wval == GPMC_DEVICETYPE_NOR)
                        regval |= GPMC_CONFIG1_MUXADDDATA;
                gpmc_cs_write_reg(cs, GPMC_CS_CONFIG1, regval);
                break;

        default:
                printk(KERN_ERR "gpmc_configure_cs: Not supported\n");
                err = -EINVAL;
        }

        return err;
}
EXPORT_SYMBOL(gpmc_cs_configure);

/**
 * gpmc_nand_read - nand specific read access request
 * @cs: chip select number
 * @cmd: command type
 */
int gpmc_nand_read(int cs, int cmd)
{
        int rval = -EINVAL;

        switch (cmd) {
        case GPMC_NAND_DATA:
                rval = gpmc_cs_read_byte(cs, GPMC_CS_NAND_DATA);
                break;

        default:
                printk(KERN_ERR "gpmc_read_nand_ctrl: Not supported\n");
        }
        return rval;
}
EXPORT_SYMBOL(gpmc_nand_read);

/**
 * gpmc_nand_write - nand specific write request
 * @cs: chip select number
 * @cmd: command type
 * @wval: value to write
 */
int gpmc_nand_write(int cs, int cmd, int wval)
{
        int err = 0;

        switch (cmd) {
        case GPMC_NAND_COMMAND:
                gpmc_cs_write_byte(cs, GPMC_CS_NAND_COMMAND, wval);
                break;

        case GPMC_NAND_ADDRESS:
                gpmc_cs_write_byte(cs, GPMC_CS_NAND_ADDRESS, wval);
                break;

        case GPMC_NAND_DATA:
                gpmc_cs_write_byte(cs, GPMC_CS_NAND_DATA, wval);

        default:
                printk(KERN_ERR "gpmc_write_nand_ctrl: Not supported\n");
                err = -EINVAL;
        }
        return err;
}
EXPORT_SYMBOL(gpmc_nand_write);



/**
 * gpmc_prefetch_enable - configures and starts prefetch transfer
 * @cs: cs (chip select) number
 * @dma_mode: dma mode enable (1) or disable (0)
 * @u32_count: number of bytes to be transferred
 * @is_write: prefetch read(0) or write post(1) mode
 */
int gpmc_prefetch_enable(int cs, int dma_mode,
                                unsigned int u32_count, int is_write)
{

        if (!(gpmc_read_reg(GPMC_PREFETCH_CONTROL))) {
                /* Set the amount of bytes to be prefetched */
                gpmc_write_reg(GPMC_PREFETCH_CONFIG2, u32_count);

                /* Set dma/mpu mode, the prefetch read / post write and
                 * enable the engine. Set which cs is has requested for.
                 */
                gpmc_write_reg(GPMC_PREFETCH_CONFIG1, ((cs << CS_NUM_SHIFT) |
                                        PREFETCH_FIFOTHRESHOLD |
                                        ENABLE_PREFETCH |
                                        (dma_mode << DMA_MPU_MODE) |
                                        (0x1 & is_write)));

                /*  Start the prefetch engine */
                gpmc_write_reg(GPMC_PREFETCH_CONTROL, 0x1);
        } else {
                return -EBUSY;
        }

        return 0;
}
EXPORT_SYMBOL(gpmc_prefetch_enable);

/**
 * gpmc_prefetch_reset - disables and stops the prefetch engine
 */
int gpmc_prefetch_reset(int cs)
{
        u32 config1;

        /* check if the same module/cs is trying to reset */
        config1 = gpmc_read_reg(GPMC_PREFETCH_CONFIG1);
        if (((config1 >> CS_NUM_SHIFT) & 0x7) != cs)
                return -EINVAL;

        /* Stop the PFPW engine */
        gpmc_write_reg(GPMC_PREFETCH_CONTROL, 0x0);

        /* Reset/disable the PFPW engine */
        gpmc_write_reg(GPMC_PREFETCH_CONFIG1, 0x0);

        return 0;
}
EXPORT_SYMBOL(gpmc_prefetch_reset);

static void __init gpmc_mem_init(void)
{
        int cs;
        unsigned long boot_rom_space = 0;

        /* never allocate the first page, to facilitate bug detection;
         * even if we didn't boot from ROM.
         */
        boot_rom_space = BOOT_ROM_SPACE;
        /* In apollon the CS0 is mapped as 0x0000 0000 */
        if (machine_is_omap_apollon())
                boot_rom_space = 0;
        gpmc_mem_root.start = GPMC_MEM_START + boot_rom_space;
        gpmc_mem_root.end = GPMC_MEM_END;

        /* Reserve all regions that has been set up by bootloader */
        for (cs = 0; cs < GPMC_CS_NUM; cs++) {
                u32 base, size;

                if (!gpmc_cs_mem_enabled(cs))
                        continue;
                gpmc_cs_get_memconf(cs, &base, &size);
                if (gpmc_cs_insert_mem(cs, base, size) < 0)
                        BUG();
        }
}

void __init gpmc_init(void)
{
        u32 l;
        char *ck = NULL;

        if (cpu_is_omap24xx()) {
                ck = "core_l3_ck";
                if (cpu_is_omap2420())
                        l = OMAP2420_GPMC_BASE;
                else
                        l = OMAP34XX_GPMC_BASE;
        } else if (cpu_is_omap34xx()) {
                ck = "gpmc_fck";
                l = OMAP34XX_GPMC_BASE;
        } else if (cpu_is_omap44xx()) {
                ck = "gpmc_ck";
                l = OMAP44XX_GPMC_BASE;
        }

        if (WARN_ON(!ck))
                return;

        gpmc_l3_clk = clk_get(NULL, ck);
        if (IS_ERR(gpmc_l3_clk)) {
                printk(KERN_ERR "Could not get GPMC clock %s\n", ck);
                BUG();
        }

        gpmc_base = ioremap(l, SZ_4K);
        if (!gpmc_base) {
                clk_put(gpmc_l3_clk);
                printk(KERN_ERR "Could not get GPMC register memory\n");
                BUG();
        }

        clk_enable(gpmc_l3_clk);

        l = gpmc_read_reg(GPMC_REVISION);
        printk(KERN_INFO "GPMC revision %d.%d\n", (l >> 4) & 0x0f, l & 0x0f);
        /* Set smart idle mode and automatic L3 clock gating */
        l = gpmc_read_reg(GPMC_SYSCONFIG);
        l &= 0x03 << 3;
        l |= (0x02 << 3) | (1 << 0);
        gpmc_write_reg(GPMC_SYSCONFIG, l);
        gpmc_mem_init();
}

#ifdef CONFIG_ARCH_OMAP3
static struct omap3_gpmc_regs gpmc_context;

void omap3_gpmc_save_context(void)
{
        int i;

        gpmc_context.sysconfig = gpmc_read_reg(GPMC_SYSCONFIG);
        gpmc_context.irqenable = gpmc_read_reg(GPMC_IRQENABLE);
        gpmc_context.timeout_ctrl = gpmc_read_reg(GPMC_TIMEOUT_CONTROL);
        gpmc_context.config = gpmc_read_reg(GPMC_CONFIG);
        gpmc_context.prefetch_config1 = gpmc_read_reg(GPMC_PREFETCH_CONFIG1);
        gpmc_context.prefetch_config2 = gpmc_read_reg(GPMC_PREFETCH_CONFIG2);
        gpmc_context.prefetch_control = gpmc_read_reg(GPMC_PREFETCH_CONTROL);
        for (i = 0; i < GPMC_CS_NUM; i++) {
                gpmc_context.cs_context[i].is_valid = gpmc_cs_mem_enabled(i);
                if (gpmc_context.cs_context[i].is_valid) {
                        gpmc_context.cs_context[i].config1 =
                                gpmc_cs_read_reg(i, GPMC_CS_CONFIG1);
                        gpmc_context.cs_context[i].config2 =
                                gpmc_cs_read_reg(i, GPMC_CS_CONFIG2);
                        gpmc_context.cs_context[i].config3 =
                                gpmc_cs_read_reg(i, GPMC_CS_CONFIG3);
                        gpmc_context.cs_context[i].config4 =
                                gpmc_cs_read_reg(i, GPMC_CS_CONFIG4);
                        gpmc_context.cs_context[i].config5 =
                                gpmc_cs_read_reg(i, GPMC_CS_CONFIG5);
                        gpmc_context.cs_context[i].config6 =
                                gpmc_cs_read_reg(i, GPMC_CS_CONFIG6);
                        gpmc_context.cs_context[i].config7 =
                                gpmc_cs_read_reg(i, GPMC_CS_CONFIG7);
                }
        }
}

void omap3_gpmc_restore_context(void)
{
        int i;

        gpmc_write_reg(GPMC_SYSCONFIG, gpmc_context.sysconfig);
        gpmc_write_reg(GPMC_IRQENABLE, gpmc_context.irqenable);
        gpmc_write_reg(GPMC_TIMEOUT_CONTROL, gpmc_context.timeout_ctrl);
        gpmc_write_reg(GPMC_CONFIG, gpmc_context.config);
        gpmc_write_reg(GPMC_PREFETCH_CONFIG1, gpmc_context.prefetch_config1);
        gpmc_write_reg(GPMC_PREFETCH_CONFIG2, gpmc_context.prefetch_config2);
        gpmc_write_reg(GPMC_PREFETCH_CONTROL, gpmc_context.prefetch_control);
        for (i = 0; i < GPMC_CS_NUM; i++) {
                if (gpmc_context.cs_context[i].is_valid) {
                        gpmc_cs_write_reg(i, GPMC_CS_CONFIG1,
                                gpmc_context.cs_context[i].config1);
                        gpmc_cs_write_reg(i, GPMC_CS_CONFIG2,
                                gpmc_context.cs_context[i].config2);
                        gpmc_cs_write_reg(i, GPMC_CS_CONFIG3,
                                gpmc_context.cs_context[i].config3);
                        gpmc_cs_write_reg(i, GPMC_CS_CONFIG4,
                                gpmc_context.cs_context[i].config4);
                        gpmc_cs_write_reg(i, GPMC_CS_CONFIG5,
                                gpmc_context.cs_context[i].config5);
                        gpmc_cs_write_reg(i, GPMC_CS_CONFIG6,
                                gpmc_context.cs_context[i].config6);
                        gpmc_cs_write_reg(i, GPMC_CS_CONFIG7,
                                gpmc_context.cs_context[i].config7);
                }
        }
}
#endif /* CONFIG_ARCH_OMAP3 */

/**
 * gpmc_enable_hwecc - enable hardware ecc functionality
 * @cs: chip select number
 * @mode: read/write mode
 * @dev_width: device bus width(1 for x16, 0 for x8)
 * @ecc_size: bytes for which ECC will be generated
 */
int gpmc_enable_hwecc(int cs, int mode, int dev_width, int ecc_size)
{
        unsigned int val;

        /* check if ecc module is in used */
        if (gpmc_ecc_used != -EINVAL)
                return -EINVAL;

        gpmc_ecc_used = cs;

        /* clear ecc and enable bits */
        val = ((0x00000001<<8) | 0x00000001);
        gpmc_write_reg(GPMC_ECC_CONTROL, val);

        /* program ecc and result sizes */
        val = ((((ecc_size >> 1) - 1) << 22) | (0x0000000F));
        gpmc_write_reg(GPMC_ECC_SIZE_CONFIG, val);

        switch (mode) {
        case GPMC_ECC_READ:
                gpmc_write_reg(GPMC_ECC_CONTROL, 0x101);
                break;
        case GPMC_ECC_READSYN:
                 gpmc_write_reg(GPMC_ECC_CONTROL, 0x100);
                break;
        case GPMC_ECC_WRITE:
                gpmc_write_reg(GPMC_ECC_CONTROL, 0x101);
                break;
        default:
                printk(KERN_INFO "Error: Unrecognized Mode[%d]!\n", mode);
                break;
        }

        /* (ECC 16 or 8 bit col) | ( CS  )  | ECC Enable */
        val = (dev_width << 7) | (cs << 1) | (0x1);
        gpmc_write_reg(GPMC_ECC_CONFIG, val);
        return 0;
}

/**
 * gpmc_calculate_ecc - generate non-inverted ecc bytes
 * @cs: chip select number
 * @dat: data pointer over which ecc is computed
 * @ecc_code: ecc code buffer
 *
 * Using non-inverted ECC is considered ugly since writing a blank
 * page (padding) will clear the ECC bytes. This is not a problem as long
 * no one is trying to write data on the seemingly unused page. Reading
 * an erased page will produce an ECC mismatch between generated and read
 * ECC bytes that has to be dealt with separately.
 */
int gpmc_calculate_ecc(int cs, const u_char *dat, u_char *ecc_code)
{
        unsigned int val = 0x0;

        if (gpmc_ecc_used != cs)
                return -EINVAL;

        /* read ecc result */
        val = gpmc_read_reg(GPMC_ECC1_RESULT);
        *ecc_code++ = val;          /* P128e, ..., P1e */
        *ecc_code++ = val >> 16;    /* P128o, ..., P1o */
        /* P2048o, P1024o, P512o, P256o, P2048e, P1024e, P512e, P256e */
        *ecc_code++ = ((val >> 8) & 0x0f) | ((val >> 20) & 0xf0);

        gpmc_ecc_used = -EINVAL;
        return 0;
}