ARM: OMAP2+: Add device-tree support for NOR flash

[deliverable/linux.git] / arch / arm / mach-omap2 / gpmc.c

/*
 * 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/irq.h>
#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 <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_mtd.h>
#include <linux/of_device.h>
#include <linux/mtd/nand.h>

#include <linux/platform_data/mtd-nand-omap2.h>

#include <asm/mach-types.h>

#include "soc.h"
#include "common.h"
#include "omap_device.h"
#include "gpmc.h"
#include "gpmc-nand.h"
#include "gpmc-onenand.h"

#define DEVICE_NAME             "omap-gpmc"

/* 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_ECC_BCH_RESULT_0   0x240   /* not available on OMAP2 */
#define GPMC_ECC_BCH_RESULT_1   0x244   /* not available on OMAP2 */
#define GPMC_ECC_BCH_RESULT_2   0x248   /* not available on OMAP2 */
#define GPMC_ECC_BCH_RESULT_3   0x24c   /* not available on OMAP2 */

/* GPMC ECC control settings */
#define GPMC_ECC_CTRL_ECCCLEAR          0x100
#define GPMC_ECC_CTRL_ECCDISABLE        0x000
#define GPMC_ECC_CTRL_ECCREG1           0x001
#define GPMC_ECC_CTRL_ECCREG2           0x002
#define GPMC_ECC_CTRL_ECCREG3           0x003
#define GPMC_ECC_CTRL_ECCREG4           0x004
#define GPMC_ECC_CTRL_ECCREG5           0x005
#define GPMC_ECC_CTRL_ECCREG6           0x006
#define GPMC_ECC_CTRL_ECCREG7           0x007
#define GPMC_ECC_CTRL_ECCREG8           0x008
#define GPMC_ECC_CTRL_ECCREG9           0x009

#define GPMC_CONFIG2_CSEXTRADELAY               BIT(7)
#define GPMC_CONFIG3_ADVEXTRADELAY              BIT(7)
#define GPMC_CONFIG4_OEEXTRADELAY               BIT(7)
#define GPMC_CONFIG4_WEEXTRADELAY               BIT(23)
#define GPMC_CONFIG6_CYCLE2CYCLEDIFFCSEN        BIT(6)
#define GPMC_CONFIG6_CYCLE2CYCLESAMECSEN        BIT(7)

#define GPMC_CS0_OFFSET         0x60
#define GPMC_CS_SIZE            0x30
#define GPMC_BCH_SIZE           0x10

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

#define GPMC_REVISION_MAJOR(l)          ((l >> 4) & 0xf)
#define GPMC_REVISION_MINOR(l)          (l & 0xf)

#define GPMC_HAS_WR_ACCESS              0x1
#define GPMC_HAS_WR_DATA_MUX_BUS        0x2
#define GPMC_HAS_MUX_AAD                0x4

#define GPMC_NR_WAITPINS                4

/* XXX: Only NAND irq has been considered,currently these are the only ones used
 */
#define GPMC_NR_IRQ             2

struct gpmc_client_irq  {
        unsigned                irq;
        u32                     bitmask;
};

/* 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 gpmc_client_irq gpmc_client_irq[GPMC_NR_IRQ];
static struct irq_chip gpmc_irq_chip;
static unsigned gpmc_irq_start;

static struct resource  gpmc_mem_root;
static struct resource  gpmc_cs_mem[GPMC_CS_NUM];
static DEFINE_SPINLOCK(gpmc_mem_lock);
/* Define chip-selects as reserved by default until probe completes */
static unsigned int gpmc_cs_map = ((1 << GPMC_CS_NUM) - 1);
static unsigned int gpmc_nr_waitpins;
static struct device *gpmc_dev;
static int gpmc_irq;
static resource_size_t phys_base, mem_size;
static unsigned gpmc_capability;
static void __iomem *gpmc_base;

static struct clk *gpmc_l3_clk;

static irqreturn_t gpmc_handle_irq(int irq, void *dev);

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);
}

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);
}

static 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 */
static 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;
}

static 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;
}

static 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;
}

static unsigned int gpmc_ticks_to_ps(unsigned int ticks)
{
        return ticks * gpmc_get_fclk_period();
}

static unsigned int gpmc_round_ps_to_ticks(unsigned int time_ps)
{
        unsigned long ticks = gpmc_ps_to_ticks(time_ps);

        return ticks * gpmc_get_fclk_period();
}

static inline void gpmc_cs_modify_reg(int cs, int reg, u32 mask, bool value)
{
        u32 l;

        l = gpmc_cs_read_reg(cs, reg);
        if (value)
                l |= mask;
        else
                l &= ~mask;
        gpmc_cs_write_reg(cs, reg, l);
}

static void gpmc_cs_bool_timings(int cs, const struct gpmc_bool_timings *p)
{
        gpmc_cs_modify_reg(cs, GPMC_CS_CONFIG1,
                           GPMC_CONFIG1_TIME_PARA_GRAN,
                           p->time_para_granularity);
        gpmc_cs_modify_reg(cs, GPMC_CS_CONFIG2,
                           GPMC_CONFIG2_CSEXTRADELAY, p->cs_extra_delay);
        gpmc_cs_modify_reg(cs, GPMC_CS_CONFIG3,
                           GPMC_CONFIG3_ADVEXTRADELAY, p->adv_extra_delay);
        gpmc_cs_modify_reg(cs, GPMC_CS_CONFIG4,
                           GPMC_CONFIG4_OEEXTRADELAY, p->oe_extra_delay);
        gpmc_cs_modify_reg(cs, GPMC_CS_CONFIG4,
                           GPMC_CONFIG4_OEEXTRADELAY, p->we_extra_delay);
        gpmc_cs_modify_reg(cs, GPMC_CS_CONFIG6,
                           GPMC_CONFIG6_CYCLE2CYCLESAMECSEN,
                           p->cycle2cyclesamecsen);
        gpmc_cs_modify_reg(cs, GPMC_CS_CONFIG6,
                           GPMC_CONFIG6_CYCLE2CYCLEDIFFCSEN,
                           p->cycle2cyclediffcsen);
}

#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_calc_divider(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_calc_divider(t->sync_clk);
        if (div < 0)
                return div;

        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);

        GPMC_SET_ONE(GPMC_CS_CONFIG6, 0, 3, bus_turnaround);
        GPMC_SET_ONE(GPMC_CS_CONFIG6, 8, 11, cycle2cycle_delay);

        GPMC_SET_ONE(GPMC_CS_CONFIG1, 18, 19, wait_monitoring);
        GPMC_SET_ONE(GPMC_CS_CONFIG1, 25, 26, clk_activation);

        if (gpmc_capability & GPMC_HAS_WR_DATA_MUX_BUS)
                GPMC_SET_ONE(GPMC_CS_CONFIG6, 16, 19, wr_data_mux_bus);
        if (gpmc_capability & GPMC_HAS_WR_ACCESS)
                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);
        }

        gpmc_cs_bool_timings(cs, &t->bool_timings);

        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;
}

static void gpmc_cs_set_reserved(int cs, int reserved)
{
        gpmc_cs_map &= ~(1 << cs);
        gpmc_cs_map |= (reserved ? 1 : 0) << cs;
}

static bool gpmc_cs_reserved(int cs)
{
        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;
}

static int gpmc_cs_delete_mem(int cs)
{
        struct resource *res = &gpmc_cs_mem[cs];
        int r;

        spin_lock(&gpmc_mem_lock);
        r = release_resource(&gpmc_cs_mem[cs]);
        res->start = 0;
        res->end = 0;
        spin_unlock(&gpmc_mem_lock);

        return r;
}

/**
 * gpmc_cs_remap - remaps a chip-select physical base address
 * @cs:         chip-select to remap
 * @base:       physical base address to re-map chip-select to
 *
 * Re-maps a chip-select to a new physical base address specified by
 * "base". Returns 0 on success and appropriate negative error code
 * on failure.
 */
static int gpmc_cs_remap(int cs, u32 base)
{
        int ret;
        u32 old_base, size;

        if (cs > GPMC_CS_NUM)
                return -ENODEV;
        gpmc_cs_get_memconf(cs, &old_base, &size);
        if (base == old_base)
                return 0;
        gpmc_cs_disable_mem(cs);
        ret = gpmc_cs_delete_mem(cs);
        if (ret < 0)
                return ret;
        ret = gpmc_cs_insert_mem(cs, base, size);
        if (ret < 0)
                return ret;
        gpmc_cs_enable_mem(cs, base, size);

        return 0;
}

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_configure - write request to configure gpmc
 * @cmd: command type
 * @wval: value to write
 * @return status of the operation
 */
int gpmc_configure(int cmd, int wval)
{
        u32 regval;

        switch (cmd) {
        case GPMC_ENABLE_IRQ:
                gpmc_write_reg(GPMC_IRQENABLE, wval);
                break;

        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;

        default:
                pr_err("%s: command not supported\n", __func__);
                return -EINVAL;
        }

        return 0;
}
EXPORT_SYMBOL(gpmc_configure);

void gpmc_update_nand_reg(struct gpmc_nand_regs *reg, int cs)
{
        int i;

        reg->gpmc_status = gpmc_base + GPMC_STATUS;
        reg->gpmc_nand_command = gpmc_base + GPMC_CS0_OFFSET +
                                GPMC_CS_NAND_COMMAND + GPMC_CS_SIZE * cs;
        reg->gpmc_nand_address = gpmc_base + GPMC_CS0_OFFSET +
                                GPMC_CS_NAND_ADDRESS + GPMC_CS_SIZE * cs;
        reg->gpmc_nand_data = gpmc_base + GPMC_CS0_OFFSET +
                                GPMC_CS_NAND_DATA + GPMC_CS_SIZE * cs;
        reg->gpmc_prefetch_config1 = gpmc_base + GPMC_PREFETCH_CONFIG1;
        reg->gpmc_prefetch_config2 = gpmc_base + GPMC_PREFETCH_CONFIG2;
        reg->gpmc_prefetch_control = gpmc_base + GPMC_PREFETCH_CONTROL;
        reg->gpmc_prefetch_status = gpmc_base + GPMC_PREFETCH_STATUS;
        reg->gpmc_ecc_config = gpmc_base + GPMC_ECC_CONFIG;
        reg->gpmc_ecc_control = gpmc_base + GPMC_ECC_CONTROL;
        reg->gpmc_ecc_size_config = gpmc_base + GPMC_ECC_SIZE_CONFIG;
        reg->gpmc_ecc1_result = gpmc_base + GPMC_ECC1_RESULT;

        for (i = 0; i < GPMC_BCH_NUM_REMAINDER; i++) {
                reg->gpmc_bch_result0[i] = gpmc_base + GPMC_ECC_BCH_RESULT_0 +
                                           GPMC_BCH_SIZE * i;
                reg->gpmc_bch_result1[i] = gpmc_base + GPMC_ECC_BCH_RESULT_1 +
                                           GPMC_BCH_SIZE * i;
                reg->gpmc_bch_result2[i] = gpmc_base + GPMC_ECC_BCH_RESULT_2 +
                                           GPMC_BCH_SIZE * i;
                reg->gpmc_bch_result3[i] = gpmc_base + GPMC_ECC_BCH_RESULT_3 +
                                           GPMC_BCH_SIZE * i;
        }
}

int gpmc_get_client_irq(unsigned irq_config)
{
        int i;

        if (hweight32(irq_config) > 1)
                return 0;

        for (i = 0; i < GPMC_NR_IRQ; i++)
                if (gpmc_client_irq[i].bitmask & irq_config)
                        return gpmc_client_irq[i].irq;

        return 0;
}

static int gpmc_irq_endis(unsigned irq, bool endis)
{
        int i;
        u32 regval;

        for (i = 0; i < GPMC_NR_IRQ; i++)
                if (irq == gpmc_client_irq[i].irq) {
                        regval = gpmc_read_reg(GPMC_IRQENABLE);
                        if (endis)
                                regval |= gpmc_client_irq[i].bitmask;
                        else
                                regval &= ~gpmc_client_irq[i].bitmask;
                        gpmc_write_reg(GPMC_IRQENABLE, regval);
                        break;
                }

        return 0;
}

static void gpmc_irq_disable(struct irq_data *p)
{
        gpmc_irq_endis(p->irq, false);
}

static void gpmc_irq_enable(struct irq_data *p)
{
        gpmc_irq_endis(p->irq, true);
}

static void gpmc_irq_noop(struct irq_data *data) { }

static unsigned int gpmc_irq_noop_ret(struct irq_data *data) { return 0; }

static int gpmc_setup_irq(void)
{
        int i;
        u32 regval;

        if (!gpmc_irq)
                return -EINVAL;

        gpmc_irq_start = irq_alloc_descs(-1, 0, GPMC_NR_IRQ, 0);
        if (gpmc_irq_start < 0) {
                pr_err("irq_alloc_descs failed\n");
                return gpmc_irq_start;
        }

        gpmc_irq_chip.name = "gpmc";
        gpmc_irq_chip.irq_startup = gpmc_irq_noop_ret;
        gpmc_irq_chip.irq_enable = gpmc_irq_enable;
        gpmc_irq_chip.irq_disable = gpmc_irq_disable;
        gpmc_irq_chip.irq_shutdown = gpmc_irq_noop;
        gpmc_irq_chip.irq_ack = gpmc_irq_noop;
        gpmc_irq_chip.irq_mask = gpmc_irq_noop;
        gpmc_irq_chip.irq_unmask = gpmc_irq_noop;

        gpmc_client_irq[0].bitmask = GPMC_IRQ_FIFOEVENTENABLE;
        gpmc_client_irq[1].bitmask = GPMC_IRQ_COUNT_EVENT;

        for (i = 0; i < GPMC_NR_IRQ; i++) {
                gpmc_client_irq[i].irq = gpmc_irq_start + i;
                irq_set_chip_and_handler(gpmc_client_irq[i].irq,
                                        &gpmc_irq_chip, handle_simple_irq);
                set_irq_flags(gpmc_client_irq[i].irq,
                                IRQF_VALID | IRQF_NOAUTOEN);
        }

        /* Disable interrupts */
        gpmc_write_reg(GPMC_IRQENABLE, 0);

        /* clear interrupts */
        regval = gpmc_read_reg(GPMC_IRQSTATUS);
        gpmc_write_reg(GPMC_IRQSTATUS, regval);

        return request_irq(gpmc_irq, gpmc_handle_irq, 0, "gpmc", NULL);
}

static int gpmc_free_irq(void)
{
        int i;

        if (gpmc_irq)
                free_irq(gpmc_irq, NULL);

        for (i = 0; i < GPMC_NR_IRQ; i++) {
                irq_set_handler(gpmc_client_irq[i].irq, NULL);
                irq_set_chip(gpmc_client_irq[i].irq, &no_irq_chip);
                irq_modify_status(gpmc_client_irq[i].irq, 0, 0);
        }

        irq_free_descs(gpmc_irq_start, GPMC_NR_IRQ);

        return 0;
}

static void gpmc_mem_exit(void)
{
        int cs;

        for (cs = 0; cs < GPMC_CS_NUM; cs++) {
                if (!gpmc_cs_mem_enabled(cs))
                        continue;
                gpmc_cs_delete_mem(cs);
        }

}

static int gpmc_mem_init(void)
{
        int cs, rc;
        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;
        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);
                rc = gpmc_cs_insert_mem(cs, base, size);
                if (rc < 0) {
                        while (--cs >= 0)
                                if (gpmc_cs_mem_enabled(cs))
                                        gpmc_cs_delete_mem(cs);
                        return rc;
                }
        }

        return 0;
}

static u32 gpmc_round_ps_to_sync_clk(u32 time_ps, u32 sync_clk)
{
        u32 temp;
        int div;

        div = gpmc_calc_divider(sync_clk);
        temp = gpmc_ps_to_ticks(time_ps);
        temp = (temp + div - 1) / div;
        return gpmc_ticks_to_ps(temp * div);
}

/* XXX: can the cycles be avoided ? */
static int gpmc_calc_sync_read_timings(struct gpmc_timings *gpmc_t,
                                       struct gpmc_device_timings *dev_t,
                                       bool mux)
{
        u32 temp;

        /* adv_rd_off */
        temp = dev_t->t_avdp_r;
        /* XXX: mux check required ? */
        if (mux) {
                /* XXX: t_avdp not to be required for sync, only added for tusb
                 * this indirectly necessitates requirement of t_avdp_r and
                 * t_avdp_w instead of having a single t_avdp
                 */
                temp = max_t(u32, temp, gpmc_t->clk_activation + dev_t->t_avdh);
                temp = max_t(u32, gpmc_t->adv_on + gpmc_ticks_to_ps(1), temp);
        }
        gpmc_t->adv_rd_off = gpmc_round_ps_to_ticks(temp);

        /* oe_on */
        temp = dev_t->t_oeasu; /* XXX: remove this ? */
        if (mux) {
                temp = max_t(u32, temp, gpmc_t->clk_activation + dev_t->t_ach);
                temp = max_t(u32, temp, gpmc_t->adv_rd_off +
                                gpmc_ticks_to_ps(dev_t->cyc_aavdh_oe));
        }
        gpmc_t->oe_on = gpmc_round_ps_to_ticks(temp);

        /* access */
        /* XXX: any scope for improvement ?, by combining oe_on
         * and clk_activation, need to check whether
         * access = clk_activation + round to sync clk ?
         */
        temp = max_t(u32, dev_t->t_iaa, dev_t->cyc_iaa * gpmc_t->sync_clk);
        temp += gpmc_t->clk_activation;
        if (dev_t->cyc_oe)
                temp = max_t(u32, temp, gpmc_t->oe_on +
                                gpmc_ticks_to_ps(dev_t->cyc_oe));
        gpmc_t->access = gpmc_round_ps_to_ticks(temp);

        gpmc_t->oe_off = gpmc_t->access + gpmc_ticks_to_ps(1);
        gpmc_t->cs_rd_off = gpmc_t->oe_off;

        /* rd_cycle */
        temp = max_t(u32, dev_t->t_cez_r, dev_t->t_oez);
        temp = gpmc_round_ps_to_sync_clk(temp, gpmc_t->sync_clk) +
                                                        gpmc_t->access;
        /* XXX: barter t_ce_rdyz with t_cez_r ? */
        if (dev_t->t_ce_rdyz)
                temp = max_t(u32, temp, gpmc_t->cs_rd_off + dev_t->t_ce_rdyz);
        gpmc_t->rd_cycle = gpmc_round_ps_to_ticks(temp);

        return 0;
}

static int gpmc_calc_sync_write_timings(struct gpmc_timings *gpmc_t,
                                        struct gpmc_device_timings *dev_t,
                                        bool mux)
{
        u32 temp;

        /* adv_wr_off */
        temp = dev_t->t_avdp_w;
        if (mux) {
                temp = max_t(u32, temp,
                        gpmc_t->clk_activation + dev_t->t_avdh);
                temp = max_t(u32, gpmc_t->adv_on + gpmc_ticks_to_ps(1), temp);
        }
        gpmc_t->adv_wr_off = gpmc_round_ps_to_ticks(temp);

        /* wr_data_mux_bus */
        temp = max_t(u32, dev_t->t_weasu,
                        gpmc_t->clk_activation + dev_t->t_rdyo);
        /* XXX: shouldn't mux be kept as a whole for wr_data_mux_bus ?,
         * and in that case remember to handle we_on properly
         */
        if (mux) {
                temp = max_t(u32, temp,
                        gpmc_t->adv_wr_off + dev_t->t_aavdh);
                temp = max_t(u32, temp, gpmc_t->adv_wr_off +
                                gpmc_ticks_to_ps(dev_t->cyc_aavdh_we));
        }
        gpmc_t->wr_data_mux_bus = gpmc_round_ps_to_ticks(temp);

        /* we_on */
        if (gpmc_capability & GPMC_HAS_WR_DATA_MUX_BUS)
                gpmc_t->we_on = gpmc_round_ps_to_ticks(dev_t->t_weasu);
        else
                gpmc_t->we_on = gpmc_t->wr_data_mux_bus;

        /* wr_access */
        /* XXX: gpmc_capability check reqd ? , even if not, will not harm */
        gpmc_t->wr_access = gpmc_t->access;

        /* we_off */
        temp = gpmc_t->we_on + dev_t->t_wpl;
        temp = max_t(u32, temp,
                        gpmc_t->wr_access + gpmc_ticks_to_ps(1));
        temp = max_t(u32, temp,
                gpmc_t->we_on + gpmc_ticks_to_ps(dev_t->cyc_wpl));
        gpmc_t->we_off = gpmc_round_ps_to_ticks(temp);

        gpmc_t->cs_wr_off = gpmc_round_ps_to_ticks(gpmc_t->we_off +
                                                        dev_t->t_wph);

        /* wr_cycle */
        temp = gpmc_round_ps_to_sync_clk(dev_t->t_cez_w, gpmc_t->sync_clk);
        temp += gpmc_t->wr_access;
        /* XXX: barter t_ce_rdyz with t_cez_w ? */
        if (dev_t->t_ce_rdyz)
                temp = max_t(u32, temp,
                                 gpmc_t->cs_wr_off + dev_t->t_ce_rdyz);
        gpmc_t->wr_cycle = gpmc_round_ps_to_ticks(temp);

        return 0;
}

static int gpmc_calc_async_read_timings(struct gpmc_timings *gpmc_t,
                                        struct gpmc_device_timings *dev_t,
                                        bool mux)
{
        u32 temp;

        /* adv_rd_off */
        temp = dev_t->t_avdp_r;
        if (mux)
                temp = max_t(u32, gpmc_t->adv_on + gpmc_ticks_to_ps(1), temp);
        gpmc_t->adv_rd_off = gpmc_round_ps_to_ticks(temp);

        /* oe_on */
        temp = dev_t->t_oeasu;
        if (mux)
                temp = max_t(u32, temp,
                        gpmc_t->adv_rd_off + dev_t->t_aavdh);
        gpmc_t->oe_on = gpmc_round_ps_to_ticks(temp);

        /* access */
        temp = max_t(u32, dev_t->t_iaa, /* XXX: remove t_iaa in async ? */
                                gpmc_t->oe_on + dev_t->t_oe);
        temp = max_t(u32, temp,
                                gpmc_t->cs_on + dev_t->t_ce);
        temp = max_t(u32, temp,
                                gpmc_t->adv_on + dev_t->t_aa);
        gpmc_t->access = gpmc_round_ps_to_ticks(temp);

        gpmc_t->oe_off = gpmc_t->access + gpmc_ticks_to_ps(1);
        gpmc_t->cs_rd_off = gpmc_t->oe_off;

        /* rd_cycle */
        temp = max_t(u32, dev_t->t_rd_cycle,
                        gpmc_t->cs_rd_off + dev_t->t_cez_r);
        temp = max_t(u32, temp, gpmc_t->oe_off + dev_t->t_oez);
        gpmc_t->rd_cycle = gpmc_round_ps_to_ticks(temp);

        return 0;
}

static int gpmc_calc_async_write_timings(struct gpmc_timings *gpmc_t,
                                         struct gpmc_device_timings *dev_t,
                                         bool mux)
{
        u32 temp;

        /* adv_wr_off */
        temp = dev_t->t_avdp_w;
        if (mux)
                temp = max_t(u32, gpmc_t->adv_on + gpmc_ticks_to_ps(1), temp);
        gpmc_t->adv_wr_off = gpmc_round_ps_to_ticks(temp);

        /* wr_data_mux_bus */
        temp = dev_t->t_weasu;
        if (mux) {
                temp = max_t(u32, temp, gpmc_t->adv_wr_off + dev_t->t_aavdh);
                temp = max_t(u32, temp, gpmc_t->adv_wr_off +
                                gpmc_ticks_to_ps(dev_t->cyc_aavdh_we));
        }
        gpmc_t->wr_data_mux_bus = gpmc_round_ps_to_ticks(temp);

        /* we_on */
        if (gpmc_capability & GPMC_HAS_WR_DATA_MUX_BUS)
                gpmc_t->we_on = gpmc_round_ps_to_ticks(dev_t->t_weasu);
        else
                gpmc_t->we_on = gpmc_t->wr_data_mux_bus;

        /* we_off */
        temp = gpmc_t->we_on + dev_t->t_wpl;
        gpmc_t->we_off = gpmc_round_ps_to_ticks(temp);

        gpmc_t->cs_wr_off = gpmc_round_ps_to_ticks(gpmc_t->we_off +
                                                        dev_t->t_wph);

        /* wr_cycle */
        temp = max_t(u32, dev_t->t_wr_cycle,
                                gpmc_t->cs_wr_off + dev_t->t_cez_w);
        gpmc_t->wr_cycle = gpmc_round_ps_to_ticks(temp);

        return 0;
}

static int gpmc_calc_sync_common_timings(struct gpmc_timings *gpmc_t,
                        struct gpmc_device_timings *dev_t)
{
        u32 temp;

        gpmc_t->sync_clk = gpmc_calc_divider(dev_t->clk) *
                                                gpmc_get_fclk_period();

        gpmc_t->page_burst_access = gpmc_round_ps_to_sync_clk(
                                        dev_t->t_bacc,
                                        gpmc_t->sync_clk);

        temp = max_t(u32, dev_t->t_ces, dev_t->t_avds);
        gpmc_t->clk_activation = gpmc_round_ps_to_ticks(temp);

        if (gpmc_calc_divider(gpmc_t->sync_clk) != 1)
                return 0;

        if (dev_t->ce_xdelay)
                gpmc_t->bool_timings.cs_extra_delay = true;
        if (dev_t->avd_xdelay)
                gpmc_t->bool_timings.adv_extra_delay = true;
        if (dev_t->oe_xdelay)
                gpmc_t->bool_timings.oe_extra_delay = true;
        if (dev_t->we_xdelay)
                gpmc_t->bool_timings.we_extra_delay = true;

        return 0;
}

static int gpmc_calc_common_timings(struct gpmc_timings *gpmc_t,
                                    struct gpmc_device_timings *dev_t,
                                    bool sync)
{
        u32 temp;

        /* cs_on */
        gpmc_t->cs_on = gpmc_round_ps_to_ticks(dev_t->t_ceasu);

        /* adv_on */
        temp = dev_t->t_avdasu;
        if (dev_t->t_ce_avd)
                temp = max_t(u32, temp,
                                gpmc_t->cs_on + dev_t->t_ce_avd);
        gpmc_t->adv_on = gpmc_round_ps_to_ticks(temp);

        if (sync)
                gpmc_calc_sync_common_timings(gpmc_t, dev_t);

        return 0;
}

/* TODO: remove this function once all peripherals are confirmed to
 * work with generic timing. Simultaneously gpmc_cs_set_timings()
 * has to be modified to handle timings in ps instead of ns
*/
static void gpmc_convert_ps_to_ns(struct gpmc_timings *t)
{
        t->cs_on /= 1000;
        t->cs_rd_off /= 1000;
        t->cs_wr_off /= 1000;
        t->adv_on /= 1000;
        t->adv_rd_off /= 1000;
        t->adv_wr_off /= 1000;
        t->we_on /= 1000;
        t->we_off /= 1000;
        t->oe_on /= 1000;
        t->oe_off /= 1000;
        t->page_burst_access /= 1000;
        t->access /= 1000;
        t->rd_cycle /= 1000;
        t->wr_cycle /= 1000;
        t->bus_turnaround /= 1000;
        t->cycle2cycle_delay /= 1000;
        t->wait_monitoring /= 1000;
        t->clk_activation /= 1000;
        t->wr_access /= 1000;
        t->wr_data_mux_bus /= 1000;
}

int gpmc_calc_timings(struct gpmc_timings *gpmc_t,
                      struct gpmc_settings *gpmc_s,
                      struct gpmc_device_timings *dev_t)
{
        bool mux = false, sync = false;

        if (gpmc_s) {
                mux = gpmc_s->mux_add_data ? true : false;
                sync = (gpmc_s->sync_read || gpmc_s->sync_write);
        }

        memset(gpmc_t, 0, sizeof(*gpmc_t));

        gpmc_calc_common_timings(gpmc_t, dev_t, sync);

        if (gpmc_s && gpmc_s->sync_read)
                gpmc_calc_sync_read_timings(gpmc_t, dev_t, mux);
        else
                gpmc_calc_async_read_timings(gpmc_t, dev_t, mux);

        if (gpmc_s && gpmc_s->sync_write)
                gpmc_calc_sync_write_timings(gpmc_t, dev_t, mux);
        else
                gpmc_calc_async_write_timings(gpmc_t, dev_t, mux);

        /* TODO: remove, see function definition */
        gpmc_convert_ps_to_ns(gpmc_t);

        return 0;
}

/**
 * gpmc_cs_program_settings - programs non-timing related settings
 * @cs:         GPMC chip-select to program
 * @p:          pointer to GPMC settings structure
 *
 * Programs non-timing related settings for a GPMC chip-select, such as
 * bus-width, burst configuration, etc. Function should be called once
 * for each chip-select that is being used and must be called before
 * calling gpmc_cs_set_timings() as timing parameters in the CONFIG1
 * register will be initialised to zero by this function. Returns 0 on
 * success and appropriate negative error code on failure.
 */
int gpmc_cs_program_settings(int cs, struct gpmc_settings *p)
{
        u32 config1;

        if ((!p->device_width) || (p->device_width > GPMC_DEVWIDTH_16BIT)) {
                pr_err("%s: invalid width %d!", __func__, p->device_width);
                return -EINVAL;
        }

        /* Address-data multiplexing not supported for NAND devices */
        if (p->device_nand && p->mux_add_data) {
                pr_err("%s: invalid configuration!\n", __func__);
                return -EINVAL;
        }

        if ((p->mux_add_data > GPMC_MUX_AD) ||
            ((p->mux_add_data == GPMC_MUX_AAD) &&
             !(gpmc_capability & GPMC_HAS_MUX_AAD))) {
                pr_err("%s: invalid multiplex configuration!\n", __func__);
                return -EINVAL;
        }

        /* Page/burst mode supports lengths of 4, 8 and 16 bytes */
        if (p->burst_read || p->burst_write) {
                switch (p->burst_len) {
                case GPMC_BURST_4:
                case GPMC_BURST_8:
                case GPMC_BURST_16:
                        break;
                default:
                        pr_err("%s: invalid page/burst-length (%d)\n",
                               __func__, p->burst_len);
                        return -EINVAL;
                }
        }

        if ((p->wait_on_read || p->wait_on_write) &&
            (p->wait_pin > gpmc_nr_waitpins)) {
                pr_err("%s: invalid wait-pin (%d)\n", __func__, p->wait_pin);
                return -EINVAL;
        }

        config1 = GPMC_CONFIG1_DEVICESIZE((p->device_width - 1));

        if (p->sync_read)
                config1 |= GPMC_CONFIG1_READTYPE_SYNC;
        if (p->sync_write)
                config1 |= GPMC_CONFIG1_WRITETYPE_SYNC;
        if (p->wait_on_read)
                config1 |= GPMC_CONFIG1_WAIT_READ_MON;
        if (p->wait_on_write)
                config1 |= GPMC_CONFIG1_WAIT_WRITE_MON;
        if (p->wait_on_read || p->wait_on_write)
                config1 |= GPMC_CONFIG1_WAIT_PIN_SEL(p->wait_pin);
        if (p->device_nand)
                config1 |= GPMC_CONFIG1_DEVICETYPE(GPMC_DEVICETYPE_NAND);
        if (p->mux_add_data)
                config1 |= GPMC_CONFIG1_MUXTYPE(p->mux_add_data);
        if (p->burst_read)
                config1 |= GPMC_CONFIG1_READMULTIPLE_SUPP;
        if (p->burst_write)
                config1 |= GPMC_CONFIG1_WRITEMULTIPLE_SUPP;
        if (p->burst_read || p->burst_write) {
                config1 |= GPMC_CONFIG1_PAGE_LEN(p->burst_len >> 3);
                config1 |= p->burst_wrap ? GPMC_CONFIG1_WRAPBURST_SUPP : 0;
        }

        gpmc_cs_write_reg(cs, GPMC_CS_CONFIG1, config1);

        return 0;
}

#ifdef CONFIG_OF
static struct of_device_id gpmc_dt_ids[] = {
        { .compatible = "ti,omap2420-gpmc" },
        { .compatible = "ti,omap2430-gpmc" },
        { .compatible = "ti,omap3430-gpmc" },   /* omap3430 & omap3630 */
        { .compatible = "ti,omap4430-gpmc" },   /* omap4430 & omap4460 & omap543x */
        { .compatible = "ti,am3352-gpmc" },     /* am335x devices */
        { }
};
MODULE_DEVICE_TABLE(of, gpmc_dt_ids);

/**
 * gpmc_read_settings_dt - read gpmc settings from device-tree
 * @np:         pointer to device-tree node for a gpmc child device
 * @p:          pointer to gpmc settings structure
 *
 * Reads the GPMC settings for a GPMC child device from device-tree and
 * stores them in the GPMC settings structure passed. The GPMC settings
 * structure is initialised to zero by this function and so any
 * previously stored settings will be cleared.
 */
void gpmc_read_settings_dt(struct device_node *np, struct gpmc_settings *p)
{
        memset(p, 0, sizeof(struct gpmc_settings));

        p->sync_read = of_property_read_bool(np, "gpmc,sync-read");
        p->sync_write = of_property_read_bool(np, "gpmc,sync-write");
        p->device_nand = of_property_read_bool(np, "gpmc,device-nand");
        of_property_read_u32(np, "gpmc,device-width", &p->device_width);
        of_property_read_u32(np, "gpmc,mux-add-data", &p->mux_add_data);

        if (!of_property_read_u32(np, "gpmc,burst-length", &p->burst_len)) {
                p->burst_wrap = of_property_read_bool(np, "gpmc,burst-wrap");
                p->burst_read = of_property_read_bool(np, "gpmc,burst-read");
                p->burst_write = of_property_read_bool(np, "gpmc,burst-write");
                if (!p->burst_read && !p->burst_write)
                        pr_warn("%s: page/burst-length set but not used!\n",
                                __func__);
        }

        if (!of_property_read_u32(np, "gpmc,wait-pin", &p->wait_pin)) {
                p->wait_on_read = of_property_read_bool(np,
                                                        "gpmc,wait-on-read");
                p->wait_on_write = of_property_read_bool(np,
                                                         "gpmc,wait-on-write");
                if (!p->wait_on_read && !p->wait_on_write)
                        pr_warn("%s: read/write wait monitoring not enabled!\n",
                                __func__);
        }
}

static void __maybe_unused gpmc_read_timings_dt(struct device_node *np,
                                                struct gpmc_timings *gpmc_t)
{
        struct gpmc_bool_timings *p;

        if (!np || !gpmc_t)
                return;

        memset(gpmc_t, 0, sizeof(*gpmc_t));

        /* minimum clock period for syncronous mode */
        of_property_read_u32(np, "gpmc,sync-clk-ps", &gpmc_t->sync_clk);

        /* chip select timtings */
        of_property_read_u32(np, "gpmc,cs-on-ns", &gpmc_t->cs_on);
        of_property_read_u32(np, "gpmc,cs-rd-off-ns", &gpmc_t->cs_rd_off);
        of_property_read_u32(np, "gpmc,cs-wr-off-ns", &gpmc_t->cs_wr_off);

        /* ADV signal timings */
        of_property_read_u32(np, "gpmc,adv-on-ns", &gpmc_t->adv_on);
        of_property_read_u32(np, "gpmc,adv-rd-off-ns", &gpmc_t->adv_rd_off);
        of_property_read_u32(np, "gpmc,adv-wr-off-ns", &gpmc_t->adv_wr_off);

        /* WE signal timings */
        of_property_read_u32(np, "gpmc,we-on-ns", &gpmc_t->we_on);
        of_property_read_u32(np, "gpmc,we-off-ns", &gpmc_t->we_off);

        /* OE signal timings */
        of_property_read_u32(np, "gpmc,oe-on-ns", &gpmc_t->oe_on);
        of_property_read_u32(np, "gpmc,oe-off-ns", &gpmc_t->oe_off);

        /* access and cycle timings */
        of_property_read_u32(np, "gpmc,page-burst-access-ns",
                             &gpmc_t->page_burst_access);
        of_property_read_u32(np, "gpmc,access-ns", &gpmc_t->access);
        of_property_read_u32(np, "gpmc,rd-cycle-ns", &gpmc_t->rd_cycle);
        of_property_read_u32(np, "gpmc,wr-cycle-ns", &gpmc_t->wr_cycle);
        of_property_read_u32(np, "gpmc,bus-turnaround-ns",
                             &gpmc_t->bus_turnaround);
        of_property_read_u32(np, "gpmc,cycle2cycle-delay-ns",
                             &gpmc_t->cycle2cycle_delay);
        of_property_read_u32(np, "gpmc,wait-monitoring-ns",
                             &gpmc_t->wait_monitoring);
        of_property_read_u32(np, "gpmc,clk-activation-ns",
                             &gpmc_t->clk_activation);

        /* only applicable to OMAP3+ */
        of_property_read_u32(np, "gpmc,wr-access-ns", &gpmc_t->wr_access);
        of_property_read_u32(np, "gpmc,wr-data-mux-bus-ns",
                             &gpmc_t->wr_data_mux_bus);

        /* bool timing parameters */
        p = &gpmc_t->bool_timings;

        p->cycle2cyclediffcsen =
                of_property_read_bool(np, "gpmc,cycle2cycle-diffcsen");
        p->cycle2cyclesamecsen =
                of_property_read_bool(np, "gpmc,cycle2cycle-samecsen");
        p->we_extra_delay = of_property_read_bool(np, "gpmc,we-extra-delay");
        p->oe_extra_delay = of_property_read_bool(np, "gpmc,oe-extra-delay");
        p->adv_extra_delay = of_property_read_bool(np, "gpmc,adv-extra-delay");
        p->cs_extra_delay = of_property_read_bool(np, "gpmc,cs-extra-delay");
        p->time_para_granularity =
                of_property_read_bool(np, "gpmc,time-para-granularity");
}

#ifdef CONFIG_MTD_NAND

static const char * const nand_ecc_opts[] = {
        [OMAP_ECC_HAMMING_CODE_DEFAULT]         = "sw",
        [OMAP_ECC_HAMMING_CODE_HW]              = "hw",
        [OMAP_ECC_HAMMING_CODE_HW_ROMCODE]      = "hw-romcode",
        [OMAP_ECC_BCH4_CODE_HW]                 = "bch4",
        [OMAP_ECC_BCH8_CODE_HW]                 = "bch8",
};

static int gpmc_probe_nand_child(struct platform_device *pdev,
                                 struct device_node *child)
{
        u32 val;
        const char *s;
        struct gpmc_timings gpmc_t;
        struct omap_nand_platform_data *gpmc_nand_data;

        if (of_property_read_u32(child, "reg", &val) < 0) {
                dev_err(&pdev->dev, "%s has no 'reg' property\n",
                        child->full_name);
                return -ENODEV;
        }

        gpmc_nand_data = devm_kzalloc(&pdev->dev, sizeof(*gpmc_nand_data),
                                      GFP_KERNEL);
        if (!gpmc_nand_data)
                return -ENOMEM;

        gpmc_nand_data->cs = val;
        gpmc_nand_data->of_node = child;

        if (!of_property_read_string(child, "ti,nand-ecc-opt", &s))
                for (val = 0; val < ARRAY_SIZE(nand_ecc_opts); val++)
                        if (!strcasecmp(s, nand_ecc_opts[val])) {
                                gpmc_nand_data->ecc_opt = val;
                                break;
                        }

        val = of_get_nand_bus_width(child);
        if (val == 16)
                gpmc_nand_data->devsize = NAND_BUSWIDTH_16;

        gpmc_read_timings_dt(child, &gpmc_t);
        gpmc_nand_init(gpmc_nand_data, &gpmc_t);

        return 0;
}
#else
static int gpmc_probe_nand_child(struct platform_device *pdev,
                                 struct device_node *child)
{
        return 0;
}
#endif

#ifdef CONFIG_MTD_ONENAND
static int gpmc_probe_onenand_child(struct platform_device *pdev,
                                 struct device_node *child)
{
        u32 val;
        struct omap_onenand_platform_data *gpmc_onenand_data;

        if (of_property_read_u32(child, "reg", &val) < 0) {
                dev_err(&pdev->dev, "%s has no 'reg' property\n",
                        child->full_name);
                return -ENODEV;
        }

        gpmc_onenand_data = devm_kzalloc(&pdev->dev, sizeof(*gpmc_onenand_data),
                                         GFP_KERNEL);
        if (!gpmc_onenand_data)
                return -ENOMEM;

        gpmc_onenand_data->cs = val;
        gpmc_onenand_data->of_node = child;
        gpmc_onenand_data->dma_channel = -1;

        if (!of_property_read_u32(child, "dma-channel", &val))
                gpmc_onenand_data->dma_channel = val;

        gpmc_onenand_init(gpmc_onenand_data);

        return 0;
}
#else
static int gpmc_probe_onenand_child(struct platform_device *pdev,
                                    struct device_node *child)
{
        return 0;
}
#endif

/**
 * gpmc_probe_nor_child - configures the gpmc for a nor device
 * @pdev:       pointer to gpmc platform device
 * @child:      pointer to device-tree node for nor device
 *
 * Allocates and configures a GPMC chip-select for a NOR flash device.
 * Returns 0 on success and appropriate negative error code on failure.
 */
static int gpmc_probe_nor_child(struct platform_device *pdev,
                                struct device_node *child)
{
        struct gpmc_settings gpmc_s;
        struct gpmc_timings gpmc_t;
        struct resource res;
        unsigned long base;
        int ret, cs;

        if (of_property_read_u32(child, "reg", &cs) < 0) {
                dev_err(&pdev->dev, "%s has no 'reg' property\n",
                        child->full_name);
                return -ENODEV;
        }

        if (of_address_to_resource(child, 0, &res) < 0) {
                dev_err(&pdev->dev, "%s has malformed 'reg' property\n",
                        child->full_name);
                return -ENODEV;
        }

        ret = gpmc_cs_request(cs, resource_size(&res), &base);
        if (ret < 0) {
                dev_err(&pdev->dev, "cannot request GPMC CS %d\n", cs);
                return ret;
        }

        /*
         * FIXME: gpmc_cs_request() will map the CS to an arbitary
         * location in the gpmc address space. When booting with
         * device-tree we want the NOR flash to be mapped to the
         * location specified in the device-tree blob. So remap the
         * CS to this location. Once DT migration is complete should
         * just make gpmc_cs_request() map a specific address.
         */
        ret = gpmc_cs_remap(cs, res.start);
        if (ret < 0) {
                dev_err(&pdev->dev, "cannot remap GPMC CS %d to 0x%x\n",
                        cs, res.start);
                goto err;
        }

        gpmc_read_settings_dt(child, &gpmc_s);

        ret = of_property_read_u32(child, "bank-width", &gpmc_s.device_width);
        if (ret < 0)
                goto err;

        ret = gpmc_cs_program_settings(cs, &gpmc_s);
        if (ret < 0)
                goto err;

        gpmc_read_timings_dt(child, &gpmc_t);
        gpmc_cs_set_timings(cs, &gpmc_t);

        if (of_platform_device_create(child, NULL, &pdev->dev))
                return 0;

        dev_err(&pdev->dev, "failed to create gpmc child %s\n", child->name);

err:
        gpmc_cs_free(cs);

        return ret;
}

static int gpmc_probe_dt(struct platform_device *pdev)
{
        int ret;
        struct device_node *child;
        const struct of_device_id *of_id =
                of_match_device(gpmc_dt_ids, &pdev->dev);

        if (!of_id)
                return 0;

        ret = of_property_read_u32(pdev->dev.of_node, "gpmc,num-waitpins",
                                   &gpmc_nr_waitpins);
        if (ret < 0) {
                pr_err("%s: number of wait pins not found!\n", __func__);
                return ret;
        }

        for_each_node_by_name(child, "nand") {
                ret = gpmc_probe_nand_child(pdev, child);
                if (ret < 0) {
                        of_node_put(child);
                        return ret;
                }
        }

        for_each_node_by_name(child, "onenand") {
                ret = gpmc_probe_onenand_child(pdev, child);
                if (ret < 0) {
                        of_node_put(child);
                        return ret;
                }
        }

        for_each_node_by_name(child, "nor") {
                ret = gpmc_probe_nor_child(pdev, child);
                if (ret < 0) {
                        of_node_put(child);
                        return ret;
                }
        }

        return 0;
}
#else
static int gpmc_probe_dt(struct platform_device *pdev)
{
        return 0;
}
#endif

static int gpmc_probe(struct platform_device *pdev)
{
        int rc;
        u32 l;
        struct resource *res;

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (res == NULL)
                return -ENOENT;

        phys_base = res->start;
        mem_size = resource_size(res);

        gpmc_base = devm_ioremap_resource(&pdev->dev, res);
        if (IS_ERR(gpmc_base))
                return PTR_ERR(gpmc_base);

        res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
        if (res == NULL)
                dev_warn(&pdev->dev, "Failed to get resource: irq\n");
        else
                gpmc_irq = res->start;

        gpmc_l3_clk = clk_get(&pdev->dev, "fck");
        if (IS_ERR(gpmc_l3_clk)) {
                dev_err(&pdev->dev, "error: clk_get\n");
                gpmc_irq = 0;
                return PTR_ERR(gpmc_l3_clk);
        }

        clk_prepare_enable(gpmc_l3_clk);

        gpmc_dev = &pdev->dev;

        l = gpmc_read_reg(GPMC_REVISION);

        /*
         * FIXME: Once device-tree migration is complete the below flags
         * should be populated based upon the device-tree compatible
         * string. For now just use the IP revision. OMAP3+ devices have
         * the wr_access and wr_data_mux_bus register fields. OMAP4+
         * devices support the addr-addr-data multiplex protocol.
         *
         * GPMC IP revisions:
         * - OMAP24xx                   = 2.0
         * - OMAP3xxx                   = 5.0
         * - OMAP44xx/54xx/AM335x       = 6.0
         */
        if (GPMC_REVISION_MAJOR(l) > 0x4)
                gpmc_capability = GPMC_HAS_WR_ACCESS | GPMC_HAS_WR_DATA_MUX_BUS;
        if (GPMC_REVISION_MAJOR(l) > 0x5)
                gpmc_capability |= GPMC_HAS_MUX_AAD;
        dev_info(gpmc_dev, "GPMC revision %d.%d\n", GPMC_REVISION_MAJOR(l),
                 GPMC_REVISION_MINOR(l));

        rc = gpmc_mem_init();
        if (rc < 0) {
                clk_disable_unprepare(gpmc_l3_clk);
                clk_put(gpmc_l3_clk);
                dev_err(gpmc_dev, "failed to reserve memory\n");
                return rc;
        }

        if (gpmc_setup_irq() < 0)
                dev_warn(gpmc_dev, "gpmc_setup_irq failed\n");

        /* Now the GPMC is initialised, unreserve the chip-selects */
        gpmc_cs_map = 0;

        if (!pdev->dev.of_node)
                gpmc_nr_waitpins = GPMC_NR_WAITPINS;

        rc = gpmc_probe_dt(pdev);
        if (rc < 0) {
                clk_disable_unprepare(gpmc_l3_clk);
                clk_put(gpmc_l3_clk);
                dev_err(gpmc_dev, "failed to probe DT parameters\n");
                return rc;
        }

        return 0;
}

static int gpmc_remove(struct platform_device *pdev)
{
        gpmc_free_irq();
        gpmc_mem_exit();
        gpmc_dev = NULL;
        return 0;
}

static struct platform_driver gpmc_driver = {
        .probe          = gpmc_probe,
        .remove         = gpmc_remove,
        .driver         = {
                .name   = DEVICE_NAME,
                .owner  = THIS_MODULE,
                .of_match_table = of_match_ptr(gpmc_dt_ids),
        },
};

static __init int gpmc_init(void)
{
        return platform_driver_register(&gpmc_driver);
}

static __exit void gpmc_exit(void)
{
        platform_driver_unregister(&gpmc_driver);

}

omap_postcore_initcall(gpmc_init);
module_exit(gpmc_exit);

static int __init omap_gpmc_init(void)
{
        struct omap_hwmod *oh;
        struct platform_device *pdev;
        char *oh_name = "gpmc";

        /*
         * if the board boots up with a populated DT, do not
         * manually add the device from this initcall
         */
        if (of_have_populated_dt())
                return -ENODEV;

        oh = omap_hwmod_lookup(oh_name);
        if (!oh) {
                pr_err("Could not look up %s\n", oh_name);
                return -ENODEV;
        }

        pdev = omap_device_build(DEVICE_NAME, -1, oh, NULL, 0);
        WARN(IS_ERR(pdev), "could not build omap_device for %s\n", oh_name);

        return IS_ERR(pdev) ? PTR_ERR(pdev) : 0;
}
omap_postcore_initcall(omap_gpmc_init);

static irqreturn_t gpmc_handle_irq(int irq, void *dev)
{
        int i;
        u32 regval;

        regval = gpmc_read_reg(GPMC_IRQSTATUS);

        if (!regval)
                return IRQ_NONE;

        for (i = 0; i < GPMC_NR_IRQ; i++)
                if (regval & gpmc_client_irq[i].bitmask)
                        generic_handle_irq(gpmc_client_irq[i].irq);

        gpmc_write_reg(GPMC_IRQSTATUS, regval);

        return IRQ_HANDLED;
}

#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 */