omap-gpmc.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * 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>
 */
#include <linux/cpu_pm.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/module.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/gpio/driver.h>
#include <linux/gpio/consumer.h> /* GPIO descriptor enum */
#include <linux/gpio/machine.h>
#include <linux/interrupt.h>
#include <linux/irqdomain.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>
#include <linux/omap-gpmc.h>
#include <linux/pm_runtime.h>
#include <linux/sizes.h>

#include <linux/platform_data/mtd-nand-omap2.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 */
#define	GPMC_ECC_BCH_RESULT_4	0x300	/* not available on OMAP2 */
#define	GPMC_ECC_BCH_RESULT_5	0x304	/* not available on OMAP2 */
#define	GPMC_ECC_BCH_RESULT_6	0x308	/* 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_CONFIG_LIMITEDADDRESS		BIT(1)

#define GPMC_STATUS_EMPTYWRITEBUFFERSTATUS	BIT(0)

#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

/*
 * The first 1MB of GPMC address space is typically mapped to
 * the internal ROM. Never allocate the first page, to
 * facilitate bug detection; even if we didn't boot from ROM.
 * As GPMC minimum partition size is 16MB we can only start from
 * there.
 */
#define GPMC_MEM_START		0x1000000
#define GPMC_MEM_END		0x3FFFFFFF

#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

#define GPMC_CS_CONFIG1		0x00
#define GPMC_CS_CONFIG2		0x04
#define GPMC_CS_CONFIG3		0x08
#define GPMC_CS_CONFIG4		0x0c
#define GPMC_CS_CONFIG5		0x10
#define GPMC_CS_CONFIG6		0x14
#define GPMC_CS_CONFIG7		0x18
#define GPMC_CS_NAND_COMMAND	0x1c
#define GPMC_CS_NAND_ADDRESS	0x20
#define GPMC_CS_NAND_DATA	0x24

/* Control Commands */
#define GPMC_CONFIG_RDY_BSY	0x00000001
#define GPMC_CONFIG_DEV_SIZE	0x00000002
#define GPMC_CONFIG_DEV_TYPE	0x00000003

#define GPMC_CONFIG_WAITPINPOLARITY(pin)	(BIT(pin) << 8)
#define GPMC_CONFIG1_WRAPBURST_SUPP     (1 << 31)
#define GPMC_CONFIG1_READMULTIPLE_SUPP  (1 << 30)
#define GPMC_CONFIG1_READTYPE_ASYNC     (0 << 29)
#define GPMC_CONFIG1_READTYPE_SYNC      (1 << 29)
#define GPMC_CONFIG1_WRITEMULTIPLE_SUPP (1 << 28)
#define GPMC_CONFIG1_WRITETYPE_ASYNC    (0 << 27)
#define GPMC_CONFIG1_WRITETYPE_SYNC     (1 << 27)
#define GPMC_CONFIG1_CLKACTIVATIONTIME(val) (((val) & 3) << 25)
/** CLKACTIVATIONTIME Max Ticks */
#define GPMC_CONFIG1_CLKACTIVATIONTIME_MAX 2
#define GPMC_CONFIG1_PAGE_LEN(val)      (((val) & 3) << 23)
/** ATTACHEDDEVICEPAGELENGTH Max Value */
#define GPMC_CONFIG1_ATTACHEDDEVICEPAGELENGTH_MAX 2
#define GPMC_CONFIG1_WAIT_READ_MON      (1 << 22)
#define GPMC_CONFIG1_WAIT_WRITE_MON     (1 << 21)
#define GPMC_CONFIG1_WAIT_MON_TIME(val) (((val) & 3) << 18)
/** WAITMONITORINGTIME Max Ticks */
#define GPMC_CONFIG1_WAITMONITORINGTIME_MAX  2
#define GPMC_CONFIG1_WAIT_PIN_SEL(val)  (((val) & 3) << 16)
#define GPMC_CONFIG1_DEVICESIZE(val)    (((val) & 3) << 12)
#define GPMC_CONFIG1_DEVICESIZE_16      GPMC_CONFIG1_DEVICESIZE(1)
/** DEVICESIZE Max Value */
#define GPMC_CONFIG1_DEVICESIZE_MAX     1
#define GPMC_CONFIG1_DEVICETYPE(val)    (((val) & 3) << 10)
#define GPMC_CONFIG1_DEVICETYPE_NOR     GPMC_CONFIG1_DEVICETYPE(0)
#define GPMC_CONFIG1_MUXTYPE(val)       (((val) & 3) << 8)
#define GPMC_CONFIG1_TIME_PARA_GRAN     (1 << 4)
#define GPMC_CONFIG1_FCLK_DIV(val)      ((val) & 3)
#define GPMC_CONFIG1_FCLK_DIV2          (GPMC_CONFIG1_FCLK_DIV(1))
#define GPMC_CONFIG1_FCLK_DIV3          (GPMC_CONFIG1_FCLK_DIV(2))
#define GPMC_CONFIG1_FCLK_DIV4          (GPMC_CONFIG1_FCLK_DIV(3))
#define GPMC_CONFIG7_CSVALID		(1 << 6)

#define GPMC_CONFIG7_BASEADDRESS_MASK	0x3f
#define GPMC_CONFIG7_CSVALID_MASK	BIT(6)
#define GPMC_CONFIG7_MASKADDRESS_OFFSET	8
#define GPMC_CONFIG7_MASKADDRESS_MASK	(0xf << GPMC_CONFIG7_MASKADDRESS_OFFSET)
/* All CONFIG7 bits except reserved bits */
#define GPMC_CONFIG7_MASK		(GPMC_CONFIG7_BASEADDRESS_MASK | \
					 GPMC_CONFIG7_CSVALID_MASK |     \
					 GPMC_CONFIG7_MASKADDRESS_MASK)

#define GPMC_DEVICETYPE_NOR		0
#define GPMC_DEVICETYPE_NAND		2
#define GPMC_CONFIG_WRITEPROTECT	0x00000010
#define WR_RD_PIN_MONITORING		0x00600000

/* ECC commands */
#define GPMC_ECC_READ		0 /* Reset Hardware ECC for read */
#define GPMC_ECC_WRITE		1 /* Reset Hardware ECC for write */
#define GPMC_ECC_READSYN	2 /* Reset before syndrom is read back */

#define	GPMC_NR_NAND_IRQS	2 /* number of NAND specific IRQs */

enum gpmc_clk_domain {
	GPMC_CD_FCLK,
	GPMC_CD_CLK
};

struct gpmc_cs_data {
	const char *name;

#define GPMC_CS_RESERVED	(1 << 0)
	u32 flags;

	struct resource mem;
};

/* 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];
};

struct gpmc_waitpin {
	u32 pin;
	u32 polarity;
	struct gpio_desc *desc;
};

struct gpmc_device {
	struct device *dev;
	int irq;
	struct irq_chip irq_chip;
	struct gpio_chip gpio_chip;
	struct notifier_block nb;
	struct omap3_gpmc_regs context;
	struct gpmc_waitpin *waitpins;
	int nirqs;
	unsigned int is_suspended:1;
	struct resource *data;
};

static struct irq_domain *gpmc_irq_domain;

static struct resource	gpmc_mem_root;
static struct gpmc_cs_data gpmc_cs[GPMC_CS_NUM];
static DEFINE_SPINLOCK(gpmc_mem_lock);
/* Define chip-selects as reserved by default until probe completes */
static unsigned int gpmc_cs_num = GPMC_CS_NUM;
static unsigned int gpmc_nr_waitpins;
static unsigned int 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)
{
	writel_relaxed(val, gpmc_base + idx);
}

static u32 gpmc_read_reg(int idx)
{
	return readl_relaxed(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;
	writel_relaxed(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 readl_relaxed(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);

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

	return rate;
}

/**
 * gpmc_get_clk_period - get period of selected clock domain in ps
 * @cs: Chip Select Region.
 * @cd: Clock Domain.
 *
 * GPMC_CS_CONFIG1 GPMCFCLKDIVIDER for cs has to be setup
 * prior to calling this function with GPMC_CD_CLK.
 */
static unsigned long gpmc_get_clk_period(int cs, enum gpmc_clk_domain cd)
{
	unsigned long tick_ps = gpmc_get_fclk_period();
	u32 l;
	int div;

	switch (cd) {
	case GPMC_CD_CLK:
		/* get current clk divider */
		l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG1);
		div = (l & 0x03) + 1;
		/* get GPMC_CLK period */
		tick_ps *= div;
		break;
	case GPMC_CD_FCLK:
	default:
		break;
	}

	return tick_ps;
}

static unsigned int gpmc_ns_to_clk_ticks(unsigned int time_ns, int cs,
					 enum gpmc_clk_domain cd)
{
	unsigned long tick_ps;

	/* Calculate in picosecs to yield more exact results */
	tick_ps = gpmc_get_clk_period(cs, cd);

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

static unsigned int gpmc_ns_to_ticks(unsigned int time_ns)
{
	return gpmc_ns_to_clk_ticks(time_ns, /* any CS */ 0, GPMC_CD_FCLK);
}

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;
}

static unsigned int gpmc_clk_ticks_to_ns(unsigned int ticks, int cs,
					 enum gpmc_clk_domain cd)
{
	return ticks * gpmc_get_clk_period(cs, cd) / 1000;
}

unsigned int gpmc_ticks_to_ns(unsigned int ticks)
{
	return gpmc_clk_ticks_to_ns(ticks, /* any CS */ 0, GPMC_CD_FCLK);
}

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_WEEXTRADELAY, 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 CONFIG_OMAP_GPMC_DEBUG
/**
 * get_gpmc_timing_reg - read a timing parameter and print DTS settings for it.
 * @cs:      Chip Select Region
 * @reg:     GPMC_CS_CONFIGn register offset.
 * @st_bit:  Start Bit
 * @end_bit: End Bit. Must be >= @st_bit.
 * @max:     Maximum parameter value (before optional @shift).
 *           If 0, maximum is as high as @st_bit and @end_bit allow.
 * @name:    DTS node name, w/o "gpmc,"
 * @cd:      Clock Domain of timing parameter.
 * @shift:   Parameter value left shifts @shift, which is then printed instead of value.
 * @raw:     Raw Format Option.
 *           raw format:  gpmc,name = <value>
 *           tick format: gpmc,name = <value> /&zwj;* x ns -- y ns; x ticks *&zwj;/
 *           Where x ns -- y ns result in the same tick value.
 *           When @max is exceeded, "invalid" is printed inside comment.
 * @noval:   Parameter values equal to 0 are not printed.
 * @return:  Specified timing parameter (after optional @shift).
 *
 */
static int get_gpmc_timing_reg(
	/* timing specifiers */
	int cs, int reg, int st_bit, int end_bit, int max,
	const char *name, const enum gpmc_clk_domain cd,
	/* value transform */
	int shift,
	/* format specifiers */
	bool raw, bool noval)
{
	u32 l;
	int nr_bits;
	int mask;
	bool invalid;

	l = gpmc_cs_read_reg(cs, reg);
	nr_bits = end_bit - st_bit + 1;
	mask = (1 << nr_bits) - 1;
	l = (l >> st_bit) & mask;
	if (!max)
		max = mask;
	invalid = l > max;
	if (shift)
		l = (shift << l);
	if (noval && (l == 0))
		return 0;
	if (!raw) {
		/* DTS tick format for timings in ns */
		unsigned int time_ns;
		unsigned int time_ns_min = 0;

		if (l)
			time_ns_min = gpmc_clk_ticks_to_ns(l - 1, cs, cd) + 1;
		time_ns = gpmc_clk_ticks_to_ns(l, cs, cd);
		pr_info("gpmc,%s = <%u>; /* %u ns - %u ns; %i ticks%s*/\n",
			name, time_ns, time_ns_min, time_ns, l,
			invalid ? "; invalid " : " ");
	} else {
		/* raw format */
		pr_info("gpmc,%s = <%u>;%s\n", name, l,
			invalid ? " /* invalid */" : "");
	}

	return l;
}

#define GPMC_PRINT_CONFIG(cs, config) \
	pr_info("cs%i %s: 0x%08x\n", cs, #config, \
		gpmc_cs_read_reg(cs, config))
#define GPMC_GET_RAW(reg, st, end, field) \
	get_gpmc_timing_reg(cs, (reg), (st), (end), 0, field, GPMC_CD_FCLK, 0, 1, 0)
#define GPMC_GET_RAW_MAX(reg, st, end, max, field) \
	get_gpmc_timing_reg(cs, (reg), (st), (end), (max), field, GPMC_CD_FCLK, 0, 1, 0)
#define GPMC_GET_RAW_BOOL(reg, st, end, field) \
	get_gpmc_timing_reg(cs, (reg), (st), (end), 0, field, GPMC_CD_FCLK, 0, 1, 1)
#define GPMC_GET_RAW_SHIFT_MAX(reg, st, end, shift, max, field) \
	get_gpmc_timing_reg(cs, (reg), (st), (end), (max), field, GPMC_CD_FCLK, (shift), 1, 1)
#define GPMC_GET_TICKS(reg, st, end, field) \
	get_gpmc_timing_reg(cs, (reg), (st), (end), 0, field, GPMC_CD_FCLK, 0, 0, 0)
#define GPMC_GET_TICKS_CD(reg, st, end, field, cd) \
	get_gpmc_timing_reg(cs, (reg), (st), (end), 0, field, (cd), 0, 0, 0)
#define GPMC_GET_TICKS_CD_MAX(reg, st, end, max, field, cd) \
	get_gpmc_timing_reg(cs, (reg), (st), (end), (max), field, (cd), 0, 0, 0)

static void gpmc_show_regs(int cs, const char *desc)
{
	pr_info("gpmc cs%i %s:\n", cs, desc);
	GPMC_PRINT_CONFIG(cs, GPMC_CS_CONFIG1);
	GPMC_PRINT_CONFIG(cs, GPMC_CS_CONFIG2);
	GPMC_PRINT_CONFIG(cs, GPMC_CS_CONFIG3);
	GPMC_PRINT_CONFIG(cs, GPMC_CS_CONFIG4);
	GPMC_PRINT_CONFIG(cs, GPMC_CS_CONFIG5);
	GPMC_PRINT_CONFIG(cs, GPMC_CS_CONFIG6);
}

/*
 * Note that gpmc,wait-pin handing wrongly assumes bit 8 is available,
 * see commit c9fb809.
 */
static void gpmc_cs_show_timings(int cs, const char *desc)
{
	gpmc_show_regs(cs, desc);

	pr_info("gpmc cs%i access configuration:\n", cs);
	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1,  4,  4, "time-para-granularity");
	GPMC_GET_RAW(GPMC_CS_CONFIG1,  8,  9, "mux-add-data");
	GPMC_GET_RAW_SHIFT_MAX(GPMC_CS_CONFIG1, 12, 13, 1,
			       GPMC_CONFIG1_DEVICESIZE_MAX, "device-width");
	GPMC_GET_RAW(GPMC_CS_CONFIG1, 16, 17, "wait-pin");
	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1, 21, 21, "wait-on-write");
	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1, 22, 22, "wait-on-read");
	GPMC_GET_RAW_SHIFT_MAX(GPMC_CS_CONFIG1, 23, 24, 4,
			       GPMC_CONFIG1_ATTACHEDDEVICEPAGELENGTH_MAX,
			       "burst-length");
	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1, 27, 27, "sync-write");
	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1, 28, 28, "burst-write");
	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1, 29, 29, "gpmc,sync-read");
	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1, 30, 30, "burst-read");
	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1, 31, 31, "burst-wrap");

	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG2,  7,  7, "cs-extra-delay");

	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG3,  7,  7, "adv-extra-delay");

	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG4, 23, 23, "we-extra-delay");
	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG4,  7,  7, "oe-extra-delay");

	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG6,  7,  7, "cycle2cycle-samecsen");
	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG6,  6,  6, "cycle2cycle-diffcsen");

	pr_info("gpmc cs%i timings configuration:\n", cs);
	GPMC_GET_TICKS(GPMC_CS_CONFIG2,  0,  3, "cs-on-ns");
	GPMC_GET_TICKS(GPMC_CS_CONFIG2,  8, 12, "cs-rd-off-ns");
	GPMC_GET_TICKS(GPMC_CS_CONFIG2, 16, 20, "cs-wr-off-ns");

	GPMC_GET_TICKS(GPMC_CS_CONFIG3,  0,  3, "adv-on-ns");
	GPMC_GET_TICKS(GPMC_CS_CONFIG3,  8, 12, "adv-rd-off-ns");
	GPMC_GET_TICKS(GPMC_CS_CONFIG3, 16, 20, "adv-wr-off-ns");
	if (gpmc_capability & GPMC_HAS_MUX_AAD) {
		GPMC_GET_TICKS(GPMC_CS_CONFIG3, 4, 6, "adv-aad-mux-on-ns");
		GPMC_GET_TICKS(GPMC_CS_CONFIG3, 24, 26,
				"adv-aad-mux-rd-off-ns");
		GPMC_GET_TICKS(GPMC_CS_CONFIG3, 28, 30,
				"adv-aad-mux-wr-off-ns");
	}

	GPMC_GET_TICKS(GPMC_CS_CONFIG4,  0,  3, "oe-on-ns");
	GPMC_GET_TICKS(GPMC_CS_CONFIG4,  8, 12, "oe-off-ns");
	if (gpmc_capability & GPMC_HAS_MUX_AAD) {
		GPMC_GET_TICKS(GPMC_CS_CONFIG4,  4,  6, "oe-aad-mux-on-ns");
		GPMC_GET_TICKS(GPMC_CS_CONFIG4, 13, 15, "oe-aad-mux-off-ns");
	}
	GPMC_GET_TICKS(GPMC_CS_CONFIG4, 16, 19, "we-on-ns");
	GPMC_GET_TICKS(GPMC_CS_CONFIG4, 24, 28, "we-off-ns");

	GPMC_GET_TICKS(GPMC_CS_CONFIG5,  0,  4, "rd-cycle-ns");
	GPMC_GET_TICKS(GPMC_CS_CONFIG5,  8, 12, "wr-cycle-ns");
	GPMC_GET_TICKS(GPMC_CS_CONFIG5, 16, 20, "access-ns");

	GPMC_GET_TICKS(GPMC_CS_CONFIG5, 24, 27, "page-burst-access-ns");

	GPMC_GET_TICKS(GPMC_CS_CONFIG6, 0, 3, "bus-turnaround-ns");
	GPMC_GET_TICKS(GPMC_CS_CONFIG6, 8, 11, "cycle2cycle-delay-ns");

	GPMC_GET_TICKS_CD_MAX(GPMC_CS_CONFIG1, 18, 19,
			      GPMC_CONFIG1_WAITMONITORINGTIME_MAX,
			      "wait-monitoring-ns", GPMC_CD_CLK);
	GPMC_GET_TICKS_CD_MAX(GPMC_CS_CONFIG1, 25, 26,
			      GPMC_CONFIG1_CLKACTIVATIONTIME_MAX,
			      "clk-activation-ns", GPMC_CD_FCLK);

	GPMC_GET_TICKS(GPMC_CS_CONFIG6, 16, 19, "wr-data-mux-bus-ns");
	GPMC_GET_TICKS(GPMC_CS_CONFIG6, 24, 28, "wr-access-ns");
}
#else
static inline void gpmc_cs_show_timings(int cs, const char *desc)
{
}
#endif

/**
 * set_gpmc_timing_reg - set a single timing parameter for Chip Select Region.
 * Caller is expected to have initialized CONFIG1 GPMCFCLKDIVIDER
 * prior to calling this function with @cd equal to GPMC_CD_CLK.
 *
 * @cs:      Chip Select Region.
 * @reg:     GPMC_CS_CONFIGn register offset.
 * @st_bit:  Start Bit
 * @end_bit: End Bit. Must be >= @st_bit.
 * @max:     Maximum parameter value.
 *           If 0, maximum is as high as @st_bit and @end_bit allow.
 * @time:    Timing parameter in ns.
 * @cd:      Timing parameter clock domain.
 * @name:    Timing parameter name.
 * @return:  0 on success, -1 on error.
 */
static int set_gpmc_timing_reg(int cs, int reg, int st_bit, int end_bit, int max,
			       int time, enum gpmc_clk_domain cd, const char *name)
{
	u32 l;
	int ticks, mask, nr_bits;

	if (time == 0)
		ticks = 0;
	else
		ticks = gpmc_ns_to_clk_ticks(time, cs, cd);
	nr_bits = end_bit - st_bit + 1;
	mask = (1 << nr_bits) - 1;

	if (!max)
		max = mask;

	if (ticks > max) {
		pr_err("%s: GPMC CS%d: %s %d ns, %d ticks > %d ticks\n",
		       __func__, cs, name, time, ticks, max);

		return -1;
	}

	l = gpmc_cs_read_reg(cs, reg);
#ifdef CONFIG_OMAP_GPMC_DEBUG
	pr_info("GPMC CS%d: %-17s: %3d ticks, %3lu ns (was %3i ticks) %3d ns\n",
		cs, name, ticks, gpmc_get_clk_period(cs, cd) * 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;
}

/**
 * gpmc_calc_waitmonitoring_divider - calculate proper GPMCFCLKDIVIDER based on WAITMONITORINGTIME
 * WAITMONITORINGTIME will be _at least_ as long as desired, i.e.
 * read  --> don't sample bus too early
 * write --> data is longer on bus
 *
 * Formula:
 * gpmc_clk_div + 1 = ceil(ceil(waitmonitoringtime_ns / gpmc_fclk_ns)
 *                    / waitmonitoring_ticks)
 * WAITMONITORINGTIME resulting in 0 or 1 tick with div = 1 are caught by
 * div <= 0 check.
 *
 * @wait_monitoring: WAITMONITORINGTIME in ns.
 * @return:          -1 on failure to scale, else proper divider > 0.
 */
static int gpmc_calc_waitmonitoring_divider(unsigned int wait_monitoring)
{
	int div = gpmc_ns_to_ticks(wait_monitoring);

	div += GPMC_CONFIG1_WAITMONITORINGTIME_MAX - 1;
	div /= GPMC_CONFIG1_WAITMONITORINGTIME_MAX;

	if (div > 4)
		return -1;
	if (div <= 0)
		div = 1;

	return div;
}

/**
 * gpmc_calc_divider - calculate GPMC_FCLK divider for sync_clk GPMC_CLK period.
 * @sync_clk: GPMC_CLK period in ps.
 * @return:   Returns at least 1 if GPMC_FCLK can be divided to GPMC_CLK.
 *            Else, returns -1.
 */
int gpmc_calc_divider(unsigned int sync_clk)
{
	int div = gpmc_ps_to_ticks(sync_clk);

	if (div > 4)
		return -1;
	if (div <= 0)
		div = 1;

	return div;
}

/**
 * gpmc_cs_set_timings - program timing parameters for Chip Select Region.
 * @cs:     Chip Select Region.
 * @t:      GPMC timing parameters.
 * @s:      GPMC timing settings.
 * @return: 0 on success, -1 on error.
 */
int gpmc_cs_set_timings(int cs, const struct gpmc_timings *t,
			const struct gpmc_settings *s)
{
	int div, ret;
	u32 l;

	div = gpmc_calc_divider(t->sync_clk);
	if (div < 0)
		return -EINVAL;

	/*
	 * See if we need to change the divider for waitmonitoringtime.
	 *
	 * Calculate GPMCFCLKDIVIDER independent of gpmc,sync-clk-ps in DT for
	 * pure asynchronous accesses, i.e. both read and write asynchronous.
	 * However, only do so if WAITMONITORINGTIME is actually used, i.e.
	 * either WAITREADMONITORING or WAITWRITEMONITORING is set.
	 *
	 * This statement must not change div to scale async WAITMONITORINGTIME
	 * to protect mixed synchronous and asynchronous accesses.
	 *
	 * We raise an error later if WAITMONITORINGTIME does not fit.
	 */
	if (!s->sync_read && !s->sync_write &&
	    (s->wait_on_read || s->wait_on_write)
	   ) {
		div = gpmc_calc_waitmonitoring_divider(t->wait_monitoring);
		if (div < 0) {
			pr_err("%s: waitmonitoringtime %3d ns too large for greatest gpmcfclkdivider.\n",
			       __func__,
			       t->wait_monitoring
			       );
			return -ENXIO;
		}
	}

	ret = 0;
	ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG2, 0, 3, 0, t->cs_on,
				   GPMC_CD_FCLK, "cs_on");
	ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG2, 8, 12, 0, t->cs_rd_off,
				   GPMC_CD_FCLK, "cs_rd_off");
	ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG2, 16, 20, 0, t->cs_wr_off,
				   GPMC_CD_FCLK, "cs_wr_off");
	if (ret)
		return -ENXIO;

	ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG3, 0, 3, 0, t->adv_on,
				   GPMC_CD_FCLK, "adv_on");
	ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG3, 8, 12, 0, t->adv_rd_off,
				   GPMC_CD_FCLK, "adv_rd_off");
	ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG3, 16, 20, 0, t->adv_wr_off,
				   GPMC_CD_FCLK, "adv_wr_off");
	if (ret)
		return -ENXIO;

	if (gpmc_capability & GPMC_HAS_MUX_AAD) {
		ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG3, 4, 6, 0,
					   t->adv_aad_mux_on, GPMC_CD_FCLK,
					   "adv_aad_mux_on");
		ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG3, 24, 26, 0,
					   t->adv_aad_mux_rd_off, GPMC_CD_FCLK,
					   "adv_aad_mux_rd_off");
		ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG3, 28, 30, 0,
					   t->adv_aad_mux_wr_off, GPMC_CD_FCLK,
					   "adv_aad_mux_wr_off");
		if (ret)
			return -ENXIO;
	}

	ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG4, 0, 3, 0, t->oe_on,
				   GPMC_CD_FCLK, "oe_on");
	ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG4, 8, 12, 0, t->oe_off,
				   GPMC_CD_FCLK, "oe_off");
	if (gpmc_capability & GPMC_HAS_MUX_AAD) {
		ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG4, 4, 6, 0,
					   t->oe_aad_mux_on, GPMC_CD_FCLK,
					   "oe_aad_mux_on");
		ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG4, 13, 15, 0,
					   t->oe_aad_mux_off, GPMC_CD_FCLK,
					   "oe_aad_mux_off");
	}
	ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG4, 16, 19, 0, t->we_on,
				   GPMC_CD_FCLK, "we_on");
	ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG4, 24, 28, 0, t->we_off,
				   GPMC_CD_FCLK, "we_off");
	if (ret)
		return -ENXIO;

	ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG5, 0, 4, 0, t->rd_cycle,
				   GPMC_CD_FCLK, "rd_cycle");
	ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG5, 8, 12, 0, t->wr_cycle,
				   GPMC_CD_FCLK, "wr_cycle");
	ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG5, 16, 20, 0, t->access,
				   GPMC_CD_FCLK, "access");
	ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG5, 24, 27, 0,
				   t->page_burst_access, GPMC_CD_FCLK,
				   "page_burst_access");
	if (ret)
		return -ENXIO;

	ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG6, 0, 3, 0,
				   t->bus_turnaround, GPMC_CD_FCLK,
				   "bus_turnaround");
	ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG6, 8, 11, 0,
				   t->cycle2cycle_delay, GPMC_CD_FCLK,
				   "cycle2cycle_delay");
	if (ret)
		return -ENXIO;

	if (gpmc_capability & GPMC_HAS_WR_DATA_MUX_BUS) {
		ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG6, 16, 19, 0,
					   t->wr_data_mux_bus, GPMC_CD_FCLK,
					   "wr_data_mux_bus");
		if (ret)
			return -ENXIO;
	}
	if (gpmc_capability & GPMC_HAS_WR_ACCESS) {
		ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG6, 24, 28, 0,
					   t->wr_access, GPMC_CD_FCLK,
					   "wr_access");
		if (ret)
			return -ENXIO;
	}

	l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG1);
	l &= ~0x03;
	l |= (div - 1);
	gpmc_cs_write_reg(cs, GPMC_CS_CONFIG1, l);

	ret = 0;
	ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG1, 18, 19,
				   GPMC_CONFIG1_WAITMONITORINGTIME_MAX,
				   t->wait_monitoring, GPMC_CD_CLK,
				   "wait_monitoring");
	ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG1, 25, 26,
				   GPMC_CONFIG1_CLKACTIVATIONTIME_MAX,
				   t->clk_activation, GPMC_CD_FCLK,
				   "clk_activation");
	if (ret)
		return -ENXIO;

#ifdef CONFIG_OMAP_GPMC_DEBUG
	pr_info("GPMC CS%d CLK period is %lu ns (div %d)\n",
			cs, (div * gpmc_get_fclk_period()) / 1000, div);
#endif

	gpmc_cs_bool_timings(cs, &t->bool_timings);
	gpmc_cs_show_timings(cs, "after gpmc_cs_set_timings");

	return 0;
}

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

	/*
	 * Ensure that base address is aligned on a
	 * boundary equal to or greater than size.
	 */
	if (base & (size - 1))
		return -EINVAL;

	base >>= GPMC_CHUNK_SHIFT;
	mask = (1 << GPMC_SECTION_SHIFT) - size;
	mask >>= GPMC_CHUNK_SHIFT;
	mask <<= GPMC_CONFIG7_MASKADDRESS_OFFSET;

	l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG7);
	l &= ~GPMC_CONFIG7_MASK;
	l |= base & GPMC_CONFIG7_BASEADDRESS_MASK;
	l |= mask & GPMC_CONFIG7_MASKADDRESS_MASK;
	l |= GPMC_CONFIG7_CSVALID;
	gpmc_cs_write_reg(cs, GPMC_CS_CONFIG7, l);

	return 0;
}

static void gpmc_cs_enable_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_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)
{
	struct gpmc_cs_data *gpmc = &gpmc_cs[cs];

	gpmc->flags |= GPMC_CS_RESERVED;
}

static bool gpmc_cs_reserved(int cs)
{
	struct gpmc_cs_data *gpmc = &gpmc_cs[cs];

	return gpmc->flags & GPMC_CS_RESERVED;
}

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 gpmc_cs_data *gpmc = &gpmc_cs[cs];
	struct resource *res = &gpmc->mem;
	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 gpmc_cs_data *gpmc = &gpmc_cs[cs];
	struct resource *res = &gpmc->mem;
	int r;

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

	return r;
}

int gpmc_cs_request(int cs, unsigned long size, unsigned long *base)
{
	struct gpmc_cs_data *gpmc = &gpmc_cs[cs];
	struct resource *res = &gpmc->mem;
	int r = -1;

	if (cs >= gpmc_cs_num) {
		pr_err("%s: requested chip-select is disabled\n", __func__);
		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;

	/* Disable CS while changing base address and size mask */
	gpmc_cs_disable_mem(cs);

	r = gpmc_cs_set_memconf(cs, res->start, resource_size(res));
	if (r < 0) {
		release_resource(res);
		goto out;
	}

	/* Enable CS */
	gpmc_cs_enable_mem(cs);
	*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)
{
	struct gpmc_cs_data *gpmc;
	struct resource *res;

	spin_lock(&gpmc_mem_lock);
	if (cs >= gpmc_cs_num || cs < 0 || !gpmc_cs_reserved(cs)) {
		WARN(1, "Trying to free non-reserved GPMC CS%d\n", cs);
		spin_unlock(&gpmc_mem_lock);
		return;
	}
	gpmc = &gpmc_cs[cs];
	res = &gpmc->mem;

	gpmc_cs_disable_mem(cs);
	if (res->flags)
		release_resource(res);
	gpmc_cs_set_reserved(cs, 0);
	spin_unlock(&gpmc_mem_lock);
}
EXPORT_SYMBOL(gpmc_cs_free);

static bool gpmc_is_valid_waitpin(u32 waitpin)
{
	return waitpin < gpmc_nr_waitpins;
}

static int gpmc_alloc_waitpin(struct gpmc_device *gpmc,
			      struct gpmc_settings *p)
{
	int ret;
	struct gpmc_waitpin *waitpin;
	struct gpio_desc *waitpin_desc;

	if (!gpmc_is_valid_waitpin(p->wait_pin))
		return -EINVAL;

	waitpin = &gpmc->waitpins[p->wait_pin];

	if (!waitpin->desc) {
		/* Reserve the GPIO for wait pin usage.
		 * GPIO polarity doesn't matter here. Wait pin polarity
		 * is set in GPMC_CONFIG register.
		 */
		waitpin_desc = gpiochip_request_own_desc(&gpmc->gpio_chip,
							 p->wait_pin, "WAITPIN",
							 GPIO_ACTIVE_HIGH,
							 GPIOD_IN);

		ret = PTR_ERR(waitpin_desc);
		if (IS_ERR(waitpin_desc) && ret != -EBUSY)
			return ret;

		/* New wait pin */
		waitpin->desc = waitpin_desc;
		waitpin->pin = p->wait_pin;
		waitpin->polarity = p->wait_pin_polarity;
	} else {
		/* Shared wait pin */
		if (p->wait_pin_polarity != waitpin->polarity ||
		    p->wait_pin != waitpin->pin) {
			dev_err(gpmc->dev,
				"shared-wait-pin: invalid configuration\n");
			return -EINVAL;
		}
		dev_info(gpmc->dev, "shared wait-pin: %d\n", waitpin->pin);
	}

	return 0;
}

static void gpmc_free_waitpin(struct gpmc_device *gpmc,
			      int wait_pin)
{
	if (gpmc_is_valid_waitpin(wait_pin))
		gpiochip_free_own_desc(gpmc->waitpins[wait_pin].desc);
}

/**
 * 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_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);

static bool gpmc_nand_writebuffer_empty(void)
{
	if (gpmc_read_reg(GPMC_STATUS) & GPMC_STATUS_EMPTYWRITEBUFFERSTATUS)
		return true;

	return false;
}

static struct gpmc_nand_ops nand_ops = {
	.nand_writebuffer_empty = gpmc_nand_writebuffer_empty,
};

/**
 * gpmc_omap_get_nand_ops - Get the GPMC NAND interface
 * @reg: the GPMC NAND register map exclusive for NAND use.
 * @cs: GPMC chip select number on which the NAND sits. The
 *      register map returned will be specific to this chip select.
 *
 * Returns NULL on error e.g. invalid cs.
 */
struct gpmc_nand_ops *gpmc_omap_get_nand_ops(struct gpmc_nand_regs *reg, int cs)
{
	int i;

	if (cs >= gpmc_cs_num)
		return NULL;

	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;
		reg->gpmc_bch_result4[i] = gpmc_base + GPMC_ECC_BCH_RESULT_4 +
					   i * GPMC_BCH_SIZE;
		reg->gpmc_bch_result5[i] = gpmc_base + GPMC_ECC_BCH_RESULT_5 +
					   i * GPMC_BCH_SIZE;
		reg->gpmc_bch_result6[i] = gpmc_base + GPMC_ECC_BCH_RESULT_6 +
					   i * GPMC_BCH_SIZE;
	}

	return &nand_ops;
}
EXPORT_SYMBOL_GPL(gpmc_omap_get_nand_ops);

static void gpmc_omap_onenand_calc_sync_timings(struct gpmc_timings *t,
						struct gpmc_settings *s,
						int freq, int latency)
{
	struct gpmc_device_timings dev_t;
	const int t_cer  = 15;
	const int t_avdp = 12;
	const int t_cez  = 20; /* max of t_cez, t_oez */
	const int t_wpl  = 40;
	const int t_wph  = 30;
	int min_gpmc_clk_period, t_ces, t_avds, t_avdh, t_ach, t_aavdh, t_rdyo;

	switch (freq) {
	case 104:
		min_gpmc_clk_period = 9600; /* 104 MHz */
		t_ces   = 3;
		t_avds  = 4;
		t_avdh  = 2;
		t_ach   = 3;
		t_aavdh = 6;
		t_rdyo  = 6;
		break;
	case 83:
		min_gpmc_clk_period = 12000; /* 83 MHz */
		t_ces   = 5;
		t_avds  = 4;
		t_avdh  = 2;
		t_ach   = 6;
		t_aavdh = 6;
		t_rdyo  = 9;
		break;
	case 66:
		min_gpmc_clk_period = 15000; /* 66 MHz */
		t_ces   = 6;
		t_avds  = 5;
		t_avdh  = 2;
		t_ach   = 6;
		t_aavdh = 6;
		t_rdyo  = 11;
		break;
	default:
		min_gpmc_clk_period = 18500; /* 54 MHz */
		t_ces   = 7;
		t_avds  = 7;
		t_avdh  = 7;
		t_ach   = 9;
		t_aavdh = 7;
		t_rdyo  = 15;
		break;
	}

	/* Set synchronous read timings */
	memset(&dev_t, 0, sizeof(dev_t));

	if (!s->sync_write) {
		dev_t.t_avdp_w = max(t_avdp, t_cer) * 1000;
		dev_t.t_wpl = t_wpl * 1000;
		dev_t.t_wph = t_wph * 1000;
		dev_t.t_aavdh = t_aavdh * 1000;
	}
	dev_t.ce_xdelay = true;
	dev_t.avd_xdelay = true;
	dev_t.oe_xdelay = true;
	dev_t.we_xdelay = true;
	dev_t.clk = min_gpmc_clk_period;
	dev_t.t_bacc = dev_t.clk;
	dev_t.t_ces = t_ces * 1000;
	dev_t.t_avds = t_avds * 1000;
	dev_t.t_avdh = t_avdh * 1000;
	dev_t.t_ach = t_ach * 1000;
	dev_t.cyc_iaa = (latency + 1);
	dev_t.t_cez_r = t_cez * 1000;
	dev_t.t_cez_w = dev_t.t_cez_r;
	dev_t.cyc_aavdh_oe = 1;
	dev_t.t_rdyo = t_rdyo * 1000 + min_gpmc_clk_period;

	gpmc_calc_timings(t, s, &dev_t);
}

int gpmc_omap_onenand_set_timings(struct device *dev, int cs, int freq,
				  int latency,
				  struct gpmc_onenand_info *info)
{
	int ret;
	struct gpmc_timings gpmc_t;
	struct gpmc_settings gpmc_s;

	gpmc_read_settings_dt(dev->of_node, &gpmc_s);

	info->sync_read = gpmc_s.sync_read;
	info->sync_write = gpmc_s.sync_write;
	info->burst_len = gpmc_s.burst_len;

	if (!gpmc_s.sync_read && !gpmc_s.sync_write)
		return 0;

	gpmc_omap_onenand_calc_sync_timings(&gpmc_t, &gpmc_s, freq, latency);

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

	return gpmc_cs_set_timings(cs, &gpmc_t, &gpmc_s);
}
EXPORT_SYMBOL_GPL(gpmc_omap_onenand_set_timings);

int gpmc_get_client_irq(unsigned int irq_config)
{
	if (!gpmc_irq_domain) {
		pr_warn("%s called before GPMC IRQ domain available\n",
			__func__);
		return 0;
	}

	/* we restrict this to NAND IRQs only */
	if (irq_config >= GPMC_NR_NAND_IRQS)
		return 0;

	return irq_create_mapping(gpmc_irq_domain, irq_config);
}

static int gpmc_irq_endis(unsigned long hwirq, bool endis)
{
	u32 regval;

	/* bits GPMC_NR_NAND_IRQS to 8 are reserved */
	if (hwirq >= GPMC_NR_NAND_IRQS)
		hwirq += 8 - GPMC_NR_NAND_IRQS;

	regval = gpmc_read_reg(GPMC_IRQENABLE);
	if (endis)
		regval |= BIT(hwirq);
	else
		regval &= ~BIT(hwirq);
	gpmc_write_reg(GPMC_IRQENABLE, regval);

	return 0;
}

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

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

static void gpmc_irq_mask(struct irq_data *d)
{
	gpmc_irq_endis(d->hwirq, false);
}

static void gpmc_irq_unmask(struct irq_data *d)
{
	gpmc_irq_endis(d->hwirq, true);
}

static void gpmc_irq_edge_config(unsigned long hwirq, bool rising_edge)
{
	u32 regval;

	/* NAND IRQs polarity is not configurable */
	if (hwirq < GPMC_NR_NAND_IRQS)
		return;

	/* WAITPIN starts at BIT 8 */
	hwirq += 8 - GPMC_NR_NAND_IRQS;

	regval = gpmc_read_reg(GPMC_CONFIG);
	if (rising_edge)
		regval &= ~BIT(hwirq);
	else
		regval |= BIT(hwirq);

	gpmc_write_reg(GPMC_CONFIG, regval);
}

static void gpmc_irq_ack(struct irq_data *d)
{
	unsigned int hwirq = d->hwirq;

	/* skip reserved bits */
	if (hwirq >= GPMC_NR_NAND_IRQS)
		hwirq += 8 - GPMC_NR_NAND_IRQS;

	/* Setting bit to 1 clears (or Acks) the interrupt */
	gpmc_write_reg(GPMC_IRQSTATUS, BIT(hwirq));
}

static int gpmc_irq_set_type(struct irq_data *d, unsigned int trigger)
{
	/* can't set type for NAND IRQs */
	if (d->hwirq < GPMC_NR_NAND_IRQS)
		return -EINVAL;

	/* We can support either rising or falling edge at a time */
	if (trigger == IRQ_TYPE_EDGE_FALLING)
		gpmc_irq_edge_config(d->hwirq, false);
	else if (trigger == IRQ_TYPE_EDGE_RISING)
		gpmc_irq_edge_config(d->hwirq, true);
	else
		return -EINVAL;

	return 0;
}

static int gpmc_irq_map(struct irq_domain *d, unsigned int virq,
			irq_hw_number_t hw)
{
	struct gpmc_device *gpmc = d->host_data;

	irq_set_chip_data(virq, gpmc);
	if (hw < GPMC_NR_NAND_IRQS) {
		irq_modify_status(virq, IRQ_NOREQUEST, IRQ_NOAUTOEN);
		irq_set_chip_and_handler(virq, &gpmc->irq_chip,
					 handle_simple_irq);
	} else {
		irq_set_chip_and_handler(virq, &gpmc->irq_chip,
					 handle_edge_irq);
	}

	return 0;
}

static const struct irq_domain_ops gpmc_irq_domain_ops = {
	.map    = gpmc_irq_map,
	.xlate  = irq_domain_xlate_twocell,
};

static irqreturn_t gpmc_handle_irq(int irq, void *data)
{
	int hwirq, virq;
	u32 regval, regvalx;
	struct gpmc_device *gpmc = data;

	regval = gpmc_read_reg(GPMC_IRQSTATUS);
	regvalx = regval;

	if (!regval)
		return IRQ_NONE;

	for (hwirq = 0; hwirq < gpmc->nirqs; hwirq++) {
		/* skip reserved status bits */
		if (hwirq == GPMC_NR_NAND_IRQS)
			regvalx >>= 8 - GPMC_NR_NAND_IRQS;

		if (regvalx & BIT(hwirq)) {
			virq = irq_find_mapping(gpmc_irq_domain, hwirq);
			if (!virq) {
				dev_warn(gpmc->dev,
					 "spurious irq detected hwirq %d, virq %d\n",
					 hwirq, virq);
			}

			generic_handle_irq(virq);
		}
	}

	gpmc_write_reg(GPMC_IRQSTATUS, regval);

	return IRQ_HANDLED;
}

static int gpmc_setup_irq(struct gpmc_device *gpmc)
{
	u32 regval;
	int rc;

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

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

	gpmc->irq_chip.name = "gpmc";
	gpmc->irq_chip.irq_enable = gpmc_irq_enable;
	gpmc->irq_chip.irq_disable = gpmc_irq_disable;
	gpmc->irq_chip.irq_ack = gpmc_irq_ack;
	gpmc->irq_chip.irq_mask = gpmc_irq_mask;
	gpmc->irq_chip.irq_unmask = gpmc_irq_unmask;
	gpmc->irq_chip.irq_set_type = gpmc_irq_set_type;

	gpmc_irq_domain = irq_domain_add_linear(gpmc->dev->of_node,
						gpmc->nirqs,
						&gpmc_irq_domain_ops,
						gpmc);
	if (!gpmc_irq_domain) {
		dev_err(gpmc->dev, "IRQ domain add failed\n");
		return -ENODEV;
	}

	rc = request_irq(gpmc->irq, gpmc_handle_irq, 0, "gpmc", gpmc);
	if (rc) {
		dev_err(gpmc->dev, "failed to request irq %d: %d\n",
			gpmc->irq, rc);
		irq_domain_remove(gpmc_irq_domain);
		gpmc_irq_domain = NULL;
	}

	return rc;
}

static int gpmc_free_irq(struct gpmc_device *gpmc)
{
	int hwirq;

	free_irq(gpmc->irq, gpmc);

	for (hwirq = 0; hwirq < gpmc->nirqs; hwirq++)
		irq_dispose_mapping(irq_find_mapping(gpmc_irq_domain, hwirq));

	irq_domain_remove(gpmc_irq_domain);
	gpmc_irq_domain = NULL;

	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 void gpmc_mem_init(struct gpmc_device *gpmc)
{
	int cs;

	if (!gpmc->data) {
		/* All legacy devices have same data IO window */
		gpmc_mem_root.start = GPMC_MEM_START;
		gpmc_mem_root.end = GPMC_MEM_END;
	} else {
		gpmc_mem_root.start = gpmc->data->start;
		gpmc_mem_root.end = gpmc->data->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)) {
			pr_warn("%s: disabling cs %d mapped at 0x%x-0x%x\n",
				__func__, cs, base, base + size);
			gpmc_cs_disable_mem(cs);
		}
	}
}

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_pin != GPMC_WAITPIN_INVALID &&
	    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);

	if (p->wait_pin_polarity != GPMC_WAITPINPOLARITY_INVALID) {
		config1 = gpmc_read_reg(GPMC_CONFIG);

		if (p->wait_pin_polarity == GPMC_WAITPINPOLARITY_ACTIVE_LOW)
			config1 &= ~GPMC_CONFIG_WAITPINPOLARITY(p->wait_pin);
		else if (p->wait_pin_polarity == GPMC_WAITPINPOLARITY_ACTIVE_HIGH)
			config1 |= GPMC_CONFIG_WAITPINPOLARITY(p->wait_pin);

		gpmc_write_reg(GPMC_CONFIG, config1);
	}

	return 0;
}

#ifdef CONFIG_OF
static void gpmc_cs_set_name(int cs, const char *name)
{
	struct gpmc_cs_data *gpmc = &gpmc_cs[cs];

	gpmc->name = name;
}

static const char *gpmc_cs_get_name(int cs)
{
	struct gpmc_cs_data *gpmc = &gpmc_cs[cs];

	return gpmc->name;
}

/**
 * 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) {
		pr_err("%s: requested chip-select is disabled\n", __func__);
		return -ENODEV;
	}

	/*
	 * Make sure we ignore any device offsets from the GPMC partition
	 * allocated for the chip select and that the new base confirms
	 * to the GPMC 16MB minimum granularity.
	 */
	base &= ~(SZ_16M - 1);

	gpmc_cs_get_memconf(cs, &old_base, &size);
	if (base == old_base)
		return 0;

	ret = gpmc_cs_delete_mem(cs);
	if (ret < 0)
		return ret;

	ret = gpmc_cs_insert_mem(cs, base, size);
	if (ret < 0)
		return ret;

	ret = gpmc_cs_set_memconf(cs, base, size);

	return ret;
}

/**
 * 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");
	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__);
	}

	p->wait_pin = GPMC_WAITPIN_INVALID;
	p->wait_pin_polarity = GPMC_WAITPINPOLARITY_INVALID;

	if (!of_property_read_u32(np, "gpmc,wait-pin", &p->wait_pin)) {
		if (!gpmc_is_valid_waitpin(p->wait_pin)) {
			pr_err("%s: Invalid wait-pin (%d)\n", __func__, p->wait_pin);
			p->wait_pin = GPMC_WAITPIN_INVALID;
		}

		if (!of_property_read_u32(np, "ti,wait-pin-polarity",
					  &p->wait_pin_polarity)) {
			if (p->wait_pin_polarity != GPMC_WAITPINPOLARITY_ACTIVE_HIGH &&
			    p->wait_pin_polarity != GPMC_WAITPINPOLARITY_ACTIVE_LOW) {
				pr_err("%s: Invalid wait-pin-polarity (%d)\n",
				       __func__, p->wait_pin_polarity);
				p->wait_pin_polarity = GPMC_WAITPINPOLARITY_INVALID;
				}
		}

		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_debug("%s: rd/wr 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);
	of_property_read_u32(np, "gpmc,adv-aad-mux-on-ns",
			     &gpmc_t->adv_aad_mux_on);
	of_property_read_u32(np, "gpmc,adv-aad-mux-rd-off-ns",
			     &gpmc_t->adv_aad_mux_rd_off);
	of_property_read_u32(np, "gpmc,adv-aad-mux-wr-off-ns",
			     &gpmc_t->adv_aad_mux_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);
	of_property_read_u32(np, "gpmc,oe-aad-mux-on-ns",
			     &gpmc_t->oe_aad_mux_on);
	of_property_read_u32(np, "gpmc,oe-aad-mux-off-ns",
			     &gpmc_t->oe_aad_mux_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");
}

/**
 * gpmc_probe_generic_child - configures the gpmc for a child device
 * @pdev:	pointer to gpmc platform device
 * @child:	pointer to device-tree node for child device
 *
 * Allocates and configures a GPMC chip-select for a child device.
 * Returns 0 on success and appropriate negative error code on failure.
 */
static int gpmc_probe_generic_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;
	const char *name;
	int ret, cs;
	u32 val;
	struct gpmc_device *gpmc = platform_get_drvdata(pdev);

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

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

	/*
	 * Check if we have multiple instances of the same device
	 * on a single chip select. If so, use the already initialized
	 * timings.
	 */
	name = gpmc_cs_get_name(cs);
	if (name && of_node_name_eq(child, name))
		goto no_timings;

	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;
	}
	gpmc_cs_set_name(cs, child->full_name);

	gpmc_read_settings_dt(child, &gpmc_s);
	gpmc_read_timings_dt(child, &gpmc_t);

	/*
	 * For some GPMC devices we still need to rely on the bootloader
	 * timings because the devices can be connected via FPGA.
	 * REVISIT: Add timing support from slls644g.pdf.
	 */
	if (!gpmc_t.cs_rd_off) {
		WARN(1, "enable GPMC debug to configure .dts timings for CS%i\n",
			cs);
		gpmc_cs_show_timings(cs,
				     "please add GPMC bootloader timings to .dts");
		goto no_timings;
	}

	/* CS must be disabled while making changes to gpmc configuration */
	gpmc_cs_disable_mem(cs);

	/*
	 * FIXME: gpmc_cs_request() will map the CS to an arbitrary
	 * 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 %pa\n",
			cs, &res.start);
		if (res.start < GPMC_MEM_START) {
			dev_info(&pdev->dev,
				 "GPMC CS %d start cannot be lesser than 0x%x\n",
				 cs, GPMC_MEM_START);
		} else if (res.end > GPMC_MEM_END) {
			dev_info(&pdev->dev,
				 "GPMC CS %d end cannot be greater than 0x%x\n",
				 cs, GPMC_MEM_END);
		}
		goto err;
	}

	if (of_node_name_eq(child, "nand")) {
		/* Warn about older DT blobs with no compatible property */
		if (!of_property_read_bool(child, "compatible")) {
			dev_warn(&pdev->dev,
				 "Incompatible NAND node: missing compatible");
			ret = -EINVAL;
			goto err;
		}
	}

	if (of_node_name_eq(child, "onenand")) {
		/* Warn about older DT blobs with no compatible property */
		if (!of_property_read_bool(child, "compatible")) {
			dev_warn(&pdev->dev,
				 "Incompatible OneNAND node: missing compatible");
			ret = -EINVAL;
			goto err;
		}
	}

	if (of_match_node(omap_nand_ids, child)) {
		/* NAND specific setup */
		val = 8;
		of_property_read_u32(child, "nand-bus-width", &val);
		switch (val) {
		case 8:
			gpmc_s.device_width = GPMC_DEVWIDTH_8BIT;
			break;
		case 16:
			gpmc_s.device_width = GPMC_DEVWIDTH_16BIT;
			break;
		default:
			dev_err(&pdev->dev, "%pOFn: invalid 'nand-bus-width'\n",
				child);
			ret = -EINVAL;
			goto err;
		}

		/* disable write protect */
		gpmc_configure(GPMC_CONFIG_WP, 0);
		gpmc_s.device_nand = true;
	} else {
		ret = of_property_read_u32(child, "bank-width",
					   &gpmc_s.device_width);
		if (ret < 0 && !gpmc_s.device_width) {
			dev_err(&pdev->dev,
				"%pOF has no 'gpmc,device-width' property\n",
				child);
			goto err;
		}
	}

	/* Reserve wait pin if it is required and valid */
	if (gpmc_s.wait_on_read || gpmc_s.wait_on_write) {
		ret = gpmc_alloc_waitpin(gpmc, &gpmc_s);
		if (ret < 0)
			goto err;
	}

	gpmc_cs_show_timings(cs, "before gpmc_cs_program_settings");

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

	ret = gpmc_cs_set_timings(cs, &gpmc_t, &gpmc_s);
	if (ret) {
		dev_err(&pdev->dev, "failed to set gpmc timings for: %pOFn\n",
			child);
		goto err_cs;
	}

	/* Clear limited address i.e. enable A26-A11 */
	val = gpmc_read_reg(GPMC_CONFIG);
	val &= ~GPMC_CONFIG_LIMITEDADDRESS;
	gpmc_write_reg(GPMC_CONFIG, val);

	/* Enable CS region */
	gpmc_cs_enable_mem(cs);

no_timings:

	/* create platform device, NULL on error or when disabled */
	if (!of_platform_device_create(child, NULL, &pdev->dev))
		goto err_child_fail;

	/* create children and other common bus children */
	if (of_platform_default_populate(child, NULL, &pdev->dev))
		goto err_child_fail;

	return 0;

err_child_fail:

	dev_err(&pdev->dev, "failed to create gpmc child %pOFn\n", child);
	ret = -ENODEV;

err_cs:
	gpmc_free_waitpin(gpmc, gpmc_s.wait_pin);
err:
	gpmc_cs_free(cs);

	return ret;
}

static const struct of_device_id gpmc_dt_ids[];

static int gpmc_probe_dt(struct platform_device *pdev)
{
	int ret;
	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-cs",
				   &gpmc_cs_num);
	if (ret < 0) {
		pr_err("%s: number of chip-selects not defined\n", __func__);
		return ret;
	} else if (gpmc_cs_num < 1) {
		pr_err("%s: all chip-selects are disabled\n", __func__);
		return -EINVAL;
	} else if (gpmc_cs_num > GPMC_CS_NUM) {
		pr_err("%s: number of supported chip-selects cannot be > %d\n",
					 __func__, GPMC_CS_NUM);
		return -EINVAL;
	}

	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;
	}

	return 0;
}

static void gpmc_probe_dt_children(struct platform_device *pdev)
{
	int ret;
	struct device_node *child;

	for_each_available_child_of_node(pdev->dev.of_node, child) {
		ret = gpmc_probe_generic_child(pdev, child);
		if (ret) {
			dev_err(&pdev->dev, "failed to probe DT child '%pOFn': %d\n",
				child, ret);
		}
	}
}
#else
void gpmc_read_settings_dt(struct device_node *np, struct gpmc_settings *p)
{
	memset(p, 0, sizeof(*p));
}
static int gpmc_probe_dt(struct platform_device *pdev)
{
	return 0;
}

static void gpmc_probe_dt_children(struct platform_device *pdev)
{
}
#endif /* CONFIG_OF */

static int gpmc_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
{
	return 1;	/* we're input only */
}

static int gpmc_gpio_direction_input(struct gpio_chip *chip,
				     unsigned int offset)
{
	return 0;	/* we're input only */
}

static int gpmc_gpio_direction_output(struct gpio_chip *chip,
				      unsigned int offset, int value)
{
	return -EINVAL;	/* we're input only */
}

static void gpmc_gpio_set(struct gpio_chip *chip, unsigned int offset,
			  int value)
{
}

static int gpmc_gpio_get(struct gpio_chip *chip, unsigned int offset)
{
	u32 reg;

	offset += 8;

	reg = gpmc_read_reg(GPMC_STATUS) & BIT(offset);

	return !!reg;
}

static int gpmc_gpio_init(struct gpmc_device *gpmc)
{
	int ret;

	gpmc->gpio_chip.parent = gpmc->dev;
	gpmc->gpio_chip.owner = THIS_MODULE;
	gpmc->gpio_chip.label = DEVICE_NAME;
	gpmc->gpio_chip.ngpio = gpmc_nr_waitpins;
	gpmc->gpio_chip.get_direction = gpmc_gpio_get_direction;
	gpmc->gpio_chip.direction_input = gpmc_gpio_direction_input;
	gpmc->gpio_chip.direction_output = gpmc_gpio_direction_output;
	gpmc->gpio_chip.set = gpmc_gpio_set;
	gpmc->gpio_chip.get = gpmc_gpio_get;
	gpmc->gpio_chip.base = -1;

	ret = devm_gpiochip_add_data(gpmc->dev, &gpmc->gpio_chip, NULL);
	if (ret < 0) {
		dev_err(gpmc->dev, "could not register gpio chip: %d\n", ret);
		return ret;
	}

	return 0;
}

static void omap3_gpmc_save_context(struct gpmc_device *gpmc)
{
	struct omap3_gpmc_regs *gpmc_context;
	int i;

	if (!gpmc || !gpmc_base)
		return;

	gpmc_context = &gpmc->context;

	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);
		}
	}
}

static void omap3_gpmc_restore_context(struct gpmc_device *gpmc)
{
	struct omap3_gpmc_regs *gpmc_context;
	int i;

	if (!gpmc || !gpmc_base)
		return;

	gpmc_context = &gpmc->context;

	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);
		} else {
			gpmc_cs_write_reg(i, GPMC_CS_CONFIG7, 0);
		}
	}
}

static int omap_gpmc_context_notifier(struct notifier_block *nb,
				      unsigned long cmd, void *v)
{
	struct gpmc_device *gpmc;

	gpmc = container_of(nb, struct gpmc_device, nb);
	if (gpmc->is_suspended || pm_runtime_suspended(gpmc->dev))
		return NOTIFY_OK;

	switch (cmd) {
	case CPU_CLUSTER_PM_ENTER:
		omap3_gpmc_save_context(gpmc);
		break;
	case CPU_CLUSTER_PM_ENTER_FAILED:	/* No need to restore context */
		break;
	case CPU_CLUSTER_PM_EXIT:
		omap3_gpmc_restore_context(gpmc);
		break;
	}

	return NOTIFY_OK;
}

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

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

	gpmc->dev = &pdev->dev;
	platform_set_drvdata(pdev, gpmc);

	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg");
	if (!res) {
		/* legacy DT */
		gpmc_base = devm_platform_ioremap_resource(pdev, 0);
		if (IS_ERR(gpmc_base))
			return PTR_ERR(gpmc_base);
	} else {
		gpmc_base = devm_ioremap_resource(&pdev->dev, res);
		if (IS_ERR(gpmc_base))
			return PTR_ERR(gpmc_base);

		res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "data");
		if (!res) {
			dev_err(&pdev->dev, "couldn't get data reg resource\n");
			return -ENOENT;
		}

		gpmc->data = res;
	}

	gpmc->irq = platform_get_irq(pdev, 0);
	if (gpmc->irq < 0)
		return gpmc->irq;

	gpmc_l3_clk = devm_clk_get(&pdev->dev, "fck");
	if (IS_ERR(gpmc_l3_clk)) {
		dev_err(&pdev->dev, "Failed to get GPMC fck\n");
		return PTR_ERR(gpmc_l3_clk);
	}

	if (!clk_get_rate(gpmc_l3_clk)) {
		dev_err(&pdev->dev, "Invalid GPMC fck clock rate\n");
		return -EINVAL;
	}

	if (pdev->dev.of_node) {
		rc = gpmc_probe_dt(pdev);
		if (rc)
			return rc;
	} else {
		gpmc_cs_num = GPMC_CS_NUM;
		gpmc_nr_waitpins = GPMC_NR_WAITPINS;
	}

	gpmc->waitpins = devm_kzalloc(&pdev->dev,
				      gpmc_nr_waitpins * sizeof(struct gpmc_waitpin),
				      GFP_KERNEL);
	if (!gpmc->waitpins)
		return -ENOMEM;

	for (i = 0; i < gpmc_nr_waitpins; i++)
		gpmc->waitpins[i].pin = GPMC_WAITPIN_INVALID;

	pm_runtime_enable(&pdev->dev);
	pm_runtime_get_sync(&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));

	gpmc_mem_init(gpmc);
	rc = gpmc_gpio_init(gpmc);
	if (rc)
		goto gpio_init_failed;

	gpmc->nirqs = GPMC_NR_NAND_IRQS + gpmc_nr_waitpins;
	rc = gpmc_setup_irq(gpmc);
	if (rc) {
		dev_err(gpmc->dev, "gpmc_setup_irq failed\n");
		goto gpio_init_failed;
	}

	gpmc_probe_dt_children(pdev);

	gpmc->nb.notifier_call = omap_gpmc_context_notifier;
	cpu_pm_register_notifier(&gpmc->nb);

	return 0;

gpio_init_failed:
	gpmc_mem_exit();
	pm_runtime_put_sync(&pdev->dev);
	pm_runtime_disable(&pdev->dev);

	return rc;
}

static int gpmc_remove(struct platform_device *pdev)
{
	int i;
	struct gpmc_device *gpmc = platform_get_drvdata(pdev);

	cpu_pm_unregister_notifier(&gpmc->nb);
	for (i = 0; i < gpmc_nr_waitpins; i++)
		gpmc_free_waitpin(gpmc, i);
	gpmc_free_irq(gpmc);
	gpmc_mem_exit();
	pm_runtime_put_sync(&pdev->dev);
	pm_runtime_disable(&pdev->dev);

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int gpmc_suspend(struct device *dev)
{
	struct gpmc_device *gpmc = dev_get_drvdata(dev);

	omap3_gpmc_save_context(gpmc);
	pm_runtime_put_sync(dev);
	gpmc->is_suspended = 1;

	return 0;
}

static int gpmc_resume(struct device *dev)
{
	struct gpmc_device *gpmc = dev_get_drvdata(dev);

	pm_runtime_get_sync(dev);
	omap3_gpmc_restore_context(gpmc);
	gpmc->is_suspended = 0;

	return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(gpmc_pm_ops, gpmc_suspend, gpmc_resume);

#ifdef CONFIG_OF
static const 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 */
	{ .compatible = "ti,am64-gpmc" },
	{ }
};
MODULE_DEVICE_TABLE(of, gpmc_dt_ids);
#endif

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

module_platform_driver(gpmc_driver);

MODULE_DESCRIPTION("Texas Instruments GPMC driver");
MODULE_LICENSE("GPL");