/*
 * 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/platform_data/mtd-nand-omap2.h>

#include <asm/mach-types.h>

#include "soc.h"
#include "common.h"
#include "omap_device.h"
#include "gpmc.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

/* 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);
static unsigned int gpmc_cs_map;	/* flag for cs which are initialized */
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);
}

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

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

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

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

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

	return rate;
}

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

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

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

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

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