/*
 *  drivers/mtd/nand/h1910.c
 *
 *  Copyright (C) 2003 Joshua Wise (joshua@joshuawise.com)
 *
 *  Derived from drivers/mtd/nand/edb7312.c
 *       Copyright (C) 2002 Marius Gröger (mag@sysgo.de)
 *       Copyright (c) 2001 Thomas Gleixner (gleixner@autronix.de)
 *
 * $Id: h1910.c,v 1.1 2004/11/03 00:04:44 joff Exp $
 *
 * 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.
 *
 *  Overview:
 *   This is a device driver for the NAND flash device found on the
 *   iPAQ h1910 board which utilizes the Samsung K9F2808 part. This is
 *   a 128Mibit (16MiB x 8 bits) NAND flash device.
 */

#include <linux/slab.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/partitions.h>
#include <asm/io.h>
#include <asm/arch/hardware.h> /* for CLPS7111_VIRT_BASE */
#include <asm/sizes.h>
#include <asm/arch/h1900-gpio.h>
#include <asm/arch/ipaq.h>

/*
 * MTD structure for EDB7312 board
 */
static struct mtd_info *h1910_nand_mtd = NULL;

/*
 * Module stuff
 */

#ifdef CONFIG_MTD_PARTITIONS
/*
 * Define static partitions for flash device
 */
static struct mtd_partition partition_info[] = {
	{ name: "h1910 NAND Flash",
		  offset: 0,
		  size: 16*1024*1024 }
};
#define NUM_PARTITIONS 1

#endif


/* 
 *	hardware specific access to control-lines
 */
static void h1910_hwcontrol(struct mtd_info *mtd, int cmd) 
{
	struct nand_chip* this = (struct nand_chip *) (mtd->priv);
	
	switch(cmd) {
		
	case NAND_CTL_SETCLE: 
		this->IO_ADDR_R |= (1 << 2);
		this->IO_ADDR_W |= (1 << 2);
		break;
	case NAND_CTL_CLRCLE: 
		this->IO_ADDR_R &= ~(1 << 2);
		this->IO_ADDR_W &= ~(1 << 2);
		break;
		
	case NAND_CTL_SETALE:
		this->IO_ADDR_R |= (1 << 3);
		this->IO_ADDR_W |= (1 << 3);
		break;
	case NAND_CTL_CLRALE:
		this->IO_ADDR_R &= ~(1 << 3);
		this->IO_ADDR_W &= ~(1 << 3);
		break;
		
	case NAND_CTL_SETNCE:
		break;
	case NAND_CTL_CLRNCE:
		break;
	}
}

/*
 *	read device ready pin
 */
#if 0
static int h1910_device_ready(struct mtd_info *mtd)
{
	return (GPLR(55) & GPIO_bit(55));
}
#endif

/*
 * Main initialization routine
 */
static int __init h1910_init (void)
{
	struct nand_chip *this;
	const char *part_type = 0;
	int mtd_parts_nb = 0;
	struct mtd_partition *mtd_parts = 0;
	void __iomem *nandaddr;
	
	if (!machine_is_h1900())
		return -ENODEV;
		
	nandaddr = (void __iomem *)__ioremap(0x08000000, 0x1000, 0, 1);
	if (!nandaddr) {
		printk("Failed to ioremap nand flash.\n");
		return -ENOMEM;
	}
	
	/* Allocate memory for MTD device structure and private data */
	h1910_nand_mtd = kmalloc(sizeof(struct mtd_info) + 
			     sizeof(struct nand_chip),
			     GFP_KERNEL);
	if (!h1910_nand_mtd) {
		printk("Unable to allocate h1910 NAND MTD device structure.\n");
		iounmap ((void *) nandaddr);
		return -ENOMEM;
	}
	
	/* Get pointer to private data */
	this = (struct nand_chip *) (&h1910_nand_mtd[1]);
	
	/* Initialize structures */
	memset((char *) h1910_nand_mtd, 0, sizeof(struct mtd_info));
	memset((char *) this, 0, sizeof(struct nand_chip));
	
	/* Link the private data with the MTD structure */
	h1910_nand_mtd->priv = this;
	
	/*
	 * Enable VPEN
	 */
	GPSR(37) = GPIO_bit(37);
	
	/* insert callbacks */
	this->IO_ADDR_R = nandaddr;
	this->IO_ADDR_W = nandaddr;
	this->hwcontrol = h1910_hwcontrol;
	this->dev_ready = NULL;	/* unknown whether that was correct or not so we will just do it like this */
	/* 15 us command delay time */
	this->chip_delay = 50;
	this->eccmode = NAND_ECC_SOFT;
	this->options = NAND_NO_AUTOINCR;
	
	/* Scan to find existence of the device */
	if (nand_scan (h1910_nand_mtd, 1)) {
		printk(KERN_NOTICE "No NAND device - returning -ENXIO\n");
		kfree (h1910_nand_mtd);
		iounmap ((void *) nandaddr);
		return -ENXIO;
	}
	
#ifdef CONFIG_MTD_CMDLINE_PARTS
	mtd_parts_nb = parse_cmdline_partitions(h1910_nand_mtd, &mtd_parts, 
						"h1910-nand");
	if (mtd_parts_nb > 0)
	  part_type = "command line";
	else
	  mtd_parts_nb = 0;
#endif
	if (mtd_parts_nb == 0)
	{
		mtd_parts = partition_info;
		mtd_parts_nb = NUM_PARTITIONS;
		part_type = "static";
	}
	
	/* Register the partitions */
	printk(KERN_NOTICE "Using %s partition definition\n", part_type);
	add_mtd_partitions(h1910_nand_mtd, mtd_parts, mtd_parts_nb);
	
	/* Return happy */
	return 0;
}
module_init(h1910_init);

/*
 * Clean up routine
 */
static void __exit h1910_cleanup (void)
{
	struct nand_chip *this = (struct nand_chip *) &h1910_nand_mtd[1];
	
	/* Release resources, unregister device */
	nand_release (h1910_nand_mtd);

	/* Release io resource */
	iounmap ((void *) this->IO_ADDR_W);

	/* Free the MTD device structure */
	kfree (h1910_nand_mtd);
}
module_exit(h1910_cleanup);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Joshua Wise <joshua at joshuawise dot com>");
MODULE_DESCRIPTION("NAND flash driver for iPAQ h1910");
