path: root/drivers/mtd/nand/atmel_nand.c

/*
 *  Copyright (C) 2003 Rick Bronson
 *
 *  Derived from drivers/mtd/nand/autcpu12.c
 *	 Copyright (c) 2001 Thomas Gleixner (gleixner@autronix.de)
 *
 *  Derived from drivers/mtd/spia.c
 *	 Copyright (C) 2000 Steven J. Hill (sjhill@cotw.com)
 *
 *
 *  Add Hardware ECC support for AT91SAM9260 / AT91SAM9263
 *     Richard Genoud (richard.genoud@gmail.com), Adeneo Copyright (C) 2007
 *
 *     Derived from Das U-Boot source code
 *     		(u-boot-1.1.5/board/atmel/at91sam9263ek/nand.c)
 *     (C) Copyright 2006 ATMEL Rousset, Lacressonniere Nicolas
 *
 *
 * 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.
 *
 */

#include <linux/slab.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/platform_device.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/partitions.h>

#include <linux/gpio.h>
#include <linux/io.h>

#include <mach/board.h>
#include <mach/cpu.h>

#ifdef CONFIG_MTD_NAND_ATMEL_ECC_HW
#define hard_ecc	1
#else
#define hard_ecc	0
#endif

#ifdef CONFIG_MTD_NAND_ATMEL_ECC_NONE
#define no_ecc		1
#else
#define no_ecc		0
#endif

static int use_dma = 1;
module_param(use_dma, int, 0);

static int on_flash_bbt = 0;
module_param(on_flash_bbt, int, 0);

/* Register access macros */
#define ecc_readl(add, reg)				\
	__raw_readl(add + ATMEL_ECC_##reg)
#define ecc_writel(add, reg, value)			\
	__raw_writel((value), add + ATMEL_ECC_##reg)

#include "atmel_nand_ecc.h"	/* Hardware ECC registers */

/* oob layout for large page size
 * bad block info is on bytes 0 and 1
 * the bytes have to be consecutives to avoid
 * several NAND_CMD_RNDOUT during read
 */
static struct nand_ecclayout atmel_oobinfo_large = {
	.eccbytes = 4,
	.eccpos = {60, 61, 62, 63},
	.oobfree = {
		{2, 58}
	},
};

/* oob layout for small page size
 * bad block info is on bytes 4 and 5
 * the bytes have to be consecutives to avoid
 * several NAND_CMD_RNDOUT during read
 */
static struct nand_ecclayout atmel_oobinfo_small = {
	.eccbytes = 4,
	.eccpos = {0, 1, 2, 3},
	.oobfree = {
		{6, 10}
	},
};

struct atmel_nand_host {
	struct nand_chip	nand_chip;
	struct mtd_info		mtd;
	void __iomem		*io_base;
	dma_addr_t		io_phys;
	struct atmel_nand_data	*board;
	struct device		*dev;
	void __iomem		*ecc;

	struct completion	comp;
	struct dma_chan		*dma_chan;
};

static int cpu_has_dma(void)
{
	return cpu_is_at91sam9rl() || cpu_is_at91sam9g45();
}

/*
 * Enable NAND.
 */
static void atmel_nand_enable(struct atmel_nand_host *host)
{
	if (host->board->enable_pin)
		gpio_set_value(host->board->enable_pin, 0);
}

/*
 * Disable NAND.
 */
static void atmel_nand_disable(struct atmel_nand_host *host)
{
	if (host->board->enable_pin)
		gpio_set_value(host->board->enable_pin, 1);
}

/*
 * Hardware specific access to control-lines
 */
static void atmel_nand_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
{
	struct nand_chip *nand_chip = mtd->priv;
	struct atmel_nand_host *host = nand_chip->priv;

	if (ctrl & NAND_CTRL_CHANGE) {
		if (ctrl & NAND_NCE)
			atmel_nand_enable(host);
		else
			atmel_nand_disable(host);
	}
	if (cmd == NAND_CMD_NONE)
		return;

	if (ctrl & NAND_CLE)
		writeb(cmd, host->io_base + (1 << host->board->cle));
	else
		writeb(cmd, host->io_base + (1 << host->board->ale));
}

/*
 * Read the Device Ready pin.
 */
static int atmel_nand_device_ready(struct mtd_info *mtd)
{
	struct nand_chip *nand_chip = mtd->priv;
	struct atmel_nand_host *host = nand_chip->priv;

	return gpio_get_value(host->board->rdy_pin) ^
                !!host->board->rdy_pin_active_low;
}

/*
 * Minimal-overhead PIO for data access.
 */
static void atmel_read_buf8(struct mtd_info *mtd, u8 *buf, int len)
{
	struct nand_chip	*nand_chip = mtd->priv;

	__raw_readsb(nand_chip->IO_ADDR_R, buf, len);
}

static void atmel_read_buf16(struct mtd_info *mtd, u8 *buf, int len)
{
	struct nand_chip	*nand_chip = mtd->priv;

	__raw_readsw(nand_chip->IO_ADDR_R, buf, len / 2);
}

static void atmel_write_buf8(struct mtd_info *mtd, const u8 *buf, int len)
{
	struct nand_chip	*nand_chip = mtd->priv;

	__raw_writesb(nand_chip->IO_ADDR_W, buf, len);
}

static void atmel_write_buf16(struct mtd_info *mtd, const u8 *buf, int len)
{
	struct nand_chip	*nand_chip = mtd->priv;

	__raw_writesw(nand_chip->IO_ADDR_W, buf, len / 2);
}

static void dma_complete_func(void *completion)
{
	complete(completion);
}

static int atmel_nand_dma_op(struct mtd_info *mtd, void *buf, int len,
			       int is_read)
{
	struct dma_device *dma_dev;
	enum dma_ctrl_flags flags;
	dma_addr_t dma_src_addr, dma_dst_addr, phys_addr;
	struct dma_async_tx_descriptor *tx = NULL;
	dma_cookie_t cookie;
	struct nand_chip *chip = mtd->priv;
	struct atmel_nand_host *host = chip->priv;
	void *p = buf;
	int err = -EIO;
	enum dma_data_direction dir = is_read ? DMA_FROM_DEVICE : DMA_TO_DEVICE;

	if (buf >= high_memory)
		goto err_buf;

	dma_dev = host->dma_chan->device;

	flags = DMA_CTRL_ACK | DMA_PREP_INTERRUPT | DMA_COMPL_SKIP_SRC_UNMAP |
		DMA_COMPL_SKIP_DEST_UNMAP;

	phys_addr = dma_map_single(dma_dev->dev, p, len, dir);
	if (dma_mapping_error(dma_dev->dev, phys_addr)) {
		dev_err(host->dev, "Failed to dma_map_single\n");