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Commit 54d33c4c authored by Mike Rapoport's avatar Mike Rapoport Committed by David Woodhouse
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[MTD] [NAND] CM-x270 MTD driver 



This patch provides MTD support for NAND flash devices on CM-x270 modules.

Signed-off-by: default avatarMike Rapoport <mike@compulab.co.il>
Signed-off-by: default avatarDavid Woodhouse <dwmw2@infradead.org>
parent d1da4e50

drivers/mtd/nand/Kconfig

+5 −0
Original line number Diff line number Diff line
@@ -258,6 +258,11 @@ config MTD_NAND_AT91 
	  Enables support for NAND Flash / Smart Media Card interface

	  on Atmel AT91 processors.



config MTD_NAND_CM_X270

	tristate "Support for NAND Flash on CM-X270 modules"

	depends on MTD_NAND && MACH_ARMCORE





config MTD_NAND_NANDSIM

	tristate "Support for NAND Flash Simulator"

	depends on MTD_PARTITIONS

drivers/mtd/nand/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ obj-$(CONFIG_MTD_NAND_NANDSIM) += nandsim.o 
obj-$(CONFIG_MTD_NAND_CS553X)		+= cs553x_nand.o

obj-$(CONFIG_MTD_NAND_NDFC)		+= ndfc.o

obj-$(CONFIG_MTD_NAND_AT91)		+= at91_nand.o

obj-$(CONFIG_MTD_NAND_CM_X270)		+= cmx270_nand.o

obj-$(CONFIG_MTD_NAND_BASLER_EXCITE)	+= excite_nandflash.o



nand-objs := nand_base.o nand_bbt.o

drivers/mtd/nand/cmx270_nand.c

0 → 100644
+267 −0
Original line number Diff line number Diff line 
/*

 *  linux/drivers/mtd/nand/cmx270-nand.c

 *

 *  Copyright (C) 2006 Compulab, Ltd.

 *  Mike Rapoport <mike@compulab.co.il>

 *

 *  Derived from drivers/mtd/nand/h1910.c

 *       Copyright (C) 2002 Marius Gröger (mag@sysgo.de)

 *       Copyright (c) 2001 Thomas Gleixner (gleixner@autronix.de)

 *

 *

 * 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

 *   CM-X270 board.

 */



#include <linux/mtd/nand.h>

#include <linux/mtd/partitions.h>



#include <asm/io.h>

#include <asm/irq.h>



#include <asm/arch/hardware.h>

#include <asm/arch/pxa-regs.h>



#define GPIO_NAND_CS	(11)

#define GPIO_NAND_RB	(89)



/* This macro needed to ensure in-order operation of GPIO and local

 * bus. Without both asm command and dummy uncached read there're

 * states when NAND access is broken. I've looked for such macro(s) in

 * include/asm-arm but found nothing approptiate.

 * dmac_clean_range is close, but is makes cache invalidation

 * unnecessary here and it cannot be used in module

 */

#define DRAIN_WB() \

	do { \

		unsigned char dummy; \

		asm volatile ("mcr p15, 0, r0, c7, c10, 4":::"r0"); \

		dummy=*((unsigned char*)UNCACHED_ADDR); \

	} while(0)



/* MTD structure for CM-X270 board */

static struct mtd_info *cmx270_nand_mtd;



/* remaped IO address of the device */

static void __iomem *cmx270_nand_io;



/*

 * Define static partitions for flash device

 */

static struct mtd_partition partition_info[] = {

	[0] = {

		.name	= "cmx270-0",

		.offset	= 0,

		.size	= MTDPART_SIZ_FULL

	}

};

#define NUM_PARTITIONS (ARRAY_SIZE(partition_info))



const char *part_probes[] = { "cmdlinepart", NULL };



static u_char cmx270_read_byte(struct mtd_info *mtd)

{

	struct nand_chip *this = mtd->priv;



	return (readl(this->IO_ADDR_R) >> 16);

}



static void cmx270_write_buf(struct mtd_info *mtd, const u_char *buf, int len)

{

	int i;

	struct nand_chip *this = mtd->priv;



	for (i=0; i<len; i++)

		writel((*buf++ << 16), this->IO_ADDR_W);

}



static void cmx270_read_buf(struct mtd_info *mtd, u_char *buf, int len)

{

	int i;

	struct nand_chip *this = mtd->priv;



	for (i=0; i<len; i++)

		*buf++ = readl(this->IO_ADDR_R) >> 16;

}



static int cmx270_verify_buf(struct mtd_info *mtd, const u_char *buf, int len)

{

	int i;

	struct nand_chip *this = mtd->priv;



	for (i=0; i<len; i++)

		if (buf[i] != (u_char)(readl(this->IO_ADDR_R) >> 16))

			return -EFAULT;



	return 0;

}



static inline void nand_cs_on(void)

{

	GPCR(GPIO_NAND_CS) = GPIO_bit(GPIO_NAND_CS);

}



static void nand_cs_off(void)

{

	DRAIN_WB();



	GPSR(GPIO_NAND_CS) = GPIO_bit(GPIO_NAND_CS);

}



/*

 *	hardware specific access to control-lines

 */

static void cmx270_hwcontrol(struct mtd_info *mtd, int dat,

			     unsigned int ctrl)

{

	struct nand_chip* this = mtd->priv;

	unsigned int nandaddr = (unsigned int)this->IO_ADDR_W;



	DRAIN_WB();



	if (ctrl & NAND_CTRL_CHANGE) {

		if ( ctrl & NAND_ALE )

			nandaddr |=  (1 << 3);

		else

			nandaddr &= ~(1 << 3);

		if ( ctrl & NAND_CLE )

			nandaddr |=  (1 << 2);

		else

			nandaddr &= ~(1 << 2);

		if ( ctrl & NAND_NCE )

			nand_cs_on();

		else

			nand_cs_off();

	}



	DRAIN_WB();

	this->IO_ADDR_W = (void __iomem*)nandaddr;

	if (dat != NAND_CMD_NONE)

		writel((dat << 16), this->IO_ADDR_W);



	DRAIN_WB();

}



/*

 *	read device ready pin

 */

static int cmx270_device_ready(struct mtd_info *mtd)

{

	DRAIN_WB();



	return (GPLR(GPIO_NAND_RB) & GPIO_bit(GPIO_NAND_RB));

}



/*

 * Main initialization routine

 */

static int cmx270_init(void)

{

	struct nand_chip *this;

	const char *part_type;

	struct mtd_partition *mtd_parts;

	int mtd_parts_nb = 0;

	int ret;



	/* Allocate memory for MTD device structure and private data */

	cmx270_nand_mtd = kzalloc(sizeof(struct mtd_info) +

				  sizeof(struct nand_chip),

				  GFP_KERNEL);

	if (!cmx270_nand_mtd) {

		printk("Unable to allocate CM-X270 NAND MTD device structure.\n");

		return -ENOMEM;

	}



	cmx270_nand_io = ioremap(PXA_CS1_PHYS, 12);

	if (!cmx270_nand_io) {

		printk("Unable to ioremap NAND device\n");

		ret = -EINVAL;

		goto err1;

	}



	/* Get pointer to private data */

	this = (struct nand_chip *)(&cmx270_nand_mtd[1]);



	/* Link the private data with the MTD structure */

	cmx270_nand_mtd->owner = THIS_MODULE;

	cmx270_nand_mtd->priv = this;



	/* insert callbacks */

	this->IO_ADDR_R = cmx270_nand_io;

	this->IO_ADDR_W = cmx270_nand_io;

	this->cmd_ctrl = cmx270_hwcontrol;

	this->dev_ready = cmx270_device_ready;



	/* 15 us command delay time */

	this->chip_delay = 20;

	this->ecc.mode = NAND_ECC_SOFT;



	/* read/write functions */

	this->read_byte = cmx270_read_byte;

	this->read_buf = cmx270_read_buf;

	this->write_buf = cmx270_write_buf;

	this->verify_buf = cmx270_verify_buf;



	/* Scan to find existence of the device */

	if (nand_scan (cmx270_nand_mtd, 1)) {

		printk(KERN_NOTICE "No NAND device\n");

		ret = -ENXIO;

		goto err2;

	}



#ifdef CONFIG_MTD_CMDLINE_PARTS

	mtd_parts_nb = parse_mtd_partitions(cmx270_nand_mtd, part_probes,

					    &mtd_parts, 0);

	if (mtd_parts_nb > 0)

		part_type = "command line";

	else

		mtd_parts_nb = 0;

#endif

	if (!mtd_parts_nb) {

		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);

	ret = add_mtd_partitions(cmx270_nand_mtd, mtd_parts, mtd_parts_nb);

	if (ret)

		goto err2;



	/* Return happy */

	return 0;



err2:

	iounmap(cmx270_nand_io);

err1:

	kfree(cmx270_nand_mtd);



	return ret;



}

module_init(cmx270_init);



/*

 * Clean up routine

 */

static void cmx270_cleanup(void)

{

	/* Release resources, unregister device */

	nand_release(cmx270_nand_mtd);



	iounmap(cmx270_nand_io);



	/* Free the MTD device structure */

	kfree (cmx270_nand_mtd);

}

module_exit(cmx270_cleanup);



MODULE_LICENSE("GPL");

MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");

MODULE_DESCRIPTION("NAND flash driver for Compulab CM-X270 Module");