Commit 14f8351a authored by Josh Boyer's avatar Josh Boyer Committed by Thomas Gleixner
Browse files

[MTD] slram driver cleanup 



Add error checks to read/write functions and add an eraseblock size.
Makes slram a suitable device for JFFS2.

Signed-off-by: default avatarJosh Boyer <jdub@us.ibm.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 49a43876

drivers/mtd/devices/slram.c

+18 −5
Original line number Diff line number Diff line 
/*======================================================================



  $Id: slram.c,v 1.33 2005/01/05 18:05:13 dwmw2 Exp $

  $Id: slram.c,v 1.34 2005/01/06 21:16:42 jwboyer Exp $



  This driver provides a method to access memory not used by the kernel

  itself (i.e. if the kernel commandline mem=xxx is used). To actually
@@ -50,6 +50,7 @@ 
#include <linux/mtd/mtd.h>



#define SLRAM_MAX_DEVICES_PARAMS 6		/* 3 parameters / device */

#define SLRAM_BLK_SZ 0x4000



#define T(fmt, args...) printk(KERN_DEBUG fmt, ## args)

#define E(fmt, args...) printk(KERN_NOTICE fmt, ## args)
@@ -108,6 +109,9 @@ static int slram_point(struct mtd_info *mtd, loff_t from, size_t len, 
{

	slram_priv_t *priv = mtd->priv;



	if (from + len > mtd->size)

		return -EINVAL;



	*mtdbuf = priv->start + from;

	*retlen = len;

	return(0);
@@ -122,6 +126,12 @@ static int slram_read(struct mtd_info *mtd, loff_t from, size_t len, 
{

	slram_priv_t *priv = mtd->priv;



	if (from > mtd->size)

		return -EINVAL;



	if (from + len > mtd->size)

		len = mtd->size - from;



	memcpy(buf, priv->start + from, len);



	*retlen = len;
@@ -133,6 +143,9 @@ static int slram_write(struct mtd_info *mtd, loff_t to, size_t len, 
{

	slram_priv_t *priv = mtd->priv;



	if (to + len > mtd->size)

		return -EINVAL;



	memcpy(priv->start + to, buf, len);



	*retlen = len;
@@ -188,7 +201,7 @@ static int register_device(char *name, unsigned long start, unsigned long length 
	(*curmtd)->mtdinfo->name = name;

	(*curmtd)->mtdinfo->size = length;

	(*curmtd)->mtdinfo->flags = MTD_CLEAR_BITS | MTD_SET_BITS |

					MTD_WRITEB_WRITEABLE | MTD_VOLATILE;

					MTD_WRITEB_WRITEABLE | MTD_VOLATILE | MTD_CAP_RAM;

        (*curmtd)->mtdinfo->erase = slram_erase;

	(*curmtd)->mtdinfo->point = slram_point;

	(*curmtd)->mtdinfo->unpoint = slram_unpoint;
@@ -196,7 +209,7 @@ static int register_device(char *name, unsigned long start, unsigned long length 
	(*curmtd)->mtdinfo->write = slram_write;

	(*curmtd)->mtdinfo->owner = THIS_MODULE;

	(*curmtd)->mtdinfo->type = MTD_RAM;

	(*curmtd)->mtdinfo->erasesize = 0x0;

	(*curmtd)->mtdinfo->erasesize = SLRAM_BLK_SZ;



	if (add_mtd_device((*curmtd)->mtdinfo))	{

		E("slram: Failed to register new device\n");
@@ -261,7 +274,7 @@ static int parse_cmdline(char *devname, char *szstart, char *szlength) 
	}

	T("slram: devname=%s, devstart=0x%lx, devlength=0x%lx\n",

			devname, devstart, devlength);

	if ((devstart < 0) || (devlength < 0)) {

	if ((devstart < 0) || (devlength < 0) || (devlength % SLRAM_BLK_SZ != 0)) {

		E("slram: Illegal start / length parameter.\n");

		return(-EINVAL);

	}