Commit cfd320fb authored by Ben Dooks's avatar Ben Dooks Committed by Thomas Gleixner
Browse files

[MTD] NAND s3c2410.c: Fix timing calculation bugs 



Spotted by basprog@mail.ru

Signed-off-by: default avatarBen Dooks <ben-linux@fluff.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 4fc67fbe

drivers/mtd/nand/s3c2410.c

+12 −9
Original line number Diff line number Diff line
@@ -17,8 +17,9 @@ 
 *	02-May-2005  BJD  Reduced hwcontrol decode

 *	20-Jun-2005  BJD  Updated s3c2440 support, fixed timing bug

 *	08-Jul-2005  BJD  Fix OOPS when no platform data supplied

 *	20-Oct-2005  BJD  Fix timing calculation bug

 *

 * $Id: s3c2410.c,v 1.17 2005/10/10 10:27:02 bjd Exp $

 * $Id: s3c2410.c,v 1.18 2005/10/20 21:22:55 bjd Exp $

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by
@@ -136,13 +137,13 @@ static struct s3c2410_platform_nand *to_nand_plat(struct device *dev) 


/* timing calculations */



#define NS_IN_KHZ 10000000

#define NS_IN_KHZ 1000000



static int s3c2410_nand_calc_rate(int wanted, unsigned long clk, int max)

{

	int result;



	result = (wanted * NS_IN_KHZ) / clk;

	result = (wanted * clk) / NS_IN_KHZ;

	result++;



	pr_debug("result %d from %ld, %d\n", result, clk, wanted);
@@ -159,7 +160,7 @@ static int s3c2410_nand_calc_rate(int wanted, unsigned long clk, int max) 
	return result;

}



#define to_ns(ticks,clk) (((clk) * (ticks)) / NS_IN_KHZ)

#define to_ns(ticks,clk) (((ticks) * NS_IN_KHZ) / (unsigned int)(clk))



/* controller setup */
@@ -167,12 +168,14 @@ static int s3c2410_nand_inithw(struct s3c2410_nand_info *info, 
			       struct device *dev)

{

	struct s3c2410_platform_nand *plat = to_nand_plat(dev);

	unsigned int tacls, twrph0, twrph1;

	unsigned long clkrate = clk_get_rate(info->clk);

	int tacls, twrph0, twrph1;

	unsigned long cfg;



	/* calculate the timing information for the controller */



	clkrate /= 1000;	/* turn clock into kHz for ease of use */



	if (plat != NULL) {

		tacls  = s3c2410_nand_calc_rate(plat->tacls, clkrate, 4);

		twrph0 = s3c2410_nand_calc_rate(plat->twrph0, clkrate, 8);
@@ -189,10 +192,10 @@ static int s3c2410_nand_inithw(struct s3c2410_nand_info *info, 
		return -EINVAL;

	}



	printk(KERN_INFO PFX "timing: Tacls %ldns, Twrph0 %ldns, Twrph1 %ldns\n",

	       to_ns(tacls, clkrate),

	       to_ns(twrph0, clkrate),

	       to_ns(twrph1, clkrate));

	printk(KERN_INFO PFX "Tacls=%d, %dns Twrph0=%d %dns, Twrph1=%d %dns\n",

	       tacls, to_ns(tacls, clkrate),

	       twrph0, to_ns(twrph0, clkrate), 

	       twrph1, to_ns(twrph1, clkrate));



	if (!info->is_s3c2440) {

		cfg  = S3C2410_NFCONF_EN;