diff options
Diffstat (limited to 'drivers/mtd')
| -rw-r--r-- | drivers/mtd/nand/Kconfig | 10 | ||||
| -rw-r--r-- | drivers/mtd/nand/s3c2410.c | 76 |
2 files changed, 81 insertions, 5 deletions
diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig index 203f90a024d..3db77eec0ed 100644 --- a/drivers/mtd/nand/Kconfig +++ b/drivers/mtd/nand/Kconfig @@ -135,6 +135,16 @@ config MTD_NAND_NDFC help NDFC Nand Flash Controllers are integrated in EP44x SoCs +config MTD_NAND_S3C2410_CLKSTOP + bool "S3C2410 NAND IDLE clock stop" + depends on MTD_NAND_S3C2410 + default n + help + Stop the clock to the NAND controller when there is no chip + selected to save power. This will mean there is a small delay + when the is NAND chip selected or released, but will save + approximately 5mA of power when there is nothing happening. + config MTD_NAND_DISKONCHIP tristate "DiskOnChip 2000, Millennium and Millennium Plus (NAND reimplementation) (EXPERIMENTAL)" depends on MTD_NAND && EXPERIMENTAL diff --git a/drivers/mtd/nand/s3c2410.c b/drivers/mtd/nand/s3c2410.c index d6365a66887..fd78fb83549 100644 --- a/drivers/mtd/nand/s3c2410.c +++ b/drivers/mtd/nand/s3c2410.c @@ -18,8 +18,9 @@ * 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 + * 14-Jan-2006 BJD Allow clock to be stopped when idle * - * $Id: s3c2410.c,v 1.20 2005/11/07 11:14:31 gleixner Exp $ + * $Id: s3c2410.c,v 1.23 2006/04/01 18:06:29 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 @@ -36,9 +37,6 @@ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ -#include <config/mtd/nand/s3c2410/hwecc.h> -#include <config/mtd/nand/s3c2410/debug.h> - #ifdef CONFIG_MTD_NAND_S3C2410_DEBUG #define DEBUG #endif @@ -73,6 +71,13 @@ static int hardware_ecc = 1; static int hardware_ecc = 0; #endif +#ifdef CONFIG_MTD_NAND_S3C2410_CLKSTOP +static int clock_stop = 1; +#else +static const int clock_stop = 0; +#endif + + /* new oob placement block for use with hardware ecc generation */ @@ -134,6 +139,11 @@ static struct s3c2410_platform_nand *to_nand_plat(struct platform_device *dev) return dev->dev.platform_data; } +static inline int allow_clk_stop(struct s3c2410_nand_info *info) +{ + return clock_stop; +} + /* timing calculations */ #define NS_IN_KHZ 1000000 @@ -201,6 +211,11 @@ static int s3c2410_nand_inithw(struct s3c2410_nand_info *info, struct platform_d cfg = S3C2440_NFCONF_TACLS(tacls - 1); cfg |= S3C2440_NFCONF_TWRPH0(twrph0 - 1); cfg |= S3C2440_NFCONF_TWRPH1(twrph1 - 1); + + /* enable the controller and de-assert nFCE */ + + writel(S3C2440_NFCONT_ENABLE | S3C2440_NFCONT_ENABLE, + info->regs + S3C2440_NFCONT); } pr_debug(PFX "NF_CONF is 0x%lx\n", cfg); @@ -226,6 +241,9 @@ static void s3c2410_nand_select_chip(struct mtd_info *mtd, int chip) bit = (info->is_s3c2440) ? S3C2440_NFCONT_nFCE : S3C2410_NFCONF_nFCE; reg = info->regs + ((info->is_s3c2440) ? S3C2440_NFCONT : S3C2410_NFCONF); + if (chip != -1 && allow_clk_stop(info)) + clk_enable(info->clk); + cur = readl(reg); if (chip == -1) { @@ -245,6 +263,9 @@ static void s3c2410_nand_select_chip(struct mtd_info *mtd, int chip) } writel(cur, reg); + + if (chip == -1 && allow_clk_stop(info)) + clk_disable(info->clk); } /* command and control functions @@ -417,7 +438,8 @@ static int s3c2410_nand_remove(struct platform_device *pdev) /* free the common resources */ if (info->clk != NULL && !IS_ERR(info->clk)) { - clk_disable(info->clk); + if (!allow_clk_stop(info)) + clk_disable(info->clk); clk_put(info->clk); } @@ -627,6 +649,11 @@ static int s3c24xx_nand_probe(struct platform_device *pdev, int is_s3c2440) sets++; } + if (allow_clk_stop(info)) { + dev_info(&pdev->dev, "clock idle support enabled\n"); + clk_disable(info->clk); + } + pr_debug("initialised ok\n"); return 0; @@ -638,6 +665,41 @@ static int s3c24xx_nand_probe(struct platform_device *pdev, int is_s3c2440) return err; } +/* PM Support */ +#ifdef CONFIG_PM + +static int s3c24xx_nand_suspend(struct platform_device *dev, pm_message_t pm) +{ + struct s3c2410_nand_info *info = platform_get_drvdata(dev); + + if (info) { + if (!allow_clk_stop(info)) + clk_disable(info->clk); + } + + return 0; +} + +static int s3c24xx_nand_resume(struct platform_device *dev) +{ + struct s3c2410_nand_info *info = platform_get_drvdata(dev); + + if (info) { + clk_enable(info->clk); + s3c2410_nand_inithw(info, dev); + + if (allow_clk_stop(info)) + clk_disable(info->clk); + } + + return 0; +} + +#else +#define s3c24xx_nand_suspend NULL +#define s3c24xx_nand_resume NULL +#endif + /* driver device registration */ static int s3c2410_nand_probe(struct platform_device *dev) @@ -653,6 +715,8 @@ static int s3c2440_nand_probe(struct platform_device *dev) static struct platform_driver s3c2410_nand_driver = { .probe = s3c2410_nand_probe, .remove = s3c2410_nand_remove, + .suspend = s3c24xx_nand_suspend, + .resume = s3c24xx_nand_resume, .driver = { .name = "s3c2410-nand", .owner = THIS_MODULE, @@ -662,6 +726,8 @@ static struct platform_driver s3c2410_nand_driver = { static struct platform_driver s3c2440_nand_driver = { .probe = s3c2440_nand_probe, .remove = s3c2410_nand_remove, + .suspend = s3c24xx_nand_suspend, + .resume = s3c24xx_nand_resume, .driver = { .name = "s3c2440-nand", .owner = THIS_MODULE, |