arch/arm/plat-samsung/pm-gpio.c - kernel/msm-4.9 - Gitiles


 /* linux/arch/arm/plat-s3c/pm-gpio.c
  *
  * Copyright 2008 Openmoko, Inc.
  * Copyright 2008 Simtec Electronics
  *	Ben Dooks <ben@simtec.co.uk>
  *	http://armlinux.simtec.co.uk/
  *
  * S3C series GPIO PM code
  *
  * 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/kernel.h>
 #include <linux/device.h>
 #include <linux/init.h>
 #include <linux/io.h>
 #include <linux/gpio.h>

 #include <plat/gpio-core.h>
 #include <plat/pm.h>

 /* PM GPIO helpers */

 #define OFFS_CON	(0x00)
 #define OFFS_DAT	(0x04)
 #define OFFS_UP		(0x08)

 static void samsung_gpio_pm_1bit_save(struct samsung_gpio_chip *chip)
 {
 	chip->pm_save[0] = __raw_readl(chip->base + OFFS_CON);
 	chip->pm_save[1] = __raw_readl(chip->base + OFFS_DAT);
 }

 static void samsung_gpio_pm_1bit_resume(struct samsung_gpio_chip *chip)
 {
 	void __iomem *base = chip->base;
 	u32 old_gpcon = __raw_readl(base + OFFS_CON);
 	u32 old_gpdat = __raw_readl(base + OFFS_DAT);
 	u32 gps_gpcon = chip->pm_save[0];
 	u32 gps_gpdat = chip->pm_save[1];
 	u32 gpcon;

 	/* GPACON only has one bit per control / data and no PULLUPs.
 	 * GPACON[x] = 0 => Output, 1 => SFN */

 	/* first set all SFN bits to SFN */

 	gpcon = old_gpcon | gps_gpcon;
 	__raw_writel(gpcon, base + OFFS_CON);

 	/* now set all the other bits */

 	__raw_writel(gps_gpdat, base + OFFS_DAT);
 	__raw_writel(gps_gpcon, base + OFFS_CON);

 	S3C_PMDBG("%s: CON %08x => %08x, DAT %08x => %08x\n",
 		  chip->chip.label, old_gpcon, gps_gpcon, old_gpdat, gps_gpdat);
 }

 struct samsung_gpio_pm samsung_gpio_pm_1bit = {
 	.save	= samsung_gpio_pm_1bit_save,
 	.resume = samsung_gpio_pm_1bit_resume,
 };

 static void samsung_gpio_pm_2bit_save(struct samsung_gpio_chip *chip)
 {
 	chip->pm_save[0] = __raw_readl(chip->base + OFFS_CON);
 	chip->pm_save[1] = __raw_readl(chip->base + OFFS_DAT);
 	chip->pm_save[2] = __raw_readl(chip->base + OFFS_UP);
 }

 /* Test whether the given masked+shifted bits of an GPIO configuration
  * are one of the SFN (special function) modes. */

 static inline int is_sfn(unsigned long con)
 {
 	return con >= 2;
 }

 /* Test if the given masked+shifted GPIO configuration is an input */

 static inline int is_in(unsigned long con)
 {
 	return con == 0;
 }

 /* Test if the given masked+shifted GPIO configuration is an output */

 static inline int is_out(unsigned long con)
 {
 	return con == 1;
 }

 /**
  * samsung_gpio_pm_2bit_resume() - restore the given GPIO bank
  * @chip: The chip information to resume.
  *
  * Restore one of the GPIO banks that was saved during suspend. This is
  * not as simple as once thought, due to the possibility of glitches
  * from the order that the CON and DAT registers are set in.
  *
  * The three states the pin can be are {IN,OUT,SFN} which gives us 9
  * combinations of changes to check. Three of these, if the pin stays
  * in the same configuration can be discounted. This leaves us with
  * the following:
  *
  * { IN => OUT }  Change DAT first
  * { IN => SFN }  Change CON first
  * { OUT => SFN } Change CON first, so new data will not glitch
  * { OUT => IN }  Change CON first, so new data will not glitch
  * { SFN => IN }  Change CON first
  * { SFN => OUT } Change DAT first, so new data will not glitch [1]
  *
  * We do not currently deal with the UP registers as these control
  * weak resistors, so a small delay in change should not need to bring
  * these into the calculations.
  *
  * [1] this assumes that writing to a pin DAT whilst in SFN will set the
  *     state for when it is next output.
  */
 static void samsung_gpio_pm_2bit_resume(struct samsung_gpio_chip *chip)
 {
 	void __iomem *base = chip->base;
 	u32 old_gpcon = __raw_readl(base + OFFS_CON);
 	u32 old_gpdat = __raw_readl(base + OFFS_DAT);
 	u32 gps_gpcon = chip->pm_save[0];
 	u32 gps_gpdat = chip->pm_save[1];
 	u32 gpcon, old, new, mask;
 	u32 change_mask = 0x0;
 	int nr;

 	/* restore GPIO pull-up settings */
 	__raw_writel(chip->pm_save[2], base + OFFS_UP);

 	/* Create a change_mask of all the items that need to have
 	 * their CON value changed before their DAT value, so that
 	 * we minimise the work between the two settings.
 	 */

 	for (nr = 0, mask = 0x03; nr < 32; nr += 2, mask <<= 2) {
 		old = (old_gpcon & mask) >> nr;
 		new = (gps_gpcon & mask) >> nr;

 		/* If there is no change, then skip */

 		if (old == new)
 			continue;

 		/* If both are special function, then skip */

 		if (is_sfn(old) && is_sfn(new))
 			continue;

 		/* Change is IN => OUT, do not change now */

 		if (is_in(old) && is_out(new))
 			continue;

 		/* Change is SFN => OUT, do not change now */

 		if (is_sfn(old) && is_out(new))
 			continue;

 		/* We should now be at the case of IN=>SFN,
 		 * OUT=>SFN, OUT=>IN, SFN=>IN. */

 		change_mask |= mask;
 	}


 	/* Write the new CON settings */

 	gpcon = old_gpcon & ~change_mask;
 	gpcon |= gps_gpcon & change_mask;

 	__raw_writel(gpcon, base + OFFS_CON);

 	/* Now change any items that require DAT,CON */

 	__raw_writel(gps_gpdat, base + OFFS_DAT);
 	__raw_writel(gps_gpcon, base + OFFS_CON);

 	S3C_PMDBG("%s: CON %08x => %08x, DAT %08x => %08x\n",
 		  chip->chip.label, old_gpcon, gps_gpcon, old_gpdat, gps_gpdat);
 }

 struct samsung_gpio_pm samsung_gpio_pm_2bit = {
 	.save	= samsung_gpio_pm_2bit_save,
 	.resume = samsung_gpio_pm_2bit_resume,
 };

 #if defined(CONFIG_ARCH_S3C64XX) || defined(CONFIG_PLAT_S5P) \
 	|| defined(CONFIG_ARCH_EXYNOS)
 static void samsung_gpio_pm_4bit_save(struct samsung_gpio_chip *chip)
 {
 	chip->pm_save[1] = __raw_readl(chip->base + OFFS_CON);
 	chip->pm_save[2] = __raw_readl(chip->base + OFFS_DAT);
 	chip->pm_save[3] = __raw_readl(chip->base + OFFS_UP);

 	if (chip->chip.ngpio > 8)
 		chip->pm_save[0] = __raw_readl(chip->base - 4);
 }

 static u32 samsung_gpio_pm_4bit_mask(u32 old_gpcon, u32 gps_gpcon)
 {
 	u32 old, new, mask;
 	u32 change_mask = 0x0;
 	int nr;

 	for (nr = 0, mask = 0x0f; nr < 16; nr += 4, mask <<= 4) {
 		old = (old_gpcon & mask) >> nr;
 		new = (gps_gpcon & mask) >> nr;

 		/* If there is no change, then skip */

 		if (old == new)
 			continue;

 		/* If both are special function, then skip */

 		if (is_sfn(old) && is_sfn(new))
 			continue;

 		/* Change is IN => OUT, do not change now */

 		if (is_in(old) && is_out(new))
 			continue;

 		/* Change is SFN => OUT, do not change now */

 		if (is_sfn(old) && is_out(new))
 			continue;

 		/* We should now be at the case of IN=>SFN,
 		 * OUT=>SFN, OUT=>IN, SFN=>IN. */

 		change_mask |= mask;
 	}

 	return change_mask;
 }

 static void samsung_gpio_pm_4bit_con(struct samsung_gpio_chip *chip, int index)
 {
 	void __iomem *con = chip->base + (index * 4);
 	u32 old_gpcon = __raw_readl(con);
 	u32 gps_gpcon = chip->pm_save[index + 1];
 	u32 gpcon, mask;

 	mask = samsung_gpio_pm_4bit_mask(old_gpcon, gps_gpcon);

 	gpcon = old_gpcon & ~mask;
 	gpcon |= gps_gpcon & mask;

 	__raw_writel(gpcon, con);
 }

 static void samsung_gpio_pm_4bit_resume(struct samsung_gpio_chip *chip)
 {
 	void __iomem *base = chip->base;
 	u32 old_gpcon[2];
 	u32 old_gpdat = __raw_readl(base + OFFS_DAT);
 	u32 gps_gpdat = chip->pm_save[2];

 	/* First, modify the CON settings */

 	old_gpcon[0] = 0;
 	old_gpcon[1] = __raw_readl(base + OFFS_CON);

 	samsung_gpio_pm_4bit_con(chip, 0);
 	if (chip->chip.ngpio > 8) {
 		old_gpcon[0] = __raw_readl(base - 4);
 		samsung_gpio_pm_4bit_con(chip, -1);
 	}

 	/* Now change the configurations that require DAT,CON */

 	__raw_writel(chip->pm_save[2], base + OFFS_DAT);
 	__raw_writel(chip->pm_save[1], base + OFFS_CON);
 	if (chip->chip.ngpio > 8)
 		__raw_writel(chip->pm_save[0], base - 4);

 	__raw_writel(chip->pm_save[2], base + OFFS_DAT);
 	__raw_writel(chip->pm_save[3], base + OFFS_UP);

 	if (chip->chip.ngpio > 8) {
 		S3C_PMDBG("%s: CON4 %08x,%08x => %08x,%08x, DAT %08x => %08x\n",
 			  chip->chip.label, old_gpcon[0], old_gpcon[1],
 			  __raw_readl(base - 4),
 			  __raw_readl(base + OFFS_CON),
 			  old_gpdat, gps_gpdat);
 	} else
 		S3C_PMDBG("%s: CON4 %08x => %08x, DAT %08x => %08x\n",
 			  chip->chip.label, old_gpcon[1],
 			  __raw_readl(base + OFFS_CON),
 			  old_gpdat, gps_gpdat);
 }

 struct samsung_gpio_pm samsung_gpio_pm_4bit = {
 	.save	= samsung_gpio_pm_4bit_save,
 	.resume = samsung_gpio_pm_4bit_resume,
 };
 #endif /* CONFIG_ARCH_S3C64XX || CONFIG_PLAT_S5P || CONFIG_ARCH_EXYNOS */

 /**
  * samsung_pm_save_gpio() - save gpio chip data for suspend
  * @ourchip: The chip for suspend.
  */
 static void samsung_pm_save_gpio(struct samsung_gpio_chip *ourchip)
 {
 	struct samsung_gpio_pm *pm = ourchip->pm;

 	if (pm == NULL || pm->save == NULL)
 		S3C_PMDBG("%s: no pm for %s\n", __func__, ourchip->chip.label);
 	else
 		pm->save(ourchip);
 }

 /**
  * samsung_pm_save_gpios() - Save the state of the GPIO banks.
  *
  * For all the GPIO banks, save the state of each one ready for going
  * into a suspend mode.
  */
 void samsung_pm_save_gpios(void)
 {
 	struct samsung_gpio_chip *ourchip;
 	unsigned int gpio_nr;

 	for (gpio_nr = 0; gpio_nr < S3C_GPIO_END;) {
 		ourchip = samsung_gpiolib_getchip(gpio_nr);
 		if (!ourchip) {
 			gpio_nr++;
 			continue;
 		}

 		samsung_pm_save_gpio(ourchip);

 		S3C_PMDBG("%s: save %08x,%08x,%08x,%08x\n",
 			  ourchip->chip.label,
 			  ourchip->pm_save[0],
 			  ourchip->pm_save[1],
 			  ourchip->pm_save[2],
 			  ourchip->pm_save[3]);

 		gpio_nr += ourchip->chip.ngpio;
 		gpio_nr += CONFIG_S3C_GPIO_SPACE;
 	}
 }

 /**
  * samsung_pm_resume_gpio() - restore gpio chip data after suspend
  * @ourchip: The suspended chip.
  */
 static void samsung_pm_resume_gpio(struct samsung_gpio_chip *ourchip)
 {
 	struct samsung_gpio_pm *pm = ourchip->pm;

 	if (pm == NULL || pm->resume == NULL)
 		S3C_PMDBG("%s: no pm for %s\n", __func__, ourchip->chip.label);
 	else
 		pm->resume(ourchip);
 }

 void samsung_pm_restore_gpios(void)
 {
 	struct samsung_gpio_chip *ourchip;
 	unsigned int gpio_nr;

 	for (gpio_nr = 0; gpio_nr < S3C_GPIO_END;) {
 		ourchip = samsung_gpiolib_getchip(gpio_nr);
 		if (!ourchip) {
 			gpio_nr++;
 			continue;
 		}

 		samsung_pm_resume_gpio(ourchip);

 		gpio_nr += ourchip->chip.ngpio;
 		gpio_nr += CONFIG_S3C_GPIO_SPACE;
 	}
 }

	/* linux/arch/arm/plat-s3c/pm-gpio.c
	*
	* Copyright 2008 Openmoko, Inc.
	* Copyright 2008 Simtec Electronics
	* Ben Dooks <ben@simtec.co.uk>
	* http://armlinux.simtec.co.uk/
	*
	* S3C series GPIO PM code
	*
	* 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/kernel.h>
	#include <linux/device.h>
	#include <linux/init.h>
	#include <linux/io.h>
	#include <linux/gpio.h>

	#include <plat/gpio-core.h>
	#include <plat/pm.h>

	/* PM GPIO helpers */

	#define OFFS_CON (0x00)
	#define OFFS_DAT (0x04)
	#define OFFS_UP (0x08)

	static void samsung_gpio_pm_1bit_save(struct samsung_gpio_chip *chip)
	{
	chip->pm_save[0] = __raw_readl(chip->base + OFFS_CON);
	chip->pm_save[1] = __raw_readl(chip->base + OFFS_DAT);
	}

	static void samsung_gpio_pm_1bit_resume(struct samsung_gpio_chip *chip)
	{
	void __iomem *base = chip->base;
	u32 old_gpcon = __raw_readl(base + OFFS_CON);
	u32 old_gpdat = __raw_readl(base + OFFS_DAT);
	u32 gps_gpcon = chip->pm_save[0];
	u32 gps_gpdat = chip->pm_save[1];
	u32 gpcon;

	/* GPACON only has one bit per control / data and no PULLUPs.
	* GPACON[x] = 0 => Output, 1 => SFN */

	/* first set all SFN bits to SFN */

	gpcon = old_gpcon \| gps_gpcon;
	__raw_writel(gpcon, base + OFFS_CON);

	/* now set all the other bits */

	__raw_writel(gps_gpdat, base + OFFS_DAT);
	__raw_writel(gps_gpcon, base + OFFS_CON);

	S3C_PMDBG("%s: CON %08x => %08x, DAT %08x => %08x\n",
	chip->chip.label, old_gpcon, gps_gpcon, old_gpdat, gps_gpdat);
	}

	struct samsung_gpio_pm samsung_gpio_pm_1bit = {
	.save = samsung_gpio_pm_1bit_save,
	.resume = samsung_gpio_pm_1bit_resume,
	};

	static void samsung_gpio_pm_2bit_save(struct samsung_gpio_chip *chip)
	{
	chip->pm_save[0] = __raw_readl(chip->base + OFFS_CON);
	chip->pm_save[1] = __raw_readl(chip->base + OFFS_DAT);
	chip->pm_save[2] = __raw_readl(chip->base + OFFS_UP);
	}

	/* Test whether the given masked+shifted bits of an GPIO configuration
	* are one of the SFN (special function) modes. */

	static inline int is_sfn(unsigned long con)
	{
	return con >= 2;
	}

	/* Test if the given masked+shifted GPIO configuration is an input */

	static inline int is_in(unsigned long con)
	{
	return con == 0;
	}

	/* Test if the given masked+shifted GPIO configuration is an output */

	static inline int is_out(unsigned long con)
	{
	return con == 1;
	}

	/**
	* samsung_gpio_pm_2bit_resume() - restore the given GPIO bank
	* @chip: The chip information to resume.
	*
	* Restore one of the GPIO banks that was saved during suspend. This is
	* not as simple as once thought, due to the possibility of glitches
	* from the order that the CON and DAT registers are set in.
	*
	* The three states the pin can be are {IN,OUT,SFN} which gives us 9
	* combinations of changes to check. Three of these, if the pin stays
	* in the same configuration can be discounted. This leaves us with
	* the following:
	*
	* { IN => OUT } Change DAT first
	* { IN => SFN } Change CON first
	* { OUT => SFN } Change CON first, so new data will not glitch
	* { OUT => IN } Change CON first, so new data will not glitch
	* { SFN => IN } Change CON first
	* { SFN => OUT } Change DAT first, so new data will not glitch [1]
	*
	* We do not currently deal with the UP registers as these control
	* weak resistors, so a small delay in change should not need to bring
	* these into the calculations.
	*
	* [1] this assumes that writing to a pin DAT whilst in SFN will set the
	* state for when it is next output.
	*/
	static void samsung_gpio_pm_2bit_resume(struct samsung_gpio_chip *chip)
	{
	void __iomem *base = chip->base;
	u32 old_gpcon = __raw_readl(base + OFFS_CON);
	u32 old_gpdat = __raw_readl(base + OFFS_DAT);
	u32 gps_gpcon = chip->pm_save[0];
	u32 gps_gpdat = chip->pm_save[1];
	u32 gpcon, old, new, mask;
	u32 change_mask = 0x0;
	int nr;

	/* restore GPIO pull-up settings */
	__raw_writel(chip->pm_save[2], base + OFFS_UP);

	/* Create a change_mask of all the items that need to have
	* their CON value changed before their DAT value, so that
	* we minimise the work between the two settings.
	*/

	for (nr = 0, mask = 0x03; nr < 32; nr += 2, mask <<= 2) {
	old = (old_gpcon & mask) >> nr;
	new = (gps_gpcon & mask) >> nr;

	/* If there is no change, then skip */

	if (old == new)
	continue;

	/* If both are special function, then skip */

	if (is_sfn(old) && is_sfn(new))
	continue;

	/* Change is IN => OUT, do not change now */

	if (is_in(old) && is_out(new))
	continue;

	/* Change is SFN => OUT, do not change now */

	if (is_sfn(old) && is_out(new))
	continue;

	/* We should now be at the case of IN=>SFN,
	* OUT=>SFN, OUT=>IN, SFN=>IN. */

	change_mask \|= mask;
	}


	/* Write the new CON settings */

	gpcon = old_gpcon & ~change_mask;
	gpcon \|= gps_gpcon & change_mask;

	__raw_writel(gpcon, base + OFFS_CON);

	/* Now change any items that require DAT,CON */

	__raw_writel(gps_gpdat, base + OFFS_DAT);
	__raw_writel(gps_gpcon, base + OFFS_CON);

	S3C_PMDBG("%s: CON %08x => %08x, DAT %08x => %08x\n",
	chip->chip.label, old_gpcon, gps_gpcon, old_gpdat, gps_gpdat);
	}

	struct samsung_gpio_pm samsung_gpio_pm_2bit = {
	.save = samsung_gpio_pm_2bit_save,
	.resume = samsung_gpio_pm_2bit_resume,
	};

	#if defined(CONFIG_ARCH_S3C64XX) \|\| defined(CONFIG_PLAT_S5P) \
	\|\| defined(CONFIG_ARCH_EXYNOS)
	static void samsung_gpio_pm_4bit_save(struct samsung_gpio_chip *chip)
	{
	chip->pm_save[1] = __raw_readl(chip->base + OFFS_CON);
	chip->pm_save[2] = __raw_readl(chip->base + OFFS_DAT);
	chip->pm_save[3] = __raw_readl(chip->base + OFFS_UP);

	if (chip->chip.ngpio > 8)
	chip->pm_save[0] = __raw_readl(chip->base - 4);
	}

	static u32 samsung_gpio_pm_4bit_mask(u32 old_gpcon, u32 gps_gpcon)
	{
	u32 old, new, mask;
	u32 change_mask = 0x0;
	int nr;

	for (nr = 0, mask = 0x0f; nr < 16; nr += 4, mask <<= 4) {
	old = (old_gpcon & mask) >> nr;
	new = (gps_gpcon & mask) >> nr;

	/* If there is no change, then skip */

	if (old == new)
	continue;

	/* If both are special function, then skip */

	if (is_sfn(old) && is_sfn(new))
	continue;

	/* Change is IN => OUT, do not change now */

	if (is_in(old) && is_out(new))
	continue;

	/* Change is SFN => OUT, do not change now */

	if (is_sfn(old) && is_out(new))
	continue;

	/* We should now be at the case of IN=>SFN,
	* OUT=>SFN, OUT=>IN, SFN=>IN. */

	change_mask \|= mask;
	}

	return change_mask;
	}

	static void samsung_gpio_pm_4bit_con(struct samsung_gpio_chip *chip, int index)
	{
	void __iomem con = chip->base + (index 4);
	u32 old_gpcon = __raw_readl(con);
	u32 gps_gpcon = chip->pm_save[index + 1];
	u32 gpcon, mask;

	mask = samsung_gpio_pm_4bit_mask(old_gpcon, gps_gpcon);

	gpcon = old_gpcon & ~mask;
	gpcon \|= gps_gpcon & mask;

	__raw_writel(gpcon, con);
	}

	static void samsung_gpio_pm_4bit_resume(struct samsung_gpio_chip *chip)
	{
	void __iomem *base = chip->base;
	u32 old_gpcon[2];
	u32 old_gpdat = __raw_readl(base + OFFS_DAT);
	u32 gps_gpdat = chip->pm_save[2];

	/* First, modify the CON settings */

	old_gpcon[0] = 0;
	old_gpcon[1] = __raw_readl(base + OFFS_CON);

	samsung_gpio_pm_4bit_con(chip, 0);
	if (chip->chip.ngpio > 8) {
	old_gpcon[0] = __raw_readl(base - 4);
	samsung_gpio_pm_4bit_con(chip, -1);
	}

	/* Now change the configurations that require DAT,CON */

	__raw_writel(chip->pm_save[2], base + OFFS_DAT);
	__raw_writel(chip->pm_save[1], base + OFFS_CON);
	if (chip->chip.ngpio > 8)
	__raw_writel(chip->pm_save[0], base - 4);

	__raw_writel(chip->pm_save[2], base + OFFS_DAT);
	__raw_writel(chip->pm_save[3], base + OFFS_UP);

	if (chip->chip.ngpio > 8) {
	S3C_PMDBG("%s: CON4 %08x,%08x => %08x,%08x, DAT %08x => %08x\n",
	chip->chip.label, old_gpcon[0], old_gpcon[1],
	__raw_readl(base - 4),
	__raw_readl(base + OFFS_CON),
	old_gpdat, gps_gpdat);
	} else
	S3C_PMDBG("%s: CON4 %08x => %08x, DAT %08x => %08x\n",
	chip->chip.label, old_gpcon[1],
	__raw_readl(base + OFFS_CON),
	old_gpdat, gps_gpdat);
	}

	struct samsung_gpio_pm samsung_gpio_pm_4bit = {
	.save = samsung_gpio_pm_4bit_save,
	.resume = samsung_gpio_pm_4bit_resume,
	};
	#endif /* CONFIG_ARCH_S3C64XX \|\| CONFIG_PLAT_S5P \|\| CONFIG_ARCH_EXYNOS */

	/**
	* samsung_pm_save_gpio() - save gpio chip data for suspend
	* @ourchip: The chip for suspend.
	*/
	static void samsung_pm_save_gpio(struct samsung_gpio_chip *ourchip)
	{
	struct samsung_gpio_pm *pm = ourchip->pm;

	if (pm == NULL \|\| pm->save == NULL)
	S3C_PMDBG("%s: no pm for %s\n", __func__, ourchip->chip.label);
	else
	pm->save(ourchip);
	}

	/**
	* samsung_pm_save_gpios() - Save the state of the GPIO banks.
	*
	* For all the GPIO banks, save the state of each one ready for going
	* into a suspend mode.
	*/
	void samsung_pm_save_gpios(void)
	{
	struct samsung_gpio_chip *ourchip;
	unsigned int gpio_nr;

	for (gpio_nr = 0; gpio_nr < S3C_GPIO_END;) {
	ourchip = samsung_gpiolib_getchip(gpio_nr);
	if (!ourchip) {
	gpio_nr++;
	continue;
	}

	samsung_pm_save_gpio(ourchip);

	S3C_PMDBG("%s: save %08x,%08x,%08x,%08x\n",
	ourchip->chip.label,
	ourchip->pm_save[0],
	ourchip->pm_save[1],
	ourchip->pm_save[2],
	ourchip->pm_save[3]);

	gpio_nr += ourchip->chip.ngpio;
	gpio_nr += CONFIG_S3C_GPIO_SPACE;
	}
	}

	/**
	* samsung_pm_resume_gpio() - restore gpio chip data after suspend
	* @ourchip: The suspended chip.
	*/
	static void samsung_pm_resume_gpio(struct samsung_gpio_chip *ourchip)
	{
	struct samsung_gpio_pm *pm = ourchip->pm;

	if (pm == NULL \|\| pm->resume == NULL)
	S3C_PMDBG("%s: no pm for %s\n", __func__, ourchip->chip.label);
	else
	pm->resume(ourchip);
	}

	void samsung_pm_restore_gpios(void)
	{
	struct samsung_gpio_chip *ourchip;
	unsigned int gpio_nr;

	for (gpio_nr = 0; gpio_nr < S3C_GPIO_END;) {
	ourchip = samsung_gpiolib_getchip(gpio_nr);
	if (!ourchip) {
	gpio_nr++;
	continue;
	}

	samsung_pm_resume_gpio(ourchip);

	gpio_nr += ourchip->chip.ngpio;
	gpio_nr += CONFIG_S3C_GPIO_SPACE;
	}
	}