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Commit e198a8de authored by Deepak Sikri's avatar Deepak Sikri Committed by Grant Likely
Browse files

GPIO/pl061: Add suspend resume capability 



This patch adds the suspend and resume operations in the driver. The patch
ensures the data save and restore for the device registers during the
suspend and resume operations respectively.

Signed-off-by: default avatarDeepak Sikri <deepak.sikri@st.com>
Signed-off-by: default avatarViresh Kumar <viresh.kumar@st.com>
Acked-by: default avatarBaruch Siach <baruch@tkos.co.il>
Acked-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Acked-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarGrant Likely <grant.likely@secretlab.ca>
parent aedd4fdf

drivers/gpio/gpio-pl061.c

+68 −0
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ 
#include <linux/amba/bus.h>

#include <linux/amba/pl061.h>

#include <linux/slab.h>

#include <linux/pm.h>



#define GPIODIR 0x400

#define GPIOIS  0x404
@@ -35,6 +36,17 @@ 


#define PL061_GPIO_NR	8



#ifdef CONFIG_PM

struct pl061_context_save_regs {

	u8 gpio_data;

	u8 gpio_dir;

	u8 gpio_is;

	u8 gpio_ibe;

	u8 gpio_iev;

	u8 gpio_ie;

};

#endif



struct pl061_gpio {

	/* We use a list of pl061_gpio structs for each trigger IRQ in the main

	 * interrupts controller of the system. We need this to support systems
@@ -54,6 +66,10 @@ struct pl061_gpio { 
	void __iomem		*base;

	unsigned		irq_base;

	struct gpio_chip	gc;



#ifdef CONFIG_PM

	struct pl061_context_save_regs csave_regs;

#endif

};



static int pl061_direction_input(struct gpio_chip *gc, unsigned offset)
@@ -330,6 +346,8 @@ static int pl061_probe(struct amba_device *dev, const struct amba_id *id) 
		irq_set_chip_data(i + chip->irq_base, chip);

	}



	amba_set_drvdata(dev, chip);



	return 0;



iounmap:
@@ -342,6 +360,53 @@ static int pl061_probe(struct amba_device *dev, const struct amba_id *id) 
	return ret;

}



#ifdef CONFIG_PM

static int pl061_suspend(struct device *dev)

{

	struct pl061_gpio *chip = dev_get_drvdata(dev);

	int offset;



	chip->csave_regs.gpio_data = 0;

	chip->csave_regs.gpio_dir = readb(chip->base + GPIODIR);

	chip->csave_regs.gpio_is = readb(chip->base + GPIOIS);

	chip->csave_regs.gpio_ibe = readb(chip->base + GPIOIBE);

	chip->csave_regs.gpio_iev = readb(chip->base + GPIOIEV);

	chip->csave_regs.gpio_ie = readb(chip->base + GPIOIE);



	for (offset = 0; offset < PL061_GPIO_NR; offset++) {

		if (chip->csave_regs.gpio_dir & (1 << offset))

			chip->csave_regs.gpio_data |=

				pl061_get_value(&chip->gc, offset) << offset;

	}



	return 0;

}



static int pl061_resume(struct device *dev)

{

	struct pl061_gpio *chip = dev_get_drvdata(dev);

	int offset;



	for (offset = 0; offset < PL061_GPIO_NR; offset++) {

		if (chip->csave_regs.gpio_dir & (1 << offset))

			pl061_direction_output(&chip->gc, offset,

					chip->csave_regs.gpio_data &

					(1 << offset));

		else

			pl061_direction_input(&chip->gc, offset);

	}



	writeb(chip->csave_regs.gpio_is, chip->base + GPIOIS);

	writeb(chip->csave_regs.gpio_ibe, chip->base + GPIOIBE);

	writeb(chip->csave_regs.gpio_iev, chip->base + GPIOIEV);

	writeb(chip->csave_regs.gpio_ie, chip->base + GPIOIE);



	return 0;

}



static SIMPLE_DEV_PM_OPS(pl061_dev_pm_ops, pl061_suspend, pl061_resume);

#endif



static struct amba_id pl061_ids[] = {

	{

		.id	= 0x00041061,
@@ -353,6 +418,9 @@ static struct amba_id pl061_ids[] = { 
static struct amba_driver pl061_gpio_driver = {

	.drv = {

		.name	= "pl061_gpio",

#ifdef CONFIG_PM

		.pm	= &pl061_dev_pm_ops,

#endif

	},

	.id_table	= pl061_ids,

	.probe		= pl061_probe,