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Commit 352a2d5b authored by Jon Hunter's avatar Jon Hunter Committed by Linus Walleij
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gpio/omap: ensure gpio context is initialised 



Commit a2797bea (gpio/omap: force restore if context loss is not
detectable) broke gpio support for OMAP when booting with device-tree
because a restore of the gpio context being performed without ever
initialising the gpio context. In other words, the context restored was
bad.

This problem could also occur in the non device-tree case, however, it
is much less likely because when booting without device-tree we can
detect context loss via a platform specific API and so context restore
is performed less often.

Nevertheless we should ensure that the gpio context is initialised
on the first pm-runtime resume for gpio banks that could lose their
state regardless of whether we are booting with device-tree or not.

The context loss count was being initialised on the first pm-runtime
suspend following a resume, by populating the get_count_loss_count()
function pointer after the first pm-runtime resume. To make the code
more readable and logical, initialise the context loss count on the
first pm-runtime resume if the context is not yet valid.

Reported-by: default avatarTony Lindgren <tony@atomide.com>
Signed-off-by: default avatarJon Hunter <jon-hunter@ti.com>
Acked-by: default avatarSantosh <Shilimkar&lt;santosh.shilimkar@ti.com>
Reviewed-by: default avatarKevin Hilman <khilman@linaro.org>
Tested-by: default avatarTony Lindgren <tony@atomide.com>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent f722406f

drivers/gpio/gpio-omap.c

+45 −3
Original line number Diff line number Diff line
@@ -69,6 +69,7 @@ struct gpio_bank { 
	bool is_mpuio;

	bool dbck_flag;

	bool loses_context;

	bool context_valid;

	int stride;

	u32 width;

	int context_loss_count;
@@ -1128,6 +1129,10 @@ static int omap_gpio_probe(struct platform_device *pdev) 
			bank->loses_context = true;

	} else {

		bank->loses_context = pdata->loses_context;



		if (bank->loses_context)

			bank->get_context_loss_count =

				pdata->get_context_loss_count;

	}
@@ -1178,9 +1183,6 @@ static int omap_gpio_probe(struct platform_device *pdev) 
	omap_gpio_chip_init(bank);

	omap_gpio_show_rev(bank);



	if (bank->loses_context)

		bank->get_context_loss_count = pdata->get_context_loss_count;



	pm_runtime_put(bank->dev);



	list_add_tail(&bank->node, &omap_gpio_list);
@@ -1259,6 +1261,8 @@ static int omap_gpio_runtime_suspend(struct device *dev) 
	return 0;

}



static void omap_gpio_init_context(struct gpio_bank *p);



static int omap_gpio_runtime_resume(struct device *dev)

{

	struct platform_device *pdev = to_platform_device(dev);
@@ -1268,6 +1272,20 @@ static int omap_gpio_runtime_resume(struct device *dev) 
	int c;



	spin_lock_irqsave(&bank->lock, flags);



	/*

	 * On the first resume during the probe, the context has not

	 * been initialised and so initialise it now. Also initialise

	 * the context loss count.

	 */

	if (bank->loses_context && !bank->context_valid) {

		omap_gpio_init_context(bank);



		if (bank->get_context_loss_count)

			bank->context_loss_count =

				bank->get_context_loss_count(bank->dev);

	}



	_gpio_dbck_enable(bank);



	/*
@@ -1384,6 +1402,29 @@ void omap2_gpio_resume_after_idle(void) 
}



#if defined(CONFIG_PM_RUNTIME)

static void omap_gpio_init_context(struct gpio_bank *p)

{

	struct omap_gpio_reg_offs *regs = p->regs;

	void __iomem *base = p->base;



	p->context.ctrl		= __raw_readl(base + regs->ctrl);

	p->context.oe		= __raw_readl(base + regs->direction);

	p->context.wake_en	= __raw_readl(base + regs->wkup_en);

	p->context.leveldetect0	= __raw_readl(base + regs->leveldetect0);

	p->context.leveldetect1	= __raw_readl(base + regs->leveldetect1);

	p->context.risingdetect	= __raw_readl(base + regs->risingdetect);

	p->context.fallingdetect = __raw_readl(base + regs->fallingdetect);

	p->context.irqenable1	= __raw_readl(base + regs->irqenable);

	p->context.irqenable2	= __raw_readl(base + regs->irqenable2);



	if (regs->set_dataout && p->regs->clr_dataout)

		p->context.dataout = __raw_readl(base + regs->set_dataout);

	else

		p->context.dataout = __raw_readl(base + regs->dataout);



	p->context_valid = true;

}



static void omap_gpio_restore_context(struct gpio_bank *bank)

{

	__raw_writel(bank->context.wake_en,
@@ -1421,6 +1462,7 @@ static void omap_gpio_restore_context(struct gpio_bank *bank) 
#else

#define omap_gpio_runtime_suspend NULL

#define omap_gpio_runtime_resume NULL

static void omap_gpio_init_context(struct gpio_bank *p) {}

#endif



static const struct dev_pm_ops gpio_pm_ops = {