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authorJon Hunter <jon-hunter@ti.com>2013-04-15 22:06:54 +0400
committerLinus Walleij <linus.walleij@linaro.org>2013-05-13 23:20:44 +0400
commit352a2d5bfc336d980af69cb0ed24f86d9026f377 (patch)
tree65b8c78f26230fd3b526709cb4490f1cf233f759 /drivers/gpio
parentf722406faae2d073cc1d01063d1123c35425939e (diff)
downloadlinux-352a2d5bfc336d980af69cb0ed24f86d9026f377.tar.xz
gpio/omap: ensure gpio context is initialised
Commit a2797be (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: Tony Lindgren <tony@atomide.com> Signed-off-by: Jon Hunter <jon-hunter@ti.com> Acked-by: Santosh Shilimkar<santosh.shilimkar@ti.com> Reviewed-by: Kevin Hilman <khilman@linaro.org> Tested-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio')
-rw-r--r--drivers/gpio/gpio-omap.c48
1 files changed, 45 insertions, 3 deletions
diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
index 2050891d9c65..d3f7d2db870f 100644
--- a/drivers/gpio/gpio-omap.c
+++ b/drivers/gpio/gpio-omap.c
@@ -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 @@ update_gpio_context_count:
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 = {