[PATCH] gpio/omap: ensure gpio context is initialised
Jon Hunter
jon-hunter at ti.com
Thu Apr 18 20:49:29 EDT 2013
On 04/18/2013 07:34 PM, Jon Hunter wrote:
>
> On 04/18/2013 06:10 PM, Jon Hunter wrote:
>> On 04/18/2013 04:34 PM, Kevin Hilman wrote:
>
> ...
>
>>> Why not just init context right here if bank->loses_context &&
>>> !bank->context_valid?
>
> I really like this idea a lot. It can really clean-up the code
> and really make it much more readable. Before we were playing
> some tricks with when we init'ed the get_context_loss_count()
> function pointer. How about the below?
>
> Tony, care to re-test?
>
> Cheers
> Jon
>
> From d7a940531d354e6be5e16ee50fa8344041df963a Mon Sep 17 00:00:00 2001
> From: Jon Hunter <jon-hunter at ti.com>
> Date: Mon, 15 Apr 2013 13:06:54 -0500
> Subject: [PATCH] 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 at atomide.com>
> Signed-off-by: Jon Hunter <jon-hunter at ti.com>
> ---
> drivers/gpio/gpio-omap.c | 45 ++++++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 42 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
> index 0557529..db3c732 100644
> --- a/drivers/gpio/gpio-omap.c
> +++ b/drivers/gpio/gpio-omap.c
> @@ -70,6 +70,7 @@ struct gpio_bank {
> bool is_mpuio;
> bool dbck_flag;
> bool loses_context;
> + bool context_valid;
> int stride;
> u32 width;
> int context_loss_count;
> @@ -1129,6 +1130,7 @@ static int omap_gpio_probe(struct platform_device *pdev)
> bank->loses_context = true;
> } else {
> bank->loses_context = pdata->loses_context;
> + bank->get_context_loss_count = pdata->get_context_loss_count;
Still need to check loses_context for populating
get_context_loss_count here. Updated patch below.
Jon
>From d02ef7b7dfcf8e13bf019aedfdecb38ca3c6749f Mon Sep 17 00:00:00 2001
From: Jon Hunter <jon-hunter at ti.com>
Date: Mon, 15 Apr 2013 13:06:54 -0500
Subject: [PATCH] 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 at atomide.com>
Signed-off-by: Jon Hunter <jon-hunter at ti.com>
---
drivers/gpio/gpio-omap.c | 48 +++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 45 insertions(+), 3 deletions(-)
diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
index 0557529..c3c3ffe 100644
--- a/drivers/gpio/gpio-omap.c
+++ b/drivers/gpio/gpio-omap.c
@@ -70,6 +70,7 @@ struct gpio_bank {
bool is_mpuio;
bool dbck_flag;
bool loses_context;
+ bool context_valid;
int stride;
u32 width;
int context_loss_count;
@@ -1129,6 +1130,10 @@ 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;
}
@@ -1179,9 +1184,6 @@ 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);
@@ -1260,6 +1262,8 @@ 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);
@@ -1269,6 +1273,20 @@ 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);
/*
@@ -1385,6 +1403,29 @@ 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,
@@ -1422,6 +1463,7 @@ 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 = {
--
1.7.10.4
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