Re: [PATCH] gpio: langwell: ensure alternate function is cleared

[Adrian Hunter]

On 04/10/11 21:37, Grant Likely wrote:
> On Mon, Oct 03, 2011 at 02:36:07PM +0300, Adrian Hunter wrote:
> > Alternate function must be zero for the pin to act as
> > a GPIO.
> >
> > Signed-off-by: Adrian Hunter<adrian.hunter@xxxxxxxxx>
> > Signed-off-by: Alan Cox<alan@xxxxxxxxxxxxxxx>
> > ---
> >   drivers/gpio/gpio-langwell.c |   27 +++++++++++++++++++++++++++
> >   1 files changed, 27 insertions(+), 0 deletions(-)
> >
> > diff --git a/drivers/gpio/gpio-langwell.c b/drivers/gpio/gpio-langwell.c
> > index d2eb57c..00692e8 100644
> > --- a/drivers/gpio/gpio-langwell.c
> > +++ b/drivers/gpio/gpio-langwell.c
> > @@ -59,6 +59,7 @@ enum GPIO_REG {
> >   	GRER,		/* rising edge detect */
> >   	GFER,		/* falling edge detect */
> >   	GEDR,		/* edge detect result */
> > +	GAFR,		/* alt function */
> >   };
> >
> >   struct lnw_gpio {
> > @@ -81,6 +82,31 @@ static void __iomem *gpio_reg(struct gpio_chip *chip, unsigned offset,
> >   	return ptr;
> >   }
> >
> > +static void __iomem *gpio_reg_2bit(struct gpio_chip *chip, unsigned offset,
> > +				   enum GPIO_REG reg_type)
> > +{
> > +	struct lnw_gpio *lnw = container_of(chip, struct lnw_gpio, chip);
> > +	unsigned nreg = chip->ngpio / 32;
> > +	u8 reg = offset / 16;
> > +	void __iomem *ptr;
> > +
> > +	ptr = (void __iomem *)(lnw->reg_base + reg_type * nreg * 4 + reg * 4);
>
> This looks wrong.  It looks to me like the __iomem annotation should
> be added to ->reg_base.
>
> Otherwise, the patch looks okay.

Deserves a separate patch...

From: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Date: Wed, 5 Oct 2011 10:29:27 +0300
Subject: [PATCH] gpio: langwell: declare reg_base as __iomem

reg_base is __iomem so add that to the declaration
and fix up assignment casts and types.

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
 drivers/gpio/gpio-langwell.c |   12 ++++++------
 1 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/gpio/gpio-langwell.c b/drivers/gpio/gpio-langwell.c
index 00692e8..b7465e5 100644
--- a/drivers/gpio/gpio-langwell.c
+++ b/drivers/gpio/gpio-langwell.c
@@ -64,7 +64,7 @@ enum GPIO_REG {

 struct lnw_gpio {
 	struct gpio_chip		chip;
-	void				*reg_base;
+	void __iomem			*reg_base;
 	spinlock_t			lock;
 	unsigned			irq_base;
 	struct pci_dev			*pdev;
@@ -78,7 +78,7 @@ static void __iomem *gpio_reg(struct gpio_chip *chip, 
unsigned offset,
 	u8 reg = offset / 32;
 	void __iomem *ptr;

-	ptr = (void __iomem *)(lnw->reg_base + reg_type * nreg * 4 + reg * 4);
+	ptr = lnw->reg_base + reg_type * nreg * 4 + reg * 4;
 	return ptr;
 }

@@ -90,7 +90,7 @@ static void __iomem *gpio_reg_2bit(struct gpio_chip 
*chip, unsigned offset,
 	u8 reg = offset / 16;
 	void __iomem *ptr;

-	ptr = (void __iomem *)(lnw->reg_base + reg_type * nreg * 4 + reg * 4);
+	ptr = lnw->reg_base + reg_type * nreg * 4 + reg * 4;
 	return ptr;
 }

@@ -299,7 +299,7 @@ static const struct dev_pm_ops lnw_gpio_pm_ops = {
 static int __devinit lnw_gpio_probe(struct pci_dev *pdev,
 			const struct pci_device_id *id)
 {
-	void *base;
+	void __iomem *base;
 	int i;
 	resource_size_t start, len;
 	struct lnw_gpio *lnw;
@@ -324,8 +324,8 @@ static int __devinit lnw_gpio_probe(struct pci_dev 
*pdev,
 		dev_err(&pdev->dev, "error mapping bar1\n");
 		goto err3;
 	}
-	irq_base = *(u32 *)base;
-	gpio_base = *((u32 *)base + 1);
+	irq_base = *(__force u32 *)base;
+	gpio_base = *((__force u32 *)base + 1);
 	/* release the IO mapping, since we already get the info from bar1 */
 	iounmap(base);
 	/* get the register base from bar0 */
--
1.7.6

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