diff options
| author | Adrian Hunter <adrian.hunter@intel.com> | 2011-10-03 11:36:07 (GMT) |
|---|---|---|
| committer | Grant Likely <grant.likely@secretlab.ca> | 2011-10-06 10:14:52 (GMT) |
| commit | 8c0f7b10f1028d0bc78486affe2ccf39cdf45282 (patch) | |
| tree | 824ac3afe0678311c95f6cc09f45da8b63f331a9 | |
| parent | 38eb18a6f92da886fc1af509d25e8f7a49e23d9a (diff) | |
| download | linux-8c0f7b10f1028d0bc78486affe2ccf39cdf45282.tar.xz | |
gpio: langwell: ensure alternate function is cleared
Alternate function must be zero for the pin to act as
a GPIO.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
| -rw-r--r-- | 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); + return ptr; +} + +static int lnw_gpio_request(struct gpio_chip *chip, unsigned offset) +{ + void __iomem *gafr = gpio_reg_2bit(chip, offset, GAFR); + u32 value = readl(gafr); + int shift = (offset % 16) << 1, af = (value >> shift) & 3; + + if (af) { + value &= ~(3 << shift); + writel(value, gafr); + } + return 0; +} + static int lnw_gpio_get(struct gpio_chip *chip, unsigned offset) { void __iomem *gplr = gpio_reg(chip, offset, GPLR); @@ -321,6 +347,7 @@ static int __devinit lnw_gpio_probe(struct pci_dev *pdev, lnw->reg_base = base; lnw->irq_base = irq_base; lnw->chip.label = dev_name(&pdev->dev); + lnw->chip.request = lnw_gpio_request; lnw->chip.direction_input = lnw_gpio_direction_input; lnw->chip.direction_output = lnw_gpio_direction_output; lnw->chip.get = lnw_gpio_get; |