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Subject[PATCHv2 6/7] basic_mmio_gpio: support different input/output registers
Date
Some controllers have separate input and output registers.  For these
controllers, allow a register named "in" to be used for reading the
value of a GPIO pin.

Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: Anton Vorontsov <cbouatmailru@gmail.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
---
drivers/gpio/basic_mmio_gpio.c | 31 +++++++++++++++++++++++++++++--
1 files changed, 29 insertions(+), 2 deletions(-)
diff --git a/drivers/gpio/basic_mmio_gpio.c b/drivers/gpio/basic_mmio_gpio.c
index 9be1867..ed4b0c6 100644
--- a/drivers/gpio/basic_mmio_gpio.c
+++ b/drivers/gpio/basic_mmio_gpio.c
@@ -70,6 +70,7 @@ struct bgpio_chip {
void __iomem *reg_dat;
void __iomem *reg_set;
void __iomem *reg_clr;
+ void __iomem *reg_in;

/* Number of bits (GPIOs): <register width> * 8. */
int bits;
@@ -148,13 +149,20 @@ static unsigned long bgpio_pin2mask_be(struct bgpio_chip *bgc,
return 1 << (bgc->bits - 1 - pin);
}

-static int bgpio_get(struct gpio_chip *gc, unsigned int gpio)
+static int bgpio_get_dat(struct gpio_chip *gc, unsigned int gpio)
{
struct bgpio_chip *bgc = to_bgpio_chip(gc);

return bgc->read_reg(bgc->reg_dat) & bgc->pin2mask(bgc, gpio);
}

+static int bgpio_get_in(struct gpio_chip *gc, unsigned int gpio)
+{
+ struct bgpio_chip *bgc = to_bgpio_chip(gc);
+
+ return bgc->read_reg(bgc->reg_in) & bgc->pin2mask(bgc, gpio);
+}
+
static void bgpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
{
struct bgpio_chip *bgc = to_bgpio_chip(gc);
@@ -254,12 +262,19 @@ static int bgpio_setup_accessors(struct platform_device *pdev,
* by clearing a bit. For the set clr pair, this drives a 1 by setting a bit
* in the set register and clears it by setting a bit in the clear register.
* The configuration is detected by which resources are present.
+ *
+ * For getting GPIO values, there are two supported configurations:
+ *
+ * - single output/input register resource (named "dat").
+ * - separate output/input register resources (named "dat" and "in").
+ *
*/
static int bgpio_setup_io(struct platform_device *pdev,
struct bgpio_chip *bgc)
{
struct resource *res_set;
struct resource *res_clr;
+ struct resource *res_in;

res_set = platform_get_resource_byname(pdev, IORESOURCE_MEM, "set");
res_clr = platform_get_resource_byname(pdev, IORESOURCE_MEM, "clr");
@@ -280,6 +295,19 @@ static int bgpio_setup_io(struct platform_device *pdev,
bgc->gc.set = bgpio_set;
}

+ res_in = platform_get_resource_byname(pdev, IORESOURCE_MEM, "in");
+ if (res_in) {
+ bgc->reg_in = bgpio_request_and_map(&pdev->dev, res_in);
+ if (!bgc->reg_in)
+ return -ENOMEM;
+ bgc->gc.get = bgpio_get_in;
+ } else {
+ bgc->gc.get = bgpio_get_dat;
+ }
+
+ return 0;
+}
+
return 0;
}

@@ -338,7 +366,6 @@ static int __devinit bgpio_probe(struct platform_device *pdev)
bgc->gc.ngpio = ngpio;
bgc->gc.direction_input = bgpio_dir_in;
bgc->gc.direction_output = bgpio_dir_out;
- bgc->gc.get = bgpio_get;
bgc->gc.dev = dev;
bgc->gc.label = dev_name(dev);

--
1.7.4.2


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