[PATCH] gpiolib: let gpiochip_add_pin_range() specify offset

Linus Walleij
2012-11-20T11:46:24Z

From: Linus Walleij <linus.walleij@linaro.org>

Like with commit 3c739ad0df5eb41cd7adad879eda6aa09879eb76
it is not always enough to specify all the pins of a gpio_chip
from offset zero to be added to a pin map range, since the
mapping from GPIO to pin controller may not be linear at all,
but need to be broken into a few consecutive sub-ranges or
1-pin entries for complicated cases. The ranges may also be
sparse.

This alters the signature of the function to accept offsets
into both the GPIO-chip local pinspace and the pin controller
local pinspace.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
drivers/gpio/gpiolib.c | 18 ++++++++++++++++--
include/asm-generic/gpio.h | 6 ++++--
include/linux/gpio.h | 3 ++-
3 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index c5f6500..0b08d27 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1187,8 +1187,18 @@ EXPORT_SYMBOL_GPL(gpiochip_find);

#ifdef CONFIG_PINCTRL

+/**
+ * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
+ * @chip: the gpiochip to add the range for
+ * @pinctrl_name: the dev_name() of the pin controller to map to
+ * @offset: the start offset in the current gpio_chip number space
+ * @pin_base: the start offset in the pin controller number space
+ * @npins: the number of pins from the offset of each pin space (GPIO and
+ * pin controller) to accumulate in this range
+ */
int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
- unsigned int pin_base, unsigned int npins)
+ unsigned int offset, unsigned int pin_base,
+ unsigned int npins)
{
struct gpio_pin_range *pin_range;

@@ -1200,7 +1210,7 @@ int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
}

pin_range->range.name = chip->label;
- pin_range->range.base = chip->base;
+ pin_range->range.base = chip->base + offset;
pin_range->range.pin_base = pin_base;
pin_range->range.npins = npins;
pin_range->pctldev = find_pinctrl_and_add_gpio_range(pinctl_name,
@@ -1212,6 +1222,10 @@ int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
}
EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);

+/**
+ * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
+ * @chip: the chip to remove all the mappings for
+ */
void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
{
struct gpio_pin_range *pin_range, *tmp;
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index 2b84fc3..ec58fdb 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -283,14 +283,16 @@ struct gpio_pin_range {
};

int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
- unsigned int pin_base, unsigned int npins);
+ unsigned int offset, unsigned int pin_base,
+ unsigned int npins);
void gpiochip_remove_pin_ranges(struct gpio_chip *chip);

#else

static inline int
gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
- unsigned int pin_base, unsigned int npins)
+ unsigned int offset, unsigned int pin_base,
+ unsigned int npins)
{
return 0;
}
diff --git a/include/linux/gpio.h b/include/linux/gpio.h
index 7ba2762..99861c6 100644
--- a/include/linux/gpio.h
+++ b/include/linux/gpio.h
@@ -233,7 +233,8 @@ static inline int irq_to_gpio(unsigned irq)

static inline int
gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
- unsigned int pin_base, unsigned int npins)
+ unsigned int offset, unsigned int pin_base,
+ unsigned int npins)
{
WARN_ON(1);
return -EINVAL;
--
1.7.11.3