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authorLinus Walleij <linus.walleij@linaro.org>2012-11-20 12:40:15 +0100
committerLinus Walleij <linus.walleij@linaro.org>2012-11-21 08:55:03 +0100
commit3f0f8670608766ef26a178d4e80cad3ce030fecc (patch)
treed2f192a4a454bd677983c7eb0b88a0016f128bf6 /drivers/gpio
parent5212d096cbed2eae1e442b3f8bf448e6a577af6f (diff)
downloadlinux-3f0f8670608766ef26a178d4e80cad3ce030fecc.tar.bz2
gpiolib: let gpiochip_add_pin_range() specify offset
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. Reviewed-by: Stephen Warren <swarren@nvidia.com> Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio')
-rw-r--r--drivers/gpio/gpiolib-of.c12
-rw-r--r--drivers/gpio/gpiolib.c32
2 files changed, 41 insertions, 3 deletions
diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index a40cd84c5c10..d542a141811a 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -238,8 +238,20 @@ static void of_gpiochip_add_pin_range(struct gpio_chip *chip)
if (!pctldev)
break;
+ /*
+ * This assumes that the n GPIO pins are consecutive in the
+ * GPIO number space, and that the pins are also consecutive
+ * in their local number space. Currently it is not possible
+ * to add different ranges for one and the same GPIO chip,
+ * as the code assumes that we have one consecutive range
+ * on both, mapping 1-to-1.
+ *
+ * TODO: make the OF bindings handle multiple sparse ranges
+ * on the same GPIO chip.
+ */
ret = gpiochip_add_pin_range(chip,
pinctrl_dev_get_name(pctldev),
+ 0, /* offset in gpiochip */
pinspec.args[0],
pinspec.args[1]);
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index c5f650095faa..6d13bea4778a 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1187,24 +1187,45 @@ 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;
- pin_range = devm_kzalloc(chip->dev, sizeof(*pin_range), GFP_KERNEL);
+ pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
if (!pin_range) {
pr_err("%s: GPIO chip: failed to allocate pin ranges\n",
chip->label);
return -ENOMEM;
}
+ /* Use local offset as range ID */
+ pin_range->range.id = offset;
+ pin_range->range.gc = chip;
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,
&pin_range->range);
+ if (!pin_range->pctldev) {
+ pr_err("%s: GPIO chip: could not create pin range\n",
+ chip->label);
+ kfree(pin_range);
+ }
+ pr_debug("%s: GPIO chip: created GPIO range %d->%d ==> PIN %d->%d\n",
+ chip->label, offset, offset + npins - 1,
+ pin_base, pin_base + npins - 1);
list_add_tail(&pin_range->node, &chip->pin_ranges);
@@ -1212,6 +1233,10 @@ 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;
@@ -1220,6 +1245,7 @@ void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
list_del(&pin_range->node);
pinctrl_remove_gpio_range(pin_range->pctldev,
&pin_range->range);
+ kfree(pin_range);
}
}
EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);