diff options
Diffstat (limited to 'target/linux/generic-2.6/patches-2.6.25/961-backport_gpio_define_gpio_valid.patch')
| -rw-r--r-- | target/linux/generic-2.6/patches-2.6.25/961-backport_gpio_define_gpio_valid.patch | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/target/linux/generic-2.6/patches-2.6.25/961-backport_gpio_define_gpio_valid.patch b/target/linux/generic-2.6/patches-2.6.25/961-backport_gpio_define_gpio_valid.patch new file mode 100644 index 000000000..2e826d43f --- /dev/null +++ b/target/linux/generic-2.6/patches-2.6.25/961-backport_gpio_define_gpio_valid.patch @@ -0,0 +1,136 @@ +From: Guennadi Liakhovetski <g.liakhovetski@pengutronix.de> +Date: Mon, 28 Apr 2008 09:14:46 +0000 (-0700) +Subject: gpio: define gpio_is_valid() +X-Git-Tag: v2.6.26-rc1~849 +X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Ftorvalds%2Flinux-2.6.git;a=commitdiff_plain;h=e6de1808f8ebfeb7e49f3c5a30cb8f2032beb287 + +gpio: define gpio_is_valid() + +Introduce a gpio_is_valid() predicate; use it in gpiolib. + +Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@pengutronix.de> + [ use inline function; follow the gpio_* naming convention; + work without gpiolib; all programming interfaces need docs ] +Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> +Signed-off-by: Andrew Morton <akpm@linux-foundation.org> +Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> +--- + +diff --git a/Documentation/gpio.txt b/Documentation/gpio.txt +index 5463009..c35ca9e 100644 +--- a/Documentation/gpio.txt ++++ b/Documentation/gpio.txt +@@ -107,6 +107,16 @@ type of GPIO controller, and on one particular board 80-95 with an FPGA. + The numbers need not be contiguous; either of those platforms could also + use numbers 2000-2063 to identify GPIOs in a bank of I2C GPIO expanders. + ++If you want to initialize a structure with an invalid GPIO number, use ++some negative number (perhaps "-EINVAL"); that will never be valid. To ++test if a number could reference a GPIO, you may use this predicate: ++ ++ int gpio_is_valid(int number); ++ ++A number that's not valid will be rejected by calls which may request ++or free GPIOs (see below). Other numbers may also be rejected; for ++example, a number might be valid but unused on a given board. ++ + Whether a platform supports multiple GPIO controllers is currently a + platform-specific implementation issue. + +diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c +index eb75d12..623fcd9 100644 +--- a/drivers/gpio/gpiolib.c ++++ b/drivers/gpio/gpiolib.c +@@ -99,7 +99,7 @@ int gpiochip_add(struct gpio_chip *chip) + * dynamic allocation. We don't currently support that. + */ + +- if (chip->base < 0 || (chip->base + chip->ngpio) >= ARCH_NR_GPIOS) { ++ if (chip->base < 0 || !gpio_is_valid(chip->base + chip->ngpio)) { + status = -EINVAL; + goto fail; + } +@@ -174,7 +174,7 @@ int gpio_request(unsigned gpio, const char *label) + + spin_lock_irqsave(&gpio_lock, flags); + +- if (gpio >= ARCH_NR_GPIOS) ++ if (!gpio_is_valid(gpio)) + goto done; + desc = &gpio_desc[gpio]; + if (desc->chip == NULL) +@@ -209,7 +209,7 @@ void gpio_free(unsigned gpio) + unsigned long flags; + struct gpio_desc *desc; + +- if (gpio >= ARCH_NR_GPIOS) { ++ if (!gpio_is_valid(gpio)) { + WARN_ON(extra_checks); + return; + } +@@ -245,7 +245,7 @@ const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset) + { + unsigned gpio = chip->base + offset; + +- if (gpio >= ARCH_NR_GPIOS || gpio_desc[gpio].chip != chip) ++ if (!gpio_is_valid(gpio) || gpio_desc[gpio].chip != chip) + return NULL; + if (test_bit(FLAG_REQUESTED, &gpio_desc[gpio].flags) == 0) + return NULL; +@@ -276,7 +276,7 @@ int gpio_direction_input(unsigned gpio) + + spin_lock_irqsave(&gpio_lock, flags); + +- if (gpio >= ARCH_NR_GPIOS) ++ if (!gpio_is_valid(gpio)) + goto fail; + chip = desc->chip; + if (!chip || !chip->get || !chip->direction_input) +@@ -314,7 +314,7 @@ int gpio_direction_output(unsigned gpio, int value) + + spin_lock_irqsave(&gpio_lock, flags); + +- if (gpio >= ARCH_NR_GPIOS) ++ if (!gpio_is_valid(gpio)) + goto fail; + chip = desc->chip; + if (!chip || !chip->set || !chip->direction_output) +@@ -531,7 +531,7 @@ static int gpiolib_show(struct seq_file *s, void *unused) + + /* REVISIT this isn't locked against gpio_chip removal ... */ + +- for (gpio = 0; gpio < ARCH_NR_GPIOS; gpio++) { ++ for (gpio = 0; gpio_is_valid(gpio); gpio++) { + if (chip == gpio_desc[gpio].chip) + continue; + chip = gpio_desc[gpio].chip; +diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h +index 7e77b6f..464c5b3 100644 +--- a/include/asm-generic/gpio.h ++++ b/include/asm-generic/gpio.h +@@ -16,6 +16,12 @@ + #define ARCH_NR_GPIOS 256 + #endif + ++static inline int gpio_is_valid(int number) ++{ ++ /* only some non-negative numbers are valid */ ++ return ((unsigned)number) < ARCH_NR_GPIOS; ++} ++ + struct seq_file; + struct module; + +@@ -99,6 +105,12 @@ extern int __gpio_cansleep(unsigned gpio); + + #else + ++static inline int gpio_is_valid(int number) ++{ ++ /* only non-negative numbers are valid */ ++ return number >= 0; ++} ++ + /* platforms that don't directly support access to GPIOs through I2C, SPI, + * or other blocking infrastructure can use these wrappers. + */ |