Here comes a bunch of patches to illustrate my idea, some are not related to
the point I mentioned, and they are not mature for now :-)
Subject: [PATCH 1/5] add gpio_is_onchip() for commonly used gpio range checking
---
lib/gpiolib.c | 32 ++++++++++++++++++++++----------
1 files changed, 22 insertions(+), 10 deletions(-)
diff --git a/lib/gpiolib.c b/lib/gpiolib.c
index f2ae689..c627efb 100644
--- a/lib/gpiolib.c
+++ b/lib/gpiolib.c
@@ -33,6 +33,14 @@ static DEFINE_SPINLOCK(gpio_lock);
static struct gpio_chip *chips[DIV_ROUND_UP(ARCH_NR_GPIOS,
ARCH_GPIOS_PER_CHIP)];
+static inline int gpio_is_onchip(unsigned gpio, struct gpio_chip *chip)
+{
+ if (chip && gpio >= chip->base && gpio < chip->base + chip->ngpio)
+ return 1;
+ else
+ return 0;
+}
+
/* Warn when drivers omit gpio_request() calls -- legal but
* ill-advised when setting direction, and otherwise illegal.
*/
@@ -139,11 +147,11 @@ int gpio_request(unsigned gpio, const char *label)
spin_lock_irqsave(&gpio_lock, flags);
chip = gpio_to_chip(gpio);
- if (!chip)
+
+ if (!gpio_is_onchip(gpio, chip))
goto done;
+
gpio -= chip->base;
- if (gpio >= chip->ngpio)
- goto done;
/* NOTE: gpio_request() can be called in early boot,
* before IRQs are enabled.
@@ -176,11 +184,11 @@ void gpio_free(unsigned gpio)
spin_lock_irqsave(&gpio_lock, flags);
chip = gpio_to_chip(gpio);
- if (!chip)
+
+ if (!gpio_is_onchip(gpio, chip))
goto done;
+
gpio -= chip->base;
- if (gpio >= chip->ngpio)
- goto done;
#ifdef CONFIG_DEBUG_FS
if (chip->requested[gpio])
@@ -218,9 +226,11 @@ int gpio_direction_input(unsigned gpio)
chip = gpio_to_chip(gpio);
if (!chip || !chip->get || !chip->direction_input)
goto fail;
- gpio -= chip->base;
- if (gpio >= chip->ngpio)
+
+ if (!gpio_is_onchip(gpio, chip))
goto fail;
+
+ gpio -= chip->base;
gpio_ensure_requested(chip, gpio);
/* now we know the gpio is valid and chip won't vanish */
@@ -250,9 +260,11 @@ int gpio_direction_output(unsigned gpio, int value)
chip = gpio_to_chip(gpio);
if (!chip || !chip->get || !chip->direction_output)
goto fail;
- gpio -= chip->base;
- if (gpio >= chip->ngpio)
+
+ if (!gpio_is_onchip(gpio, chip))
goto fail;
+
+ gpio -= chip->base;
gpio_ensure_requested(chip, gpio);
/* now we know the gpio is valid and chip won't vanish */
--
1.5.2.5.GIT
-
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