Add gpio_to_irq() implementation allowing the
gpio_chip registration to also specify an function
to map GPIO offsets into IRQs.
Signed-off-by: Ben Dooks <[email protected]>
Index: linux-2.6.26-quilt3/drivers/gpio/gpiolib.c
===================================================================
--- linux-2.6.26-quilt3.orig/drivers/gpio/gpiolib.c 2008-07-18 13:50:32.000000000 +0100
+++ linux-2.6.26-quilt3/drivers/gpio/gpiolib.c 2008-07-22 15:20:26.000000000 +0100
@@ -339,6 +339,36 @@ const char *gpiochip_is_requested(struct
}
EXPORT_SYMBOL_GPL(gpiochip_is_requested);
+int __gpio_to_irq(unsigned gpio)
+{
+ struct gpio_chip *chip;
+ struct gpio_desc *desc = &gpio_desc[gpio];
+ unsigned long flags;
+ int status = -EINVAL;
+
+ spin_lock_irqsave(&gpio_lock, flags);
+
+ if (!gpio_is_valid(gpio))
+ goto fail;
+
+ chip = desc->chip;
+ if (!chip || !chip->to_irq)
+ goto fail;
+
+ gpio -= chip->base;
+ if (gpio >= chip->ngpio)
+ goto fail;
+
+ status = chip->to_irq(chip, gpio);
+
+ fail:
+ spin_unlock_irqrestore(&gpio_lock, flags);
+ if (status)
+ pr_debug("%s: gpio-%d status %d\n",
+ __func__, gpio, status);
+ return status;
+}
+EXPORT_SYMBOL_GPL(__gpio_to_irq);
/* Drivers MUST set GPIO direction before making get/set calls. In
* some cases this is done in early boot, before IRQs are enabled.
Index: linux-2.6.26-quilt3/include/asm-generic/gpio.h
===================================================================
--- linux-2.6.26-quilt3.orig/include/asm-generic/gpio.h 2008-07-18 13:50:32.000000000 +0100
+++ linux-2.6.26-quilt3/include/asm-generic/gpio.h 2008-07-22 15:21:05.000000000 +0100
@@ -40,6 +40,7 @@ struct module;
* @dbg_show: optional routine to show contents in debugfs; default code
* will be used when this is omitted, but custom code can show extra
* state (such as pullup/pulldown configuration).
+ * @to_irq: convert gpio offset to IRQ number.
* @base: identifies the first GPIO number handled by this chip; or, if
* negative during registration, requests dynamic ID allocation.
* @ngpio: the number of GPIOs handled by this controller; the last GPIO
@@ -71,6 +72,9 @@ struct gpio_chip {
unsigned offset, int value);
void (*dbg_show)(struct seq_file *s,
struct gpio_chip *chip);
+ int (*to_irq)(struct gpio_chip *chip,
+ unsigned offset);
+
int base;
u16 ngpio;
unsigned can_sleep:1;
@@ -97,6 +101,7 @@ extern int gpio_direction_output(unsigne
extern int gpio_get_value_cansleep(unsigned gpio);
extern void gpio_set_value_cansleep(unsigned gpio, int value);
+extern int __gpio_to_irq(unsigned gpio);
/* A platform's <asm/gpio.h> code may want to inline the I/O calls when
* the GPIO is constant and refers to some always-present controller,
Index: linux-2.6.26-quilt3/Documentation/gpio.txt
===================================================================
--- linux-2.6.26-quilt3.orig/Documentation/gpio.txt 2008-07-22 15:22:08.000000000 +0100
+++ linux-2.6.26-quilt3/Documentation/gpio.txt 2008-07-22 15:27:14.000000000 +0100
@@ -273,8 +273,9 @@ some GPIOs can't be used as IRQs.) It i
number that wasn't set up as an input using gpio_direction_input(), or
to use an IRQ number that didn't originally come from gpio_to_irq().
-These two mapping calls are expected to cost on the order of a single
-addition or subtraction. They're not allowed to sleep.
+These two mapping calls are expected to cost on between the order of a
+single addition or subtraction to obtaining an spinlock and using the
+to_irq method of the relevant gpio chip. They're not allowed to sleep.
Non-error values returned from gpio_to_irq() can be passed to request_irq()
or free_irq(). They will often be stored into IRQ resources for platform
@@ -400,6 +401,7 @@ They may also want to provide a custom v
Trivial implementations of those functions can directly use framework
code, which always dispatches through the gpio_chip:
+ #define gpio_to_irq __gpio_to_irq
#define gpio_get_value __gpio_get_value
#define gpio_set_value __gpio_set_value
#define gpio_cansleep __gpio_cansleep
--
Ben ([email protected], http://www.fluff.org/)
'a smiley only costs 4 bytes'
On Thu, Jul 24, 2008 at 12:46:27PM +0100, Ben Dooks wrote:
> Add gpio_to_irq() implementation allowing the
> gpio_chip registration to also specify an function
> to map GPIO offsets into IRQs.
>
> Signed-off-by: Ben Dooks <[email protected]>
>
> Index: linux-2.6.26-quilt3/drivers/gpio/gpiolib.c
> ===================================================================
> --- linux-2.6.26-quilt3.orig/drivers/gpio/gpiolib.c 2008-07-18 13:50:32.000000000 +0100
> +++ linux-2.6.26-quilt3/drivers/gpio/gpiolib.c 2008-07-22 15:20:26.000000000 +0100
> @@ -339,6 +339,36 @@ const char *gpiochip_is_requested(struct
> }
> EXPORT_SYMBOL_GPL(gpiochip_is_requested);
>
> +int __gpio_to_irq(unsigned gpio)
> +{
> + struct gpio_chip *chip;
> + struct gpio_desc *desc = &gpio_desc[gpio];
> + unsigned long flags;
> + int status = -EINVAL;
> +
> + spin_lock_irqsave(&gpio_lock, flags);
> +
> + if (!gpio_is_valid(gpio))
> + goto fail;
> +
> + chip = desc->chip;
> + if (!chip || !chip->to_irq)
> + goto fail;
> +
> + gpio -= chip->base;
> + if (gpio >= chip->ngpio)
> + goto fail;
> +
> + status = chip->to_irq(chip, gpio);
hmm, this should have a check for chip->to_irq
being non-null before it.
> +
> + fail:
> + spin_unlock_irqrestore(&gpio_lock, flags);
> + if (status)
> + pr_debug("%s: gpio-%d status %d\n",
> + __func__, gpio, status);
> + return status;
> +}
> +EXPORT_SYMBOL_GPL(__gpio_to_irq);
>
> /* Drivers MUST set GPIO direction before making get/set calls. In
> * some cases this is done in early boot, before IRQs are enabled.
> Index: linux-2.6.26-quilt3/include/asm-generic/gpio.h
> ===================================================================
> --- linux-2.6.26-quilt3.orig/include/asm-generic/gpio.h 2008-07-18 13:50:32.000000000 +0100
> +++ linux-2.6.26-quilt3/include/asm-generic/gpio.h 2008-07-22 15:21:05.000000000 +0100
> @@ -40,6 +40,7 @@ struct module;
> * @dbg_show: optional routine to show contents in debugfs; default code
> * will be used when this is omitted, but custom code can show extra
> * state (such as pullup/pulldown configuration).
> + * @to_irq: convert gpio offset to IRQ number.
> * @base: identifies the first GPIO number handled by this chip; or, if
> * negative during registration, requests dynamic ID allocation.
> * @ngpio: the number of GPIOs handled by this controller; the last GPIO
> @@ -71,6 +72,9 @@ struct gpio_chip {
> unsigned offset, int value);
> void (*dbg_show)(struct seq_file *s,
> struct gpio_chip *chip);
> + int (*to_irq)(struct gpio_chip *chip,
> + unsigned offset);
> +
> int base;
> u16 ngpio;
> unsigned can_sleep:1;
> @@ -97,6 +101,7 @@ extern int gpio_direction_output(unsigne
> extern int gpio_get_value_cansleep(unsigned gpio);
> extern void gpio_set_value_cansleep(unsigned gpio, int value);
>
> +extern int __gpio_to_irq(unsigned gpio);
>
> /* A platform's <asm/gpio.h> code may want to inline the I/O calls when
> * the GPIO is constant and refers to some always-present controller,
> Index: linux-2.6.26-quilt3/Documentation/gpio.txt
> ===================================================================
> --- linux-2.6.26-quilt3.orig/Documentation/gpio.txt 2008-07-22 15:22:08.000000000 +0100
> +++ linux-2.6.26-quilt3/Documentation/gpio.txt 2008-07-22 15:27:14.000000000 +0100
> @@ -273,8 +273,9 @@ some GPIOs can't be used as IRQs.) It i
> number that wasn't set up as an input using gpio_direction_input(), or
> to use an IRQ number that didn't originally come from gpio_to_irq().
>
> -These two mapping calls are expected to cost on the order of a single
> -addition or subtraction. They're not allowed to sleep.
> +These two mapping calls are expected to cost on between the order of a
> +single addition or subtraction to obtaining an spinlock and using the
> +to_irq method of the relevant gpio chip. They're not allowed to sleep.
>
> Non-error values returned from gpio_to_irq() can be passed to request_irq()
> or free_irq(). They will often be stored into IRQ resources for platform
> @@ -400,6 +401,7 @@ They may also want to provide a custom v
> Trivial implementations of those functions can directly use framework
> code, which always dispatches through the gpio_chip:
>
> + #define gpio_to_irq __gpio_to_irq
> #define gpio_get_value __gpio_get_value
> #define gpio_set_value __gpio_set_value
> #define gpio_cansleep __gpio_cansleep
>
> --
> Ben ([email protected], http://www.fluff.org/)
>
> 'a smiley only costs 4 bytes'
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
--
Ben ([email protected], http://www.fluff.org/)
'a smiley only costs 4 bytes'
Ben Dooks writes:
> Add gpio_to_irq() implementation allowing the
> gpio_chip registration to also specify an function
> to map GPIO offsets into IRQs.
>
> Signed-off-by: Ben Dooks <[email protected]>
>
> Index: linux-2.6.26-quilt3/drivers/gpio/gpiolib.c
> ===================================================================
> --- linux-2.6.26-quilt3.orig/drivers/gpio/gpiolib.c 2008-07-18 13:50:32.000000000 +0100
> +++ linux-2.6.26-quilt3/drivers/gpio/gpiolib.c 2008-07-22 15:20:26.000000000 +0100
> @@ -339,6 +339,36 @@ const char *gpiochip_is_requested(struct
> }
> EXPORT_SYMBOL_GPL(gpiochip_is_requested);
>
> +int __gpio_to_irq(unsigned gpio)
> +{
> + struct gpio_chip *chip;
> + struct gpio_desc *desc = &gpio_desc[gpio];
> + unsigned long flags;
> + int status = -EINVAL;
> +
> + spin_lock_irqsave(&gpio_lock, flags);
> +
> + if (!gpio_is_valid(gpio))
> + goto fail;
Please move the &gpio_desc[gpio] expression after the gpio_is_valid(gpio)
test. Otherwise you risk violating C's pointer rules if the gpio is invalid.
> +
> + chip = desc->chip;
> + if (!chip || !chip->to_irq)
> + goto fail;
> +
> + gpio -= chip->base;
> + if (gpio >= chip->ngpio)
> + goto fail;
> +
> + status = chip->to_irq(chip, gpio);
> +
> + fail:
> + spin_unlock_irqrestore(&gpio_lock, flags);
> + if (status)
> + pr_debug("%s: gpio-%d status %d\n",
> + __func__, gpio, status);
> + return status;
> +}