Add support for GPIO interrupts where the interrupt number
is dynamically allocated at first request from gpiolib.
This method is employed as the newer SoCs have a large number
of possible interrupt numbers which are very rarely heavily
used. However, the classic code has always registered all
possible interrupts, using a large amount of memory for the
irq_desc[] table.
For example, S5PV210 has 178 possible GPIO interrupt sources
of which few boards actually use any of these. The current
size of a single irq_desc entry is 80 bytes, meaing to fully
support GPIO interrupts on the V210 we use 14240 bytes when
a board may only need a few of these.
NOTE: This code is not tested, and not even booted. it is
offered here as an example and if people think it is a good
idea, I will do the necessary run testing and checking.
not-quite-signed-off-by: Ben Dooks <ben-linux@xxxxxxxxx>
---
arch/arm/mach-s5pv210/gpiolib.c | 10 +++++++++-
arch/arm/mach-s5pv210/include/mach/irqs.h | 5 ++++-
arch/arm/plat-s5p/Kconfig | 5 +++++
arch/arm/plat-s5p/Makefile | 1 +
arch/arm/plat-samsung/include/plat/gpio-core.h | 5 +++++
5 files changed, 24 insertions(+), 2 deletions(-)
diff --git a/arch/arm/mach-s5pv210/gpiolib.c b/arch/arm/mach-s5pv210/gpiolib.c
index 99dad92..68972ea 100644
--- a/arch/arm/mach-s5pv210/gpiolib.c
+++ b/arch/arm/mach-s5pv210/gpiolib.c
@@ -237,6 +237,12 @@ static struct s3c_gpio_chip s5pv210_gpio_4bit[] = {
},
};
+static int to_gpio_irq_bank(int nr)
+{
+ if (nr >= 17)
+ return nr - 4;
+}
+
static __init int s5pv210_gpiolib_init(void)
{
struct s3c_gpio_chip *chip = s5pv210_gpio_4bit;
@@ -244,8 +250,10 @@ static __init int s5pv210_gpiolib_init(void)
int i = 0;
for (i = 0; i < nr_chips; i++, chip++) {
- if (chip->config == NULL)
+ if (chip->config == NULL) {
chip->config = &gpio_cfg;
+ s5p_gpio_irq_register(chip, to_gpio_irq_bank(i));
+ }
if (chip->base == NULL)
chip->base = S5PV210_BANK_BASE(i);
}
diff --git a/arch/arm/mach-s5pv210/include/mach/irqs.h b/arch/arm/mach-s5pv210/include/mach/irqs.h
index 1714be2..dca0067 100644
--- a/arch/arm/mach-s5pv210/include/mach/irqs.h
+++ b/arch/arm/mach-s5pv210/include/mach/irqs.h
@@ -144,8 +144,11 @@
#define S5P_EINT_SET2(x) S5PV210_GPH2(x)
#define S5P_EINT_SET3(x) S5PV210_GPH3(x)
+#define IRQ_GPIO_BASE IRQ_EINT(31) + 1
+#define NR_GPIO_IRQS (24)
+
/* Set the default NR_IRQS */
-#define NR_IRQS (IRQ_EINT(31) + 1)
+#define NR_IRQS (IRQ_GPIO_BASE + NR_GPIO_IRQS)
#endif /* ASM_ARCH_IRQS_H */
diff --git a/arch/arm/plat-s5p/Kconfig b/arch/arm/plat-s5p/Kconfig
index 7d1fc40..c6be4c0 100644
--- a/arch/arm/plat-s5p/Kconfig
+++ b/arch/arm/plat-s5p/Kconfig
@@ -28,3 +28,8 @@ config S5P_EXT_INT
bool
help
Use the external interrupts (other than GPIO interrupts.)
+
+config S5P_GPIO_INT
+ bool "Support GPIO based interrupts"
+ help
+ Enable support for GPIO interrupts
diff --git a/arch/arm/plat-s5p/Makefile b/arch/arm/plat-s5p/Makefile
index 25941a5..826f8a6 100644
--- a/arch/arm/plat-s5p/Makefile
+++ b/arch/arm/plat-s5p/Makefile
@@ -17,4 +17,5 @@ obj-y += cpu.o
obj-y += clock.o
obj-y += irq.o
obj-$(CONFIG_S5P_EXT_INT) += irq-eint.o
+obj-$(CONFIG_S5P_GPIO_INT) += irq-gpio.o
obj-y += setup-i2c0.o
diff --git a/arch/arm/plat-samsung/include/plat/gpio-core.h b/arch/arm/plat-samsung/include/plat/gpio-core.h
index 49ff406..8c246ce 100644
--- a/arch/arm/plat-samsung/include/plat/gpio-core.h
+++ b/arch/arm/plat-samsung/include/plat/gpio-core.h
@@ -38,6 +38,7 @@ struct s3c_gpio_pm {
};
struct s3c_gpio_cfg;
+struct s3c_gpio_irq; /* irq implementation information */
/**
* struct s3c_gpio_chip - wrapper for specific implementation of gpio
@@ -53,6 +54,7 @@ struct s3c_gpio_chip {
struct gpio_chip chip;
struct s3c_gpio_cfg *config;
struct s3c_gpio_pm *pm;
+ struct s3c_gpio_irq *irq;
void __iomem *base;
#ifdef CONFIG_PM
u32 pm_save[4];
@@ -108,6 +110,9 @@ extern void samsung_gpiolib_add_4bit2_chips(struct s3c_gpio_chip *chip,
extern void samsung_gpiolib_add_4bit(struct s3c_gpio_chip *chip);
extern void samsung_gpiolib_add_4bit2(struct s3c_gpio_chip *chip);
+extern void s5p_gpio_irq_register(struct s3c_gpio_chip *chip,
+ unsigned int bank_nr);
+
#ifdef CONFIG_S3C_GPIO_TRACK
extern struct s3c_gpio_chip *s3c_gpios[S3C_GPIO_END];
--
1.6.3.3
--
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