[PATCH] ARM: S5P64X0: External Interrupt Support

[PATCH] ARM: S5P64X0: External Interrupt Support

[Padmavathi Venna]

Add external interrupt support for S5P64X0. The external interrupts
supported are 0 to 15.

Signed-off-by: Padmavathi Venna <padma.v@samsung.com>
---
 arch/arm/mach-s5p64x0/Makefile                 |    1 +
 arch/arm/mach-s5p64x0/include/mach/regs-gpio.h |    6 +
 arch/arm/mach-s5p64x0/irq-eint.c               |  185 ++++++++++++++++++++++++
 3 files changed, 192 insertions(+), 0 deletions(-)
 create mode 100644 arch/arm/mach-s5p64x0/irq-eint.c

diff --git a/arch/arm/mach-s5p64x0/Makefile b/arch/arm/mach-s5p64x0/Makefile
index ae6bf6f..30f34f0 100644
--- a/arch/arm/mach-s5p64x0/Makefile
+++ b/arch/arm/mach-s5p64x0/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_ARCH_S5P64X0)	+= cpu.o init.o clock.o dma.o gpiolib.o
 obj-$(CONFIG_ARCH_S5P64X0)	+= setup-i2c0.o
 obj-$(CONFIG_CPU_S5P6440)	+= clock-s5p6440.o
 obj-$(CONFIG_CPU_S5P6450)	+= clock-s5p6450.o
+obj-y				+= irq-eint.o
 
 # machine support
 
diff --git a/arch/arm/mach-s5p64x0/include/mach/regs-gpio.h b/arch/arm/mach-s5p64x0/include/mach/regs-gpio.h
index 0953ef6..de005ac 100644
--- a/arch/arm/mach-s5p64x0/include/mach/regs-gpio.h
+++ b/arch/arm/mach-s5p64x0/include/mach/regs-gpio.h
@@ -34,4 +34,10 @@
 #define S5P6450_GPQ_BASE		(S5P_VA_GPIO + 0x0180)
 #define S5P6450_GPS_BASE		(S5P_VA_GPIO + 0x0300)
 
+/* External interrupt control registers for group0 */
+
+#define S5P64X0_EINT0CON0		(S5P_VA_GPIO + 0x900)
+#define S5P64X0_EINT0MASK		(S5P_VA_GPIO + 0x920)
+#define S5P64X0_EINT0PEND		(S5P_VA_GPIO + 0x924)
+
 #endif /* __ASM_ARCH_REGS_GPIO_H */
diff --git a/arch/arm/mach-s5p64x0/irq-eint.c b/arch/arm/mach-s5p64x0/irq-eint.c
new file mode 100644
index 0000000..cfaf599
--- /dev/null
+++ b/arch/arm/mach-s5p64x0/irq-eint.c
@@ -0,0 +1,185 @@
+/* arch/arm/mach-s5p64x0/irq-eint.c
+ *
+ * Copyright (c) 2011 Samsung Electronics Co., Ltd
+ *		http://www.samsung.com/
+ *
+ * Based on linux/arch/arm/mach-s3c64xx/irq-eint.c
+ *
+ * S5P64X0 - Interrupt handling for External Interrupts.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/gpio.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+
+#include <plat/regs-irqtype.h>
+#include <plat/gpio-cfg.h>
+
+#include <mach/regs-gpio.h>
+#include <mach/regs-clock.h>
+
+#define eint_offset(irq)	((irq) - IRQ_EINT(0))
+#define eint_irq_to_bit(irq)	((u32)(1 << eint_offset(irq)))
+
+static inline void s5p64x0_irq_eint_mask(struct irq_data *data)
+{
+	u32 mask;
+
+	mask = __raw_readl(S5P64X0_EINT0MASK);
+	mask |= (u32)data->chip_data;
+	__raw_writel(mask, S5P64X0_EINT0MASK);
+}
+
+static void s5p64x0_irq_eint_unmask(struct irq_data *data)
+{
+	u32 mask;
+
+	mask = __raw_readl(S5P64X0_EINT0MASK);
+	mask &= ~((u32)data->chip_data);
+	__raw_writel(mask, S5P64X0_EINT0MASK);
+}
+
+static inline void s5p64x0_irq_eint_ack(struct irq_data *data)
+{
+	__raw_writel((u32)data->chip_data, S5P64X0_EINT0PEND);
+}
+
+static void s5p64x0_irq_eint_maskack(struct irq_data *data)
+{
+	/* compiler should in-line these */
+	s5p64x0_irq_eint_mask(data);
+	s5p64x0_irq_eint_ack(data);
+}
+
+static int s5p64x0_irq_eint_set_type(struct irq_data *data, unsigned int type)
+{
+	int offs = eint_offset(data->irq);
+	int shift;
+	u32 ctrl, mask;
+	u32 newvalue = 0;
+	unsigned int id;
+
+	if (offs > 15)
+		return -EINVAL;
+
+	switch (type) {
+	case IRQ_TYPE_NONE:
+		printk(KERN_WARNING "No edge setting!\n");
+		break;
+
+	case IRQ_TYPE_EDGE_RISING:
+		newvalue = S3C2410_EXTINT_RISEEDGE;
+		break;
+
+	case IRQ_TYPE_EDGE_FALLING:
+		newvalue = S3C2410_EXTINT_FALLEDGE;
+		break;
+
+	case IRQ_TYPE_EDGE_BOTH:
+		newvalue = S3C2410_EXTINT_BOTHEDGE;
+		break;
+
+	case IRQ_TYPE_LEVEL_LOW:
+		newvalue = S3C2410_EXTINT_LOWLEV;
+		break;
+
+	case IRQ_TYPE_LEVEL_HIGH:
+		newvalue = S3C2410_EXTINT_HILEV;
+		break;
+
+	default:
+		printk(KERN_ERR "No such irq type %d", type);
+		return -1;
+	}
+
+	shift = (offs / 2) * 4;
+	mask = 0x7 << shift;
+
+	ctrl = __raw_readl(S5P64X0_EINT0CON0) & ~mask;
+	ctrl |= newvalue << shift;
+	__raw_writel(ctrl, S5P64X0_EINT0CON0);
+
+	id = __raw_readl(S5P64X0_SYS_ID) & 0xFF000;
+
+	if (id == 0x50000)
+		s3c_gpio_cfgpin(S5P6450_GPN(offs), S3C_GPIO_SFN(2));
+	else
+		s3c_gpio_cfgpin(S5P6440_GPN(offs), S3C_GPIO_SFN(2));
+
+	return 0;
+}
+
+static struct irq_chip s5p64x0_irq_eint = {
+	.name		= "s5p64x0-eint",
+	.irq_mask	= s5p64x0_irq_eint_mask,
+	.irq_unmask	= s5p64x0_irq_eint_unmask,
+	.irq_mask_ack	= s5p64x0_irq_eint_maskack,
+	.irq_ack	= s5p64x0_irq_eint_ack,
+	.irq_set_type	= s5p64x0_irq_eint_set_type,
+};
+
+/*
+ * s5p64x0_irq_demux_eint
+ *
+ * This function demuxes the IRQ from the group0 external interrupts,
+ * from IRQ_EINT(0) to IRQ_EINT(15). It is designed to be inlined into
+ * the specific handlers s5p64x0_irq_demux_eintX_Y.
+ */
+static inline void s5p64x0_irq_demux_eint(unsigned int start, unsigned int end)
+{
+	u32 status = __raw_readl(S5P64X0_EINT0PEND);
+	u32 mask = __raw_readl(S5P64X0_EINT0MASK);
+	unsigned int irq;
+
+	status &= ~mask;
+	status >>= start;
+	status &= (1 << (end - start + 1)) - 1;
+
+	for (irq = IRQ_EINT(start); irq <= IRQ_EINT(end); irq++) {
+		if (status & 1)
+			generic_handle_irq(irq);
+
+		status >>= 1;
+	}
+}
+
+static void s5p64x0_irq_demux_eint0_3(unsigned int irq, struct irq_desc *desc)
+{
+	s5p64x0_irq_demux_eint(0, 3);
+}
+
+static void s5p64x0_irq_demux_eint4_11(unsigned int irq, struct irq_desc *desc)
+{
+	s5p64x0_irq_demux_eint(4, 11);
+}
+
+static void s5p64x0_irq_demux_eint12_15(unsigned int irq,
+					struct irq_desc *desc)
+{
+	s5p64x0_irq_demux_eint(12, 15);
+}
+
+static int __init s5p64x0_init_irq_eint(void)
+{
+	int irq;
+
+	for (irq = IRQ_EINT(0); irq <= IRQ_EINT(15); irq++) {
+		irq_set_chip_and_handler(irq, &s5p64x0_irq_eint,
+					 handle_level_irq);
+		irq_set_chip_data(irq, (void *)eint_irq_to_bit(irq));
+		set_irq_flags(irq, IRQF_VALID);
+	}
+
+	irq_set_chained_handler(IRQ_EINT0_3, s5p64x0_irq_demux_eint0_3);
+	irq_set_chained_handler(IRQ_EINT4_11, s5p64x0_irq_demux_eint4_11);
+	irq_set_chained_handler(IRQ_EINT12_15, s5p64x0_irq_demux_eint12_15);
+
+	return 0;
+}
+
+arch_initcall(s5p64x0_init_irq_eint);
-- 
1.7.4.4

[PATCH] ARM: S5P64X0: External Interrupt Support

[Russell King - ARM Linux]

On Fri, Jul 15, 2011 at 12:11:34PM +0530, Padmavathi Venna wrote:
> +#define eint_offset(irq)	((irq) - IRQ_EINT(0))
> +#define eint_irq_to_bit(irq)	((u32)(1 << eint_offset(irq)))
> +
> +static inline void s5p64x0_irq_eint_mask(struct irq_data *data)
> +{
> +	u32 mask;
> +
> +	mask = __raw_readl(S5P64X0_EINT0MASK);
> +	mask |= (u32)data->chip_data;
> +	__raw_writel(mask, S5P64X0_EINT0MASK);
> +}
> +
> +static void s5p64x0_irq_eint_unmask(struct irq_data *data)
> +{
> +	u32 mask;
> +
> +	mask = __raw_readl(S5P64X0_EINT0MASK);
> +	mask &= ~((u32)data->chip_data);
> +	__raw_writel(mask, S5P64X0_EINT0MASK);
> +}
> +
> +static inline void s5p64x0_irq_eint_ack(struct irq_data *data)
> +{
> +	__raw_writel((u32)data->chip_data, S5P64X0_EINT0PEND);
> +}
> +
> +static void s5p64x0_irq_eint_maskack(struct irq_data *data)
> +{
> +	/* compiler should in-line these */
> +	s5p64x0_irq_eint_mask(data);
> +	s5p64x0_irq_eint_ack(data);
> +}

Won't genirqchip support deal with all of the above for you?

> +
> +static int s5p64x0_irq_eint_set_type(struct irq_data *data, unsigned int type)
> +{
> +	int offs = eint_offset(data->irq);
> +	int shift;
> +	u32 ctrl, mask;
> +	u32 newvalue = 0;
> +	unsigned int id;
> +
> +	if (offs > 15)
> +		return -EINVAL;
> +
> +	switch (type) {
> +	case IRQ_TYPE_NONE:
> +		printk(KERN_WARNING "No edge setting!\n");
> +		break;
> +
> +	case IRQ_TYPE_EDGE_RISING:
> +		newvalue = S3C2410_EXTINT_RISEEDGE;
> +		break;
> +
> +	case IRQ_TYPE_EDGE_FALLING:
> +		newvalue = S3C2410_EXTINT_FALLEDGE;
> +		break;
> +
> +	case IRQ_TYPE_EDGE_BOTH:
> +		newvalue = S3C2410_EXTINT_BOTHEDGE;
> +		break;
> +
> +	case IRQ_TYPE_LEVEL_LOW:
> +		newvalue = S3C2410_EXTINT_LOWLEV;
> +		break;
> +
> +	case IRQ_TYPE_LEVEL_HIGH:
> +		newvalue = S3C2410_EXTINT_HILEV;
> +		break;
> +
> +	default:
> +		printk(KERN_ERR "No such irq type %d", type);
> +		return -1;

NO!  Stop this right now and never do it again.  Please _always_ look
up the right error code and use it.

'return -1' is almost never valid.

[PATCH] ARM: S5P64X0: External Interrupt Support

[padma venkat]

Hi Russell,

On Fri, Jul 15, 2011 at 2:30 PM, Russell King - ARM Linux
<linux@arm.linux.org.uk> wrote:
> On Fri, Jul 15, 2011 at 12:11:34PM +0530, Padmavathi Venna wrote:
>> +#define eint_offset(irq) ? ? ((irq) - IRQ_EINT(0))
>> +#define eint_irq_to_bit(irq) ((u32)(1 << eint_offset(irq)))
>> +
>> +static inline void s5p64x0_irq_eint_mask(struct irq_data *data)
>> +{
>> + ? ? u32 mask;
>> +
>> + ? ? mask = __raw_readl(S5P64X0_EINT0MASK);
>> + ? ? mask |= (u32)data->chip_data;
>> + ? ? __raw_writel(mask, S5P64X0_EINT0MASK);
>> +}
>> +
>> +static void s5p64x0_irq_eint_unmask(struct irq_data *data)
>> +{
>> + ? ? u32 mask;
>> +
>> + ? ? mask = __raw_readl(S5P64X0_EINT0MASK);
>> + ? ? mask &= ~((u32)data->chip_data);
>> + ? ? __raw_writel(mask, S5P64X0_EINT0MASK);
>> +}
>> +
>> +static inline void s5p64x0_irq_eint_ack(struct irq_data *data)
>> +{
>> + ? ? __raw_writel((u32)data->chip_data, S5P64X0_EINT0PEND);
>> +}
>> +
>> +static void s5p64x0_irq_eint_maskack(struct irq_data *data)
>> +{
>> + ? ? /* compiler should in-line these */
>> + ? ? s5p64x0_irq_eint_mask(data);
>> + ? ? s5p64x0_irq_eint_ack(data);
>> +}
>
> Won't genirqchip support deal with all of the above for you?
As per my understanding, to deal with low level interrupt hardware access
we need to use the accessor functions. Please suggest me if there is
any better way of doing this.
>
>> +
>> +static int s5p64x0_irq_eint_set_type(struct irq_data *data, unsigned int type)
>> +{
>> + ? ? int offs = eint_offset(data->irq);
>> + ? ? int shift;
>> + ? ? u32 ctrl, mask;
>> + ? ? u32 newvalue = 0;
>> + ? ? unsigned int id;
>> +
>> + ? ? if (offs > 15)
>> + ? ? ? ? ? ? return -EINVAL;
>> +
>> + ? ? switch (type) {
>> + ? ? case IRQ_TYPE_NONE:
>> + ? ? ? ? ? ? printk(KERN_WARNING "No edge setting!\n");
>> + ? ? ? ? ? ? break;
>> +
>> + ? ? case IRQ_TYPE_EDGE_RISING:
>> + ? ? ? ? ? ? newvalue = S3C2410_EXTINT_RISEEDGE;
>> + ? ? ? ? ? ? break;
>> +
>> + ? ? case IRQ_TYPE_EDGE_FALLING:
>> + ? ? ? ? ? ? newvalue = S3C2410_EXTINT_FALLEDGE;
>> + ? ? ? ? ? ? break;
>> +
>> + ? ? case IRQ_TYPE_EDGE_BOTH:
>> + ? ? ? ? ? ? newvalue = S3C2410_EXTINT_BOTHEDGE;
>> + ? ? ? ? ? ? break;
>> +
>> + ? ? case IRQ_TYPE_LEVEL_LOW:
>> + ? ? ? ? ? ? newvalue = S3C2410_EXTINT_LOWLEV;
>> + ? ? ? ? ? ? break;
>> +
>> + ? ? case IRQ_TYPE_LEVEL_HIGH:
>> + ? ? ? ? ? ? newvalue = S3C2410_EXTINT_HILEV;
>> + ? ? ? ? ? ? break;
>> +
>> + ? ? default:
>> + ? ? ? ? ? ? printk(KERN_ERR "No such irq type %d", type);
>> + ? ? ? ? ? ? return -1;
>
> NO! ?Stop this right now and never do it again. ?Please _always_ look
> up the right error code and use it.
>
> 'return -1' is almost never valid.
I will correct this.
> --
> To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in
> the body of a message to majordomo at vger.kernel.org
> More majordomo info at ?http://vger.kernel.org/majordomo-info.html
>

[PATCH] ARM: S5P64X0: External Interrupt Support

[Russell King - ARM Linux]

On Fri, Jul 15, 2011 at 05:23:33PM +0530, padma venkat wrote:
> Hi Russell,
> 
> On Fri, Jul 15, 2011 at 2:30 PM, Russell King - ARM Linux
> <linux@arm.linux.org.uk> wrote:
> > On Fri, Jul 15, 2011 at 12:11:34PM +0530, Padmavathi Venna wrote:
> >> +#define eint_offset(irq) ? ? ((irq) - IRQ_EINT(0))
> >> +#define eint_irq_to_bit(irq) ((u32)(1 << eint_offset(irq)))
> >> +
> >> +static inline void s5p64x0_irq_eint_mask(struct irq_data *data)
> >> +{
> >> + ? ? u32 mask;
> >> +
> >> + ? ? mask = __raw_readl(S5P64X0_EINT0MASK);
> >> + ? ? mask |= (u32)data->chip_data;
> >> + ? ? __raw_writel(mask, S5P64X0_EINT0MASK);
> >> +}
> >> +
> >> +static void s5p64x0_irq_eint_unmask(struct irq_data *data)
> >> +{
> >> + ? ? u32 mask;
> >> +
> >> + ? ? mask = __raw_readl(S5P64X0_EINT0MASK);
> >> + ? ? mask &= ~((u32)data->chip_data);
> >> + ? ? __raw_writel(mask, S5P64X0_EINT0MASK);
> >> +}
> >> +
> >> +static inline void s5p64x0_irq_eint_ack(struct irq_data *data)
> >> +{
> >> + ? ? __raw_writel((u32)data->chip_data, S5P64X0_EINT0PEND);
> >> +}
> >> +
> >> +static void s5p64x0_irq_eint_maskack(struct irq_data *data)
> >> +{
> >> + ? ? /* compiler should in-line these */
> >> + ? ? s5p64x0_irq_eint_mask(data);
> >> + ? ? s5p64x0_irq_eint_ack(data);
> >> +}
> >
> > Won't genirqchip support deal with all of the above for you?
> As per my understanding, to deal with low level interrupt hardware access
> we need to use the accessor functions. Please suggest me if there is
> any better way of doing this.

I'm not saying don't have these.  I'm saying use the _generic_ irqchip
support which has the code implemented to set and clear bits in registers.
Something like this:

	struct irq_chip_generic *gc;

	gc = irq_alloc_generic_chip(name, 1, first_irq, base_of_controller,
			handler);

	gc->chip_types->chip.irq_ack = irq_gc_ack;
	gc->chip_types->chip.irq_mask = irq_gc_mask_set_bit;
	gc->chip_types->chip.irq_unmask = irq_gc_mask_clr_bit;

	/* replace the two below with the _real_ offset, rather than these calculations */
	gc->chip_types->reg.ack = S5P64X0_EINT0PEND - base_of_controller;
	gc->chip_types->reg.mask = S5P64X0_EINT0MASK - base_of_controller;

	irq_setup_generic_chip(gc, mask_of_irqs_to_setup,
		IRQ_GC_INIT_MASK_CACHE, flags_to_clear, flags_to_set);

[PATCH] ARM: S5P64X0: External Interrupt Support

[padma venkat]

Hi Russell,

On Fri, Jul 15, 2011 at 6:04 PM, Russell King - ARM Linux
<linux@arm.linux.org.uk> wrote:
> On Fri, Jul 15, 2011 at 05:23:33PM +0530, padma venkat wrote:
>> Hi Russell,
>>
>> On Fri, Jul 15, 2011 at 2:30 PM, Russell King - ARM Linux
>> <linux@arm.linux.org.uk> wrote:
>> > On Fri, Jul 15, 2011 at 12:11:34PM +0530, Padmavathi Venna wrote:
>> >> +#define eint_offset(irq) ? ? ((irq) - IRQ_EINT(0))
>> >> +#define eint_irq_to_bit(irq) ((u32)(1 << eint_offset(irq)))
>> >> +
>> >> +static inline void s5p64x0_irq_eint_mask(struct irq_data *data)
>> >> +{
>> >> + ? ? u32 mask;
>> >> +
>> >> + ? ? mask = __raw_readl(S5P64X0_EINT0MASK);
>> >> + ? ? mask |= (u32)data->chip_data;
>> >> + ? ? __raw_writel(mask, S5P64X0_EINT0MASK);
>> >> +}
>> >> +
>> >> +static void s5p64x0_irq_eint_unmask(struct irq_data *data)
>> >> +{
>> >> + ? ? u32 mask;
>> >> +
>> >> + ? ? mask = __raw_readl(S5P64X0_EINT0MASK);
>> >> + ? ? mask &= ~((u32)data->chip_data);
>> >> + ? ? __raw_writel(mask, S5P64X0_EINT0MASK);
>> >> +}
>> >> +
>> >> +static inline void s5p64x0_irq_eint_ack(struct irq_data *data)
>> >> +{
>> >> + ? ? __raw_writel((u32)data->chip_data, S5P64X0_EINT0PEND);
>> >> +}
>> >> +
>> >> +static void s5p64x0_irq_eint_maskack(struct irq_data *data)
>> >> +{
>> >> + ? ? /* compiler should in-line these */
>> >> + ? ? s5p64x0_irq_eint_mask(data);
>> >> + ? ? s5p64x0_irq_eint_ack(data);
>> >> +}
>> >
>> > Won't genirqchip support deal with all of the above for you?
>> As per my understanding, to deal with low level interrupt hardware access
>> we need to use the accessor functions. Please suggest me if there is
>> any better way of doing this.
>
> I'm not saying don't have these. ?I'm saying use the _generic_ irqchip
> support which has the code implemented to set and clear bits in registers.
> Something like this:
>
> ? ? ? ?struct irq_chip_generic *gc;
>
> ? ? ? ?gc = irq_alloc_generic_chip(name, 1, first_irq, base_of_controller,
> ? ? ? ? ? ? ? ? ? ? ? ?handler);
>
> ? ? ? ?gc->chip_types->chip.irq_ack = irq_gc_ack;
> ? ? ? ?gc->chip_types->chip.irq_mask = irq_gc_mask_set_bit;
> ? ? ? ?gc->chip_types->chip.irq_unmask = irq_gc_mask_clr_bit;
>
> ? ? ? ?/* replace the two below with the _real_ offset, rather than these calculations */
> ? ? ? ?gc->chip_types->reg.ack = S5P64X0_EINT0PEND - base_of_controller;
> ? ? ? ?gc->chip_types->reg.mask = S5P64X0_EINT0MASK - base_of_controller;
>
> ? ? ? ?irq_setup_generic_chip(gc, mask_of_irqs_to_setup,
> ? ? ? ? ? ? ? ?IRQ_GC_INIT_MASK_CACHE, flags_to_clear, flags_to_set);
>
Thanks for your explanation.
I will remake the patch based on generic_irq_chip support and resend the same.

Best Regards
Padma

[PATCH] ARM: S5P64X0: External Interrupt Support

[Kukjin Kim]

padma venkat wrote:
> 
> Hi Russell,
> 
> On Fri, Jul 15, 2011 at 6:04 PM, Russell King - ARM Linux
> <linux@arm.linux.org.uk> wrote:
> > On Fri, Jul 15, 2011 at 05:23:33PM +0530, padma venkat wrote:
> >> Hi Russell,
> >>
> >> On Fri, Jul 15, 2011 at 2:30 PM, Russell King - ARM Linux
> >> <linux@arm.linux.org.uk> wrote:
> >> > On Fri, Jul 15, 2011 at 12:11:34PM +0530, Padmavathi Venna wrote:
> >> >> +#define eint_offset(irq) ? ? ((irq) - IRQ_EINT(0))
> >> >> +#define eint_irq_to_bit(irq) ((u32)(1 << eint_offset(irq)))
> >> >> +
> >> >> +static inline void s5p64x0_irq_eint_mask(struct irq_data *data)
> >> >> +{
> >> >> + ? ? u32 mask;
> >> >> +
> >> >> + ? ? mask = __raw_readl(S5P64X0_EINT0MASK);
> >> >> + ? ? mask |= (u32)data->chip_data;
> >> >> + ? ? __raw_writel(mask, S5P64X0_EINT0MASK);
> >> >> +}
> >> >> +
> >> >> +static void s5p64x0_irq_eint_unmask(struct irq_data *data)
> >> >> +{
> >> >> + ? ? u32 mask;
> >> >> +
> >> >> + ? ? mask = __raw_readl(S5P64X0_EINT0MASK);
> >> >> + ? ? mask &= ~((u32)data->chip_data);
> >> >> + ? ? __raw_writel(mask, S5P64X0_EINT0MASK);
> >> >> +}
> >> >> +
> >> >> +static inline void s5p64x0_irq_eint_ack(struct irq_data *data)
> >> >> +{
> >> >> + ? ? __raw_writel((u32)data->chip_data, S5P64X0_EINT0PEND);
> >> >> +}
> >> >> +
> >> >> +static void s5p64x0_irq_eint_maskack(struct irq_data *data)
> >> >> +{
> >> >> + ? ? /* compiler should in-line these */
> >> >> + ? ? s5p64x0_irq_eint_mask(data);
> >> >> + ? ? s5p64x0_irq_eint_ack(data);
> >> >> +}
> >> >
> >> > Won't genirqchip support deal with all of the above for you?
> >> As per my understanding, to deal with low level interrupt hardware
access
> >> we need to use the accessor functions. Please suggest me if there is
> >> any better way of doing this.
> >
> > I'm not saying don't have these. ?I'm saying use the _generic_ irqchip
> > support which has the code implemented to set and clear bits in
registers.
> > Something like this:
> >
> > ? ? ? ?struct irq_chip_generic *gc;
> >
> > ? ? ? ?gc = irq_alloc_generic_chip(name, 1, first_irq,
base_of_controller,
> > ? ? ? ? ? ? ? ? ? ? ? ?handler);
> >
> > ? ? ? ?gc->chip_types->chip.irq_ack = irq_gc_ack;
> > ? ? ? ?gc->chip_types->chip.irq_mask = irq_gc_mask_set_bit;
> > ? ? ? ?gc->chip_types->chip.irq_unmask = irq_gc_mask_clr_bit;
> >
> > ? ? ? ?/* replace the two below with the _real_ offset, rather than
these
> calculations */
> > ? ? ? ?gc->chip_types->reg.ack = S5P64X0_EINT0PEND - base_of_controller;
> > ? ? ? ?gc->chip_types->reg.mask = S5P64X0_EINT0MASK -
base_of_controller;
> >
> > ? ? ? ?irq_setup_generic_chip(gc, mask_of_irqs_to_setup,
> > ? ? ? ? ? ? ? ?IRQ_GC_INIT_MASK_CACHE, flags_to_clear, flags_to_set);
> >
> Thanks for your explanation.
> I will remake the patch based on generic_irq_chip support and resend the
same.
> 
Hmm...any updated patch on this?

Thanks.

Best regards,
Kgene.
--
Kukjin Kim <kgene.kim@samsung.com>, Senior Engineer,
SW Solution Development Team, Samsung Electronics Co., Ltd.

[PATCH] ARM: S5P64X0: External Interrupt Support

[Padmavathi Venna]

Add external interrupt support for S5P64X0.The external interrupt
group 0(0 to 15) is used for wake-up source in stop and sleep mode.
Add generic irq chip support

Signed-off-by: Padmavathi Venna <padma.v@samsung.com>
---
 arch/arm/mach-s5p64x0/Makefile                 |    2 +-
 arch/arm/mach-s5p64x0/include/mach/regs-gpio.h |   10 ++
 arch/arm/mach-s5p64x0/irq-eint.c               |  151 ++++++++++++++++++++++++
 3 files changed, 162 insertions(+), 1 deletions(-)
 create mode 100644 arch/arm/mach-s5p64x0/irq-eint.c

diff --git a/arch/arm/mach-s5p64x0/Makefile b/arch/arm/mach-s5p64x0/Makefile
index ae6bf6f..5f6afdf 100644
--- a/arch/arm/mach-s5p64x0/Makefile
+++ b/arch/arm/mach-s5p64x0/Makefile
@@ -13,7 +13,7 @@ obj-				:=
 # Core support for S5P64X0 system
 
 obj-$(CONFIG_ARCH_S5P64X0)	+= cpu.o init.o clock.o dma.o gpiolib.o
-obj-$(CONFIG_ARCH_S5P64X0)	+= setup-i2c0.o
+obj-$(CONFIG_ARCH_S5P64X0)	+= setup-i2c0.o irq-eint.o
 obj-$(CONFIG_CPU_S5P6440)	+= clock-s5p6440.o
 obj-$(CONFIG_CPU_S5P6450)	+= clock-s5p6450.o
 
diff --git a/arch/arm/mach-s5p64x0/include/mach/regs-gpio.h b/arch/arm/mach-s5p64x0/include/mach/regs-gpio.h
index 0953ef6..6ce2547 100644
--- a/arch/arm/mach-s5p64x0/include/mach/regs-gpio.h
+++ b/arch/arm/mach-s5p64x0/include/mach/regs-gpio.h
@@ -34,4 +34,14 @@
 #define S5P6450_GPQ_BASE		(S5P_VA_GPIO + 0x0180)
 #define S5P6450_GPS_BASE		(S5P_VA_GPIO + 0x0300)
 
+/* External interrupt control registers for group0 */
+
+#define EINT0CON0_OFFSET		(0x900)
+#define EINT0MASK_OFFSET		(0x920)
+#define EINT0PEND_OFFSET		(0x924)
+
+#define S5P64X0_EINT0CON0		(S5P_VA_GPIO + EINT0CON0_OFFSET)
+#define S5P64X0_EINT0MASK		(S5P_VA_GPIO + EINT0MASK_OFFSET)
+#define S5P64X0_EINT0PEND		(S5P_VA_GPIO + EINT0PEND_OFFSET)
+
 #endif /* __ASM_ARCH_REGS_GPIO_H */
diff --git a/arch/arm/mach-s5p64x0/irq-eint.c b/arch/arm/mach-s5p64x0/irq-eint.c
new file mode 100644
index 0000000..eeb56f0
--- /dev/null
+++ b/arch/arm/mach-s5p64x0/irq-eint.c
@@ -0,0 +1,151 @@
+/* arch/arm/mach-s5p64x0/irq-eint.c
+ *
+ * Copyright (c) 2011 Samsung Electronics Co., Ltd
+ *		http://www.samsung.com/
+ *
+ * Based on linux/arch/arm/mach-s3c64xx/irq-eint.c
+ *
+ * S5P64X0 - Interrupt handling for External Interrupts.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/gpio.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+
+#include <plat/regs-irqtype.h>
+#include <plat/gpio-cfg.h>
+
+#include <mach/regs-gpio.h>
+#include <mach/regs-clock.h>
+
+#define eint_offset(irq)	((irq) - IRQ_EINT(0))
+
+static int s5p64x0_irq_eint_set_type(struct irq_data *data, unsigned int type)
+{
+	int offs = eint_offset(data->irq);
+	int shift;
+	u32 ctrl, mask;
+	u32 newvalue = 0;
+
+	if (offs > 15)
+		return -EINVAL;
+
+	switch (type) {
+	case IRQ_TYPE_NONE:
+		printk(KERN_WARNING "No edge setting!\n");
+		break;
+	case IRQ_TYPE_EDGE_RISING:
+		newvalue = S3C2410_EXTINT_RISEEDGE;
+		break;
+	case IRQ_TYPE_EDGE_FALLING:
+		newvalue = S3C2410_EXTINT_FALLEDGE;
+		break;
+	case IRQ_TYPE_EDGE_BOTH:
+		newvalue = S3C2410_EXTINT_BOTHEDGE;
+		break;
+	case IRQ_TYPE_LEVEL_LOW:
+		newvalue = S3C2410_EXTINT_LOWLEV;
+		break;
+	case IRQ_TYPE_LEVEL_HIGH:
+		newvalue = S3C2410_EXTINT_HILEV;
+		break;
+	default:
+		printk(KERN_ERR "No such irq type %d", type);
+		return -EINVAL;
+	}
+
+	shift = (offs / 2) * 4;
+	mask = 0x7 << shift;
+
+	ctrl = __raw_readl(S5P64X0_EINT0CON0) & ~mask;
+	ctrl |= newvalue << shift;
+	__raw_writel(ctrl, S5P64X0_EINT0CON0);
+
+	/* Configure the GPIO pin for 6450 or 6440 based on CPU ID */
+	if (0x50000 == (__raw_readl(S5P64X0_SYS_ID) & 0xFF000))
+		s3c_gpio_cfgpin(S5P6450_GPN(offs), S3C_GPIO_SFN(2));
+	else
+		s3c_gpio_cfgpin(S5P6440_GPN(offs), S3C_GPIO_SFN(2));
+
+	return 0;
+}
+
+/*
+ * s5p64x0_irq_demux_eint
+ *
+ * This function demuxes the IRQ from the group0 external interrupts,
+ * from IRQ_EINT(0) to IRQ_EINT(15). It is designed to be inlined into
+ * the specific handlers s5p64x0_irq_demux_eintX_Y.
+ */
+static inline void s5p64x0_irq_demux_eint(unsigned int start, unsigned int end)
+{
+	u32 status = __raw_readl(S5P64X0_EINT0PEND);
+	u32 mask = __raw_readl(S5P64X0_EINT0MASK);
+	unsigned int irq;
+
+	status &= ~mask;
+	status >>= start;
+	status &= (1 << (end - start + 1)) - 1;
+
+	for (irq = IRQ_EINT(start); irq <= IRQ_EINT(end); irq++) {
+		if (status & 1)
+			generic_handle_irq(irq);
+		status >>= 1;
+	}
+}
+
+static void s5p64x0_irq_demux_eint0_3(unsigned int irq, struct irq_desc *desc)
+{
+	s5p64x0_irq_demux_eint(0, 3);
+}
+
+static void s5p64x0_irq_demux_eint4_11(unsigned int irq, struct irq_desc *desc)
+{
+	s5p64x0_irq_demux_eint(4, 11);
+}
+
+static void s5p64x0_irq_demux_eint12_15(unsigned int irq,
+					struct irq_desc *desc)
+{
+	s5p64x0_irq_demux_eint(12, 15);
+}
+
+static void s5p64x0_alloc_gc(void)
+{
+	struct irq_chip_generic *gc;
+	struct irq_chip_type *ct;
+
+	gc = irq_alloc_generic_chip("s5p64x0-eint", 1, S5P_IRQ_EINT_BASE,
+				    S5P_VA_GPIO, handle_level_irq);
+	if (!gc) {
+		printk(KERN_ERR "%s: irq_alloc_generic_chip for group 0"
+			"external interrupts failed\n", __func__);
+		return;
+	}
+
+	ct = gc->chip_types;
+	ct->chip.irq_ack = irq_gc_ack;
+	ct->chip.irq_mask = irq_gc_mask_set_bit;
+	ct->chip.irq_unmask = irq_gc_mask_clr_bit;
+	ct->chip.irq_set_type = s5p64x0_irq_eint_set_type;
+	ct->regs.ack = EINT0PEND_OFFSET;
+	ct->regs.mask = EINT0MASK_OFFSET;
+	irq_setup_generic_chip(gc, IRQ_MSK(16), IRQ_GC_INIT_MASK_CACHE,
+			       IRQ_NOREQUEST | IRQ_NOPROBE, 0);
+}
+
+static int __init s5p64x0_init_irq_eint(void)
+{
+	s5p64x0_alloc_gc();
+	irq_set_chained_handler(IRQ_EINT0_3, s5p64x0_irq_demux_eint0_3);
+	irq_set_chained_handler(IRQ_EINT4_11, s5p64x0_irq_demux_eint4_11);
+	irq_set_chained_handler(IRQ_EINT12_15, s5p64x0_irq_demux_eint12_15);
+
+	return 0;
+}
+arch_initcall(s5p64x0_init_irq_eint);
-- 
1.7.0.4