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Commit 5f93ef5c authored by Paul Burton's avatar Paul Burton Committed by Ralf Baechle
Browse files

MIPS: i8259: DT support 



Support probing the i8259 programmable interrupt controller, as found on
the Malta board, and using its interrupts via device tree.

Signed-off-by: default avatarPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: Kumar Gala <galak@codeaurora.org>
Cc: Qais Yousef <qais.yousef@imgtec.com>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: linux-kernel@vger.kernel.org
Patchwork: http://patchwork.linux-mips.org/patch/10114/


Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent e8823d26

arch/mips/include/asm/i8259.h

+1 −0
Original line number Diff line number Diff line
@@ -41,6 +41,7 @@ extern int i8259A_irq_pending(unsigned int irq); 
extern void make_8259A_irq(unsigned int irq);



extern void init_i8259_irqs(void);

extern int i8259_of_init(struct device_node *node, struct device_node *parent);



/*

 * Do the traditional i8259 interrupt polling thing.  This is for the few

arch/mips/kernel/i8259.c

+41 −2
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <linux/interrupt.h>

#include <linux/irqdomain.h>

#include <linux/kernel.h>

#include <linux/of_irq.h>

#include <linux/spinlock.h>

#include <linux/syscore_ops.h>

#include <linux/irq.h>
@@ -21,6 +22,8 @@ 
#include <asm/i8259.h>

#include <asm/io.h>



#include "../../drivers/irqchip/irqchip.h"



/*

 * This is the 'legacy' 8259A Programmable Interrupt Controller,

 * present in the majority of PC/AT boxes.
@@ -327,7 +330,7 @@ static struct irq_domain_ops i8259A_ops = { 
 * driver compatibility reasons interrupts 0 - 15 to be the i8259

 * interrupts even if the hardware uses a different interrupt numbering.

 */

void __init init_i8259_irqs(void)

struct irq_domain * __init __init_i8259_irqs(struct device_node *node)

{

	struct irq_domain *domain;
@@ -336,10 +339,46 @@ void __init init_i8259_irqs(void) 


	init_8259A(0);



	domain = irq_domain_add_legacy(NULL, 16, I8259A_IRQ_BASE, 0,

	domain = irq_domain_add_legacy(node, 16, I8259A_IRQ_BASE, 0,

				       &i8259A_ops, NULL);

	if (!domain)

		panic("Failed to add i8259 IRQ domain");



	setup_irq(I8259A_IRQ_BASE + PIC_CASCADE_IR, &irq2);

	return domain;

}



void __init init_i8259_irqs(void)

{

	__init_i8259_irqs(NULL);

}



static void i8259_irq_dispatch(unsigned int irq, struct irq_desc *desc)

{

	struct irq_domain *domain = irq_get_handler_data(irq);

	int hwirq = i8259_irq();



	if (hwirq < 0)

		return;



	irq = irq_linear_revmap(domain, hwirq);

	generic_handle_irq(irq);

}



int __init i8259_of_init(struct device_node *node, struct device_node *parent)

{

	struct irq_domain *domain;

	unsigned int parent_irq;



	parent_irq = irq_of_parse_and_map(node, 0);

	if (!parent_irq) {

		pr_err("Failed to map i8259 parent IRQ\n");

		return -ENODEV;

	}



	domain = __init_i8259_irqs(node);

	irq_set_handler_data(parent_irq, domain);

	irq_set_chained_handler(parent_irq, i8259_irq_dispatch);

	return 0;

}

IRQCHIP_DECLARE(i8259, "intel,i8259", i8259_of_init);