irqchip: bcm7120-l2: Add Broadcom BCM7120-style Level 2 interrupt controller

obj-$(CONFIG_XTENSA)			+= irq-xtensa-pic.o

obj-$(CONFIG_XTENSA_MX)			+= irq-xtensa-mx.o

obj-$(CONFIG_IRQ_CROSSBAR)		+= irq-crossbar.o

obj-$(CONFIG_BRCMSTB_L2_IRQ)		+= irq-brcmstb-l2.o

obj-$(CONFIG_BRCMSTB_L2_IRQ)		+= irq-brcmstb-l2.o \

					   irq-bcm7120-l2.o

/*

 * Broadcom BCM7120 style Level 2 interrupt controller driver

 *

 * Copyright (C) 2014 Broadcom Corporation

 *

 * 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.

 */

#define pr_fmt(fmt)	KBUILD_MODNAME	": " fmt

#include <linux/init.h>

#include <linux/slab.h>

#include <linux/module.h>

#include <linux/platform_device.h>

#include <linux/of.h>

#include <linux/of_irq.h>

#include <linux/of_address.h>

#include <linux/of_platform.h>

#include <linux/interrupt.h>

#include <linux/irq.h>

#include <linux/io.h>

#include <linux/irqdomain.h>

#include <linux/reboot.h>

#include <linux/irqchip/chained_irq.h>

#include "irqchip.h"

#include <asm/mach/irq.h>

/* Register offset in the L2 interrupt controller */

#define IRQEN		0x00

#define IRQSTAT		0x04

struct bcm7120_l2_intc_data {

	void __iomem *base;

	struct irq_domain *domain;

	bool can_wake;

	u32 irq_fwd_mask;

	u32 irq_map_mask;

	u32 saved_mask;

};

static void bcm7120_l2_intc_irq_handle(unsigned int irq, struct irq_desc *desc)

{

	struct bcm7120_l2_intc_data *b = irq_desc_get_handler_data(desc);

	struct irq_chip *chip = irq_desc_get_chip(desc);

	u32 status;

	chained_irq_enter(chip, desc);

	status = __raw_readl(b->base + IRQSTAT);

	if (status == 0) {

		do_bad_IRQ(irq, desc);

		goto out;

	}

	do {

		irq = ffs(status) - 1;

		status &= ~(1 << irq);

		generic_handle_irq(irq_find_mapping(b->domain, irq));

	} while (status);

out:

	chained_irq_exit(chip, desc);

}

static void bcm7120_l2_intc_suspend(struct irq_data *d)

{

	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);

	struct bcm7120_l2_intc_data *b = gc->private;

	u32 reg;

	irq_gc_lock(gc);

	/* Save the current mask and the interrupt forward mask */

	b->saved_mask = __raw_readl(b->base) | b->irq_fwd_mask;

	if (b->can_wake) {

		reg = b->saved_mask | gc->wake_active;

		__raw_writel(reg, b->base);

	}

	irq_gc_unlock(gc);

}

static void bcm7120_l2_intc_resume(struct irq_data *d)

{

	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);

	struct bcm7120_l2_intc_data *b = gc->private;

	/* Restore the saved mask */

	irq_gc_lock(gc);

	__raw_writel(b->saved_mask, b->base);

	irq_gc_unlock(gc);

}

static int bcm7120_l2_intc_init_one(struct device_node *dn,

					struct bcm7120_l2_intc_data *data,

					int irq, const __be32 *map_mask)

{

	int parent_irq;

	parent_irq = irq_of_parse_and_map(dn, irq);

	if (parent_irq < 0) {

		pr_err("failed to map interrupt %d\n", irq);

		return parent_irq;

	}

	data->irq_map_mask |= be32_to_cpup(map_mask + irq);

	irq_set_handler_data(parent_irq, data);

	irq_set_chained_handler(parent_irq, bcm7120_l2_intc_irq_handle);

	return 0;

}

int __init bcm7120_l2_intc_of_init(struct device_node *dn,

					struct device_node *parent)

{

	unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;

	struct bcm7120_l2_intc_data *data;

	struct irq_chip_generic *gc;

	struct irq_chip_type *ct;

	const __be32 *map_mask;

	int num_parent_irqs;

	int ret = 0, len, irq;

	data = kzalloc(sizeof(*data), GFP_KERNEL);

	if (!data)

		return -ENOMEM;

	data->base = of_iomap(dn, 0);

	if (!data->base) {

		pr_err("failed to remap intc L2 registers\n");

		ret = -ENOMEM;

		goto out_free;

	}

	if (of_property_read_u32(dn, "brcm,int-fwd-mask", &data->irq_fwd_mask))

		data->irq_fwd_mask = 0;

	/* Enable all interrupt specified in the interrupt forward mask and have

	 * the other disabled

	 */

	__raw_writel(data->irq_fwd_mask, data->base + IRQEN);

	num_parent_irqs = of_irq_count(dn);

	if (num_parent_irqs <= 0) {

		pr_err("invalid number of parent interrupts\n");

		ret = -ENOMEM;

		goto out_unmap;

	}

	map_mask = of_get_property(dn, "brcm,int-map-mask", &len);

	if (!map_mask || (len != (sizeof(*map_mask) * num_parent_irqs))) {

		pr_err("invalid brcm,int-map-mask property\n");

		ret = -EINVAL;

		goto out_unmap;

	}

	for (irq = 0; irq < num_parent_irqs; irq++) {

		ret = bcm7120_l2_intc_init_one(dn, data, irq, map_mask);

		if (ret)

			goto out_unmap;

	}

	data->domain = irq_domain_add_linear(dn, 32,

					&irq_generic_chip_ops, NULL);

	if (!data->domain) {

		ret = -ENOMEM;

		goto out_unmap;

	}

	ret = irq_alloc_domain_generic_chips(data->domain, 32, 1,

				dn->full_name, handle_level_irq, clr, 0,

				IRQ_GC_INIT_MASK_CACHE);

	if (ret) {

		pr_err("failed to allocate generic irq chip\n");

		goto out_free_domain;

	}

	gc = irq_get_domain_generic_chip(data->domain, 0);

	gc->unused = 0xfffffff & ~data->irq_map_mask;

	gc->reg_base = data->base;

	gc->private = data;

	ct = gc->chip_types;

	ct->regs.mask = IRQEN;

	ct->chip.irq_mask = irq_gc_mask_clr_bit;

	ct->chip.irq_unmask = irq_gc_mask_set_bit;

	ct->chip.irq_ack = irq_gc_noop;

	ct->chip.irq_suspend = bcm7120_l2_intc_suspend;

	ct->chip.irq_resume = bcm7120_l2_intc_resume;

	if (of_property_read_bool(dn, "brcm,irq-can-wake")) {

		data->can_wake = true;

		/* This IRQ chip can wake the system, set all relevant child

		 * interupts in wake_enabled mask

		 */

		gc->wake_enabled = 0xffffffff;

		gc->wake_enabled &= ~gc->unused;

		ct->chip.irq_set_wake = irq_gc_set_wake;

	}

	pr_info("registered BCM7120 L2 intc (mem: 0x%p, parent IRQ(s): %d)\n",

			data->base, num_parent_irqs);

	return 0;

out_free_domain:

	irq_domain_remove(data->domain);

out_unmap:

	iounmap(data->base);

out_free:

	kfree(data);

	return ret;

}

IRQCHIP_DECLARE(brcmstb_l2_intc, "brcm,bcm7120-l2-intc",

		bcm7120_l2_intc_of_init);