irqchip: Add Mediatek mtk-cirq driver

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

obj-$(CONFIG_KEYSTONE_IRQ)		+= irq-keystone.o

obj-$(CONFIG_MIPS_GIC)			+= irq-mips-gic.o

obj-$(CONFIG_ARCH_MEDIATEK)		+= irq-mtk-sysirq.o

obj-$(CONFIG_ARCH_MEDIATEK)		+= irq-mtk-sysirq.o irq-mtk-cirq.o

obj-$(CONFIG_ARCH_DIGICOLOR)		+= irq-digicolor.o

obj-$(CONFIG_RENESAS_H8300H_INTC)	+= irq-renesas-h8300h.o

obj-$(CONFIG_RENESAS_H8S_INTC)		+= irq-renesas-h8s.o

/*

 * Copyright (c) 2016 MediaTek Inc.

 * Author: Youlin.Pei <youlin.pei@mediatek.com>

 *

 * 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.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 */

#include <linux/interrupt.h>

#include <linux/io.h>

#include <linux/irq.h>

#include <linux/irqchip.h>

#include <linux/irqdomain.h>

#include <linux/of.h>

#include <linux/of_irq.h>

#include <linux/of_address.h>

#include <linux/slab.h>

#include <linux/syscore_ops.h>

#define CIRQ_ACK	0x40

#define CIRQ_MASK_SET	0xc0

#define CIRQ_MASK_CLR	0x100

#define CIRQ_SENS_SET	0x180

#define CIRQ_SENS_CLR	0x1c0

#define CIRQ_POL_SET	0x240

#define CIRQ_POL_CLR	0x280

#define CIRQ_CONTROL	0x300

#define CIRQ_EN	0x1

#define CIRQ_EDGE	0x2

#define CIRQ_FLUSH	0x4

struct mtk_cirq_chip_data {

	void __iomem *base;

	unsigned int ext_irq_start;

	unsigned int ext_irq_end;

	struct irq_domain *domain;

};

static struct mtk_cirq_chip_data *cirq_data;

static void mtk_cirq_write_mask(struct irq_data *data, unsigned int offset)

{

	struct mtk_cirq_chip_data *chip_data = data->chip_data;

	unsigned int cirq_num = data->hwirq;

	u32 mask = 1 << (cirq_num % 32);

	writel_relaxed(mask, chip_data->base + offset + (cirq_num / 32) * 4);

}

static void mtk_cirq_mask(struct irq_data *data)

{

	mtk_cirq_write_mask(data, CIRQ_MASK_SET);

	irq_chip_mask_parent(data);

}

static void mtk_cirq_unmask(struct irq_data *data)

{

	mtk_cirq_write_mask(data, CIRQ_MASK_CLR);

	irq_chip_unmask_parent(data);

}

static int mtk_cirq_set_type(struct irq_data *data, unsigned int type)

{

	int ret;

	switch (type & IRQ_TYPE_SENSE_MASK) {

	case IRQ_TYPE_EDGE_FALLING:

		mtk_cirq_write_mask(data, CIRQ_POL_CLR);

		mtk_cirq_write_mask(data, CIRQ_SENS_CLR);

		break;

	case IRQ_TYPE_EDGE_RISING:

		mtk_cirq_write_mask(data, CIRQ_POL_SET);

		mtk_cirq_write_mask(data, CIRQ_SENS_CLR);

		break;

	case IRQ_TYPE_LEVEL_LOW:

		mtk_cirq_write_mask(data, CIRQ_POL_CLR);

		mtk_cirq_write_mask(data, CIRQ_SENS_SET);

		break;

	case IRQ_TYPE_LEVEL_HIGH:

		mtk_cirq_write_mask(data, CIRQ_POL_SET);

		mtk_cirq_write_mask(data, CIRQ_SENS_SET);

		break;

	default:

		break;

	}

	data = data->parent_data;

	ret = data->chip->irq_set_type(data, type);

	return ret;

}

static struct irq_chip mtk_cirq_chip = {

	.name			= "MT_CIRQ",

	.irq_mask		= mtk_cirq_mask,

	.irq_unmask		= mtk_cirq_unmask,

	.irq_eoi		= irq_chip_eoi_parent,

	.irq_set_type		= mtk_cirq_set_type,

	.irq_retrigger		= irq_chip_retrigger_hierarchy,

#ifdef CONFIG_SMP

	.irq_set_affinity	= irq_chip_set_affinity_parent,

#endif

};

static int mtk_cirq_domain_translate(struct irq_domain *d,

				     struct irq_fwspec *fwspec,

				     unsigned long *hwirq,

				     unsigned int *type)

{

	if (is_of_node(fwspec->fwnode)) {

		if (fwspec->param_count != 3)

			return -EINVAL;

		/* No PPI should point to this domain */

		if (fwspec->param[0] != 0)

			return -EINVAL;

		/* cirq support irq number check */

		if (fwspec->param[1] < cirq_data->ext_irq_start ||

		    fwspec->param[1] > cirq_data->ext_irq_end)

			return -EINVAL;

		*hwirq = fwspec->param[1] - cirq_data->ext_irq_start;

		*type = fwspec->param[2] & IRQ_TYPE_SENSE_MASK;

		return 0;

	}

	return -EINVAL;

}

static int mtk_cirq_domain_alloc(struct irq_domain *domain, unsigned int virq,

				 unsigned int nr_irqs, void *arg)

{

	int ret;

	irq_hw_number_t hwirq;

	unsigned int type;

	struct irq_fwspec *fwspec = arg;

	struct irq_fwspec parent_fwspec = *fwspec;

	ret = mtk_cirq_domain_translate(domain, fwspec, &hwirq, &type);

	if (ret)

		return ret;

	if (WARN_ON(nr_irqs != 1))

		return -EINVAL;

	irq_domain_set_hwirq_and_chip(domain, virq, hwirq,

				      &mtk_cirq_chip,

				      domain->host_data);

	parent_fwspec.fwnode = domain->parent->fwnode;

	return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,

					    &parent_fwspec);

}

static const struct irq_domain_ops cirq_domain_ops = {

	.translate	= mtk_cirq_domain_translate,

	.alloc		= mtk_cirq_domain_alloc,

	.free		= irq_domain_free_irqs_common,

};

#ifdef CONFIG_PM_SLEEP

static int mtk_cirq_suspend(void)

{

	u32 value, mask;

	unsigned int irq, hwirq_num;

	bool pending, masked;

	int i, pendret, maskret;

	/*

	 * When external interrupts happened, CIRQ will record the status

	 * even CIRQ is not enabled. When execute flush command, CIRQ will

	 * resend the signals according to the status. So if don't clear the

	 * status, CIRQ will resend the wrong signals.

	 *

	 * arch_suspend_disable_irqs() will be called before CIRQ suspend

	 * callback. If clear all the status simply, the external interrupts

	 * which happened between arch_suspend_disable_irqs and CIRQ suspend

	 * callback will be lost. Using following steps to avoid this issue;

	 *

	 * - Iterate over all the CIRQ supported interrupts;

	 * - For each interrupt, inspect its pending and masked status at GIC

	 *   level;

	 * - If pending and unmasked, it happened between

	 *   arch_suspend_disable_irqs and CIRQ suspend callback, don't ACK

	 *   it. Otherwise, ACK it.

	 */

	hwirq_num = cirq_data->ext_irq_end - cirq_data->ext_irq_start + 1;

	for (i = 0; i < hwirq_num; i++) {

		irq = irq_find_mapping(cirq_data->domain, i);

		if (irq) {

			pendret = irq_get_irqchip_state(irq,

							IRQCHIP_STATE_PENDING,

							&pending);

			maskret = irq_get_irqchip_state(irq,

							IRQCHIP_STATE_MASKED,

							&masked);

			if (pendret == 0 && maskret == 0 &&

			    (pending && !masked))

				continue;

		}

		mask = 1 << (i % 32);

		writel_relaxed(mask, cirq_data->base + CIRQ_ACK + (i / 32) * 4);

	}

	/* set edge_only mode, record edge-triggerd interrupts */

	/* enable cirq */

	value = readl_relaxed(cirq_data->base + CIRQ_CONTROL);

	value |= (CIRQ_EDGE | CIRQ_EN);

	writel_relaxed(value, cirq_data->base + CIRQ_CONTROL);

	return 0;

}

static void mtk_cirq_resume(void)

{

	u32 value;

	/* flush recored interrupts, will send signals to parent controller */

	value = readl_relaxed(cirq_data->base + CIRQ_CONTROL);

	writel_relaxed(value | CIRQ_FLUSH, cirq_data->base + CIRQ_CONTROL);

	/* disable cirq */

	value = readl_relaxed(cirq_data->base + CIRQ_CONTROL);

	value &= ~(CIRQ_EDGE | CIRQ_EN);

	writel_relaxed(value, cirq_data->base + CIRQ_CONTROL);

}

static struct syscore_ops mtk_cirq_syscore_ops = {

	.suspend	= mtk_cirq_suspend,

	.resume		= mtk_cirq_resume,

};

static void mtk_cirq_syscore_init(void)

{

	register_syscore_ops(&mtk_cirq_syscore_ops);

}

#else

static inline void mtk_cirq_syscore_init(void) {}

#endif

static int __init mtk_cirq_of_init(struct device_node *node,

				   struct device_node *parent)

{

	struct irq_domain *domain, *domain_parent;

	unsigned int irq_num;

	int ret;

	domain_parent = irq_find_host(parent);

	if (!domain_parent) {

		pr_err("mtk_cirq: interrupt-parent not found\n");

		return -EINVAL;

	}

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

	if (!cirq_data)

		return -ENOMEM;

	cirq_data->base = of_iomap(node, 0);

	if (!cirq_data->base) {

		pr_err("mtk_cirq: unable to map cirq register\n");

		ret = -ENXIO;

		goto out_free;

	}

	ret = of_property_read_u32_index(node, "mediatek,ext-irq-range", 0,

					 &cirq_data->ext_irq_start);

	if (ret)

		goto out_unmap;

	ret = of_property_read_u32_index(node, "mediatek,ext-irq-range", 1,

					 &cirq_data->ext_irq_end);

	if (ret)

		goto out_unmap;

	irq_num = cirq_data->ext_irq_end - cirq_data->ext_irq_start + 1;

	domain = irq_domain_add_hierarchy(domain_parent, 0,

					  irq_num, node,

					  &cirq_domain_ops, cirq_data);

	if (!domain) {

		ret = -ENOMEM;

		goto out_unmap;

	}

	cirq_data->domain = domain;

	mtk_cirq_syscore_init();

	return 0;

out_unmap:

	iounmap(cirq_data->base);

out_free:

	kfree(cirq_data);

	return ret;

}

IRQCHIP_DECLARE(mtk_cirq, "mediatek,mtk-cirq", mtk_cirq_of_init);