drivers/irqchip/irq-mtk-cirq.c - kernel/common - Git at Google

 /*
  * Copyright (c) 2016 MediaTek Inc.
  * Author: Youlin.Pei <[email protected]>
  *
  * 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);
	/*
	* Copyright (c) 2016 MediaTek Inc.
	* Author: Youlin.Pei <[email protected]>
	*
	* 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);