drivers/irqchip/irq-crossbar.c - codeaurora/cp-linux - Gitiles

 /*
  *  drivers/irqchip/irq-crossbar.c
  *
  *  Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
  *  Author: Sricharan R <r.sricharan@ti.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.
  *
  */
 #include <linux/err.h>
 #include <linux/io.h>
 #include <linux/irqchip.h>
 #include <linux/irqdomain.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
 #include <linux/slab.h>

 #define IRQ_FREE	-1
 #define IRQ_RESERVED	-2
 #define IRQ_SKIP	-3
 #define GIC_IRQ_START	32

 /**
  * struct crossbar_device - crossbar device description
  * @lock: spinlock serializing access to @irq_map
  * @int_max: maximum number of supported interrupts
  * @safe_map: safe default value to initialize the crossbar
  * @max_crossbar_sources: Maximum number of crossbar sources
  * @irq_map: array of interrupts to crossbar number mapping
  * @crossbar_base: crossbar base address
  * @register_offsets: offsets for each irq number
  * @write: register write function pointer
  */
 struct crossbar_device {
 	raw_spinlock_t lock;
 	uint int_max;
 	uint safe_map;
 	uint max_crossbar_sources;
 	uint *irq_map;
 	void __iomem *crossbar_base;
 	int *register_offsets;
 	void (*write)(int, int);
 };

 static struct crossbar_device *cb;

 static void crossbar_writel(int irq_no, int cb_no)
 {
 	writel(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]);
 }

 static void crossbar_writew(int irq_no, int cb_no)
 {
 	writew(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]);
 }

 static void crossbar_writeb(int irq_no, int cb_no)
 {
 	writeb(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]);
 }

 static struct irq_chip crossbar_chip = {
 	.name			= "CBAR",
 	.irq_eoi		= irq_chip_eoi_parent,
 	.irq_mask		= irq_chip_mask_parent,
 	.irq_unmask		= irq_chip_unmask_parent,
 	.irq_retrigger		= irq_chip_retrigger_hierarchy,
 	.irq_set_type		= irq_chip_set_type_parent,
 	.flags			= IRQCHIP_MASK_ON_SUSPEND |
 				  IRQCHIP_SKIP_SET_WAKE,
 #ifdef CONFIG_SMP
 	.irq_set_affinity	= irq_chip_set_affinity_parent,
 #endif
 };

 static int allocate_gic_irq(struct irq_domain *domain, unsigned virq,
 			    irq_hw_number_t hwirq)
 {
 	struct irq_fwspec fwspec;
 	int i;
 	int err;

 	if (!irq_domain_get_of_node(domain->parent))
 		return -EINVAL;

 	raw_spin_lock(&cb->lock);
 	for (i = cb->int_max - 1; i >= 0; i--) {
 		if (cb->irq_map[i] == IRQ_FREE) {
 			cb->irq_map[i] = hwirq;
 			break;
 		}
 	}
 	raw_spin_unlock(&cb->lock);

 	if (i < 0)
 		return -ENODEV;

 	fwspec.fwnode = domain->parent->fwnode;
 	fwspec.param_count = 3;
 	fwspec.param[0] = 0;	/* SPI */
 	fwspec.param[1] = i;
 	fwspec.param[2] = IRQ_TYPE_LEVEL_HIGH;

 	err = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
 	if (err)
 		cb->irq_map[i] = IRQ_FREE;
 	else
 		cb->write(i, hwirq);

 	return err;
 }

 static int crossbar_domain_alloc(struct irq_domain *d, unsigned int virq,
 				 unsigned int nr_irqs, void *data)
 {
 	struct irq_fwspec *fwspec = data;
 	irq_hw_number_t hwirq;
 	int i;

 	if (fwspec->param_count != 3)
 		return -EINVAL;	/* Not GIC compliant */
 	if (fwspec->param[0] != 0)
 		return -EINVAL;	/* No PPI should point to this domain */

 	hwirq = fwspec->param[1];
 	if ((hwirq + nr_irqs) > cb->max_crossbar_sources)
 		return -EINVAL;	/* Can't deal with this */

 	for (i = 0; i < nr_irqs; i++) {
 		int err = allocate_gic_irq(d, virq + i, hwirq + i);

 		if (err)
 			return err;

 		irq_domain_set_hwirq_and_chip(d, virq + i, hwirq + i,
 					      &crossbar_chip, NULL);
 	}

 	return 0;
 }

 /**
  * crossbar_domain_free - unmap/free a crossbar<->irq connection
  * @domain: domain of irq to unmap
  * @virq: virq number
  * @nr_irqs: number of irqs to free
  *
  * We do not maintain a use count of total number of map/unmap
  * calls for a particular irq to find out if a irq can be really
  * unmapped. This is because unmap is called during irq_dispose_mapping(irq),
  * after which irq is anyways unusable. So an explicit map has to be called
  * after that.
  */
 static void crossbar_domain_free(struct irq_domain *domain, unsigned int virq,
 				 unsigned int nr_irqs)
 {
 	int i;

 	raw_spin_lock(&cb->lock);
 	for (i = 0; i < nr_irqs; i++) {
 		struct irq_data *d = irq_domain_get_irq_data(domain, virq + i);

 		irq_domain_reset_irq_data(d);
 		cb->irq_map[d->hwirq] = IRQ_FREE;
 		cb->write(d->hwirq, cb->safe_map);
 	}
 	raw_spin_unlock(&cb->lock);
 }

 static int crossbar_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;

 		*hwirq = fwspec->param[1];
 		*type = fwspec->param[2];
 		return 0;
 	}

 	return -EINVAL;
 }

 static const struct irq_domain_ops crossbar_domain_ops = {
 	.alloc		= crossbar_domain_alloc,
 	.free		= crossbar_domain_free,
 	.translate	= crossbar_domain_translate,
 };

 static int __init crossbar_of_init(struct device_node *node)
 {
 	int i, size, reserved = 0;
 	u32 max = 0, entry;
 	const __be32 *irqsr;
 	int ret = -ENOMEM;

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

 	if (!cb)
 		return ret;

 	cb->crossbar_base = of_iomap(node, 0);
 	if (!cb->crossbar_base)
 		goto err_cb;

 	of_property_read_u32(node, "ti,max-crossbar-sources",
 			     &cb->max_crossbar_sources);
 	if (!cb->max_crossbar_sources) {
 		pr_err("missing 'ti,max-crossbar-sources' property\n");
 		ret = -EINVAL;
 		goto err_base;
 	}

 	of_property_read_u32(node, "ti,max-irqs", &max);
 	if (!max) {
 		pr_err("missing 'ti,max-irqs' property\n");
 		ret = -EINVAL;
 		goto err_base;
 	}
 	cb->irq_map = kcalloc(max, sizeof(int), GFP_KERNEL);
 	if (!cb->irq_map)
 		goto err_base;

 	cb->int_max = max;

 	for (i = 0; i < max; i++)
 		cb->irq_map[i] = IRQ_FREE;

 	/* Get and mark reserved irqs */
 	irqsr = of_get_property(node, "ti,irqs-reserved", &size);
 	if (irqsr) {
 		size /= sizeof(__be32);

 		for (i = 0; i < size; i++) {
 			of_property_read_u32_index(node,
 						   "ti,irqs-reserved",
 						   i, &entry);
 			if (entry >= max) {
 				pr_err("Invalid reserved entry\n");
 				ret = -EINVAL;
 				goto err_irq_map;
 			}
 			cb->irq_map[entry] = IRQ_RESERVED;
 		}
 	}

 	/* Skip irqs hardwired to bypass the crossbar */
 	irqsr = of_get_property(node, "ti,irqs-skip", &size);
 	if (irqsr) {
 		size /= sizeof(__be32);

 		for (i = 0; i < size; i++) {
 			of_property_read_u32_index(node,
 						   "ti,irqs-skip",
 						   i, &entry);
 			if (entry >= max) {
 				pr_err("Invalid skip entry\n");
 				ret = -EINVAL;
 				goto err_irq_map;
 			}
 			cb->irq_map[entry] = IRQ_SKIP;
 		}
 	}


 	cb->register_offsets = kcalloc(max, sizeof(int), GFP_KERNEL);
 	if (!cb->register_offsets)
 		goto err_irq_map;

 	of_property_read_u32(node, "ti,reg-size", &size);

 	switch (size) {
 	case 1:
 		cb->write = crossbar_writeb;
 		break;
 	case 2:
 		cb->write = crossbar_writew;
 		break;
 	case 4:
 		cb->write = crossbar_writel;
 		break;
 	default:
 		pr_err("Invalid reg-size property\n");
 		ret = -EINVAL;
 		goto err_reg_offset;
 		break;
 	}

 	/*
 	 * Register offsets are not linear because of the
 	 * reserved irqs. so find and store the offsets once.
 	 */
 	for (i = 0; i < max; i++) {
 		if (cb->irq_map[i] == IRQ_RESERVED)
 			continue;

 		cb->register_offsets[i] = reserved;
 		reserved += size;
 	}

 	of_property_read_u32(node, "ti,irqs-safe-map", &cb->safe_map);
 	/* Initialize the crossbar with safe map to start with */
 	for (i = 0; i < max; i++) {
 		if (cb->irq_map[i] == IRQ_RESERVED ||
 		    cb->irq_map[i] == IRQ_SKIP)
 			continue;

 		cb->write(i, cb->safe_map);
 	}

 	raw_spin_lock_init(&cb->lock);

 	return 0;

 err_reg_offset:
 	kfree(cb->register_offsets);
 err_irq_map:
 	kfree(cb->irq_map);
 err_base:
 	iounmap(cb->crossbar_base);
 err_cb:
 	kfree(cb);

 	cb = NULL;
 	return ret;
 }

 static int __init irqcrossbar_init(struct device_node *node,
 				   struct device_node *parent)
 {
 	struct irq_domain *parent_domain, *domain;
 	int err;

 	if (!parent) {
 		pr_err("%s: no parent, giving up\n", node->full_name);
 		return -ENODEV;
 	}

 	parent_domain = irq_find_host(parent);
 	if (!parent_domain) {
 		pr_err("%s: unable to obtain parent domain\n", node->full_name);
 		return -ENXIO;
 	}

 	err = crossbar_of_init(node);
 	if (err)
 		return err;

 	domain = irq_domain_add_hierarchy(parent_domain, 0,
 					  cb->max_crossbar_sources,
 					  node, &crossbar_domain_ops,
 					  NULL);
 	if (!domain) {
 		pr_err("%s: failed to allocated domain\n", node->full_name);
 		return -ENOMEM;
 	}

 	return 0;
 }

 IRQCHIP_DECLARE(ti_irqcrossbar, "ti,irq-crossbar", irqcrossbar_init);
	/*
	* drivers/irqchip/irq-crossbar.c
	*
	* Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
	* Author: Sricharan R <r.sricharan@ti.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.
	*
	*/
	#include <linux/err.h>
	#include <linux/io.h>
	#include <linux/irqchip.h>
	#include <linux/irqdomain.h>
	#include <linux/of_address.h>
	#include <linux/of_irq.h>
	#include <linux/slab.h>

	#define IRQ_FREE -1
	#define IRQ_RESERVED -2
	#define IRQ_SKIP -3
	#define GIC_IRQ_START 32

	/**
	* struct crossbar_device - crossbar device description
	* @lock: spinlock serializing access to @irq_map
	* @int_max: maximum number of supported interrupts
	* @safe_map: safe default value to initialize the crossbar
	* @max_crossbar_sources: Maximum number of crossbar sources
	* @irq_map: array of interrupts to crossbar number mapping
	* @crossbar_base: crossbar base address
	* @register_offsets: offsets for each irq number
	* @write: register write function pointer
	*/
	struct crossbar_device {
	raw_spinlock_t lock;
	uint int_max;
	uint safe_map;
	uint max_crossbar_sources;
	uint *irq_map;
	void __iomem *crossbar_base;
	int *register_offsets;
	void (*write)(int, int);
	};

	static struct crossbar_device *cb;

	static void crossbar_writel(int irq_no, int cb_no)
	{
	writel(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]);
	}

	static void crossbar_writew(int irq_no, int cb_no)
	{
	writew(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]);
	}

	static void crossbar_writeb(int irq_no, int cb_no)
	{
	writeb(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]);
	}

	static struct irq_chip crossbar_chip = {
	.name = "CBAR",
	.irq_eoi = irq_chip_eoi_parent,
	.irq_mask = irq_chip_mask_parent,
	.irq_unmask = irq_chip_unmask_parent,
	.irq_retrigger = irq_chip_retrigger_hierarchy,
	.irq_set_type = irq_chip_set_type_parent,
	.flags = IRQCHIP_MASK_ON_SUSPEND \|
	IRQCHIP_SKIP_SET_WAKE,
	#ifdef CONFIG_SMP
	.irq_set_affinity = irq_chip_set_affinity_parent,
	#endif
	};

	static int allocate_gic_irq(struct irq_domain *domain, unsigned virq,
	irq_hw_number_t hwirq)
	{
	struct irq_fwspec fwspec;
	int i;
	int err;

	if (!irq_domain_get_of_node(domain->parent))
	return -EINVAL;

	raw_spin_lock(&cb->lock);
	for (i = cb->int_max - 1; i >= 0; i--) {
	if (cb->irq_map[i] == IRQ_FREE) {
	cb->irq_map[i] = hwirq;
	break;
	}
	}
	raw_spin_unlock(&cb->lock);

	if (i < 0)
	return -ENODEV;

	fwspec.fwnode = domain->parent->fwnode;
	fwspec.param_count = 3;
	fwspec.param[0] = 0; /* SPI */
	fwspec.param[1] = i;
	fwspec.param[2] = IRQ_TYPE_LEVEL_HIGH;

	err = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
	if (err)
	cb->irq_map[i] = IRQ_FREE;
	else
	cb->write(i, hwirq);

	return err;
	}

	static int crossbar_domain_alloc(struct irq_domain *d, unsigned int virq,
	unsigned int nr_irqs, void *data)
	{
	struct irq_fwspec *fwspec = data;
	irq_hw_number_t hwirq;
	int i;

	if (fwspec->param_count != 3)
	return -EINVAL; /* Not GIC compliant */
	if (fwspec->param[0] != 0)
	return -EINVAL; /* No PPI should point to this domain */

	hwirq = fwspec->param[1];
	if ((hwirq + nr_irqs) > cb->max_crossbar_sources)
	return -EINVAL; /* Can't deal with this */

	for (i = 0; i < nr_irqs; i++) {
	int err = allocate_gic_irq(d, virq + i, hwirq + i);

	if (err)
	return err;

	irq_domain_set_hwirq_and_chip(d, virq + i, hwirq + i,
	&crossbar_chip, NULL);
	}

	return 0;
	}

	/**
	* crossbar_domain_free - unmap/free a crossbar<->irq connection
	* @domain: domain of irq to unmap
	* @virq: virq number
	* @nr_irqs: number of irqs to free
	*
	* We do not maintain a use count of total number of map/unmap
	* calls for a particular irq to find out if a irq can be really
	* unmapped. This is because unmap is called during irq_dispose_mapping(irq),
	* after which irq is anyways unusable. So an explicit map has to be called
	* after that.
	*/
	static void crossbar_domain_free(struct irq_domain *domain, unsigned int virq,
	unsigned int nr_irqs)
	{
	int i;

	raw_spin_lock(&cb->lock);
	for (i = 0; i < nr_irqs; i++) {
	struct irq_data *d = irq_domain_get_irq_data(domain, virq + i);

	irq_domain_reset_irq_data(d);
	cb->irq_map[d->hwirq] = IRQ_FREE;
	cb->write(d->hwirq, cb->safe_map);
	}
	raw_spin_unlock(&cb->lock);
	}

	static int crossbar_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;

	*hwirq = fwspec->param[1];
	*type = fwspec->param[2];
	return 0;
	}

	return -EINVAL;
	}

	static const struct irq_domain_ops crossbar_domain_ops = {
	.alloc = crossbar_domain_alloc,
	.free = crossbar_domain_free,
	.translate = crossbar_domain_translate,
	};

	static int __init crossbar_of_init(struct device_node *node)
	{
	int i, size, reserved = 0;
	u32 max = 0, entry;
	const __be32 *irqsr;
	int ret = -ENOMEM;

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

	if (!cb)
	return ret;

	cb->crossbar_base = of_iomap(node, 0);
	if (!cb->crossbar_base)
	goto err_cb;

	of_property_read_u32(node, "ti,max-crossbar-sources",
	&cb->max_crossbar_sources);
	if (!cb->max_crossbar_sources) {
	pr_err("missing 'ti,max-crossbar-sources' property\n");
	ret = -EINVAL;
	goto err_base;
	}

	of_property_read_u32(node, "ti,max-irqs", &max);
	if (!max) {
	pr_err("missing 'ti,max-irqs' property\n");
	ret = -EINVAL;
	goto err_base;
	}
	cb->irq_map = kcalloc(max, sizeof(int), GFP_KERNEL);
	if (!cb->irq_map)
	goto err_base;

	cb->int_max = max;

	for (i = 0; i < max; i++)
	cb->irq_map[i] = IRQ_FREE;

	/* Get and mark reserved irqs */
	irqsr = of_get_property(node, "ti,irqs-reserved", &size);
	if (irqsr) {
	size /= sizeof(__be32);

	for (i = 0; i < size; i++) {
	of_property_read_u32_index(node,
	"ti,irqs-reserved",
	i, &entry);
	if (entry >= max) {
	pr_err("Invalid reserved entry\n");
	ret = -EINVAL;
	goto err_irq_map;
	}
	cb->irq_map[entry] = IRQ_RESERVED;
	}
	}

	/* Skip irqs hardwired to bypass the crossbar */
	irqsr = of_get_property(node, "ti,irqs-skip", &size);
	if (irqsr) {
	size /= sizeof(__be32);

	for (i = 0; i < size; i++) {
	of_property_read_u32_index(node,
	"ti,irqs-skip",
	i, &entry);
	if (entry >= max) {
	pr_err("Invalid skip entry\n");
	ret = -EINVAL;
	goto err_irq_map;
	}
	cb->irq_map[entry] = IRQ_SKIP;
	}
	}


	cb->register_offsets = kcalloc(max, sizeof(int), GFP_KERNEL);
	if (!cb->register_offsets)
	goto err_irq_map;

	of_property_read_u32(node, "ti,reg-size", &size);

	switch (size) {
	case 1:
	cb->write = crossbar_writeb;
	break;
	case 2:
	cb->write = crossbar_writew;
	break;
	case 4:
	cb->write = crossbar_writel;
	break;
	default:
	pr_err("Invalid reg-size property\n");
	ret = -EINVAL;
	goto err_reg_offset;
	break;
	}

	/*
	* Register offsets are not linear because of the
	* reserved irqs. so find and store the offsets once.
	*/
	for (i = 0; i < max; i++) {
	if (cb->irq_map[i] == IRQ_RESERVED)
	continue;

	cb->register_offsets[i] = reserved;
	reserved += size;
	}

	of_property_read_u32(node, "ti,irqs-safe-map", &cb->safe_map);
	/* Initialize the crossbar with safe map to start with */
	for (i = 0; i < max; i++) {
	if (cb->irq_map[i] == IRQ_RESERVED \|\|
	cb->irq_map[i] == IRQ_SKIP)
	continue;

	cb->write(i, cb->safe_map);
	}

	raw_spin_lock_init(&cb->lock);

	return 0;

	err_reg_offset:
	kfree(cb->register_offsets);
	err_irq_map:
	kfree(cb->irq_map);
	err_base:
	iounmap(cb->crossbar_base);
	err_cb:
	kfree(cb);

	cb = NULL;
	return ret;
	}

	static int __init irqcrossbar_init(struct device_node *node,
	struct device_node *parent)
	{
	struct irq_domain parent_domain, domain;
	int err;

	if (!parent) {
	pr_err("%s: no parent, giving up\n", node->full_name);
	return -ENODEV;
	}

	parent_domain = irq_find_host(parent);
	if (!parent_domain) {
	pr_err("%s: unable to obtain parent domain\n", node->full_name);
	return -ENXIO;
	}

	err = crossbar_of_init(node);
	if (err)
	return err;

	domain = irq_domain_add_hierarchy(parent_domain, 0,
	cb->max_crossbar_sources,
	node, &crossbar_domain_ops,
	NULL);
	if (!domain) {
	pr_err("%s: failed to allocated domain\n", node->full_name);
	return -ENOMEM;
	}

	return 0;
	}

	IRQCHIP_DECLARE(ti_irqcrossbar, "ti,irq-crossbar", irqcrossbar_init);