arch/c6x/platforms/megamod-pic.c - kernel/quantenna - Git at Google

 /*
  *  Support for C64x+ Megamodule Interrupt Controller
  *
  *  Copyright (C) 2010, 2011 Texas Instruments Incorporated
  *  Contributed by: Mark Salter <msalter@redhat.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/module.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/of.h>
 #include <linux/of_irq.h>
 #include <linux/of_address.h>
 #include <linux/slab.h>
 #include <asm/soc.h>
 #include <asm/megamod-pic.h>

 #define NR_COMBINERS	4
 #define NR_MUX_OUTPUTS  12

 #define IRQ_UNMAPPED 0xffff

 /*
  * Megamodule Interrupt Controller register layout
  */
 struct megamod_regs {
 	u32	evtflag[8];
 	u32	evtset[8];
 	u32	evtclr[8];
 	u32	reserved0[8];
 	u32	evtmask[8];
 	u32	mevtflag[8];
 	u32	expmask[8];
 	u32	mexpflag[8];
 	u32	intmux_unused;
 	u32	intmux[7];
 	u32	reserved1[8];
 	u32	aegmux[2];
 	u32	reserved2[14];
 	u32	intxstat;
 	u32	intxclr;
 	u32	intdmask;
 	u32	reserved3[13];
 	u32	evtasrt;
 };

 struct megamod_pic {
 	struct irq_domain *irqhost;
 	struct megamod_regs __iomem *regs;
 	raw_spinlock_t lock;

 	/* hw mux mapping */
 	unsigned int output_to_irq[NR_MUX_OUTPUTS];
 };

 static struct megamod_pic *mm_pic;

 struct megamod_cascade_data {
 	struct megamod_pic *pic;
 	int index;
 };

 static struct megamod_cascade_data cascade_data[NR_COMBINERS];

 static void mask_megamod(struct irq_data *data)
 {
 	struct megamod_pic *pic = irq_data_get_irq_chip_data(data);
 	irq_hw_number_t src = irqd_to_hwirq(data);
 	u32 __iomem *evtmask = &pic->regs->evtmask[src / 32];

 	raw_spin_lock(&pic->lock);
 	soc_writel(soc_readl(evtmask) | (1 << (src & 31)), evtmask);
 	raw_spin_unlock(&pic->lock);
 }

 static void unmask_megamod(struct irq_data *data)
 {
 	struct megamod_pic *pic = irq_data_get_irq_chip_data(data);
 	irq_hw_number_t src = irqd_to_hwirq(data);
 	u32 __iomem *evtmask = &pic->regs->evtmask[src / 32];

 	raw_spin_lock(&pic->lock);
 	soc_writel(soc_readl(evtmask) & ~(1 << (src & 31)), evtmask);
 	raw_spin_unlock(&pic->lock);
 }

 static struct irq_chip megamod_chip = {
 	.name		= "megamod",
 	.irq_mask	= mask_megamod,
 	.irq_unmask	= unmask_megamod,
 };

 static void megamod_irq_cascade(struct irq_desc *desc)
 {
 	struct megamod_cascade_data *cascade;
 	struct megamod_pic *pic;
 	unsigned int irq;
 	u32 events;
 	int n, idx;

 	cascade = irq_desc_get_handler_data(desc);

 	pic = cascade->pic;
 	idx = cascade->index;

 	while ((events = soc_readl(&pic->regs->mevtflag[idx])) != 0) {
 		n = __ffs(events);

 		irq = irq_linear_revmap(pic->irqhost, idx * 32 + n);

 		soc_writel(1 << n, &pic->regs->evtclr[idx]);

 		generic_handle_irq(irq);
 	}
 }

 static int megamod_map(struct irq_domain *h, unsigned int virq,
 		       irq_hw_number_t hw)
 {
 	struct megamod_pic *pic = h->host_data;
 	int i;

 	/* We shouldn't see a hwirq which is muxed to core controller */
 	for (i = 0; i < NR_MUX_OUTPUTS; i++)
 		if (pic->output_to_irq[i] == hw)
 			return -1;

 	irq_set_chip_data(virq, pic);
 	irq_set_chip_and_handler(virq, &megamod_chip, handle_level_irq);

 	/* Set default irq type */
 	irq_set_irq_type(virq, IRQ_TYPE_NONE);

 	return 0;
 }

 static const struct irq_domain_ops megamod_domain_ops = {
 	.map	= megamod_map,
 	.xlate	= irq_domain_xlate_onecell,
 };

 static void __init set_megamod_mux(struct megamod_pic *pic, int src, int output)
 {
 	int index, offset;
 	u32 val;

 	if (src < 0 || src >= (NR_COMBINERS * 32)) {
 		pic->output_to_irq[output] = IRQ_UNMAPPED;
 		return;
 	}

 	/* four mappings per mux register */
 	index = output / 4;
 	offset = (output & 3) * 8;

 	val = soc_readl(&pic->regs->intmux[index]);
 	val &= ~(0xff << offset);
 	val |= src << offset;
 	soc_writel(val, &pic->regs->intmux[index]);
 }

 /*
  * Parse the MUX mapping, if one exists.
  *
  * The MUX map is an array of up to 12 cells; one for each usable core priority
  * interrupt. The value of a given cell is the megamodule interrupt source
  * which is to me MUXed to the output corresponding to the cell position
  * withing the array. The first cell in the array corresponds to priority
  * 4 and the last (12th) cell corresponds to priority 15. The allowed
  * values are 4 - ((NR_COMBINERS * 32) - 1). Note that the combined interrupt
  * sources (0 - 3) are not allowed to be mapped through this property. They
  * are handled through the "interrupts" property. This allows us to use a
  * value of zero as a "do not map" placeholder.
  */
 static void __init parse_priority_map(struct megamod_pic *pic,
 				      int *mapping, int size)
 {
 	struct device_node *np = irq_domain_get_of_node(pic->irqhost);
 	const __be32 *map;
 	int i, maplen;
 	u32 val;

 	map = of_get_property(np, "ti,c64x+megamod-pic-mux", &maplen);
 	if (map) {
 		maplen /= 4;
 		if (maplen > size)
 			maplen = size;

 		for (i = 0; i < maplen; i++) {
 			val = be32_to_cpup(map);
 			if (val && val >= 4)
 				mapping[i] = val;
 			++map;
 		}
 	}
 }

 static struct megamod_pic * __init init_megamod_pic(struct device_node *np)
 {
 	struct megamod_pic *pic;
 	int i, irq;
 	int mapping[NR_MUX_OUTPUTS];

 	pr_info("Initializing C64x+ Megamodule PIC\n");

 	pic = kzalloc(sizeof(struct megamod_pic), GFP_KERNEL);
 	if (!pic) {
 		pr_err("%s: Could not alloc PIC structure.\n", np->full_name);
 		return NULL;
 	}

 	pic->irqhost = irq_domain_add_linear(np, NR_COMBINERS * 32,
 					     &megamod_domain_ops, pic);
 	if (!pic->irqhost) {
 		pr_err("%s: Could not alloc host.\n", np->full_name);
 		goto error_free;
 	}

 	pic->irqhost->host_data = pic;

 	raw_spin_lock_init(&pic->lock);

 	pic->regs = of_iomap(np, 0);
 	if (!pic->regs) {
 		pr_err("%s: Could not map registers.\n", np->full_name);
 		goto error_free;
 	}

 	/* Initialize MUX map */
 	for (i = 0; i < ARRAY_SIZE(mapping); i++)
 		mapping[i] = IRQ_UNMAPPED;

 	parse_priority_map(pic, mapping, ARRAY_SIZE(mapping));

 	/*
 	 * We can have up to 12 interrupts cascading to the core controller.
 	 * These cascades can be from the combined interrupt sources or for
 	 * individual interrupt sources. The "interrupts" property only
 	 * deals with the cascaded combined interrupts. The individual
 	 * interrupts muxed to the core controller use the core controller
 	 * as their interrupt parent.
 	 */
 	for (i = 0; i < NR_COMBINERS; i++) {
 		struct irq_data *irq_data;
 		irq_hw_number_t hwirq;

 		irq = irq_of_parse_and_map(np, i);
 		if (irq == NO_IRQ)
 			continue;

 		irq_data = irq_get_irq_data(irq);
 		if (!irq_data) {
 			pr_err("%s: combiner-%d no irq_data for virq %d!\n",
 			       np->full_name, i, irq);
 			continue;
 		}

 		hwirq = irq_data->hwirq;

 		/*
 		 * Check that device tree provided something in the range
 		 * of the core priority interrupts (4 - 15).
 		 */
 		if (hwirq < 4 || hwirq >= NR_PRIORITY_IRQS) {
 			pr_err("%s: combiner-%d core irq %ld out of range!\n",
 			       np->full_name, i, hwirq);
 			continue;
 		}

 		/* record the mapping */
 		mapping[hwirq - 4] = i;

 		pr_debug("%s: combiner-%d cascading to hwirq %ld\n",
 			 np->full_name, i, hwirq);

 		cascade_data[i].pic = pic;
 		cascade_data[i].index = i;

 		/* mask and clear all events in combiner */
 		soc_writel(~0, &pic->regs->evtmask[i]);
 		soc_writel(~0, &pic->regs->evtclr[i]);

 		irq_set_chained_handler_and_data(irq, megamod_irq_cascade,
 						 &cascade_data[i]);
 	}

 	/* Finally, set up the MUX registers */
 	for (i = 0; i < NR_MUX_OUTPUTS; i++) {
 		if (mapping[i] != IRQ_UNMAPPED) {
 			pr_debug("%s: setting mux %d to priority %d\n",
 				 np->full_name, mapping[i], i + 4);
 			set_megamod_mux(pic, mapping[i], i);
 		}
 	}

 	return pic;

 error_free:
 	kfree(pic);

 	return NULL;
 }

 /*
  * Return next active event after ACK'ing it.
  * Return -1 if no events active.
  */
 static int get_exception(void)
 {
 	int i, bit;
 	u32 mask;

 	for (i = 0; i < NR_COMBINERS; i++) {
 		mask = soc_readl(&mm_pic->regs->mexpflag[i]);
 		if (mask) {
 			bit = __ffs(mask);
 			soc_writel(1 << bit, &mm_pic->regs->evtclr[i]);
 			return (i * 32) + bit;
 		}
 	}
 	return -1;
 }

 static void assert_event(unsigned int val)
 {
 	soc_writel(val, &mm_pic->regs->evtasrt);
 }

 void __init megamod_pic_init(void)
 {
 	struct device_node *np;

 	np = of_find_compatible_node(NULL, NULL, "ti,c64x+megamod-pic");
 	if (!np)
 		return;

 	mm_pic = init_megamod_pic(np);
 	of_node_put(np);

 	soc_ops.get_exception = get_exception;
 	soc_ops.assert_event = assert_event;

 	return;
 }
	/*
	* Support for C64x+ Megamodule Interrupt Controller
	*
	* Copyright (C) 2010, 2011 Texas Instruments Incorporated
	* Contributed by: Mark Salter <msalter@redhat.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/module.h>
	#include <linux/interrupt.h>
	#include <linux/io.h>
	#include <linux/of.h>
	#include <linux/of_irq.h>
	#include <linux/of_address.h>
	#include <linux/slab.h>
	#include <asm/soc.h>
	#include <asm/megamod-pic.h>

	#define NR_COMBINERS 4
	#define NR_MUX_OUTPUTS 12

	#define IRQ_UNMAPPED 0xffff

	/*
	* Megamodule Interrupt Controller register layout
	*/
	struct megamod_regs {
	u32 evtflag[8];
	u32 evtset[8];
	u32 evtclr[8];
	u32 reserved0[8];
	u32 evtmask[8];
	u32 mevtflag[8];
	u32 expmask[8];
	u32 mexpflag[8];
	u32 intmux_unused;
	u32 intmux[7];
	u32 reserved1[8];
	u32 aegmux[2];
	u32 reserved2[14];
	u32 intxstat;
	u32 intxclr;
	u32 intdmask;
	u32 reserved3[13];
	u32 evtasrt;
	};

	struct megamod_pic {
	struct irq_domain *irqhost;
	struct megamod_regs __iomem *regs;
	raw_spinlock_t lock;

	/* hw mux mapping */
	unsigned int output_to_irq[NR_MUX_OUTPUTS];
	};

	static struct megamod_pic *mm_pic;

	struct megamod_cascade_data {
	struct megamod_pic *pic;
	int index;
	};

	static struct megamod_cascade_data cascade_data[NR_COMBINERS];

	static void mask_megamod(struct irq_data *data)
	{
	struct megamod_pic *pic = irq_data_get_irq_chip_data(data);
	irq_hw_number_t src = irqd_to_hwirq(data);
	u32 __iomem *evtmask = &pic->regs->evtmask[src / 32];

	raw_spin_lock(&pic->lock);
	soc_writel(soc_readl(evtmask) \| (1 << (src & 31)), evtmask);
	raw_spin_unlock(&pic->lock);
	}

	static void unmask_megamod(struct irq_data *data)
	{
	struct megamod_pic *pic = irq_data_get_irq_chip_data(data);
	irq_hw_number_t src = irqd_to_hwirq(data);
	u32 __iomem *evtmask = &pic->regs->evtmask[src / 32];

	raw_spin_lock(&pic->lock);
	soc_writel(soc_readl(evtmask) & ~(1 << (src & 31)), evtmask);
	raw_spin_unlock(&pic->lock);
	}

	static struct irq_chip megamod_chip = {
	.name = "megamod",
	.irq_mask = mask_megamod,
	.irq_unmask = unmask_megamod,
	};

	static void megamod_irq_cascade(struct irq_desc *desc)
	{
	struct megamod_cascade_data *cascade;
	struct megamod_pic *pic;
	unsigned int irq;
	u32 events;
	int n, idx;

	cascade = irq_desc_get_handler_data(desc);

	pic = cascade->pic;
	idx = cascade->index;

	while ((events = soc_readl(&pic->regs->mevtflag[idx])) != 0) {
	n = __ffs(events);

	irq = irq_linear_revmap(pic->irqhost, idx * 32 + n);

	soc_writel(1 << n, &pic->regs->evtclr[idx]);

	generic_handle_irq(irq);
	}
	}

	static int megamod_map(struct irq_domain *h, unsigned int virq,
	irq_hw_number_t hw)
	{
	struct megamod_pic *pic = h->host_data;
	int i;

	/* We shouldn't see a hwirq which is muxed to core controller */
	for (i = 0; i < NR_MUX_OUTPUTS; i++)
	if (pic->output_to_irq[i] == hw)
	return -1;

	irq_set_chip_data(virq, pic);
	irq_set_chip_and_handler(virq, &megamod_chip, handle_level_irq);

	/* Set default irq type */
	irq_set_irq_type(virq, IRQ_TYPE_NONE);

	return 0;
	}

	static const struct irq_domain_ops megamod_domain_ops = {
	.map = megamod_map,
	.xlate = irq_domain_xlate_onecell,
	};

	static void __init set_megamod_mux(struct megamod_pic *pic, int src, int output)
	{
	int index, offset;
	u32 val;

	if (src < 0 \|\| src >= (NR_COMBINERS * 32)) {
	pic->output_to_irq[output] = IRQ_UNMAPPED;
	return;
	}

	/* four mappings per mux register */
	index = output / 4;
	offset = (output & 3) * 8;

	val = soc_readl(&pic->regs->intmux[index]);
	val &= ~(0xff << offset);
	val \|= src << offset;
	soc_writel(val, &pic->regs->intmux[index]);
	}

	/*
	* Parse the MUX mapping, if one exists.
	*
	* The MUX map is an array of up to 12 cells; one for each usable core priority
	* interrupt. The value of a given cell is the megamodule interrupt source
	* which is to me MUXed to the output corresponding to the cell position
	* withing the array. The first cell in the array corresponds to priority
	* 4 and the last (12th) cell corresponds to priority 15. The allowed
	* values are 4 - ((NR_COMBINERS * 32) - 1). Note that the combined interrupt
	* sources (0 - 3) are not allowed to be mapped through this property. They
	* are handled through the "interrupts" property. This allows us to use a
	* value of zero as a "do not map" placeholder.
	*/
	static void __init parse_priority_map(struct megamod_pic *pic,
	int *mapping, int size)
	{
	struct device_node *np = irq_domain_get_of_node(pic->irqhost);
	const __be32 *map;
	int i, maplen;
	u32 val;

	map = of_get_property(np, "ti,c64x+megamod-pic-mux", &maplen);
	if (map) {
	maplen /= 4;
	if (maplen > size)
	maplen = size;

	for (i = 0; i < maplen; i++) {
	val = be32_to_cpup(map);
	if (val && val >= 4)
	mapping[i] = val;
	++map;
	}
	}
	}

	static struct megamod_pic * __init init_megamod_pic(struct device_node *np)
	{
	struct megamod_pic *pic;
	int i, irq;
	int mapping[NR_MUX_OUTPUTS];

	pr_info("Initializing C64x+ Megamodule PIC\n");

	pic = kzalloc(sizeof(struct megamod_pic), GFP_KERNEL);
	if (!pic) {
	pr_err("%s: Could not alloc PIC structure.\n", np->full_name);
	return NULL;
	}

	pic->irqhost = irq_domain_add_linear(np, NR_COMBINERS * 32,
	&megamod_domain_ops, pic);
	if (!pic->irqhost) {
	pr_err("%s: Could not alloc host.\n", np->full_name);
	goto error_free;
	}

	pic->irqhost->host_data = pic;

	raw_spin_lock_init(&pic->lock);

	pic->regs = of_iomap(np, 0);
	if (!pic->regs) {
	pr_err("%s: Could not map registers.\n", np->full_name);
	goto error_free;
	}

	/* Initialize MUX map */
	for (i = 0; i < ARRAY_SIZE(mapping); i++)
	mapping[i] = IRQ_UNMAPPED;

	parse_priority_map(pic, mapping, ARRAY_SIZE(mapping));

	/*
	* We can have up to 12 interrupts cascading to the core controller.
	* These cascades can be from the combined interrupt sources or for
	* individual interrupt sources. The "interrupts" property only
	* deals with the cascaded combined interrupts. The individual
	* interrupts muxed to the core controller use the core controller
	* as their interrupt parent.
	*/
	for (i = 0; i < NR_COMBINERS; i++) {
	struct irq_data *irq_data;
	irq_hw_number_t hwirq;

	irq = irq_of_parse_and_map(np, i);
	if (irq == NO_IRQ)
	continue;

	irq_data = irq_get_irq_data(irq);
	if (!irq_data) {
	pr_err("%s: combiner-%d no irq_data for virq %d!\n",
	np->full_name, i, irq);
	continue;
	}

	hwirq = irq_data->hwirq;

	/*
	* Check that device tree provided something in the range
	* of the core priority interrupts (4 - 15).
	*/
	if (hwirq < 4 \|\| hwirq >= NR_PRIORITY_IRQS) {
	pr_err("%s: combiner-%d core irq %ld out of range!\n",
	np->full_name, i, hwirq);
	continue;
	}

	/* record the mapping */
	mapping[hwirq - 4] = i;

	pr_debug("%s: combiner-%d cascading to hwirq %ld\n",
	np->full_name, i, hwirq);

	cascade_data[i].pic = pic;
	cascade_data[i].index = i;

	/* mask and clear all events in combiner */
	soc_writel(~0, &pic->regs->evtmask[i]);
	soc_writel(~0, &pic->regs->evtclr[i]);

	irq_set_chained_handler_and_data(irq, megamod_irq_cascade,
	&cascade_data[i]);
	}

	/* Finally, set up the MUX registers */
	for (i = 0; i < NR_MUX_OUTPUTS; i++) {
	if (mapping[i] != IRQ_UNMAPPED) {
	pr_debug("%s: setting mux %d to priority %d\n",
	np->full_name, mapping[i], i + 4);
	set_megamod_mux(pic, mapping[i], i);
	}
	}

	return pic;

	error_free:
	kfree(pic);

	return NULL;
	}

	/*
	* Return next active event after ACK'ing it.
	* Return -1 if no events active.
	*/
	static int get_exception(void)
	{
	int i, bit;
	u32 mask;

	for (i = 0; i < NR_COMBINERS; i++) {
	mask = soc_readl(&mm_pic->regs->mexpflag[i]);
	if (mask) {
	bit = __ffs(mask);
	soc_writel(1 << bit, &mm_pic->regs->evtclr[i]);
	return (i * 32) + bit;
	}
	}
	return -1;
	}

	static void assert_event(unsigned int val)
	{
	soc_writel(val, &mm_pic->regs->evtasrt);
	}

	void __init megamod_pic_init(void)
	{
	struct device_node *np;

	np = of_find_compatible_node(NULL, NULL, "ti,c64x+megamod-pic");
	if (!np)
	return;

	mm_pic = init_megamod_pic(np);
	of_node_put(np);

	soc_ops.get_exception = get_exception;
	soc_ops.assert_event = assert_event;

	return;
	}