drivers/irqchip/irq-imgpdc.c - pub/scm/linux/kernel/git/tiwai/sound - Git at Google

 /*
  * IMG PowerDown Controller (PDC)
  *
  * Copyright 2010-2013 Imagination Technologies Ltd.
  *
  * Exposes the syswake and PDC peripheral wake interrupts to the system.
  *
  */

 #include <linux/bitops.h>
 #include <linux/interrupt.h>
 #include <linux/irqdomain.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/spinlock.h>

 /* PDC interrupt register numbers */

 #define PDC_IRQ_STATUS			0x310
 #define PDC_IRQ_ENABLE			0x314
 #define PDC_IRQ_CLEAR			0x318
 #define PDC_IRQ_ROUTE			0x31c
 #define PDC_SYS_WAKE_BASE		0x330
 #define PDC_SYS_WAKE_STRIDE		0x8
 #define PDC_SYS_WAKE_CONFIG_BASE	0x334
 #define PDC_SYS_WAKE_CONFIG_STRIDE	0x8

 /* PDC interrupt register field masks */

 #define PDC_IRQ_SYS3			0x08
 #define PDC_IRQ_SYS2			0x04
 #define PDC_IRQ_SYS1			0x02
 #define PDC_IRQ_SYS0			0x01
 #define PDC_IRQ_ROUTE_WU_EN_SYS3	0x08000000
 #define PDC_IRQ_ROUTE_WU_EN_SYS2	0x04000000
 #define PDC_IRQ_ROUTE_WU_EN_SYS1	0x02000000
 #define PDC_IRQ_ROUTE_WU_EN_SYS0	0x01000000
 #define PDC_IRQ_ROUTE_WU_EN_WD		0x00040000
 #define PDC_IRQ_ROUTE_WU_EN_IR		0x00020000
 #define PDC_IRQ_ROUTE_WU_EN_RTC		0x00010000
 #define PDC_IRQ_ROUTE_EXT_EN_SYS3	0x00000800
 #define PDC_IRQ_ROUTE_EXT_EN_SYS2	0x00000400
 #define PDC_IRQ_ROUTE_EXT_EN_SYS1	0x00000200
 #define PDC_IRQ_ROUTE_EXT_EN_SYS0	0x00000100
 #define PDC_IRQ_ROUTE_EXT_EN_WD		0x00000004
 #define PDC_IRQ_ROUTE_EXT_EN_IR		0x00000002
 #define PDC_IRQ_ROUTE_EXT_EN_RTC	0x00000001
 #define PDC_SYS_WAKE_RESET		0x00000010
 #define PDC_SYS_WAKE_INT_MODE		0x0000000e
 #define PDC_SYS_WAKE_INT_MODE_SHIFT	1
 #define PDC_SYS_WAKE_PIN_VAL		0x00000001

 /* PDC interrupt constants */

 #define PDC_SYS_WAKE_INT_LOW		0x0
 #define PDC_SYS_WAKE_INT_HIGH		0x1
 #define PDC_SYS_WAKE_INT_DOWN		0x2
 #define PDC_SYS_WAKE_INT_UP		0x3
 #define PDC_SYS_WAKE_INT_CHANGE		0x6
 #define PDC_SYS_WAKE_INT_NONE		0x4

 /**
  * struct pdc_intc_priv - private pdc interrupt data.
  * @nr_perips:		Number of peripheral interrupt signals.
  * @nr_syswakes:	Number of syswake signals.
  * @perip_irqs:		List of peripheral IRQ numbers handled.
  * @syswake_irq:	Shared PDC syswake IRQ number.
  * @domain:		IRQ domain for PDC peripheral and syswake IRQs.
  * @pdc_base:		Base of PDC registers.
  * @irq_route:		Cached version of PDC_IRQ_ROUTE register.
  * @lock:		Lock to protect the PDC syswake registers and the cached
  *			values of those registers in this struct.
  */
 struct pdc_intc_priv {
 	unsigned int		nr_perips;
 	unsigned int		nr_syswakes;
 	unsigned int		*perip_irqs;
 	unsigned int		syswake_irq;
 	struct irq_domain	*domain;
 	void __iomem		*pdc_base;

 	u32			irq_route;
 	raw_spinlock_t		lock;
 };

 static void pdc_write(struct pdc_intc_priv *priv, unsigned int reg_offs,
 		      unsigned int data)
 {
 	iowrite32(data, priv->pdc_base + reg_offs);
 }

 static unsigned int pdc_read(struct pdc_intc_priv *priv,
 			     unsigned int reg_offs)
 {
 	return ioread32(priv->pdc_base + reg_offs);
 }

 /* Generic IRQ callbacks */

 #define SYS0_HWIRQ	8

 static unsigned int hwirq_is_syswake(irq_hw_number_t hw)
 {
 	return hw >= SYS0_HWIRQ;
 }

 static unsigned int hwirq_to_syswake(irq_hw_number_t hw)
 {
 	return hw - SYS0_HWIRQ;
 }

 static irq_hw_number_t syswake_to_hwirq(unsigned int syswake)
 {
 	return SYS0_HWIRQ + syswake;
 }

 static struct pdc_intc_priv *irqd_to_priv(struct irq_data *data)
 {
 	return (struct pdc_intc_priv *)data->domain->host_data;
 }

 /*
  * perip_irq_mask() and perip_irq_unmask() use IRQ_ROUTE which also contains
  * wake bits, therefore we cannot use the generic irqchip mask callbacks as they
  * cache the mask.
  */

 static void perip_irq_mask(struct irq_data *data)
 {
 	struct pdc_intc_priv *priv = irqd_to_priv(data);

 	raw_spin_lock(&priv->lock);
 	priv->irq_route &= ~data->mask;
 	pdc_write(priv, PDC_IRQ_ROUTE, priv->irq_route);
 	raw_spin_unlock(&priv->lock);
 }

 static void perip_irq_unmask(struct irq_data *data)
 {
 	struct pdc_intc_priv *priv = irqd_to_priv(data);

 	raw_spin_lock(&priv->lock);
 	priv->irq_route |= data->mask;
 	pdc_write(priv, PDC_IRQ_ROUTE, priv->irq_route);
 	raw_spin_unlock(&priv->lock);
 }

 static int syswake_irq_set_type(struct irq_data *data, unsigned int flow_type)
 {
 	struct pdc_intc_priv *priv = irqd_to_priv(data);
 	unsigned int syswake = hwirq_to_syswake(data->hwirq);
 	unsigned int irq_mode;
 	unsigned int soc_sys_wake_regoff, soc_sys_wake;

 	/* translate to syswake IRQ mode */
 	switch (flow_type) {
 	case IRQ_TYPE_EDGE_BOTH:
 		irq_mode = PDC_SYS_WAKE_INT_CHANGE;
 		break;
 	case IRQ_TYPE_EDGE_RISING:
 		irq_mode = PDC_SYS_WAKE_INT_UP;
 		break;
 	case IRQ_TYPE_EDGE_FALLING:
 		irq_mode = PDC_SYS_WAKE_INT_DOWN;
 		break;
 	case IRQ_TYPE_LEVEL_HIGH:
 		irq_mode = PDC_SYS_WAKE_INT_HIGH;
 		break;
 	case IRQ_TYPE_LEVEL_LOW:
 		irq_mode = PDC_SYS_WAKE_INT_LOW;
 		break;
 	default:
 		return -EINVAL;
 	}

 	raw_spin_lock(&priv->lock);

 	/* set the IRQ mode */
 	soc_sys_wake_regoff = PDC_SYS_WAKE_BASE + syswake*PDC_SYS_WAKE_STRIDE;
 	soc_sys_wake = pdc_read(priv, soc_sys_wake_regoff);
 	soc_sys_wake &= ~PDC_SYS_WAKE_INT_MODE;
 	soc_sys_wake |= irq_mode << PDC_SYS_WAKE_INT_MODE_SHIFT;
 	pdc_write(priv, soc_sys_wake_regoff, soc_sys_wake);

 	/* and update the handler */
 	irq_setup_alt_chip(data, flow_type);

 	raw_spin_unlock(&priv->lock);

 	return 0;
 }

 /* applies to both peripheral and syswake interrupts */
 static int pdc_irq_set_wake(struct irq_data *data, unsigned int on)
 {
 	struct pdc_intc_priv *priv = irqd_to_priv(data);
 	irq_hw_number_t hw = data->hwirq;
 	unsigned int mask = (1 << 16) << hw;
 	unsigned int dst_irq;

 	raw_spin_lock(&priv->lock);
 	if (on)
 		priv->irq_route |= mask;
 	else
 		priv->irq_route &= ~mask;
 	pdc_write(priv, PDC_IRQ_ROUTE, priv->irq_route);
 	raw_spin_unlock(&priv->lock);

 	/* control the destination IRQ wakeup too for standby mode */
 	if (hwirq_is_syswake(hw))
 		dst_irq = priv->syswake_irq;
 	else
 		dst_irq = priv->perip_irqs[hw];
 	irq_set_irq_wake(dst_irq, on);

 	return 0;
 }

 static void pdc_intc_perip_isr(unsigned int irq, struct irq_desc *desc)
 {
 	struct pdc_intc_priv *priv;
 	unsigned int i, irq_no;

 	priv = (struct pdc_intc_priv *)irq_desc_get_handler_data(desc);

 	/* find the peripheral number */
 	for (i = 0; i < priv->nr_perips; ++i)
 		if (irq == priv->perip_irqs[i])
 			goto found;

 	/* should never get here */
 	return;
 found:

 	/* pass on the interrupt */
 	irq_no = irq_linear_revmap(priv->domain, i);
 	generic_handle_irq(irq_no);
 }

 static void pdc_intc_syswake_isr(unsigned int irq, struct irq_desc *desc)
 {
 	struct pdc_intc_priv *priv;
 	unsigned int syswake, irq_no;
 	unsigned int status;

 	priv = (struct pdc_intc_priv *)irq_desc_get_handler_data(desc);

 	status = pdc_read(priv, PDC_IRQ_STATUS) &
 		 pdc_read(priv, PDC_IRQ_ENABLE);
 	status &= (1 << priv->nr_syswakes) - 1;

 	for (syswake = 0; status; status >>= 1, ++syswake) {
 		/* Has this sys_wake triggered? */
 		if (!(status & 1))
 			continue;

 		irq_no = irq_linear_revmap(priv->domain,
 					   syswake_to_hwirq(syswake));
 		generic_handle_irq(irq_no);
 	}
 }

 static void pdc_intc_setup(struct pdc_intc_priv *priv)
 {
 	int i;
 	unsigned int soc_sys_wake_regoff;
 	unsigned int soc_sys_wake;

 	/*
 	 * Mask all syswake interrupts before routing, or we could receive an
 	 * interrupt before we're ready to handle it.
 	 */
 	pdc_write(priv, PDC_IRQ_ENABLE, 0);

 	/*
 	 * Enable routing of all syswakes
 	 * Disable all wake sources
 	 */
 	priv->irq_route = ((PDC_IRQ_ROUTE_EXT_EN_SYS0 << priv->nr_syswakes) -
 				PDC_IRQ_ROUTE_EXT_EN_SYS0);
 	pdc_write(priv, PDC_IRQ_ROUTE, priv->irq_route);

 	/* Initialise syswake IRQ */
 	for (i = 0; i < priv->nr_syswakes; ++i) {
 		/* set the IRQ mode to none */
 		soc_sys_wake_regoff = PDC_SYS_WAKE_BASE + i*PDC_SYS_WAKE_STRIDE;
 		soc_sys_wake = PDC_SYS_WAKE_INT_NONE
 				<< PDC_SYS_WAKE_INT_MODE_SHIFT;
 		pdc_write(priv, soc_sys_wake_regoff, soc_sys_wake);
 	}
 }

 static int pdc_intc_probe(struct platform_device *pdev)
 {
 	struct pdc_intc_priv *priv;
 	struct device_node *node = pdev->dev.of_node;
 	struct resource *res_regs;
 	struct irq_chip_generic *gc;
 	unsigned int i;
 	int irq, ret;
 	u32 val;

 	if (!node)
 		return -ENOENT;

 	/* Get registers */
 	res_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (res_regs == NULL) {
 		dev_err(&pdev->dev, "cannot find registers resource\n");
 		return -ENOENT;
 	}

 	/* Allocate driver data */
 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv) {
 		dev_err(&pdev->dev, "cannot allocate device data\n");
 		return -ENOMEM;
 	}
 	raw_spin_lock_init(&priv->lock);
 	platform_set_drvdata(pdev, priv);

 	/* Ioremap the registers */
 	priv->pdc_base = devm_ioremap(&pdev->dev, res_regs->start,
 				      res_regs->end - res_regs->start);
 	if (!priv->pdc_base)
 		return -EIO;

 	/* Get number of peripherals */
 	ret = of_property_read_u32(node, "num-perips", &val);
 	if (ret) {
 		dev_err(&pdev->dev, "No num-perips node property found\n");
 		return -EINVAL;
 	}
 	if (val > SYS0_HWIRQ) {
 		dev_err(&pdev->dev, "num-perips (%u) out of range\n", val);
 		return -EINVAL;
 	}
 	priv->nr_perips = val;

 	/* Get number of syswakes */
 	ret = of_property_read_u32(node, "num-syswakes", &val);
 	if (ret) {
 		dev_err(&pdev->dev, "No num-syswakes node property found\n");
 		return -EINVAL;
 	}
 	if (val > SYS0_HWIRQ) {
 		dev_err(&pdev->dev, "num-syswakes (%u) out of range\n", val);
 		return -EINVAL;
 	}
 	priv->nr_syswakes = val;

 	/* Get peripheral IRQ numbers */
 	priv->perip_irqs = devm_kzalloc(&pdev->dev, 4 * priv->nr_perips,
 					GFP_KERNEL);
 	if (!priv->perip_irqs) {
 		dev_err(&pdev->dev, "cannot allocate perip IRQ list\n");
 		return -ENOMEM;
 	}
 	for (i = 0; i < priv->nr_perips; ++i) {
 		irq = platform_get_irq(pdev, 1 + i);
 		if (irq < 0) {
 			dev_err(&pdev->dev, "cannot find perip IRQ #%u\n", i);
 			return irq;
 		}
 		priv->perip_irqs[i] = irq;
 	}
 	/* check if too many were provided */
 	if (platform_get_irq(pdev, 1 + i) >= 0) {
 		dev_err(&pdev->dev, "surplus perip IRQs detected\n");
 		return -EINVAL;
 	}

 	/* Get syswake IRQ number */
 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0) {
 		dev_err(&pdev->dev, "cannot find syswake IRQ\n");
 		return irq;
 	}
 	priv->syswake_irq = irq;

 	/* Set up an IRQ domain */
 	priv->domain = irq_domain_add_linear(node, 16, &irq_generic_chip_ops,
 					     priv);
 	if (unlikely(!priv->domain)) {
 		dev_err(&pdev->dev, "cannot add IRQ domain\n");
 		return -ENOMEM;
 	}

 	/*
 	 * Set up 2 generic irq chips with 2 chip types.
 	 * The first one for peripheral irqs (only 1 chip type used)
 	 * The second one for syswake irqs (edge and level chip types)
 	 */
 	ret = irq_alloc_domain_generic_chips(priv->domain, 8, 2, "pdc",
 					     handle_level_irq, 0, 0,
 					     IRQ_GC_INIT_NESTED_LOCK);
 	if (ret)
 		goto err_generic;

 	/* peripheral interrupt chip */

 	gc = irq_get_domain_generic_chip(priv->domain, 0);
 	gc->unused	= ~(BIT(priv->nr_perips) - 1);
 	gc->reg_base	= priv->pdc_base;
 	/*
 	 * IRQ_ROUTE contains wake bits, so we can't use the generic versions as
 	 * they cache the mask
 	 */
 	gc->chip_types[0].regs.mask		= PDC_IRQ_ROUTE;
 	gc->chip_types[0].chip.irq_mask		= perip_irq_mask;
 	gc->chip_types[0].chip.irq_unmask	= perip_irq_unmask;
 	gc->chip_types[0].chip.irq_set_wake	= pdc_irq_set_wake;

 	/* syswake interrupt chip */

 	gc = irq_get_domain_generic_chip(priv->domain, 8);
 	gc->unused	= ~(BIT(priv->nr_syswakes) - 1);
 	gc->reg_base	= priv->pdc_base;

 	/* edge interrupts */
 	gc->chip_types[0].type			= IRQ_TYPE_EDGE_BOTH;
 	gc->chip_types[0].handler		= handle_edge_irq;
 	gc->chip_types[0].regs.ack		= PDC_IRQ_CLEAR;
 	gc->chip_types[0].regs.mask		= PDC_IRQ_ENABLE;
 	gc->chip_types[0].chip.irq_ack		= irq_gc_ack_set_bit;
 	gc->chip_types[0].chip.irq_mask		= irq_gc_mask_clr_bit;
 	gc->chip_types[0].chip.irq_unmask	= irq_gc_mask_set_bit;
 	gc->chip_types[0].chip.irq_set_type	= syswake_irq_set_type;
 	gc->chip_types[0].chip.irq_set_wake	= pdc_irq_set_wake;
 	/* for standby we pass on to the shared syswake IRQ */
 	gc->chip_types[0].chip.flags		= IRQCHIP_MASK_ON_SUSPEND;

 	/* level interrupts */
 	gc->chip_types[1].type			= IRQ_TYPE_LEVEL_MASK;
 	gc->chip_types[1].handler		= handle_level_irq;
 	gc->chip_types[1].regs.ack		= PDC_IRQ_CLEAR;
 	gc->chip_types[1].regs.mask		= PDC_IRQ_ENABLE;
 	gc->chip_types[1].chip.irq_ack		= irq_gc_ack_set_bit;
 	gc->chip_types[1].chip.irq_mask		= irq_gc_mask_clr_bit;
 	gc->chip_types[1].chip.irq_unmask	= irq_gc_mask_set_bit;
 	gc->chip_types[1].chip.irq_set_type	= syswake_irq_set_type;
 	gc->chip_types[1].chip.irq_set_wake	= pdc_irq_set_wake;
 	/* for standby we pass on to the shared syswake IRQ */
 	gc->chip_types[1].chip.flags		= IRQCHIP_MASK_ON_SUSPEND;

 	/* Set up the hardware to enable interrupt routing */
 	pdc_intc_setup(priv);

 	/* Setup chained handlers for the peripheral IRQs */
 	for (i = 0; i < priv->nr_perips; ++i) {
 		irq = priv->perip_irqs[i];
 		irq_set_handler_data(irq, priv);
 		irq_set_chained_handler(irq, pdc_intc_perip_isr);
 	}

 	/* Setup chained handler for the syswake IRQ */
 	irq_set_handler_data(priv->syswake_irq, priv);
 	irq_set_chained_handler(priv->syswake_irq, pdc_intc_syswake_isr);

 	dev_info(&pdev->dev,
 		 "PDC IRQ controller initialised (%u perip IRQs, %u syswake IRQs)\n",
 		 priv->nr_perips,
 		 priv->nr_syswakes);

 	return 0;
 err_generic:
 	irq_domain_remove(priv->domain);
 	return ret;
 }

 static int pdc_intc_remove(struct platform_device *pdev)
 {
 	struct pdc_intc_priv *priv = platform_get_drvdata(pdev);

 	irq_domain_remove(priv->domain);
 	return 0;
 }

 static const struct of_device_id pdc_intc_match[] = {
 	{ .compatible = "img,pdc-intc" },
 	{}
 };

 static struct platform_driver pdc_intc_driver = {
 	.driver = {
 		.name		= "pdc-intc",
 		.of_match_table	= pdc_intc_match,
 	},
 	.probe = pdc_intc_probe,
 	.remove = pdc_intc_remove,
 };

 static int __init pdc_intc_init(void)
 {
 	return platform_driver_register(&pdc_intc_driver);
 }
 core_initcall(pdc_intc_init);
	/*
	* IMG PowerDown Controller (PDC)
	*
	* Copyright 2010-2013 Imagination Technologies Ltd.
	*
	* Exposes the syswake and PDC peripheral wake interrupts to the system.
	*
	*/

	#include <linux/bitops.h>
	#include <linux/interrupt.h>
	#include <linux/irqdomain.h>
	#include <linux/io.h>
	#include <linux/kernel.h>
	#include <linux/of.h>
	#include <linux/platform_device.h>
	#include <linux/spinlock.h>

	/* PDC interrupt register numbers */

	#define PDC_IRQ_STATUS 0x310
	#define PDC_IRQ_ENABLE 0x314
	#define PDC_IRQ_CLEAR 0x318
	#define PDC_IRQ_ROUTE 0x31c
	#define PDC_SYS_WAKE_BASE 0x330
	#define PDC_SYS_WAKE_STRIDE 0x8
	#define PDC_SYS_WAKE_CONFIG_BASE 0x334
	#define PDC_SYS_WAKE_CONFIG_STRIDE 0x8

	/* PDC interrupt register field masks */

	#define PDC_IRQ_SYS3 0x08
	#define PDC_IRQ_SYS2 0x04
	#define PDC_IRQ_SYS1 0x02
	#define PDC_IRQ_SYS0 0x01
	#define PDC_IRQ_ROUTE_WU_EN_SYS3 0x08000000
	#define PDC_IRQ_ROUTE_WU_EN_SYS2 0x04000000
	#define PDC_IRQ_ROUTE_WU_EN_SYS1 0x02000000
	#define PDC_IRQ_ROUTE_WU_EN_SYS0 0x01000000
	#define PDC_IRQ_ROUTE_WU_EN_WD 0x00040000
	#define PDC_IRQ_ROUTE_WU_EN_IR 0x00020000
	#define PDC_IRQ_ROUTE_WU_EN_RTC 0x00010000
	#define PDC_IRQ_ROUTE_EXT_EN_SYS3 0x00000800
	#define PDC_IRQ_ROUTE_EXT_EN_SYS2 0x00000400
	#define PDC_IRQ_ROUTE_EXT_EN_SYS1 0x00000200
	#define PDC_IRQ_ROUTE_EXT_EN_SYS0 0x00000100
	#define PDC_IRQ_ROUTE_EXT_EN_WD 0x00000004
	#define PDC_IRQ_ROUTE_EXT_EN_IR 0x00000002
	#define PDC_IRQ_ROUTE_EXT_EN_RTC 0x00000001
	#define PDC_SYS_WAKE_RESET 0x00000010
	#define PDC_SYS_WAKE_INT_MODE 0x0000000e
	#define PDC_SYS_WAKE_INT_MODE_SHIFT 1
	#define PDC_SYS_WAKE_PIN_VAL 0x00000001

	/* PDC interrupt constants */

	#define PDC_SYS_WAKE_INT_LOW 0x0
	#define PDC_SYS_WAKE_INT_HIGH 0x1
	#define PDC_SYS_WAKE_INT_DOWN 0x2
	#define PDC_SYS_WAKE_INT_UP 0x3
	#define PDC_SYS_WAKE_INT_CHANGE 0x6
	#define PDC_SYS_WAKE_INT_NONE 0x4

	/**
	* struct pdc_intc_priv - private pdc interrupt data.
	* @nr_perips: Number of peripheral interrupt signals.
	* @nr_syswakes: Number of syswake signals.
	* @perip_irqs: List of peripheral IRQ numbers handled.
	* @syswake_irq: Shared PDC syswake IRQ number.
	* @domain: IRQ domain for PDC peripheral and syswake IRQs.
	* @pdc_base: Base of PDC registers.
	* @irq_route: Cached version of PDC_IRQ_ROUTE register.
	* @lock: Lock to protect the PDC syswake registers and the cached
	* values of those registers in this struct.
	*/
	struct pdc_intc_priv {
	unsigned int nr_perips;
	unsigned int nr_syswakes;
	unsigned int *perip_irqs;
	unsigned int syswake_irq;
	struct irq_domain *domain;
	void __iomem *pdc_base;

	u32 irq_route;
	raw_spinlock_t lock;
	};

	static void pdc_write(struct pdc_intc_priv *priv, unsigned int reg_offs,
	unsigned int data)
	{
	iowrite32(data, priv->pdc_base + reg_offs);
	}

	static unsigned int pdc_read(struct pdc_intc_priv *priv,
	unsigned int reg_offs)
	{
	return ioread32(priv->pdc_base + reg_offs);
	}

	/* Generic IRQ callbacks */

	#define SYS0_HWIRQ 8

	static unsigned int hwirq_is_syswake(irq_hw_number_t hw)
	{
	return hw >= SYS0_HWIRQ;
	}

	static unsigned int hwirq_to_syswake(irq_hw_number_t hw)
	{
	return hw - SYS0_HWIRQ;
	}

	static irq_hw_number_t syswake_to_hwirq(unsigned int syswake)
	{
	return SYS0_HWIRQ + syswake;
	}

	static struct pdc_intc_priv irqd_to_priv(struct irq_data data)
	{
	return (struct pdc_intc_priv *)data->domain->host_data;
	}

	/*
	* perip_irq_mask() and perip_irq_unmask() use IRQ_ROUTE which also contains
	* wake bits, therefore we cannot use the generic irqchip mask callbacks as they
	* cache the mask.
	*/

	static void perip_irq_mask(struct irq_data *data)
	{
	struct pdc_intc_priv *priv = irqd_to_priv(data);

	raw_spin_lock(&priv->lock);
	priv->irq_route &= ~data->mask;
	pdc_write(priv, PDC_IRQ_ROUTE, priv->irq_route);
	raw_spin_unlock(&priv->lock);
	}

	static void perip_irq_unmask(struct irq_data *data)
	{
	struct pdc_intc_priv *priv = irqd_to_priv(data);

	raw_spin_lock(&priv->lock);
	priv->irq_route \|= data->mask;
	pdc_write(priv, PDC_IRQ_ROUTE, priv->irq_route);
	raw_spin_unlock(&priv->lock);
	}

	static int syswake_irq_set_type(struct irq_data *data, unsigned int flow_type)
	{
	struct pdc_intc_priv *priv = irqd_to_priv(data);
	unsigned int syswake = hwirq_to_syswake(data->hwirq);
	unsigned int irq_mode;
	unsigned int soc_sys_wake_regoff, soc_sys_wake;

	/* translate to syswake IRQ mode */
	switch (flow_type) {
	case IRQ_TYPE_EDGE_BOTH:
	irq_mode = PDC_SYS_WAKE_INT_CHANGE;
	break;
	case IRQ_TYPE_EDGE_RISING:
	irq_mode = PDC_SYS_WAKE_INT_UP;
	break;
	case IRQ_TYPE_EDGE_FALLING:
	irq_mode = PDC_SYS_WAKE_INT_DOWN;
	break;
	case IRQ_TYPE_LEVEL_HIGH:
	irq_mode = PDC_SYS_WAKE_INT_HIGH;
	break;
	case IRQ_TYPE_LEVEL_LOW:
	irq_mode = PDC_SYS_WAKE_INT_LOW;
	break;
	default:
	return -EINVAL;
	}

	raw_spin_lock(&priv->lock);

	/* set the IRQ mode */
	soc_sys_wake_regoff = PDC_SYS_WAKE_BASE + syswake*PDC_SYS_WAKE_STRIDE;
	soc_sys_wake = pdc_read(priv, soc_sys_wake_regoff);
	soc_sys_wake &= ~PDC_SYS_WAKE_INT_MODE;
	soc_sys_wake \|= irq_mode << PDC_SYS_WAKE_INT_MODE_SHIFT;
	pdc_write(priv, soc_sys_wake_regoff, soc_sys_wake);

	/* and update the handler */
	irq_setup_alt_chip(data, flow_type);

	raw_spin_unlock(&priv->lock);

	return 0;
	}

	/* applies to both peripheral and syswake interrupts */
	static int pdc_irq_set_wake(struct irq_data *data, unsigned int on)
	{
	struct pdc_intc_priv *priv = irqd_to_priv(data);
	irq_hw_number_t hw = data->hwirq;
	unsigned int mask = (1 << 16) << hw;
	unsigned int dst_irq;

	raw_spin_lock(&priv->lock);
	if (on)
	priv->irq_route \|= mask;
	else
	priv->irq_route &= ~mask;
	pdc_write(priv, PDC_IRQ_ROUTE, priv->irq_route);
	raw_spin_unlock(&priv->lock);

	/* control the destination IRQ wakeup too for standby mode */
	if (hwirq_is_syswake(hw))
	dst_irq = priv->syswake_irq;
	else
	dst_irq = priv->perip_irqs[hw];
	irq_set_irq_wake(dst_irq, on);

	return 0;
	}

	static void pdc_intc_perip_isr(unsigned int irq, struct irq_desc *desc)
	{
	struct pdc_intc_priv *priv;
	unsigned int i, irq_no;

	priv = (struct pdc_intc_priv *)irq_desc_get_handler_data(desc);

	/* find the peripheral number */
	for (i = 0; i < priv->nr_perips; ++i)
	if (irq == priv->perip_irqs[i])
	goto found;

	/* should never get here */
	return;
	found:

	/* pass on the interrupt */
	irq_no = irq_linear_revmap(priv->domain, i);
	generic_handle_irq(irq_no);
	}

	static void pdc_intc_syswake_isr(unsigned int irq, struct irq_desc *desc)
	{
	struct pdc_intc_priv *priv;
	unsigned int syswake, irq_no;
	unsigned int status;

	priv = (struct pdc_intc_priv *)irq_desc_get_handler_data(desc);

	status = pdc_read(priv, PDC_IRQ_STATUS) &
	pdc_read(priv, PDC_IRQ_ENABLE);
	status &= (1 << priv->nr_syswakes) - 1;

	for (syswake = 0; status; status >>= 1, ++syswake) {
	/* Has this sys_wake triggered? */
	if (!(status & 1))
	continue;

	irq_no = irq_linear_revmap(priv->domain,
	syswake_to_hwirq(syswake));
	generic_handle_irq(irq_no);
	}
	}

	static void pdc_intc_setup(struct pdc_intc_priv *priv)
	{
	int i;
	unsigned int soc_sys_wake_regoff;
	unsigned int soc_sys_wake;

	/*
	* Mask all syswake interrupts before routing, or we could receive an
	* interrupt before we're ready to handle it.
	*/
	pdc_write(priv, PDC_IRQ_ENABLE, 0);

	/*
	* Enable routing of all syswakes
	* Disable all wake sources
	*/
	priv->irq_route = ((PDC_IRQ_ROUTE_EXT_EN_SYS0 << priv->nr_syswakes) -
	PDC_IRQ_ROUTE_EXT_EN_SYS0);
	pdc_write(priv, PDC_IRQ_ROUTE, priv->irq_route);

	/* Initialise syswake IRQ */
	for (i = 0; i < priv->nr_syswakes; ++i) {
	/* set the IRQ mode to none */
	soc_sys_wake_regoff = PDC_SYS_WAKE_BASE + i*PDC_SYS_WAKE_STRIDE;
	soc_sys_wake = PDC_SYS_WAKE_INT_NONE
	<< PDC_SYS_WAKE_INT_MODE_SHIFT;
	pdc_write(priv, soc_sys_wake_regoff, soc_sys_wake);
	}
	}

	static int pdc_intc_probe(struct platform_device *pdev)
	{
	struct pdc_intc_priv *priv;
	struct device_node *node = pdev->dev.of_node;
	struct resource *res_regs;
	struct irq_chip_generic *gc;
	unsigned int i;
	int irq, ret;
	u32 val;

	if (!node)
	return -ENOENT;

	/* Get registers */
	res_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (res_regs == NULL) {
	dev_err(&pdev->dev, "cannot find registers resource\n");
	return -ENOENT;
	}

	/* Allocate driver data */
	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
	if (!priv) {
	dev_err(&pdev->dev, "cannot allocate device data\n");
	return -ENOMEM;
	}
	raw_spin_lock_init(&priv->lock);
	platform_set_drvdata(pdev, priv);

	/* Ioremap the registers */
	priv->pdc_base = devm_ioremap(&pdev->dev, res_regs->start,
	res_regs->end - res_regs->start);
	if (!priv->pdc_base)
	return -EIO;

	/* Get number of peripherals */
	ret = of_property_read_u32(node, "num-perips", &val);
	if (ret) {
	dev_err(&pdev->dev, "No num-perips node property found\n");
	return -EINVAL;
	}
	if (val > SYS0_HWIRQ) {
	dev_err(&pdev->dev, "num-perips (%u) out of range\n", val);
	return -EINVAL;
	}
	priv->nr_perips = val;

	/* Get number of syswakes */
	ret = of_property_read_u32(node, "num-syswakes", &val);
	if (ret) {
	dev_err(&pdev->dev, "No num-syswakes node property found\n");
	return -EINVAL;
	}
	if (val > SYS0_HWIRQ) {
	dev_err(&pdev->dev, "num-syswakes (%u) out of range\n", val);
	return -EINVAL;
	}
	priv->nr_syswakes = val;

	/* Get peripheral IRQ numbers */
	priv->perip_irqs = devm_kzalloc(&pdev->dev, 4 * priv->nr_perips,
	GFP_KERNEL);
	if (!priv->perip_irqs) {
	dev_err(&pdev->dev, "cannot allocate perip IRQ list\n");
	return -ENOMEM;
	}
	for (i = 0; i < priv->nr_perips; ++i) {
	irq = platform_get_irq(pdev, 1 + i);
	if (irq < 0) {
	dev_err(&pdev->dev, "cannot find perip IRQ #%u\n", i);
	return irq;
	}
	priv->perip_irqs[i] = irq;
	}
	/* check if too many were provided */
	if (platform_get_irq(pdev, 1 + i) >= 0) {
	dev_err(&pdev->dev, "surplus perip IRQs detected\n");
	return -EINVAL;
	}

	/* Get syswake IRQ number */
	irq = platform_get_irq(pdev, 0);
	if (irq < 0) {
	dev_err(&pdev->dev, "cannot find syswake IRQ\n");
	return irq;
	}
	priv->syswake_irq = irq;

	/* Set up an IRQ domain */
	priv->domain = irq_domain_add_linear(node, 16, &irq_generic_chip_ops,
	priv);
	if (unlikely(!priv->domain)) {
	dev_err(&pdev->dev, "cannot add IRQ domain\n");
	return -ENOMEM;
	}

	/*
	* Set up 2 generic irq chips with 2 chip types.
	* The first one for peripheral irqs (only 1 chip type used)
	* The second one for syswake irqs (edge and level chip types)
	*/
	ret = irq_alloc_domain_generic_chips(priv->domain, 8, 2, "pdc",
	handle_level_irq, 0, 0,
	IRQ_GC_INIT_NESTED_LOCK);
	if (ret)
	goto err_generic;

	/* peripheral interrupt chip */

	gc = irq_get_domain_generic_chip(priv->domain, 0);
	gc->unused = ~(BIT(priv->nr_perips) - 1);
	gc->reg_base = priv->pdc_base;
	/*
	* IRQ_ROUTE contains wake bits, so we can't use the generic versions as
	* they cache the mask
	*/
	gc->chip_types[0].regs.mask = PDC_IRQ_ROUTE;
	gc->chip_types[0].chip.irq_mask = perip_irq_mask;
	gc->chip_types[0].chip.irq_unmask = perip_irq_unmask;
	gc->chip_types[0].chip.irq_set_wake = pdc_irq_set_wake;

	/* syswake interrupt chip */

	gc = irq_get_domain_generic_chip(priv->domain, 8);
	gc->unused = ~(BIT(priv->nr_syswakes) - 1);
	gc->reg_base = priv->pdc_base;

	/* edge interrupts */
	gc->chip_types[0].type = IRQ_TYPE_EDGE_BOTH;
	gc->chip_types[0].handler = handle_edge_irq;
	gc->chip_types[0].regs.ack = PDC_IRQ_CLEAR;
	gc->chip_types[0].regs.mask = PDC_IRQ_ENABLE;
	gc->chip_types[0].chip.irq_ack = irq_gc_ack_set_bit;
	gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit;
	gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit;
	gc->chip_types[0].chip.irq_set_type = syswake_irq_set_type;
	gc->chip_types[0].chip.irq_set_wake = pdc_irq_set_wake;
	/* for standby we pass on to the shared syswake IRQ */
	gc->chip_types[0].chip.flags = IRQCHIP_MASK_ON_SUSPEND;

	/* level interrupts */
	gc->chip_types[1].type = IRQ_TYPE_LEVEL_MASK;
	gc->chip_types[1].handler = handle_level_irq;
	gc->chip_types[1].regs.ack = PDC_IRQ_CLEAR;
	gc->chip_types[1].regs.mask = PDC_IRQ_ENABLE;
	gc->chip_types[1].chip.irq_ack = irq_gc_ack_set_bit;
	gc->chip_types[1].chip.irq_mask = irq_gc_mask_clr_bit;
	gc->chip_types[1].chip.irq_unmask = irq_gc_mask_set_bit;
	gc->chip_types[1].chip.irq_set_type = syswake_irq_set_type;
	gc->chip_types[1].chip.irq_set_wake = pdc_irq_set_wake;
	/* for standby we pass on to the shared syswake IRQ */
	gc->chip_types[1].chip.flags = IRQCHIP_MASK_ON_SUSPEND;

	/* Set up the hardware to enable interrupt routing */
	pdc_intc_setup(priv);

	/* Setup chained handlers for the peripheral IRQs */
	for (i = 0; i < priv->nr_perips; ++i) {
	irq = priv->perip_irqs[i];
	irq_set_handler_data(irq, priv);
	irq_set_chained_handler(irq, pdc_intc_perip_isr);
	}

	/* Setup chained handler for the syswake IRQ */
	irq_set_handler_data(priv->syswake_irq, priv);
	irq_set_chained_handler(priv->syswake_irq, pdc_intc_syswake_isr);

	dev_info(&pdev->dev,
	"PDC IRQ controller initialised (%u perip IRQs, %u syswake IRQs)\n",
	priv->nr_perips,
	priv->nr_syswakes);

	return 0;
	err_generic:
	irq_domain_remove(priv->domain);
	return ret;
	}

	static int pdc_intc_remove(struct platform_device *pdev)
	{
	struct pdc_intc_priv *priv = platform_get_drvdata(pdev);

	irq_domain_remove(priv->domain);
	return 0;
	}

	static const struct of_device_id pdc_intc_match[] = {
	{ .compatible = "img,pdc-intc" },
	{}
	};

	static struct platform_driver pdc_intc_driver = {
	.driver = {
	.name = "pdc-intc",
	.of_match_table = pdc_intc_match,
	},
	.probe = pdc_intc_probe,
	.remove = pdc_intc_remove,
	};

	static int __init pdc_intc_init(void)
	{
	return platform_driver_register(&pdc_intc_driver);
	}
	core_initcall(pdc_intc_init);