drivers/irqchip/irq-renesas-intc-irqpin.c - kernel/msm-4.9 - Gitiles

 /*
  * Renesas INTC External IRQ Pin Driver
  *
  *  Copyright (C) 2013 Magnus Damm
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License
  *
  * 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.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */

 #include <linux/clk.h>
 #include <linux/init.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/spinlock.h>
 #include <linux/interrupt.h>
 #include <linux/ioport.h>
 #include <linux/io.h>
 #include <linux/irq.h>
 #include <linux/irqdomain.h>
 #include <linux/err.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/platform_data/irq-renesas-intc-irqpin.h>
 #include <linux/pm_runtime.h>

 #define INTC_IRQPIN_MAX 8 /* maximum 8 interrupts per driver instance */

 #define INTC_IRQPIN_REG_SENSE 0 /* ICRn */
 #define INTC_IRQPIN_REG_PRIO 1 /* INTPRInn */
 #define INTC_IRQPIN_REG_SOURCE 2 /* INTREQnn */
 #define INTC_IRQPIN_REG_MASK 3 /* INTMSKnn */
 #define INTC_IRQPIN_REG_CLEAR 4 /* INTMSKCLRnn */
 #define INTC_IRQPIN_REG_NR_MANDATORY 5
 #define INTC_IRQPIN_REG_IRLM 5 /* ICR0 with IRLM bit (optional) */
 #define INTC_IRQPIN_REG_NR 6

 /* INTC external IRQ PIN hardware register access:
  *
  * SENSE is read-write 32-bit with 2-bits or 4-bits per IRQ (*)
  * PRIO is read-write 32-bit with 4-bits per IRQ (**)
  * SOURCE is read-only 32-bit or 8-bit with 1-bit per IRQ (***)
  * MASK is write-only 32-bit or 8-bit with 1-bit per IRQ (***)
  * CLEAR is write-only 32-bit or 8-bit with 1-bit per IRQ (***)
  *
  * (*) May be accessed by more than one driver instance - lock needed
  * (**) Read-modify-write access by one driver instance - lock needed
  * (***) Accessed by one driver instance only - no locking needed
  */

 struct intc_irqpin_iomem {
 	void __iomem *iomem;
 	unsigned long (*read)(void __iomem *iomem);
 	void (*write)(void __iomem *iomem, unsigned long data);
 	int width;
 };

 struct intc_irqpin_irq {
 	int hw_irq;
 	int requested_irq;
 	int domain_irq;
 	struct intc_irqpin_priv *p;
 };

 struct intc_irqpin_priv {
 	struct intc_irqpin_iomem iomem[INTC_IRQPIN_REG_NR];
 	struct intc_irqpin_irq irq[INTC_IRQPIN_MAX];
 	struct renesas_intc_irqpin_config config;
 	unsigned int number_of_irqs;
 	struct platform_device *pdev;
 	struct irq_chip irq_chip;
 	struct irq_domain *irq_domain;
 	struct clk *clk;
 	bool shared_irqs;
 	u8 shared_irq_mask;
 };

 struct intc_irqpin_irlm_config {
 	unsigned int irlm_bit;
 };

 static unsigned long intc_irqpin_read32(void __iomem *iomem)
 {
 	return ioread32(iomem);
 }

 static unsigned long intc_irqpin_read8(void __iomem *iomem)
 {
 	return ioread8(iomem);
 }

 static void intc_irqpin_write32(void __iomem *iomem, unsigned long data)
 {
 	iowrite32(data, iomem);
 }

 static void intc_irqpin_write8(void __iomem *iomem, unsigned long data)
 {
 	iowrite8(data, iomem);
 }

 static inline unsigned long intc_irqpin_read(struct intc_irqpin_priv *p,
 					     int reg)
 {
 	struct intc_irqpin_iomem *i = &p->iomem[reg];

 	return i->read(i->iomem);
 }

 static inline void intc_irqpin_write(struct intc_irqpin_priv *p,
 				     int reg, unsigned long data)
 {
 	struct intc_irqpin_iomem *i = &p->iomem[reg];

 	i->write(i->iomem, data);
 }

 static inline unsigned long intc_irqpin_hwirq_mask(struct intc_irqpin_priv *p,
 						   int reg, int hw_irq)
 {
 	return BIT((p->iomem[reg].width - 1) - hw_irq);
 }

 static inline void intc_irqpin_irq_write_hwirq(struct intc_irqpin_priv *p,
 					       int reg, int hw_irq)
 {
 	intc_irqpin_write(p, reg, intc_irqpin_hwirq_mask(p, reg, hw_irq));
 }

 static DEFINE_RAW_SPINLOCK(intc_irqpin_lock); /* only used by slow path */

 static void intc_irqpin_read_modify_write(struct intc_irqpin_priv *p,
 					  int reg, int shift,
 					  int width, int value)
 {
 	unsigned long flags;
 	unsigned long tmp;

 	raw_spin_lock_irqsave(&intc_irqpin_lock, flags);

 	tmp = intc_irqpin_read(p, reg);
 	tmp &= ~(((1 << width) - 1) << shift);
 	tmp |= value << shift;
 	intc_irqpin_write(p, reg, tmp);

 	raw_spin_unlock_irqrestore(&intc_irqpin_lock, flags);
 }

 static void intc_irqpin_mask_unmask_prio(struct intc_irqpin_priv *p,
 					 int irq, int do_mask)
 {
 	/* The PRIO register is assumed to be 32-bit with fixed 4-bit fields. */
 	int bitfield_width = 4;
 	int shift = 32 - (irq + 1) * bitfield_width;

 	intc_irqpin_read_modify_write(p, INTC_IRQPIN_REG_PRIO,
 				      shift, bitfield_width,
 				      do_mask ? 0 : (1 << bitfield_width) - 1);
 }

 static int intc_irqpin_set_sense(struct intc_irqpin_priv *p, int irq, int value)
 {
 	/* The SENSE register is assumed to be 32-bit. */
 	int bitfield_width = p->config.sense_bitfield_width;
 	int shift = 32 - (irq + 1) * bitfield_width;

 	dev_dbg(&p->pdev->dev, "sense irq = %d, mode = %d\n", irq, value);

 	if (value >= (1 << bitfield_width))
 		return -EINVAL;

 	intc_irqpin_read_modify_write(p, INTC_IRQPIN_REG_SENSE, shift,
 				      bitfield_width, value);
 	return 0;
 }

 static void intc_irqpin_dbg(struct intc_irqpin_irq *i, char *str)
 {
 	dev_dbg(&i->p->pdev->dev, "%s (%d:%d:%d)\n",
 		str, i->requested_irq, i->hw_irq, i->domain_irq);
 }

 static void intc_irqpin_irq_enable(struct irq_data *d)
 {
 	struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 	int hw_irq = irqd_to_hwirq(d);

 	intc_irqpin_dbg(&p->irq[hw_irq], "enable");
 	intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_CLEAR, hw_irq);
 }

 static void intc_irqpin_irq_disable(struct irq_data *d)
 {
 	struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 	int hw_irq = irqd_to_hwirq(d);

 	intc_irqpin_dbg(&p->irq[hw_irq], "disable");
 	intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_MASK, hw_irq);
 }

 static void intc_irqpin_shared_irq_enable(struct irq_data *d)
 {
 	struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 	int hw_irq = irqd_to_hwirq(d);

 	intc_irqpin_dbg(&p->irq[hw_irq], "shared enable");
 	intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_CLEAR, hw_irq);

 	p->shared_irq_mask &= ~BIT(hw_irq);
 }

 static void intc_irqpin_shared_irq_disable(struct irq_data *d)
 {
 	struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 	int hw_irq = irqd_to_hwirq(d);

 	intc_irqpin_dbg(&p->irq[hw_irq], "shared disable");
 	intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_MASK, hw_irq);

 	p->shared_irq_mask |= BIT(hw_irq);
 }

 static void intc_irqpin_irq_enable_force(struct irq_data *d)
 {
 	struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 	int irq = p->irq[irqd_to_hwirq(d)].requested_irq;

 	intc_irqpin_irq_enable(d);

 	/* enable interrupt through parent interrupt controller,
 	 * assumes non-shared interrupt with 1:1 mapping
 	 * needed for busted IRQs on some SoCs like sh73a0
 	 */
 	irq_get_chip(irq)->irq_unmask(irq_get_irq_data(irq));
 }

 static void intc_irqpin_irq_disable_force(struct irq_data *d)
 {
 	struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 	int irq = p->irq[irqd_to_hwirq(d)].requested_irq;

 	/* disable interrupt through parent interrupt controller,
 	 * assumes non-shared interrupt with 1:1 mapping
 	 * needed for busted IRQs on some SoCs like sh73a0
 	 */
 	irq_get_chip(irq)->irq_mask(irq_get_irq_data(irq));
 	intc_irqpin_irq_disable(d);
 }

 #define INTC_IRQ_SENSE_VALID 0x10
 #define INTC_IRQ_SENSE(x) (x + INTC_IRQ_SENSE_VALID)

 static unsigned char intc_irqpin_sense[IRQ_TYPE_SENSE_MASK + 1] = {
 	[IRQ_TYPE_EDGE_FALLING] = INTC_IRQ_SENSE(0x00),
 	[IRQ_TYPE_EDGE_RISING] = INTC_IRQ_SENSE(0x01),
 	[IRQ_TYPE_LEVEL_LOW] = INTC_IRQ_SENSE(0x02),
 	[IRQ_TYPE_LEVEL_HIGH] = INTC_IRQ_SENSE(0x03),
 	[IRQ_TYPE_EDGE_BOTH] = INTC_IRQ_SENSE(0x04),
 };

 static int intc_irqpin_irq_set_type(struct irq_data *d, unsigned int type)
 {
 	unsigned char value = intc_irqpin_sense[type & IRQ_TYPE_SENSE_MASK];
 	struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);

 	if (!(value & INTC_IRQ_SENSE_VALID))
 		return -EINVAL;

 	return intc_irqpin_set_sense(p, irqd_to_hwirq(d),
 				     value ^ INTC_IRQ_SENSE_VALID);
 }

 static int intc_irqpin_irq_set_wake(struct irq_data *d, unsigned int on)
 {
 	struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 	int hw_irq = irqd_to_hwirq(d);

 	irq_set_irq_wake(p->irq[hw_irq].requested_irq, on);

 	if (!p->clk)
 		return 0;

 	if (on)
 		clk_enable(p->clk);
 	else
 		clk_disable(p->clk);

 	return 0;
 }

 static irqreturn_t intc_irqpin_irq_handler(int irq, void *dev_id)
 {
 	struct intc_irqpin_irq *i = dev_id;
 	struct intc_irqpin_priv *p = i->p;
 	unsigned long bit;

 	intc_irqpin_dbg(i, "demux1");
 	bit = intc_irqpin_hwirq_mask(p, INTC_IRQPIN_REG_SOURCE, i->hw_irq);

 	if (intc_irqpin_read(p, INTC_IRQPIN_REG_SOURCE) & bit) {
 		intc_irqpin_write(p, INTC_IRQPIN_REG_SOURCE, ~bit);
 		intc_irqpin_dbg(i, "demux2");
 		generic_handle_irq(i->domain_irq);
 		return IRQ_HANDLED;
 	}
 	return IRQ_NONE;
 }

 static irqreturn_t intc_irqpin_shared_irq_handler(int irq, void *dev_id)
 {
 	struct intc_irqpin_priv *p = dev_id;
 	unsigned int reg_source = intc_irqpin_read(p, INTC_IRQPIN_REG_SOURCE);
 	irqreturn_t status = IRQ_NONE;
 	int k;

 	for (k = 0; k < 8; k++) {
 		if (reg_source & BIT(7 - k)) {
 			if (BIT(k) & p->shared_irq_mask)
 				continue;

 			status |= intc_irqpin_irq_handler(irq, &p->irq[k]);
 		}
 	}

 	return status;
 }

 /*
  * This lock class tells lockdep that INTC External IRQ Pin irqs are in a
  * different category than their parents, so it won't report false recursion.
  */
 static struct lock_class_key intc_irqpin_irq_lock_class;

 static int intc_irqpin_irq_domain_map(struct irq_domain *h, unsigned int virq,
 				      irq_hw_number_t hw)
 {
 	struct intc_irqpin_priv *p = h->host_data;

 	p->irq[hw].domain_irq = virq;
 	p->irq[hw].hw_irq = hw;

 	intc_irqpin_dbg(&p->irq[hw], "map");
 	irq_set_chip_data(virq, h->host_data);
 	irq_set_lockdep_class(virq, &intc_irqpin_irq_lock_class);
 	irq_set_chip_and_handler(virq, &p->irq_chip, handle_level_irq);
 	return 0;
 }

 static const struct irq_domain_ops intc_irqpin_irq_domain_ops = {
 	.map	= intc_irqpin_irq_domain_map,
 	.xlate  = irq_domain_xlate_twocell,
 };

 static const struct intc_irqpin_irlm_config intc_irqpin_irlm_r8a7779 = {
 	.irlm_bit = 23, /* ICR0.IRLM0 */
 };

 static const struct of_device_id intc_irqpin_dt_ids[] = {
 	{ .compatible = "renesas,intc-irqpin", },
 	{ .compatible = "renesas,intc-irqpin-r8a7779",
 	  .data = &intc_irqpin_irlm_r8a7779 },
 	{},
 };
 MODULE_DEVICE_TABLE(of, intc_irqpin_dt_ids);

 static int intc_irqpin_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct renesas_intc_irqpin_config *pdata = dev->platform_data;
 	const struct of_device_id *of_id;
 	struct intc_irqpin_priv *p;
 	struct intc_irqpin_iomem *i;
 	struct resource *io[INTC_IRQPIN_REG_NR];
 	struct resource *irq;
 	struct irq_chip *irq_chip;
 	void (*enable_fn)(struct irq_data *d);
 	void (*disable_fn)(struct irq_data *d);
 	const char *name = dev_name(dev);
 	int ref_irq;
 	int ret;
 	int k;

 	p = devm_kzalloc(dev, sizeof(*p), GFP_KERNEL);
 	if (!p) {
 		dev_err(dev, "failed to allocate driver data\n");
 		return -ENOMEM;
 	}

 	/* deal with driver instance configuration */
 	if (pdata) {
 		memcpy(&p->config, pdata, sizeof(*pdata));
 	} else {
 		of_property_read_u32(dev->of_node, "sense-bitfield-width",
 				     &p->config.sense_bitfield_width);
 		p->config.control_parent = of_property_read_bool(dev->of_node,
 								 "control-parent");
 	}
 	if (!p->config.sense_bitfield_width)
 		p->config.sense_bitfield_width = 4; /* default to 4 bits */

 	p->pdev = pdev;
 	platform_set_drvdata(pdev, p);

 	p->clk = devm_clk_get(dev, NULL);
 	if (IS_ERR(p->clk)) {
 		dev_warn(dev, "unable to get clock\n");
 		p->clk = NULL;
 	}

 	pm_runtime_enable(dev);
 	pm_runtime_get_sync(dev);

 	/* get hold of register banks */
 	memset(io, 0, sizeof(io));
 	for (k = 0; k < INTC_IRQPIN_REG_NR; k++) {
 		io[k] = platform_get_resource(pdev, IORESOURCE_MEM, k);
 		if (!io[k] && k < INTC_IRQPIN_REG_NR_MANDATORY) {
 			dev_err(dev, "not enough IOMEM resources\n");
 			ret = -EINVAL;
 			goto err0;
 		}
 	}

 	/* allow any number of IRQs between 1 and INTC_IRQPIN_MAX */
 	for (k = 0; k < INTC_IRQPIN_MAX; k++) {
 		irq = platform_get_resource(pdev, IORESOURCE_IRQ, k);
 		if (!irq)
 			break;

 		p->irq[k].p = p;
 		p->irq[k].requested_irq = irq->start;
 	}

 	p->number_of_irqs = k;
 	if (p->number_of_irqs < 1) {
 		dev_err(dev, "not enough IRQ resources\n");
 		ret = -EINVAL;
 		goto err0;
 	}

 	/* ioremap IOMEM and setup read/write callbacks */
 	for (k = 0; k < INTC_IRQPIN_REG_NR; k++) {
 		i = &p->iomem[k];

 		/* handle optional registers */
 		if (!io[k])
 			continue;

 		switch (resource_size(io[k])) {
 		case 1:
 			i->width = 8;
 			i->read = intc_irqpin_read8;
 			i->write = intc_irqpin_write8;
 			break;
 		case 4:
 			i->width = 32;
 			i->read = intc_irqpin_read32;
 			i->write = intc_irqpin_write32;
 			break;
 		default:
 			dev_err(dev, "IOMEM size mismatch\n");
 			ret = -EINVAL;
 			goto err0;
 		}

 		i->iomem = devm_ioremap_nocache(dev, io[k]->start,
 						resource_size(io[k]));
 		if (!i->iomem) {
 			dev_err(dev, "failed to remap IOMEM\n");
 			ret = -ENXIO;
 			goto err0;
 		}
 	}

 	/* configure "individual IRQ mode" where needed */
 	of_id = of_match_device(intc_irqpin_dt_ids, dev);
 	if (of_id && of_id->data) {
 		const struct intc_irqpin_irlm_config *irlm_config = of_id->data;

 		if (io[INTC_IRQPIN_REG_IRLM])
 			intc_irqpin_read_modify_write(p, INTC_IRQPIN_REG_IRLM,
 						      irlm_config->irlm_bit,
 						      1, 1);
 		else
 			dev_warn(dev, "unable to select IRLM mode\n");
 	}

 	/* mask all interrupts using priority */
 	for (k = 0; k < p->number_of_irqs; k++)
 		intc_irqpin_mask_unmask_prio(p, k, 1);

 	/* clear all pending interrupts */
 	intc_irqpin_write(p, INTC_IRQPIN_REG_SOURCE, 0x0);

 	/* scan for shared interrupt lines */
 	ref_irq = p->irq[0].requested_irq;
 	p->shared_irqs = true;
 	for (k = 1; k < p->number_of_irqs; k++) {
 		if (ref_irq != p->irq[k].requested_irq) {
 			p->shared_irqs = false;
 			break;
 		}
 	}

 	/* use more severe masking method if requested */
 	if (p->config.control_parent) {
 		enable_fn = intc_irqpin_irq_enable_force;
 		disable_fn = intc_irqpin_irq_disable_force;
 	} else if (!p->shared_irqs) {
 		enable_fn = intc_irqpin_irq_enable;
 		disable_fn = intc_irqpin_irq_disable;
 	} else {
 		enable_fn = intc_irqpin_shared_irq_enable;
 		disable_fn = intc_irqpin_shared_irq_disable;
 	}

 	irq_chip = &p->irq_chip;
 	irq_chip->name = name;
 	irq_chip->irq_mask = disable_fn;
 	irq_chip->irq_unmask = enable_fn;
 	irq_chip->irq_set_type = intc_irqpin_irq_set_type;
 	irq_chip->irq_set_wake = intc_irqpin_irq_set_wake;
 	irq_chip->flags	= IRQCHIP_MASK_ON_SUSPEND;

 	p->irq_domain = irq_domain_add_simple(dev->of_node,
 					      p->number_of_irqs,
 					      p->config.irq_base,
 					      &intc_irqpin_irq_domain_ops, p);
 	if (!p->irq_domain) {
 		ret = -ENXIO;
 		dev_err(dev, "cannot initialize irq domain\n");
 		goto err0;
 	}

 	if (p->shared_irqs) {
 		/* request one shared interrupt */
 		if (devm_request_irq(dev, p->irq[0].requested_irq,
 				intc_irqpin_shared_irq_handler,
 				IRQF_SHARED, name, p)) {
 			dev_err(dev, "failed to request low IRQ\n");
 			ret = -ENOENT;
 			goto err1;
 		}
 	} else {
 		/* request interrupts one by one */
 		for (k = 0; k < p->number_of_irqs; k++) {
 			if (devm_request_irq(dev, p->irq[k].requested_irq,
 					     intc_irqpin_irq_handler, 0, name,
 					     &p->irq[k])) {
 				dev_err(dev, "failed to request low IRQ\n");
 				ret = -ENOENT;
 				goto err1;
 			}
 		}
 	}

 	/* unmask all interrupts on prio level */
 	for (k = 0; k < p->number_of_irqs; k++)
 		intc_irqpin_mask_unmask_prio(p, k, 0);

 	dev_info(dev, "driving %d irqs\n", p->number_of_irqs);

 	/* warn in case of mismatch if irq base is specified */
 	if (p->config.irq_base) {
 		if (p->config.irq_base != p->irq[0].domain_irq)
 			dev_warn(dev, "irq base mismatch (%d/%d)\n",
 				 p->config.irq_base, p->irq[0].domain_irq);
 	}

 	return 0;

 err1:
 	irq_domain_remove(p->irq_domain);
 err0:
 	pm_runtime_put(dev);
 	pm_runtime_disable(dev);
 	return ret;
 }

 static int intc_irqpin_remove(struct platform_device *pdev)
 {
 	struct intc_irqpin_priv *p = platform_get_drvdata(pdev);

 	irq_domain_remove(p->irq_domain);
 	pm_runtime_put(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 	return 0;
 }

 static struct platform_driver intc_irqpin_device_driver = {
 	.probe		= intc_irqpin_probe,
 	.remove		= intc_irqpin_remove,
 	.driver		= {
 		.name	= "renesas_intc_irqpin",
 		.of_match_table = intc_irqpin_dt_ids,
 	}
 };

 static int __init intc_irqpin_init(void)
 {
 	return platform_driver_register(&intc_irqpin_device_driver);
 }
 postcore_initcall(intc_irqpin_init);

 static void __exit intc_irqpin_exit(void)
 {
 	platform_driver_unregister(&intc_irqpin_device_driver);
 }
 module_exit(intc_irqpin_exit);

 MODULE_AUTHOR("Magnus Damm");
 MODULE_DESCRIPTION("Renesas INTC External IRQ Pin Driver");
 MODULE_LICENSE("GPL v2");
	/*
	* Renesas INTC External IRQ Pin Driver
	*
	* Copyright (C) 2013 Magnus Damm
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License
	*
	* 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.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*/

	#include <linux/clk.h>
	#include <linux/init.h>
	#include <linux/of.h>
	#include <linux/platform_device.h>
	#include <linux/spinlock.h>
	#include <linux/interrupt.h>
	#include <linux/ioport.h>
	#include <linux/io.h>
	#include <linux/irq.h>
	#include <linux/irqdomain.h>
	#include <linux/err.h>
	#include <linux/slab.h>
	#include <linux/module.h>
	#include <linux/of_device.h>
	#include <linux/platform_data/irq-renesas-intc-irqpin.h>
	#include <linux/pm_runtime.h>

	#define INTC_IRQPIN_MAX 8 /* maximum 8 interrupts per driver instance */

	#define INTC_IRQPIN_REG_SENSE 0 /* ICRn */
	#define INTC_IRQPIN_REG_PRIO 1 /* INTPRInn */
	#define INTC_IRQPIN_REG_SOURCE 2 /* INTREQnn */
	#define INTC_IRQPIN_REG_MASK 3 /* INTMSKnn */
	#define INTC_IRQPIN_REG_CLEAR 4 /* INTMSKCLRnn */
	#define INTC_IRQPIN_REG_NR_MANDATORY 5
	#define INTC_IRQPIN_REG_IRLM 5 /* ICR0 with IRLM bit (optional) */
	#define INTC_IRQPIN_REG_NR 6

	/* INTC external IRQ PIN hardware register access:
	*
	* SENSE is read-write 32-bit with 2-bits or 4-bits per IRQ (*)
	* PRIO is read-write 32-bit with 4-bits per IRQ (**)
	* SOURCE is read-only 32-bit or 8-bit with 1-bit per IRQ (***)
	* MASK is write-only 32-bit or 8-bit with 1-bit per IRQ (***)
	* CLEAR is write-only 32-bit or 8-bit with 1-bit per IRQ (***)
	*
	* (*) May be accessed by more than one driver instance - lock needed
	* (**) Read-modify-write access by one driver instance - lock needed
	* (***) Accessed by one driver instance only - no locking needed
	*/

	struct intc_irqpin_iomem {
	void __iomem *iomem;
	unsigned long (read)(void __iomem iomem);
	void (write)(void __iomem iomem, unsigned long data);
	int width;
	};

	struct intc_irqpin_irq {
	int hw_irq;
	int requested_irq;
	int domain_irq;
	struct intc_irqpin_priv *p;
	};

	struct intc_irqpin_priv {
	struct intc_irqpin_iomem iomem[INTC_IRQPIN_REG_NR];
	struct intc_irqpin_irq irq[INTC_IRQPIN_MAX];
	struct renesas_intc_irqpin_config config;
	unsigned int number_of_irqs;
	struct platform_device *pdev;
	struct irq_chip irq_chip;
	struct irq_domain *irq_domain;
	struct clk *clk;
	bool shared_irqs;
	u8 shared_irq_mask;
	};

	struct intc_irqpin_irlm_config {
	unsigned int irlm_bit;
	};

	static unsigned long intc_irqpin_read32(void __iomem *iomem)
	{
	return ioread32(iomem);
	}

	static unsigned long intc_irqpin_read8(void __iomem *iomem)
	{
	return ioread8(iomem);
	}

	static void intc_irqpin_write32(void __iomem *iomem, unsigned long data)
	{
	iowrite32(data, iomem);
	}

	static void intc_irqpin_write8(void __iomem *iomem, unsigned long data)
	{
	iowrite8(data, iomem);
	}

	static inline unsigned long intc_irqpin_read(struct intc_irqpin_priv *p,
	int reg)
	{
	struct intc_irqpin_iomem *i = &p->iomem[reg];

	return i->read(i->iomem);
	}

	static inline void intc_irqpin_write(struct intc_irqpin_priv *p,
	int reg, unsigned long data)
	{
	struct intc_irqpin_iomem *i = &p->iomem[reg];

	i->write(i->iomem, data);
	}

	static inline unsigned long intc_irqpin_hwirq_mask(struct intc_irqpin_priv *p,
	int reg, int hw_irq)
	{
	return BIT((p->iomem[reg].width - 1) - hw_irq);
	}

	static inline void intc_irqpin_irq_write_hwirq(struct intc_irqpin_priv *p,
	int reg, int hw_irq)
	{
	intc_irqpin_write(p, reg, intc_irqpin_hwirq_mask(p, reg, hw_irq));
	}

	static DEFINE_RAW_SPINLOCK(intc_irqpin_lock); /* only used by slow path */

	static void intc_irqpin_read_modify_write(struct intc_irqpin_priv *p,
	int reg, int shift,
	int width, int value)
	{
	unsigned long flags;
	unsigned long tmp;

	raw_spin_lock_irqsave(&intc_irqpin_lock, flags);

	tmp = intc_irqpin_read(p, reg);
	tmp &= ~(((1 << width) - 1) << shift);
	tmp \|= value << shift;
	intc_irqpin_write(p, reg, tmp);

	raw_spin_unlock_irqrestore(&intc_irqpin_lock, flags);
	}

	static void intc_irqpin_mask_unmask_prio(struct intc_irqpin_priv *p,
	int irq, int do_mask)
	{
	/* The PRIO register is assumed to be 32-bit with fixed 4-bit fields. */
	int bitfield_width = 4;
	int shift = 32 - (irq + 1) * bitfield_width;

	intc_irqpin_read_modify_write(p, INTC_IRQPIN_REG_PRIO,
	shift, bitfield_width,
	do_mask ? 0 : (1 << bitfield_width) - 1);
	}

	static int intc_irqpin_set_sense(struct intc_irqpin_priv *p, int irq, int value)
	{
	/* The SENSE register is assumed to be 32-bit. */
	int bitfield_width = p->config.sense_bitfield_width;
	int shift = 32 - (irq + 1) * bitfield_width;

	dev_dbg(&p->pdev->dev, "sense irq = %d, mode = %d\n", irq, value);

	if (value >= (1 << bitfield_width))
	return -EINVAL;

	intc_irqpin_read_modify_write(p, INTC_IRQPIN_REG_SENSE, shift,
	bitfield_width, value);
	return 0;
	}

	static void intc_irqpin_dbg(struct intc_irqpin_irq i, char str)
	{
	dev_dbg(&i->p->pdev->dev, "%s (%d:%d:%d)\n",
	str, i->requested_irq, i->hw_irq, i->domain_irq);
	}

	static void intc_irqpin_irq_enable(struct irq_data *d)
	{
	struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
	int hw_irq = irqd_to_hwirq(d);

	intc_irqpin_dbg(&p->irq[hw_irq], "enable");
	intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_CLEAR, hw_irq);
	}

	static void intc_irqpin_irq_disable(struct irq_data *d)
	{
	struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
	int hw_irq = irqd_to_hwirq(d);

	intc_irqpin_dbg(&p->irq[hw_irq], "disable");
	intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_MASK, hw_irq);
	}

	static void intc_irqpin_shared_irq_enable(struct irq_data *d)
	{
	struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
	int hw_irq = irqd_to_hwirq(d);

	intc_irqpin_dbg(&p->irq[hw_irq], "shared enable");
	intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_CLEAR, hw_irq);

	p->shared_irq_mask &= ~BIT(hw_irq);
	}

	static void intc_irqpin_shared_irq_disable(struct irq_data *d)
	{
	struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
	int hw_irq = irqd_to_hwirq(d);

	intc_irqpin_dbg(&p->irq[hw_irq], "shared disable");
	intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_MASK, hw_irq);

	p->shared_irq_mask \|= BIT(hw_irq);
	}

	static void intc_irqpin_irq_enable_force(struct irq_data *d)
	{
	struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
	int irq = p->irq[irqd_to_hwirq(d)].requested_irq;

	intc_irqpin_irq_enable(d);

	/* enable interrupt through parent interrupt controller,
	* assumes non-shared interrupt with 1:1 mapping
	* needed for busted IRQs on some SoCs like sh73a0
	*/
	irq_get_chip(irq)->irq_unmask(irq_get_irq_data(irq));
	}

	static void intc_irqpin_irq_disable_force(struct irq_data *d)
	{
	struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
	int irq = p->irq[irqd_to_hwirq(d)].requested_irq;

	/* disable interrupt through parent interrupt controller,
	* assumes non-shared interrupt with 1:1 mapping
	* needed for busted IRQs on some SoCs like sh73a0
	*/
	irq_get_chip(irq)->irq_mask(irq_get_irq_data(irq));
	intc_irqpin_irq_disable(d);
	}

	#define INTC_IRQ_SENSE_VALID 0x10
	#define INTC_IRQ_SENSE(x) (x + INTC_IRQ_SENSE_VALID)

	static unsigned char intc_irqpin_sense[IRQ_TYPE_SENSE_MASK + 1] = {
	[IRQ_TYPE_EDGE_FALLING] = INTC_IRQ_SENSE(0x00),
	[IRQ_TYPE_EDGE_RISING] = INTC_IRQ_SENSE(0x01),
	[IRQ_TYPE_LEVEL_LOW] = INTC_IRQ_SENSE(0x02),
	[IRQ_TYPE_LEVEL_HIGH] = INTC_IRQ_SENSE(0x03),
	[IRQ_TYPE_EDGE_BOTH] = INTC_IRQ_SENSE(0x04),
	};

	static int intc_irqpin_irq_set_type(struct irq_data *d, unsigned int type)
	{
	unsigned char value = intc_irqpin_sense[type & IRQ_TYPE_SENSE_MASK];
	struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);

	if (!(value & INTC_IRQ_SENSE_VALID))
	return -EINVAL;

	return intc_irqpin_set_sense(p, irqd_to_hwirq(d),
	value ^ INTC_IRQ_SENSE_VALID);
	}

	static int intc_irqpin_irq_set_wake(struct irq_data *d, unsigned int on)
	{
	struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
	int hw_irq = irqd_to_hwirq(d);

	irq_set_irq_wake(p->irq[hw_irq].requested_irq, on);

	if (!p->clk)
	return 0;

	if (on)
	clk_enable(p->clk);
	else
	clk_disable(p->clk);

	return 0;
	}

	static irqreturn_t intc_irqpin_irq_handler(int irq, void *dev_id)
	{
	struct intc_irqpin_irq *i = dev_id;
	struct intc_irqpin_priv *p = i->p;
	unsigned long bit;

	intc_irqpin_dbg(i, "demux1");
	bit = intc_irqpin_hwirq_mask(p, INTC_IRQPIN_REG_SOURCE, i->hw_irq);

	if (intc_irqpin_read(p, INTC_IRQPIN_REG_SOURCE) & bit) {
	intc_irqpin_write(p, INTC_IRQPIN_REG_SOURCE, ~bit);
	intc_irqpin_dbg(i, "demux2");
	generic_handle_irq(i->domain_irq);
	return IRQ_HANDLED;
	}
	return IRQ_NONE;
	}

	static irqreturn_t intc_irqpin_shared_irq_handler(int irq, void *dev_id)
	{
	struct intc_irqpin_priv *p = dev_id;
	unsigned int reg_source = intc_irqpin_read(p, INTC_IRQPIN_REG_SOURCE);
	irqreturn_t status = IRQ_NONE;
	int k;

	for (k = 0; k < 8; k++) {
	if (reg_source & BIT(7 - k)) {
	if (BIT(k) & p->shared_irq_mask)
	continue;

	status \|= intc_irqpin_irq_handler(irq, &p->irq[k]);
	}
	}

	return status;
	}

	/*
	* This lock class tells lockdep that INTC External IRQ Pin irqs are in a
	* different category than their parents, so it won't report false recursion.
	*/
	static struct lock_class_key intc_irqpin_irq_lock_class;

	static int intc_irqpin_irq_domain_map(struct irq_domain *h, unsigned int virq,
	irq_hw_number_t hw)
	{
	struct intc_irqpin_priv *p = h->host_data;

	p->irq[hw].domain_irq = virq;
	p->irq[hw].hw_irq = hw;

	intc_irqpin_dbg(&p->irq[hw], "map");
	irq_set_chip_data(virq, h->host_data);
	irq_set_lockdep_class(virq, &intc_irqpin_irq_lock_class);
	irq_set_chip_and_handler(virq, &p->irq_chip, handle_level_irq);
	return 0;
	}

	static const struct irq_domain_ops intc_irqpin_irq_domain_ops = {
	.map = intc_irqpin_irq_domain_map,
	.xlate = irq_domain_xlate_twocell,
	};

	static const struct intc_irqpin_irlm_config intc_irqpin_irlm_r8a7779 = {
	.irlm_bit = 23, /* ICR0.IRLM0 */
	};

	static const struct of_device_id intc_irqpin_dt_ids[] = {
	{ .compatible = "renesas,intc-irqpin", },
	{ .compatible = "renesas,intc-irqpin-r8a7779",
	.data = &intc_irqpin_irlm_r8a7779 },
	{},
	};
	MODULE_DEVICE_TABLE(of, intc_irqpin_dt_ids);

	static int intc_irqpin_probe(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct renesas_intc_irqpin_config *pdata = dev->platform_data;
	const struct of_device_id *of_id;
	struct intc_irqpin_priv *p;
	struct intc_irqpin_iomem *i;
	struct resource *io[INTC_IRQPIN_REG_NR];
	struct resource *irq;
	struct irq_chip *irq_chip;
	void (enable_fn)(struct irq_data d);
	void (disable_fn)(struct irq_data d);
	const char *name = dev_name(dev);
	int ref_irq;
	int ret;
	int k;

	p = devm_kzalloc(dev, sizeof(*p), GFP_KERNEL);
	if (!p) {
	dev_err(dev, "failed to allocate driver data\n");
	return -ENOMEM;
	}

	/* deal with driver instance configuration */
	if (pdata) {
	memcpy(&p->config, pdata, sizeof(*pdata));
	} else {
	of_property_read_u32(dev->of_node, "sense-bitfield-width",
	&p->config.sense_bitfield_width);
	p->config.control_parent = of_property_read_bool(dev->of_node,
	"control-parent");
	}
	if (!p->config.sense_bitfield_width)
	p->config.sense_bitfield_width = 4; /* default to 4 bits */

	p->pdev = pdev;
	platform_set_drvdata(pdev, p);

	p->clk = devm_clk_get(dev, NULL);
	if (IS_ERR(p->clk)) {
	dev_warn(dev, "unable to get clock\n");
	p->clk = NULL;
	}

	pm_runtime_enable(dev);
	pm_runtime_get_sync(dev);

	/* get hold of register banks */
	memset(io, 0, sizeof(io));
	for (k = 0; k < INTC_IRQPIN_REG_NR; k++) {
	io[k] = platform_get_resource(pdev, IORESOURCE_MEM, k);
	if (!io[k] && k < INTC_IRQPIN_REG_NR_MANDATORY) {
	dev_err(dev, "not enough IOMEM resources\n");
	ret = -EINVAL;
	goto err0;
	}
	}

	/* allow any number of IRQs between 1 and INTC_IRQPIN_MAX */
	for (k = 0; k < INTC_IRQPIN_MAX; k++) {
	irq = platform_get_resource(pdev, IORESOURCE_IRQ, k);
	if (!irq)
	break;

	p->irq[k].p = p;
	p->irq[k].requested_irq = irq->start;
	}

	p->number_of_irqs = k;
	if (p->number_of_irqs < 1) {
	dev_err(dev, "not enough IRQ resources\n");
	ret = -EINVAL;
	goto err0;
	}

	/* ioremap IOMEM and setup read/write callbacks */
	for (k = 0; k < INTC_IRQPIN_REG_NR; k++) {
	i = &p->iomem[k];

	/* handle optional registers */
	if (!io[k])
	continue;

	switch (resource_size(io[k])) {
	case 1:
	i->width = 8;
	i->read = intc_irqpin_read8;
	i->write = intc_irqpin_write8;
	break;
	case 4:
	i->width = 32;
	i->read = intc_irqpin_read32;
	i->write = intc_irqpin_write32;
	break;
	default:
	dev_err(dev, "IOMEM size mismatch\n");
	ret = -EINVAL;
	goto err0;
	}

	i->iomem = devm_ioremap_nocache(dev, io[k]->start,
	resource_size(io[k]));
	if (!i->iomem) {
	dev_err(dev, "failed to remap IOMEM\n");
	ret = -ENXIO;
	goto err0;
	}
	}

	/* configure "individual IRQ mode" where needed */
	of_id = of_match_device(intc_irqpin_dt_ids, dev);
	if (of_id && of_id->data) {
	const struct intc_irqpin_irlm_config *irlm_config = of_id->data;

	if (io[INTC_IRQPIN_REG_IRLM])
	intc_irqpin_read_modify_write(p, INTC_IRQPIN_REG_IRLM,
	irlm_config->irlm_bit,
	1, 1);
	else
	dev_warn(dev, "unable to select IRLM mode\n");
	}

	/* mask all interrupts using priority */
	for (k = 0; k < p->number_of_irqs; k++)
	intc_irqpin_mask_unmask_prio(p, k, 1);

	/* clear all pending interrupts */
	intc_irqpin_write(p, INTC_IRQPIN_REG_SOURCE, 0x0);

	/* scan for shared interrupt lines */
	ref_irq = p->irq[0].requested_irq;
	p->shared_irqs = true;
	for (k = 1; k < p->number_of_irqs; k++) {
	if (ref_irq != p->irq[k].requested_irq) {
	p->shared_irqs = false;
	break;
	}
	}

	/* use more severe masking method if requested */
	if (p->config.control_parent) {
	enable_fn = intc_irqpin_irq_enable_force;
	disable_fn = intc_irqpin_irq_disable_force;
	} else if (!p->shared_irqs) {
	enable_fn = intc_irqpin_irq_enable;
	disable_fn = intc_irqpin_irq_disable;
	} else {
	enable_fn = intc_irqpin_shared_irq_enable;
	disable_fn = intc_irqpin_shared_irq_disable;
	}

	irq_chip = &p->irq_chip;
	irq_chip->name = name;
	irq_chip->irq_mask = disable_fn;
	irq_chip->irq_unmask = enable_fn;
	irq_chip->irq_set_type = intc_irqpin_irq_set_type;
	irq_chip->irq_set_wake = intc_irqpin_irq_set_wake;
	irq_chip->flags = IRQCHIP_MASK_ON_SUSPEND;

	p->irq_domain = irq_domain_add_simple(dev->of_node,
	p->number_of_irqs,
	p->config.irq_base,
	&intc_irqpin_irq_domain_ops, p);
	if (!p->irq_domain) {
	ret = -ENXIO;
	dev_err(dev, "cannot initialize irq domain\n");
	goto err0;
	}

	if (p->shared_irqs) {
	/* request one shared interrupt */
	if (devm_request_irq(dev, p->irq[0].requested_irq,
	intc_irqpin_shared_irq_handler,
	IRQF_SHARED, name, p)) {
	dev_err(dev, "failed to request low IRQ\n");
	ret = -ENOENT;
	goto err1;
	}
	} else {
	/* request interrupts one by one */
	for (k = 0; k < p->number_of_irqs; k++) {
	if (devm_request_irq(dev, p->irq[k].requested_irq,
	intc_irqpin_irq_handler, 0, name,
	&p->irq[k])) {
	dev_err(dev, "failed to request low IRQ\n");
	ret = -ENOENT;
	goto err1;
	}
	}
	}

	/* unmask all interrupts on prio level */
	for (k = 0; k < p->number_of_irqs; k++)
	intc_irqpin_mask_unmask_prio(p, k, 0);

	dev_info(dev, "driving %d irqs\n", p->number_of_irqs);

	/* warn in case of mismatch if irq base is specified */
	if (p->config.irq_base) {
	if (p->config.irq_base != p->irq[0].domain_irq)
	dev_warn(dev, "irq base mismatch (%d/%d)\n",
	p->config.irq_base, p->irq[0].domain_irq);
	}

	return 0;

	err1:
	irq_domain_remove(p->irq_domain);
	err0:
	pm_runtime_put(dev);
	pm_runtime_disable(dev);
	return ret;
	}

	static int intc_irqpin_remove(struct platform_device *pdev)
	{
	struct intc_irqpin_priv *p = platform_get_drvdata(pdev);

	irq_domain_remove(p->irq_domain);
	pm_runtime_put(&pdev->dev);
	pm_runtime_disable(&pdev->dev);
	return 0;
	}

	static struct platform_driver intc_irqpin_device_driver = {
	.probe = intc_irqpin_probe,
	.remove = intc_irqpin_remove,
	.driver = {
	.name = "renesas_intc_irqpin",
	.of_match_table = intc_irqpin_dt_ids,
	}
	};

	static int __init intc_irqpin_init(void)
	{
	return platform_driver_register(&intc_irqpin_device_driver);
	}
	postcore_initcall(intc_irqpin_init);

	static void __exit intc_irqpin_exit(void)
	{
	platform_driver_unregister(&intc_irqpin_device_driver);
	}
	module_exit(intc_irqpin_exit);

	MODULE_AUTHOR("Magnus Damm");
	MODULE_DESCRIPTION("Renesas INTC External IRQ Pin Driver");
	MODULE_LICENSE("GPL v2");