// SPDX-License-Identifier: GPL-2.0-or-later

  /*
   *  CLPS711X IRQ driver
   *
   *  Copyright (C) 2013 Alexander Shiyan <shc_work@mail.ru>

   */
  
  #include <linux/io.h>
  #include <linux/irq.h>

  #include <linux/irqchip.h>

  #include <linux/irqdomain.h>
  #include <linux/of_address.h>
  #include <linux/of_irq.h>
  #include <linux/slab.h>
  
  #include <asm/exception.h>
  #include <asm/mach/irq.h>

  #define CLPS711X_INTSR1	(0x0240)
  #define CLPS711X_INTMR1	(0x0280)
  #define CLPS711X_BLEOI	(0x0600)
  #define CLPS711X_MCEOI	(0x0640)
  #define CLPS711X_TEOI	(0x0680)
  #define CLPS711X_TC1EOI	(0x06c0)
  #define CLPS711X_TC2EOI	(0x0700)
  #define CLPS711X_RTCEOI	(0x0740)
  #define CLPS711X_UMSEOI	(0x0780)
  #define CLPS711X_COEOI	(0x07c0)
  #define CLPS711X_INTSR2	(0x1240)
  #define CLPS711X_INTMR2	(0x1280)
  #define CLPS711X_SRXEOF	(0x1600)
  #define CLPS711X_KBDEOI	(0x1700)
  #define CLPS711X_INTSR3	(0x2240)
  #define CLPS711X_INTMR3	(0x2280)
  
  static const struct {
  #define CLPS711X_FLAG_EN	(1 << 0)
  #define CLPS711X_FLAG_FIQ	(1 << 1)
  	unsigned int	flags;
  	phys_addr_t	eoi;
  } clps711x_irqs[] = {
  	[1]	= { CLPS711X_FLAG_FIQ, CLPS711X_BLEOI, },
  	[3]	= { CLPS711X_FLAG_FIQ, CLPS711X_MCEOI, },
  	[4]	= { CLPS711X_FLAG_EN, CLPS711X_COEOI, },
  	[5]	= { CLPS711X_FLAG_EN, },
  	[6]	= { CLPS711X_FLAG_EN, },
  	[7]	= { CLPS711X_FLAG_EN, },
  	[8]	= { CLPS711X_FLAG_EN, CLPS711X_TC1EOI, },
  	[9]	= { CLPS711X_FLAG_EN, CLPS711X_TC2EOI, },
  	[10]	= { CLPS711X_FLAG_EN, CLPS711X_RTCEOI, },
  	[11]	= { CLPS711X_FLAG_EN, CLPS711X_TEOI, },
  	[12]	= { CLPS711X_FLAG_EN, },
  	[13]	= { CLPS711X_FLAG_EN, },
  	[14]	= { CLPS711X_FLAG_EN, CLPS711X_UMSEOI, },
  	[15]	= { CLPS711X_FLAG_EN, CLPS711X_SRXEOF, },
  	[16]	= { CLPS711X_FLAG_EN, CLPS711X_KBDEOI, },
  	[17]	= { CLPS711X_FLAG_EN, },
  	[18]	= { CLPS711X_FLAG_EN, },
  	[28]	= { CLPS711X_FLAG_EN, },
  	[29]	= { CLPS711X_FLAG_EN, },
  	[32]	= { CLPS711X_FLAG_FIQ, },
  };
  
  static struct {
  	void __iomem		*base;
  	void __iomem		*intmr[3];
  	void __iomem		*intsr[3];
  	struct irq_domain	*domain;
  	struct irq_domain_ops	ops;
  } *clps711x_intc;
  
  static asmlinkage void __exception_irq_entry clps711x_irqh(struct pt_regs *regs)
  {

  	u32 irqstat;

  
  	do {
  		irqstat = readw_relaxed(clps711x_intc->intmr[0]) &
  			  readw_relaxed(clps711x_intc->intsr[0]);

  		if (irqstat)
  			handle_domain_irq(clps711x_intc->domain,
  					  fls(irqstat) - 1, regs);

  
  		irqstat = readw_relaxed(clps711x_intc->intmr[1]) &
  			  readw_relaxed(clps711x_intc->intsr[1]);

  		if (irqstat)
  			handle_domain_irq(clps711x_intc->domain,
  					  fls(irqstat) - 1 + 16, regs);

  	} while (irqstat);
  }
  
  static void clps711x_intc_eoi(struct irq_data *d)
  {
  	irq_hw_number_t hwirq = irqd_to_hwirq(d);
  
  	writel_relaxed(0, clps711x_intc->base + clps711x_irqs[hwirq].eoi);
  }
  
  static void clps711x_intc_mask(struct irq_data *d)
  {
  	irq_hw_number_t hwirq = irqd_to_hwirq(d);
  	void __iomem *intmr = clps711x_intc->intmr[hwirq / 16];
  	u32 tmp;
  
  	tmp = readl_relaxed(intmr);
  	tmp &= ~(1 << (hwirq % 16));
  	writel_relaxed(tmp, intmr);
  }
  
  static void clps711x_intc_unmask(struct irq_data *d)
  {
  	irq_hw_number_t hwirq = irqd_to_hwirq(d);
  	void __iomem *intmr = clps711x_intc->intmr[hwirq / 16];
  	u32 tmp;
  
  	tmp = readl_relaxed(intmr);
  	tmp |= 1 << (hwirq % 16);
  	writel_relaxed(tmp, intmr);
  }
  
  static struct irq_chip clps711x_intc_chip = {
  	.name		= "clps711x-intc",
  	.irq_eoi	= clps711x_intc_eoi,
  	.irq_mask	= clps711x_intc_mask,
  	.irq_unmask	= clps711x_intc_unmask,
  };
  
  static int __init clps711x_intc_irq_map(struct irq_domain *h, unsigned int virq,
  					irq_hw_number_t hw)
  {
  	irq_flow_handler_t handler = handle_level_irq;

  	unsigned int flags = 0;

  
  	if (!clps711x_irqs[hw].flags)
  		return 0;
  
  	if (clps711x_irqs[hw].flags & CLPS711X_FLAG_FIQ) {
  		handler = handle_bad_irq;

  		flags |= IRQ_NOAUTOEN;

  	} else if (clps711x_irqs[hw].eoi) {
  		handler = handle_fasteoi_irq;
  	}
  
  	/* Clear down pending interrupt */
  	if (clps711x_irqs[hw].eoi)
  		writel_relaxed(0, clps711x_intc->base + clps711x_irqs[hw].eoi);
  
  	irq_set_chip_and_handler(virq, &clps711x_intc_chip, handler);

  	irq_modify_status(virq, IRQ_NOPROBE, flags);

  
  	return 0;
  }
  
  static int __init _clps711x_intc_init(struct device_node *np,
  				      phys_addr_t base, resource_size_t size)
  {
  	int err;
  
  	clps711x_intc = kzalloc(sizeof(*clps711x_intc), GFP_KERNEL);
  	if (!clps711x_intc)
  		return -ENOMEM;
  
  	clps711x_intc->base = ioremap(base, size);
  	if (!clps711x_intc->base) {
  		err = -ENOMEM;
  		goto out_kfree;
  	}
  
  	clps711x_intc->intsr[0] = clps711x_intc->base + CLPS711X_INTSR1;
  	clps711x_intc->intmr[0] = clps711x_intc->base + CLPS711X_INTMR1;
  	clps711x_intc->intsr[1] = clps711x_intc->base + CLPS711X_INTSR2;
  	clps711x_intc->intmr[1] = clps711x_intc->base + CLPS711X_INTMR2;
  	clps711x_intc->intsr[2] = clps711x_intc->base + CLPS711X_INTSR3;
  	clps711x_intc->intmr[2] = clps711x_intc->base + CLPS711X_INTMR3;
  
  	/* Mask all interrupts */
  	writel_relaxed(0, clps711x_intc->intmr[0]);
  	writel_relaxed(0, clps711x_intc->intmr[1]);
  	writel_relaxed(0, clps711x_intc->intmr[2]);
  
  	err = irq_alloc_descs(-1, 0, ARRAY_SIZE(clps711x_irqs), numa_node_id());

  	if (err < 0)

  		goto out_iounmap;
  
  	clps711x_intc->ops.map = clps711x_intc_irq_map;
  	clps711x_intc->ops.xlate = irq_domain_xlate_onecell;
  	clps711x_intc->domain =
  		irq_domain_add_legacy(np, ARRAY_SIZE(clps711x_irqs),
  				      0, 0, &clps711x_intc->ops, NULL);
  	if (!clps711x_intc->domain) {
  		err = -ENOMEM;
  		goto out_irqfree;
  	}
  
  	irq_set_default_host(clps711x_intc->domain);
  	set_handle_irq(clps711x_irqh);
  
  #ifdef CONFIG_FIQ
  	init_FIQ(0);
  #endif
  
  	return 0;
  
  out_irqfree:
  	irq_free_descs(0, ARRAY_SIZE(clps711x_irqs));
  
  out_iounmap:
  	iounmap(clps711x_intc->base);
  
  out_kfree:
  	kfree(clps711x_intc);
  
  	return err;
  }
  
  void __init clps711x_intc_init(phys_addr_t base, resource_size_t size)
  {
  	BUG_ON(_clps711x_intc_init(NULL, base, size));
  }
  
  #ifdef CONFIG_IRQCHIP
  static int __init clps711x_intc_init_dt(struct device_node *np,
  					struct device_node *parent)
  {
  	struct resource res;
  	int err;
  
  	err = of_address_to_resource(np, 0, &res);
  	if (err)
  		return err;
  
  	return _clps711x_intc_init(np, res.start, resource_size(&res));
  }

  IRQCHIP_DECLARE(clps711x, "cirrus,ep7209-intc", clps711x_intc_init_dt);

  #endif