/*
 * Copyright (C)2004-2010 Freescale Semiconductor, Inc. All Rights Reserved.
 *
 * The code contained herein is licensed under the GNU General Public
 * License. You may obtain a copy of the GNU General Public License
 * Version 2 or later at the following locations:
 *
 * http://www.opensource.org/licenses/gpl-license.html
 * http://www.gnu.org/copyleft/gpl.html
 */

#include <linux/init.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/io.h>
#include <linux/irqchip.h>
#include <linux/irqdomain.h>
#include <linux/of.h>
#include <linux/of_address.h>

#include <asm/mach/irq.h>
#include <asm/exception.h>

#include "common.h"
#include "hardware.h"
#include "irq-common.h"

/*
 *****************************************
 * TZIC Registers                        *
 *****************************************
 */

#define TZIC_INTCNTL	0x0000	/* Control register */
#define TZIC_INTTYPE	0x0004	/* Controller Type register */
#define TZIC_IMPID	0x0008	/* Distributor Implementer Identification */
#define TZIC_PRIOMASK	0x000C	/* Priority Mask Reg */
#define TZIC_SYNCCTRL	0x0010	/* Synchronizer Control register */
#define TZIC_DSMINT	0x0014	/* DSM interrupt Holdoffregister */
#define TZIC_INTSEC0(i)	(0x0080 + ((i) << 2)) /* Interrupt Security Reg 0 */
#define TZIC_ENSET0(i)	(0x0100 + ((i) << 2)) /* Enable Set Reg 0 */
#define TZIC_ENCLEAR0(i) (0x0180 + ((i) << 2)) /* Enable Clear Reg 0 */
#define TZIC_SRCSET0	0x0200	/* Source Set Register 0 */
#define TZIC_SRCCLAR0	0x0280	/* Source Clear Register 0 */
#define TZIC_PRIORITY0	0x0400	/* Priority Register 0 */
#define TZIC_PND0	0x0D00	/* Pending Register 0 */
#define TZIC_HIPND(i)	(0x0D80+ ((i) << 2))	/* High Priority Pending Register */
#define TZIC_WAKEUP0(i)	(0x0E00 + ((i) << 2))	/* Wakeup Config Register */
#define TZIC_SWINT	0x0F00	/* Software Interrupt Rigger Register */
#define TZIC_ID0	0x0FD0	/* Indentification Register 0 */

static void __iomem *tzic_base;
static struct irq_domain *domain;

#define TZIC_NUM_IRQS 128

#ifdef CONFIG_FIQ
static int tzic_set_irq_fiq(unsigned int hwirq, unsigned int type)
{
	unsigned int index, mask, value;

	index = hwirq >> 5;
	if (unlikely(index >= 4))
		return -EINVAL;
	mask = 1U << (hwirq & 0x1F);

	value = imx_readl(tzic_base + TZIC_INTSEC0(index)) | mask;
	if (type)
		value &= ~mask;
	imx_writel(value, tzic_base + TZIC_INTSEC0(index));

	return 0;
}
#else
#define tzic_set_irq_fiq NULL
#endif

#ifdef CONFIG_PM
static void tzic_irq_suspend(struct irq_data *d)
{
	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
	int idx = d->hwirq >> 5;

	imx_writel(gc->wake_active, tzic_base + TZIC_WAKEUP0(idx));
}

static void tzic_irq_resume(struct irq_data *d)
{
	int idx = d->hwirq >> 5;

	imx_writel(imx_readl(tzic_base + TZIC_ENSET0(idx)),
		   tzic_base + TZIC_WAKEUP0(idx));
}

#else
#define tzic_irq_suspend NULL
#define tzic_irq_resume NULL
#endif

static struct mxc_extra_irq tzic_extra_irq = {
#ifdef CONFIG_FIQ
	.set_irq_fiq = tzic_set_irq_fiq,
#endif
};

static __init void tzic_init_gc(int idx, unsigned int irq_start)
{
	struct irq_chip_generic *gc;
	struct irq_chip_type *ct;

	gc = irq_alloc_generic_chip("tzic", 1, irq_start, tzic_base,
				    handle_level_irq);
	gc->private = &tzic_extra_irq;
	gc->wake_enabled = IRQ_MSK(32);

	ct = gc->chip_types;
	ct->chip.irq_mask = irq_gc_mask_disable_reg;
	ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
	ct->chip.irq_set_wake = irq_gc_set_wake;
	ct->chip.irq_suspend = tzic_irq_suspend;
	ct->chip.irq_resume = tzic_irq_resume;
	ct->regs.disable = TZIC_ENCLEAR0(idx);
	ct->regs.enable = TZIC_ENSET0(idx);

	irq_setup_generic_chip(gc, IRQ_MSK(32), 0, IRQ_NOREQUEST, 0);
}

static void __exception_irq_entry tzic_handle_irq(struct pt_regs *regs)
{
	u32 stat;
	int i, irqofs, handled;

	do {
		handled = 0;

		for (i = 0; i < 4; i++) {
			stat = imx_readl(tzic_base + TZIC_HIPND(i)) &
				imx_readl(tzic_base + TZIC_INTSEC0(i));

			while (stat) {
				handled = 1;
				irqofs = fls(stat) - 1;
				handle_domain_irq(domain, irqofs + i * 32, regs);
				stat &= ~(1 << irqofs);
			}
		}
	} while (handled);
}

/*
 * This function initializes the TZIC hardware and disables all the
 * interrupts. It registers the interrupt enable and disable functions
 * to the kernel for each interrupt source.
 */
static int __init tzic_init_dt(struct device_node *np, struct device_node *p)
{
	int irq_base;
	int i;

	tzic_base = of_iomap(np, 0);
	WARN_ON(!tzic_base);

	/* put the TZIC into the reset value with
	 * all interrupts disabled
	 */
	i = imx_readl(tzic_base + TZIC_INTCNTL);

	imx_writel(0x80010001, tzic_base + TZIC_INTCNTL);
	imx_writel(0x1f, tzic_base + TZIC_PRIOMASK);
	imx_writel(0x02, tzic_base + TZIC_SYNCCTRL);

	for (i = 0; i < 4; i++)
		imx_writel(0xFFFFFFFF, tzic_base + TZIC_INTSEC0(i));

	/* disable all interrupts */
	for (i = 0; i < 4; i++)
		imx_writel(0xFFFFFFFF, tzic_base + TZIC_ENCLEAR0(i));

	/* all IRQ no FIQ Warning :: No selection */

	irq_base = irq_alloc_descs(-1, 0, TZIC_NUM_IRQS, numa_node_id());
	WARN_ON(irq_base < 0);

	domain = irq_domain_add_legacy(np, TZIC_NUM_IRQS, irq_base, 0,
				       &irq_domain_simple_ops, NULL);
	WARN_ON(!domain);

	for (i = 0; i < 4; i++, irq_base += 32)
		tzic_init_gc(i, irq_base);

	set_handle_irq(tzic_handle_irq);

#ifdef CONFIG_FIQ
	/* Initialize FIQ */
	init_FIQ(FIQ_START);
#endif

	pr_info("TrustZone Interrupt Controller (TZIC) initialized\n");

	return 0;
}
IRQCHIP_DECLARE(tzic, "fsl,tzic", tzic_init_dt);

/**
 * tzic_enable_wake() - enable wakeup interrupt
 *
 * @return			0 if successful; non-zero otherwise
 *
 * This function provides an interrupt synchronization point that is required
 * by tzic enabled platforms before entering imx specific low power modes (ie,
 * those low power modes beyond the WAIT_CLOCKED basic ARM WFI only mode).
 */
int tzic_enable_wake(void)
{
	unsigned int i;

	imx_writel(1, tzic_base + TZIC_DSMINT);
	if (unlikely(imx_readl(tzic_base + TZIC_DSMINT) == 0))
		return -EAGAIN;

	for (i = 0; i < 4; i++)
		imx_writel(imx_readl(tzic_base + TZIC_ENSET0(i)),
			   tzic_base + TZIC_WAKEUP0(i));

	return 0;
}
