/*
 * 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;
}