/* linux/arch/arm/mach-s3c2410/irq.c
 *
 * Copyright (c) 2003,2004 Simtec Electronics
 *	Ben Dooks <ben@simtec.co.uk>
 *
 * 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, or
 * (at your option) any later version.
 *
 * 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
 *
 * Changelog:
 *
 *   22-Jul-2004  Ben Dooks <ben@simtec.co.uk>
 *                Fixed compile warnings
 *
 *   22-Jul-2004  Roc Wu <cooloney@yahoo.com.cn>
 *                Fixed s3c_extirq_type
 *
 *   21-Jul-2004  Arnaud Patard (Rtp) <arnaud.patard@rtp-net.org>
 *                Addition of ADC/TC demux
 *
 *   04-Oct-2004  Klaus Fetscher <k.fetscher@fetron.de>
 *		  Fix for set_irq_type() on low EINT numbers
 *
 *   05-Oct-2004  Ben Dooks <ben@simtec.co.uk>
 *		  Tidy up KF's patch and sort out new release
 *
 *   05-Oct-2004  Ben Dooks <ben@simtec.co.uk>
 *		  Add support for power management controls
 *
 *   04-Nov-2004  Ben Dooks
 *		  Fix standard IRQ wake for EINT0..4 and RTC
 *
 *   22-Feb-2005  Ben Dooks
 *		  Fixed edge-triggering on ADC IRQ
 *
 *   28-Jun-2005  Ben Dooks
 *		  Mark IRQ_LCD valid
 *
 *   25-Jul-2005  Ben Dooks
 *		  Split the S3C2440 IRQ code to seperate file
*/

#include <linux/init.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/ptrace.h>
#include <linux/sysdev.h>

#include <asm/hardware.h>
#include <asm/irq.h>
#include <asm/io.h>

#include <asm/mach/irq.h>

#include <asm/arch/regs-irq.h>
#include <asm/arch/regs-gpio.h>

#include "cpu.h"
#include "pm.h"
#include "irq.h"

/* wakeup irq control */

#ifdef CONFIG_PM

/* state for IRQs over sleep */

/* default is to allow for EINT0..EINT15, and IRQ_RTC as wakeup sources
 *
 * set bit to 1 in allow bitfield to enable the wakeup settings on it
*/

unsigned long s3c_irqwake_intallow	= 1L << (IRQ_RTC - IRQ_EINT0) | 0xfL;
unsigned long s3c_irqwake_intmask	= 0xffffffffL;
unsigned long s3c_irqwake_eintallow	= 0x0000fff0L;
unsigned long s3c_irqwake_eintmask	= 0xffffffffL;

static int
s3c_irq_wake(unsigned int irqno, unsigned int state)
{
	unsigned long irqbit = 1 << (irqno - IRQ_EINT0);

	if (!(s3c_irqwake_intallow & irqbit))
		return -ENOENT;

	printk(KERN_INFO "wake %s for irq %d\n",
	       state ? "enabled" : "disabled", irqno);

	if (!state)
		s3c_irqwake_intmask |= irqbit;
	else
		s3c_irqwake_intmask &= ~irqbit;

	return 0;
}

static int
s3c_irqext_wake(unsigned int irqno, unsigned int state)
{
	unsigned long bit = 1L << (irqno - EXTINT_OFF);

	if (!(s3c_irqwake_eintallow & bit))
		return -ENOENT;

	printk(KERN_INFO "wake %s for irq %d\n",
	       state ? "enabled" : "disabled", irqno);

	if (!state)
		s3c_irqwake_eintmask |= bit;
	else
		s3c_irqwake_eintmask &= ~bit;

	return 0;
}

#else
#define s3c_irqext_wake NULL
#define s3c_irq_wake NULL
#endif


static void
s3c_irq_mask(unsigned int irqno)
{
	unsigned long mask;

	irqno -= IRQ_EINT0;

	mask = __raw_readl(S3C2410_INTMSK);
	mask |= 1UL << irqno;
	__raw_writel(mask, S3C2410_INTMSK);
}

static inline void
s3c_irq_ack(unsigned int irqno)
{
	unsigned long bitval = 1UL << (irqno - IRQ_EINT0);

	__raw_writel(bitval, S3C2410_SRCPND);
	__raw_writel(bitval, S3C2410_INTPND);
}

static inline void
s3c_irq_maskack(unsigned int irqno)
{
	unsigned long bitval = 1UL << (irqno - IRQ_EINT0);
	unsigned long mask;

	mask = __raw_readl(S3C2410_INTMSK);
	__raw_writel(mask|bitval, S3C2410_INTMSK);

	__raw_writel(bitval, S3C2410_SRCPND);
	__raw_writel(bitval, S3C2410_INTPND);
}


static void
s3c_irq_unmask(unsigned int irqno)
{
	unsigned long mask;

	if (irqno != IRQ_TIMER4 && irqno != IRQ_EINT8t23)
		irqdbf2("s3c_irq_unmask %d\n", irqno);

	irqno -= IRQ_EINT0;

	mask = __raw_readl(S3C2410_INTMSK);
	mask &= ~(1UL << irqno);
	__raw_writel(mask, S3C2410_INTMSK);
}

struct irqchip s3c_irq_level_chip = {
	.ack	   = s3c_irq_maskack,
	.mask	   = s3c_irq_mask,
	.unmask	   = s3c_irq_unmask,
	.set_wake	   = s3c_irq_wake
};

static struct irqchip s3c_irq_chip = {
	.ack	   = s3c_irq_ack,
	.mask	   = s3c_irq_mask,
	.unmask	   = s3c_irq_unmask,
	.set_wake  = s3c_irq_wake
};

static void
s3c_irqext_mask(unsigned int irqno)
{
	unsigned long mask;

	irqno -= EXTINT_OFF;

	mask = __raw_readl(S3C24XX_EINTMASK);
	mask |= ( 1UL << irqno);
	__raw_writel(mask, S3C24XX_EINTMASK);

	if (irqno <= (IRQ_EINT7 - EXTINT_OFF)) {
		/* check to see if all need masking */

		if ((mask & (0xf << 4)) == (0xf << 4)) {
			/* all masked, mask the parent */
			s3c_irq_mask(IRQ_EINT4t7);
		}
	} else {
		/* todo: the same check as above for the rest of the irq regs...*/

	}
}

static void
s3c_irqext_ack(unsigned int irqno)
{
	unsigned long req;
	unsigned long bit;
	unsigned long mask;

	bit = 1UL << (irqno - EXTINT_OFF);


	mask = __raw_readl(S3C24XX_EINTMASK);

	__raw_writel(bit, S3C24XX_EINTPEND);

	req = __raw_readl(S3C24XX_EINTPEND);
	req &= ~mask;

	/* not sure if we should be acking the parent irq... */

	if (irqno <= IRQ_EINT7 ) {
		if ((req & 0xf0) == 0)
			s3c_irq_ack(IRQ_EINT4t7);
	} else {
		if ((req >> 8) == 0)
			s3c_irq_ack(IRQ_EINT8t23);
	}
}

static void
s3c_irqext_unmask(unsigned int irqno)
{
	unsigned long mask;

	irqno -= EXTINT_OFF;

	mask = __raw_readl(S3C24XX_EINTMASK);
	mask &= ~( 1UL << irqno);
	__raw_writel(mask, S3C24XX_EINTMASK);

	s3c_irq_unmask((irqno <= (IRQ_EINT7 - EXTINT_OFF)) ? IRQ_EINT4t7 : IRQ_EINT8t23);
}

static int
s3c_irqext_type(unsigned int irq, unsigned int type)
{
	void __iomem *extint_reg;
	void __iomem *gpcon_reg;
	unsigned long gpcon_offset, extint_offset;
	unsigned long newvalue = 0, value;

	if ((irq >= IRQ_EINT0) && (irq <= IRQ_EINT3))
	{
		gpcon_reg = S3C2410_GPFCON;
		extint_reg = S3C24XX_EXTINT0;
		gpcon_offset = (irq - IRQ_EINT0) * 2;
		extint_offset = (irq - IRQ_EINT0) * 4;
	}
	else if ((irq >= IRQ_EINT4) && (irq <= IRQ_EINT7))
	{
		gpcon_reg = S3C2410_GPFCON;
		extint_reg = S3C24XX_EXTINT0;
		gpcon_offset = (irq - (EXTINT_OFF)) * 2;
		extint_offset = (irq - (EXTINT_OFF)) * 4;
	}
	else if ((irq >= IRQ_EINT8) && (irq <= IRQ_EINT15))
	{
		gpcon_reg = S3C2410_GPGCON;
		extint_reg = S3C24XX_EXTINT1;
		gpcon_offset = (irq - IRQ_EINT8) * 2;
		extint_offset = (irq - IRQ_EINT8) * 4;
	}
	else if ((irq >= IRQ_EINT16) && (irq <= IRQ_EINT23))
	{
		gpcon_reg = S3C2410_GPGCON;
		extint_reg = S3C24XX_EXTINT2;
		gpcon_offset = (irq - IRQ_EINT8) * 2;
		extint_offset = (irq - IRQ_EINT16) * 4;
	} else
		return -1;

	/* Set the GPIO to external interrupt mode */
	value = __raw_readl(gpcon_reg);
	value = (value & ~(3 << gpcon_offset)) | (0x02 << gpcon_offset);
	__raw_writel(value, gpcon_reg);

	/* Set the external interrupt to pointed trigger type */
	switch (type)
	{
		case IRQT_NOEDGE:
			printk(KERN_WARNING "No edge setting!\n");
			break;

		case IRQT_RISING:
			newvalue = S3C2410_EXTINT_RISEEDGE;
			break;

		case IRQT_FALLING:
			newvalue = S3C2410_EXTINT_FALLEDGE;
			break;

		case IRQT_BOTHEDGE:
			newvalue = S3C2410_EXTINT_BOTHEDGE;
			break;

		case IRQT_LOW:
			newvalue = S3C2410_EXTINT_LOWLEV;
			break;

		case IRQT_HIGH:
			newvalue = S3C2410_EXTINT_HILEV;
			break;

		default:
			printk(KERN_ERR "No such irq type %d", type);
			return -1;
	}

	value = __raw_readl(extint_reg);
	value = (value & ~(7 << extint_offset)) | (newvalue << extint_offset);
	__raw_writel(value, extint_reg);

	return 0;
}

static struct irqchip s3c_irqext_chip = {
	.mask	    = s3c_irqext_mask,
	.unmask	    = s3c_irqext_unmask,
	.ack	    = s3c_irqext_ack,
	.set_type    = s3c_irqext_type,
	.set_wake    = s3c_irqext_wake
};

static struct irqchip s3c_irq_eint0t4 = {
	.ack	   = s3c_irq_ack,
	.mask	   = s3c_irq_mask,
	.unmask	   = s3c_irq_unmask,
	.set_wake  = s3c_irq_wake,
	.set_type  = s3c_irqext_type,
};

/* mask values for the parent registers for each of the interrupt types */

#define INTMSK_UART0	 (1UL << (IRQ_UART0 - IRQ_EINT0))
#define INTMSK_UART1	 (1UL << (IRQ_UART1 - IRQ_EINT0))
#define INTMSK_UART2	 (1UL << (IRQ_UART2 - IRQ_EINT0))
#define INTMSK_ADCPARENT (1UL << (IRQ_ADCPARENT - IRQ_EINT0))


/* UART0 */

static void
s3c_irq_uart0_mask(unsigned int irqno)
{
	s3c_irqsub_mask(irqno, INTMSK_UART0, 7);
}

static void
s3c_irq_uart0_unmask(unsigned int irqno)
{
	s3c_irqsub_unmask(irqno, INTMSK_UART0);
}

static void
s3c_irq_uart0_ack(unsigned int irqno)
{
	s3c_irqsub_maskack(irqno, INTMSK_UART0, 7);
}

static struct irqchip s3c_irq_uart0 = {
	.mask	    = s3c_irq_uart0_mask,
	.unmask	    = s3c_irq_uart0_unmask,
	.ack	    = s3c_irq_uart0_ack,
};

/* UART1 */

static void
s3c_irq_uart1_mask(unsigned int irqno)
{
	s3c_irqsub_mask(irqno, INTMSK_UART1, 7 << 3);
}

static void
s3c_irq_uart1_unmask(unsigned int irqno)
{
	s3c_irqsub_unmask(irqno, INTMSK_UART1);
}

static void
s3c_irq_uart1_ack(unsigned int irqno)
{
	s3c_irqsub_maskack(irqno, INTMSK_UART1, 7 << 3);
}

static struct irqchip s3c_irq_uart1 = {
	.mask	    = s3c_irq_uart1_mask,
	.unmask	    = s3c_irq_uart1_unmask,
	.ack	    = s3c_irq_uart1_ack,
};

/* UART2 */

static void
s3c_irq_uart2_mask(unsigned int irqno)
{
	s3c_irqsub_mask(irqno, INTMSK_UART2, 7 << 6);
}

static void
s3c_irq_uart2_unmask(unsigned int irqno)
{
	s3c_irqsub_unmask(irqno, INTMSK_UART2);
}

static void
s3c_irq_uart2_ack(unsigned int irqno)
{
	s3c_irqsub_maskack(irqno, INTMSK_UART2, 7 << 6);
}

static struct irqchip s3c_irq_uart2 = {
	.mask	    = s3c_irq_uart2_mask,
	.unmask	    = s3c_irq_uart2_unmask,
	.ack	    = s3c_irq_uart2_ack,
};

/* ADC and Touchscreen */

static void
s3c_irq_adc_mask(unsigned int irqno)
{
	s3c_irqsub_mask(irqno, INTMSK_ADCPARENT, 3 << 9);
}

static void
s3c_irq_adc_unmask(unsigned int irqno)
{
	s3c_irqsub_unmask(irqno, INTMSK_ADCPARENT);
}

static void
s3c_irq_adc_ack(unsigned int irqno)
{
	s3c_irqsub_ack(irqno, INTMSK_ADCPARENT, 3 << 9);
}

static struct irqchip s3c_irq_adc = {
	.mask	    = s3c_irq_adc_mask,
	.unmask	    = s3c_irq_adc_unmask,
	.ack	    = s3c_irq_adc_ack,
};

/* irq demux for adc */
static void s3c_irq_demux_adc(unsigned int irq,
			      struct irqdesc *desc,
			      struct pt_regs *regs)
{
	unsigned int subsrc, submsk;
	unsigned int offset = 9;
	struct irqdesc *mydesc;

	/* read the current pending interrupts, and the mask
	 * for what it is available */

	subsrc = __raw_readl(S3C2410_SUBSRCPND);
	submsk = __raw_readl(S3C2410_INTSUBMSK);

	subsrc &= ~submsk;
	subsrc >>= offset;
	subsrc &= 3;

	if (subsrc != 0) {
		if (subsrc & 1) {
			mydesc = irq_desc + IRQ_TC;
			desc_handle_irq(IRQ_TC, mydesc, regs);
		}
		if (subsrc & 2) {
			mydesc = irq_desc + IRQ_ADC;
			desc_handle_irq(IRQ_ADC, mydesc, regs);
		}
	}
}

static void s3c_irq_demux_uart(unsigned int start,
			       struct pt_regs *regs)
{
	unsigned int subsrc, submsk;
	unsigned int offset = start - IRQ_S3CUART_RX0;
	struct irqdesc *desc;

	/* read the current pending interrupts, and the mask
	 * for what it is available */

	subsrc = __raw_readl(S3C2410_SUBSRCPND);
	submsk = __raw_readl(S3C2410_INTSUBMSK);

	irqdbf2("s3c_irq_demux_uart: start=%d (%d), subsrc=0x%08x,0x%08x\n",
		start, offset, subsrc, submsk);

	subsrc &= ~submsk;
	subsrc >>= offset;
	subsrc &= 7;

	if (subsrc != 0) {
		desc = irq_desc + start;

		if (subsrc & 1)
			desc_handle_irq(start, desc, regs);

		desc++;

		if (subsrc & 2)
			desc_handle_irq(start+1, desc, regs);

		desc++;

		if (subsrc & 4)
			desc_handle_irq(start+2, desc, regs);
	}
}

/* uart demux entry points */

static void
s3c_irq_demux_uart0(unsigned int irq,
		    struct irqdesc *desc,
		    struct pt_regs *regs)
{
	irq = irq;
	s3c_irq_demux_uart(IRQ_S3CUART_RX0, regs);
}

static void
s3c_irq_demux_uart1(unsigned int irq,
		    struct irqdesc *desc,
		    struct pt_regs *regs)
{
	irq = irq;
	s3c_irq_demux_uart(IRQ_S3CUART_RX1, regs);
}

static void
s3c_irq_demux_uart2(unsigned int irq,
		    struct irqdesc *desc,
		    struct pt_regs *regs)
{
	irq = irq;
	s3c_irq_demux_uart(IRQ_S3CUART_RX2, regs);
}

static void
s3c_irq_demux_extint(unsigned int irq,
		     struct irqdesc *desc,
		     struct pt_regs *regs)
{
	unsigned long eintpnd = __raw_readl(S3C24XX_EINTPEND);
	unsigned long eintmsk = __raw_readl(S3C24XX_EINTMASK);

	eintpnd &= ~eintmsk;

	if (eintpnd) {
		irq = fls(eintpnd);
		irq += (IRQ_EINT4 - (4 + 1));

		desc_handle_irq(irq, irq_desc + irq, regs);
	}
}

/* s3c24xx_init_irq
 *
 * Initialise S3C2410 IRQ system
*/

void __init s3c24xx_init_irq(void)
{
	unsigned long pend;
	unsigned long last;
	int irqno;
	int i;

	irqdbf("s3c2410_init_irq: clearing interrupt status flags\n");

	/* first, clear all interrupts pending... */

	last = 0;
	for (i = 0; i < 4; i++) {
		pend = __raw_readl(S3C24XX_EINTPEND);

		if (pend == 0 || pend == last)
			break;

		__raw_writel(pend, S3C24XX_EINTPEND);
		printk("irq: clearing pending ext status %08x\n", (int)pend);
		last = pend;
	}

	last = 0;
	for (i = 0; i < 4; i++) {
		pend = __raw_readl(S3C2410_INTPND);

		if (pend == 0 || pend == last)
			break;

		__raw_writel(pend, S3C2410_SRCPND);
		__raw_writel(pend, S3C2410_INTPND);
		printk("irq: clearing pending status %08x\n", (int)pend);
		last = pend;
	}

	last = 0;
	for (i = 0; i < 4; i++) {
		pend = __raw_readl(S3C2410_SUBSRCPND);

		if (pend == 0 || pend == last)
			break;

		printk("irq: clearing subpending status %08x\n", (int)pend);
		__raw_writel(pend, S3C2410_SUBSRCPND);
		last = pend;
	}

	/* register the main interrupts */

	irqdbf("s3c2410_init_irq: registering s3c2410 interrupt handlers\n");

	for (irqno = IRQ_EINT4t7; irqno <= IRQ_ADCPARENT; irqno++) {
		/* set all the s3c2410 internal irqs */

		switch (irqno) {
			/* deal with the special IRQs (cascaded) */

		case IRQ_EINT4t7:
		case IRQ_EINT8t23:
		case IRQ_UART0:
		case IRQ_UART1:
		case IRQ_UART2:
		case IRQ_ADCPARENT:
			set_irq_chip(irqno, &s3c_irq_level_chip);
			set_irq_handler(irqno, do_level_IRQ);
			break;

		case IRQ_RESERVED6:
		case IRQ_RESERVED24:
			/* no IRQ here */
			break;

		default:
			//irqdbf("registering irq %d (s3c irq)\n", irqno);
			set_irq_chip(irqno, &s3c_irq_chip);
			set_irq_handler(irqno, do_edge_IRQ);
			set_irq_flags(irqno, IRQF_VALID);
		}
	}

	/* setup the cascade irq handlers */

	set_irq_chained_handler(IRQ_EINT4t7, s3c_irq_demux_extint);
	set_irq_chained_handler(IRQ_EINT8t23, s3c_irq_demux_extint);

	set_irq_chained_handler(IRQ_UART0, s3c_irq_demux_uart0);
	set_irq_chained_handler(IRQ_UART1, s3c_irq_demux_uart1);
	set_irq_chained_handler(IRQ_UART2, s3c_irq_demux_uart2);
	set_irq_chained_handler(IRQ_ADCPARENT, s3c_irq_demux_adc);

	/* external interrupts */

	for (irqno = IRQ_EINT0; irqno <= IRQ_EINT3; irqno++) {
		irqdbf("registering irq %d (ext int)\n", irqno);
		set_irq_chip(irqno, &s3c_irq_eint0t4);
		set_irq_handler(irqno, do_edge_IRQ);
		set_irq_flags(irqno, IRQF_VALID);
	}

	for (irqno = IRQ_EINT4; irqno <= IRQ_EINT23; irqno++) {
		irqdbf("registering irq %d (extended s3c irq)\n", irqno);
		set_irq_chip(irqno, &s3c_irqext_chip);
		set_irq_handler(irqno, do_edge_IRQ);
		set_irq_flags(irqno, IRQF_VALID);
	}

	/* register the uart interrupts */

	irqdbf("s3c2410: registering external interrupts\n");

	for (irqno = IRQ_S3CUART_RX0; irqno <= IRQ_S3CUART_ERR0; irqno++) {
		irqdbf("registering irq %d (s3c uart0 irq)\n", irqno);
		set_irq_chip(irqno, &s3c_irq_uart0);
		set_irq_handler(irqno, do_level_IRQ);
		set_irq_flags(irqno, IRQF_VALID);
	}

	for (irqno = IRQ_S3CUART_RX1; irqno <= IRQ_S3CUART_ERR1; irqno++) {
		irqdbf("registering irq %d (s3c uart1 irq)\n", irqno);
		set_irq_chip(irqno, &s3c_irq_uart1);
		set_irq_handler(irqno, do_level_IRQ);
		set_irq_flags(irqno, IRQF_VALID);
	}

	for (irqno = IRQ_S3CUART_RX2; irqno <= IRQ_S3CUART_ERR2; irqno++) {
		irqdbf("registering irq %d (s3c uart2 irq)\n", irqno);
		set_irq_chip(irqno, &s3c_irq_uart2);
		set_irq_handler(irqno, do_level_IRQ);
		set_irq_flags(irqno, IRQF_VALID);
	}

	for (irqno = IRQ_TC; irqno <= IRQ_ADC; irqno++) {
		irqdbf("registering irq %d (s3c adc irq)\n", irqno);
		set_irq_chip(irqno, &s3c_irq_adc);
		set_irq_handler(irqno, do_edge_IRQ);
		set_irq_flags(irqno, IRQF_VALID);
	}

	irqdbf("s3c2410: registered interrupt handlers\n");
}