/*
 * linux/arch/sh/kernel/setup_ec3104.c
 *  EC3104 companion chip support
 *
 * Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
 *
 */
/* EC3104 note:
 * This code was written without any documentation about the EC3104 chip.  While
 * I hope I got most of the basic functionality right, the register names I use
 * are most likely completely different from those in the chip documentation.
 *
 * If you have any further information about the EC3104, please tell me
 * (prumpf@tux.org).
 */

#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/param.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/types.h>

#include <asm/io.h>
#include <asm/irq.h>
#include <asm/ec3104.h>

/* This is for debugging mostly;  here's the table that I intend to keep
 * in here:
 *
 *   index	function	base addr	power		interrupt bit   
 *	 0	power		b0ec0000	---		00000001 (unused)
 *	 1	irqs		b0ec1000	---		00000002 (unused)
 *	 2	??		b0ec2000	b0ec0008	00000004
 *	 3	PS2 (1)		b0ec3000	b0ec000c	00000008
 *	 4	PS2 (2)		b0ec4000	b0ec0010	00000010
 *	 5	??		b0ec5000	b0ec0014	00000020
 *	 6	I2C		b0ec6000	b0ec0018	00000040
 *	 7	serial (1)	b0ec7000	b0ec001c	00000080
 *	 8	serial (2)	b0ec8000	b0ec0020	00000100
 *	 9	serial (3)	b0ec9000	b0ec0024	00000200
 *	10	serial (4)	b0eca000	b0ec0028	00000400
 *	12	GPIO (1)	b0ecc000	b0ec0030
 *	13      GPIO (2)	b0ecc000	b0ec0030
 *	16	pcmcia (1)	b0ed0000	b0ec0040	00010000
 *	17	pcmcia (2)	b0ed1000	b0ec0044	00020000
 */

/* I used the register names from another interrupt controller I worked with,
 * since it seems to be identical to the ec3104 except that all bits are
 * inverted:
 *
 * IRR: Interrupt Request Register (pending and enabled interrupts)
 * IMR: Interrupt Mask Register (which interrupts are enabled)
 * IPR: Interrupt Pending Register (pending interrupts, even disabled ones)
 *
 * 0 bits mean pending or enabled, 1 bits mean not pending or disabled.  all
 * IRQs seem to be level-triggered.
 */

#define EC3104_IRR (EC3104_BASE + 0x1000)
#define EC3104_IMR (EC3104_BASE + 0x1004)
#define EC3104_IPR (EC3104_BASE + 0x1008)

#define ctrl_readl(addr) (*(volatile u32 *)(addr))
#define ctrl_writel(data,addr) (*(volatile u32 *)(addr) = (data))
#define ctrl_readb(addr) (*(volatile u8 *)(addr))

static char *ec3104_name(unsigned index)
{
	switch(index) {
	case 0:
		return "power management";
	case 1:
		return "interrupts";
	case 3:
		return "PS2 (1)";
	case 4:
		return "PS2 (2)";
	case 5:
		return "I2C (1)";
	case 6:
		return "I2C (2)";
	case 7:
		return "serial (1)";
	case 8:
		return "serial (2)";
	case 9:
		return "serial (3)";
	case 10:
		return "serial (4)";
	case 16:
		return "pcmcia (1)";
	case 17:
		return "pcmcia (2)";
	default: {
		static char buf[32];
		
		sprintf(buf, "unknown (%d)", index);

		return buf;
		}
	}
}

int get_pending_interrupts(char *buf)
{
	u32 ipr;
	u32 bit;
	char *p = buf;

        p += sprintf(p, "pending: (");
	
	ipr = ctrl_inl(EC3104_IPR);

	for (bit = 1; bit < 32; bit++)
		if (!(ipr & (1<<bit)))
			p += sprintf(p, "%s ", ec3104_name(bit));
	
	p += sprintf(p, ")\n");

	return p - buf;
}
	
static inline u32 ec3104_irq2mask(unsigned int irq)
{
	return (1 << (irq - EC3104_IRQBASE));
}

static inline void mask_ec3104_irq(unsigned int irq)
{
	u32 mask;

	mask = ctrl_readl(EC3104_IMR);

	mask |= ec3104_irq2mask(irq);
	
	ctrl_writel(mask, EC3104_IMR);
}
	
static inline void unmask_ec3104_irq(unsigned int irq)
{
	u32 mask;

	mask = ctrl_readl(EC3104_IMR);

	mask &= ~ec3104_irq2mask(irq);
	
	ctrl_writel(mask, EC3104_IMR);
}
	
static void disable_ec3104_irq(unsigned int irq)
{
	mask_ec3104_irq(irq);
}

static void enable_ec3104_irq(unsigned int irq)
{
	unmask_ec3104_irq(irq);
}

static void mask_and_ack_ec3104_irq(unsigned int irq)
{
	mask_ec3104_irq(irq);
}

static void end_ec3104_irq(unsigned int irq)
{
	if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
		unmask_ec3104_irq(irq);
}

static unsigned int startup_ec3104_irq(unsigned int irq)
{
	unmask_ec3104_irq(irq);

	return 0;
}

static void shutdown_ec3104_irq(unsigned int irq)
{
	mask_ec3104_irq(irq);

}

static struct hw_interrupt_type ec3104_int = {
	typename:	"EC3104",
	enable:		enable_ec3104_irq,
	disable:	disable_ec3104_irq,
	ack:		mask_and_ack_ec3104_irq,
	end:		end_ec3104_irq,
	startup:	startup_ec3104_irq,
	shutdown:	shutdown_ec3104_irq,
};

/* Yuck.  the _demux API is ugly */
int ec3104_irq_demux(int irq)
{
	if (irq == EC3104_IRQ) {
		unsigned int mask;

		mask = ctrl_readl(EC3104_IRR);

		if (mask == 0xffffffff)
			return EC3104_IRQ;
		else
			return EC3104_IRQBASE + ffz(mask);
	}

	return irq;
}

int __init setup_ec3104(void)
{
	char str[8];
	int i;
	
	if (!MACH_EC3104)
		printk("!MACH_EC3104\n");

	if (0)
		return 0;

	for (i=0; i<8; i++)
		str[i] = ctrl_readb(EC3104_BASE + i);

	for (i = EC3104_IRQBASE; i < EC3104_IRQBASE + 32; i++)
		irq_desc[i].handler = &ec3104_int;

	printk("initializing EC3104 \"%.8s\" at %08x, IRQ %d, IRQ base %d\n",
	       str, EC3104_BASE, EC3104_IRQ, EC3104_IRQBASE);


	/* mask all interrupts.  this should have been done by the boot
	 * loader for us but we want to be sure ... */
	ctrl_writel(0xffffffff, EC3104_IMR);
	
	return 0;
}

module_init(setup_ec3104);