arch/sparc/kernel/sun4c_irq.c

/*  sun4c_irq.c
 *  arch/sparc/kernel/sun4c_irq.c:
 *
 *  djhr: Hacked out of irq.c into a CPU dependent version.
 *
 *  Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
 *  Copyright (C) 1995 Miguel de Icaza (miguel@nuclecu.unam.mx)
 *  Copyright (C) 1995 Pete A. Zaitcev (zaitcev@yahoo.com)
 *  Copyright (C) 1996 Dave Redman (djhr@tadpole.co.uk)
 */

#include <linux/errno.h>
#include <linux/linkage.h>
#include <linux/kernel_stat.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/ptrace.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include "irq.h"

#include <asm/ptrace.h>
#include <asm/processor.h>
#include <asm/system.h>
#include <asm/psr.h>
#include <asm/vaddrs.h>
#include <asm/timer.h>
#include <asm/openprom.h>
#include <asm/oplib.h>
#include <asm/traps.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/idprom.h>
#include <asm/machines.h>

/*
 * Bit field defines for the interrupt registers on various
 * Sparc machines.
 */

/* The sun4c interrupt register. */
#define SUN4C_INT_ENABLE  0x01     /* Allow interrupts. */
#define SUN4C_INT_E14     0x80     /* Enable level 14 IRQ. */
#define SUN4C_INT_E10     0x20     /* Enable level 10 IRQ. */
#define SUN4C_INT_E8      0x10     /* Enable level 8 IRQ. */
#define SUN4C_INT_E6      0x08     /* Enable level 6 IRQ. */
#define SUN4C_INT_E4      0x04     /* Enable level 4 IRQ. */
#define SUN4C_INT_E1      0x02     /* Enable level 1 IRQ. */

/* Pointer to the interrupt enable byte
 *
 * Dave Redman (djhr@tadpole.co.uk)
 * What you may not be aware of is that entry.S requires this variable.
 *
 *  --- linux_trap_nmi_sun4c --
 *
 * so don't go making it static, like I tried. sigh.
 */
unsigned char *interrupt_enable = NULL;

static void sun4c_disable_irq(unsigned int irq_nr)
{
	unsigned long flags;
	unsigned char current_mask, new_mask;
    
	local_irq_save(flags);
	irq_nr &= (NR_IRQS - 1);
	current_mask = *interrupt_enable;
	switch(irq_nr) {
	case 1:
		new_mask = ((current_mask) & (~(SUN4C_INT_E1)));
		break;
	case 8:
		new_mask = ((current_mask) & (~(SUN4C_INT_E8)));
		break;
	case 10:
		new_mask = ((current_mask) & (~(SUN4C_INT_E10)));
		break;
	case 14:
		new_mask = ((current_mask) & (~(SUN4C_INT_E14)));
		break;
	default:
		local_irq_restore(flags);
		return;
	}
	*interrupt_enable = new_mask;
	local_irq_restore(flags);
}

static void sun4c_enable_irq(unsigned int irq_nr)
{
	unsigned long flags;
	unsigned char current_mask, new_mask;
    
	local_irq_save(flags);
	irq_nr &= (NR_IRQS - 1);
	current_mask = *interrupt_enable;
	switch(irq_nr) {
	case 1:
		new_mask = ((current_mask) | SUN4C_INT_E1);
		break;
	case 8:
		new_mask = ((current_mask) | SUN4C_INT_E8);
		break;
	case 10:
		new_mask = ((current_mask) | SUN4C_INT_E10);
		break;
	case 14:
		new_mask = ((current_mask) | SUN4C_INT_E14);
		break;
	default:
		local_irq_restore(flags);
		return;
	}
	*interrupt_enable = new_mask;
	local_irq_restore(flags);
}

#define TIMER_IRQ  	10    /* Also at level 14, but we ignore that one. */
#define PROFILE_IRQ	14    /* Level14 ticker.. used by OBP for polling */

volatile struct sun4c_timer_info *sun4c_timers;

static void sun4c_clear_clock_irq(void)
{
	volatile unsigned int clear_intr;

	clear_intr = sun4c_timers->timer_limit10;
}

static void sun4c_load_profile_irq(int cpu, unsigned int limit)
{
	/* Errm.. not sure how to do this.. */
}

static void __init sun4c_init_timers(irq_handler_t counter_fn)
{
	int irq;

	/* Map the Timer chip, this is implemented in hardware inside
	 * the cache chip on the sun4c.
	 */
	sun4c_timers = ioremap(SUN_TIMER_PHYSADDR,
	    sizeof(struct sun4c_timer_info));

	/* Have the level 10 timer tick at 100HZ.  We don't touch the
	 * level 14 timer limit since we are letting the prom handle
	 * them until we have a real console driver so L1-A works.
	 */
	sun4c_timers->timer_limit10 = (((1000000/HZ) + 1) << 10);
	master_l10_counter = &sun4c_timers->cur_count10;
	master_l10_limit = &sun4c_timers->timer_limit10;

	irq = request_irq(TIMER_IRQ,
			  counter_fn,
			  (IRQF_DISABLED | SA_STATIC_ALLOC),
			  "timer", NULL);
	if (irq) {
		prom_printf("time_init: unable to attach IRQ%d\n",TIMER_IRQ);
		prom_halt();
	}
    
	sun4c_disable_irq(PROFILE_IRQ);
}

#ifdef CONFIG_SMP
static void sun4c_nop(void) {}
#endif

void __init sun4c_init_IRQ(void)
{
	struct linux_prom_registers int_regs[2];
	int ie_node;
	struct resource phyres;

	ie_node = prom_searchsiblings (prom_getchild(prom_root_node),
				       "interrupt-enable");
	if(ie_node == 0)
		panic("Cannot find /interrupt-enable node");

	/* Depending on the "address" property is bad news... */
	interrupt_enable = NULL;
	if (prom_getproperty(ie_node, "reg", (char *) int_regs,
			     sizeof(int_regs)) != -1) {
		memset(&phyres, 0, sizeof(struct resource));
		phyres.flags = int_regs[0].which_io;
		phyres.start = int_regs[0].phys_addr;
		interrupt_enable = (char *) of_ioremap(&phyres, 0,
		    int_regs[0].reg_size, "sun4c_intr");
	}
	if (!interrupt_enable)
		panic("Cannot map interrupt_enable");

	BTFIXUPSET_CALL(enable_irq, sun4c_enable_irq, BTFIXUPCALL_NORM);
	BTFIXUPSET_CALL(disable_irq, sun4c_disable_irq, BTFIXUPCALL_NORM);
	BTFIXUPSET_CALL(enable_pil_irq, sun4c_enable_irq, BTFIXUPCALL_NORM);
	BTFIXUPSET_CALL(disable_pil_irq, sun4c_disable_irq, BTFIXUPCALL_NORM);
	BTFIXUPSET_CALL(clear_clock_irq, sun4c_clear_clock_irq, BTFIXUPCALL_NORM);
	BTFIXUPSET_CALL(load_profile_irq, sun4c_load_profile_irq, BTFIXUPCALL_NOP);
	sparc_init_timers = sun4c_init_timers;
#ifdef CONFIG_SMP
	BTFIXUPSET_CALL(set_cpu_int, sun4c_nop, BTFIXUPCALL_NOP);
	BTFIXUPSET_CALL(clear_cpu_int, sun4c_nop, BTFIXUPCALL_NOP);
	BTFIXUPSET_CALL(set_irq_udt, sun4c_nop, BTFIXUPCALL_NOP);
#endif
	*interrupt_enable = (SUN4C_INT_ENABLE);
	/* Cannot enable interrupts until OBP ticker is disabled. */
}