Initial import

1 files changed, 326 insertions, 0 deletions

diff --git a/arch/m68k/q40/q40ints.c b/arch/m68k/q40/q40ints.c
new file mode 100644
index 000000000..513f9bb17
--- /dev/null
+++ b/arch/m68k/q40/q40ints.c
@@ -0,0 +1,326 @@
+/*
+ * arch/m68k/q40/q40ints.c
+ *
+ * Copyright (C) 1999,2001 Richard Zidlicky
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of this archive
+ * for more details.
+ *
+ * .. used to be loosely based on bvme6000ints.c
+ *
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+
+#include <asm/ptrace.h>
+#include <asm/traps.h>
+
+#include <asm/q40_master.h>
+#include <asm/q40ints.h>
+
+/*
+ * Q40 IRQs are defined as follows:
+ *            3,4,5,6,7,10,11,14,15 : ISA dev IRQs
+ *            16-31: reserved
+ *            32   : keyboard int
+ *            33   : frame int (50/200 Hz periodic timer)
+ *            34   : sample int (10/20 KHz periodic timer)
+ *
+*/
+
+static void q40_irq_handler(unsigned int, struct pt_regs *fp);
+static void q40_irq_enable(struct irq_data *data);
+static void q40_irq_disable(struct irq_data *data);
+
+unsigned short q40_ablecount[35];
+unsigned short q40_state[35];
+
+static unsigned int q40_irq_startup(struct irq_data *data)
+{
+	unsigned int irq = data->irq;
+
+	/* test for ISA ints not implemented by HW */
+	switch (irq) {
+	case 1: case 2: case 8: case 9:
+	case 11: case 12: case 13:
+		printk("%s: ISA IRQ %d not implemented by HW\n", __func__, irq);
+		/* FIXME return -ENXIO; */
+	}
+	return 0;
+}
+
+static void q40_irq_shutdown(struct irq_data *data)
+{
+}
+
+static struct irq_chip q40_irq_chip = {
+	.name		= "q40",
+	.irq_startup	= q40_irq_startup,
+	.irq_shutdown	= q40_irq_shutdown,
+	.irq_enable	= q40_irq_enable,
+	.irq_disable	= q40_irq_disable,
+};
+
+/*
+ * void q40_init_IRQ (void)
+ *
+ * Parameters:	None
+ *
+ * Returns:	Nothing
+ *
+ * This function is called during kernel startup to initialize
+ * the q40 IRQ handling routines.
+ */
+
+static int disabled;
+
+void __init q40_init_IRQ(void)
+{
+	m68k_setup_irq_controller(&q40_irq_chip, handle_simple_irq, 1,
+				  Q40_IRQ_MAX);
+
+	/* setup handler for ISA ints */
+	m68k_setup_auto_interrupt(q40_irq_handler);
+
+	m68k_irq_startup_irq(IRQ_AUTO_2);
+	m68k_irq_startup_irq(IRQ_AUTO_4);
+
+	/* now enable some ints.. */
+	master_outb(1, EXT_ENABLE_REG);  /* ISA IRQ 5-15 */
+
+	/* make sure keyboard IRQ is disabled */
+	master_outb(0, KEY_IRQ_ENABLE_REG);
+}
+
+
+/*
+ * this stuff doesn't really belong here..
+ */
+
+int ql_ticks;              /* 200Hz ticks since last jiffie */
+static int sound_ticks;
+
+#define SVOL 45
+
+void q40_mksound(unsigned int hz, unsigned int ticks)
+{
+	/* for now ignore hz, except that hz==0 switches off sound */
+	/* simply alternate the ampl (128-SVOL)-(128+SVOL)-..-.. at 200Hz */
+	if (hz == 0) {
+		if (sound_ticks)
+			sound_ticks = 1;
+
+		*DAC_LEFT = 128;
+		*DAC_RIGHT = 128;
+
+		return;
+	}
+	/* sound itself is done in q40_timer_int */
+	if (sound_ticks == 0)
+		sound_ticks = 1000; /* pretty long beep */
+	sound_ticks = ticks << 1;
+}
+
+static irq_handler_t q40_timer_routine;
+
+static irqreturn_t q40_timer_int (int irq, void * dev)
+{
+	ql_ticks = ql_ticks ? 0 : 1;
+	if (sound_ticks) {
+		unsigned char sval=(sound_ticks & 1) ? 128-SVOL : 128+SVOL;
+		sound_ticks--;
+		*DAC_LEFT=sval;
+		*DAC_RIGHT=sval;
+	}
+
+	if (!ql_ticks)
+		q40_timer_routine(irq, dev);
+	return IRQ_HANDLED;
+}
+
+void q40_sched_init (irq_handler_t timer_routine)
+{
+	int timer_irq;
+
+	q40_timer_routine = timer_routine;
+	timer_irq = Q40_IRQ_FRAME;
+
+	if (request_irq(timer_irq, q40_timer_int, 0,
+				"timer", q40_timer_int))
+		panic("Couldn't register timer int");
+
+	master_outb(-1, FRAME_CLEAR_REG);
+	master_outb( 1, FRAME_RATE_REG);
+}
+
+
+/*
+ * tables to translate bits into IRQ numbers
+ * it is a good idea to order the entries by priority
+ *
+*/
+
+struct IRQ_TABLE{ unsigned mask; int irq ;};
+#if 0
+static struct IRQ_TABLE iirqs[]={
+  {Q40_IRQ_FRAME_MASK,Q40_IRQ_FRAME},
+  {Q40_IRQ_KEYB_MASK,Q40_IRQ_KEYBOARD},
+  {0,0}};
+#endif
+static struct IRQ_TABLE eirqs[] = {
+  { .mask = Q40_IRQ3_MASK,	.irq = 3 },	/* ser 1 */
+  { .mask = Q40_IRQ4_MASK,	.irq = 4 },	/* ser 2 */
+  { .mask = Q40_IRQ14_MASK,	.irq = 14 },	/* IDE 1 */
+  { .mask = Q40_IRQ15_MASK,	.irq = 15 },	/* IDE 2 */
+  { .mask = Q40_IRQ6_MASK,	.irq = 6 },	/* floppy, handled elsewhere */
+  { .mask = Q40_IRQ7_MASK,	.irq = 7 },	/* par */
+  { .mask = Q40_IRQ5_MASK,	.irq = 5 },
+  { .mask = Q40_IRQ10_MASK,	.irq = 10 },
+  {0,0}
+};
+
+/* complain only this many times about spurious ints : */
+static int ccleirq=60;    /* ISA dev IRQs*/
+/*static int cclirq=60;*/     /* internal */
+
+/* FIXME: add shared ints,mask,unmask,probing.... */
+
+#define IRQ_INPROGRESS 1
+/*static unsigned short saved_mask;*/
+//static int do_tint=0;
+
+#define DEBUG_Q40INT
+/*#define IP_USE_DISABLE *//* would be nice, but crashes ???? */
+
+static int mext_disabled=0;  /* ext irq disabled by master chip? */
+static int aliased_irq=0;  /* how many times inside handler ?*/
+
+
+/* got interrupt, dispatch to ISA or keyboard/timer IRQs */
+static void q40_irq_handler(unsigned int irq, struct pt_regs *fp)
+{
+	unsigned mir, mer;
+	int i;
+
+//repeat:
+	mir = master_inb(IIRQ_REG);
+#ifdef CONFIG_BLK_DEV_FD
+	if ((mir & Q40_IRQ_EXT_MASK) &&
+	    (master_inb(EIRQ_REG) & Q40_IRQ6_MASK)) {
+		floppy_hardint();
+		return;
+	}
+#endif
+	switch (irq) {
+	case 4:
+	case 6:
+		do_IRQ(Q40_IRQ_SAMPLE, fp);
+		return;
+	}
+	if (mir & Q40_IRQ_FRAME_MASK) {
+		do_IRQ(Q40_IRQ_FRAME, fp);
+		master_outb(-1, FRAME_CLEAR_REG);
+	}
+	if ((mir & Q40_IRQ_SER_MASK) || (mir & Q40_IRQ_EXT_MASK)) {
+		mer = master_inb(EIRQ_REG);
+		for (i = 0; eirqs[i].mask; i++) {
+			if (mer & eirqs[i].mask) {
+				irq = eirqs[i].irq;
+/*
+ * There is a little mess wrt which IRQ really caused this irq request. The
+ * main problem is that IIRQ_REG and EIRQ_REG reflect the state when they
+ * are read - which is long after the request came in. In theory IRQs should
+ * not just go away but they occasionally do
+ */
+				if (irq > 4 && irq <= 15 && mext_disabled) {
+					/*aliased_irq++;*/
+					goto iirq;
+				}
+				if (q40_state[irq] & IRQ_INPROGRESS) {
+					/* some handlers do local_irq_enable() for irq latency reasons, */
+					/* however reentering an active irq handler is not permitted */
+#ifdef IP_USE_DISABLE
+					/* in theory this is the better way to do it because it still */
+					/* lets through eg the serial irqs, unfortunately it crashes */
+					disable_irq(irq);
+					disabled = 1;
+#else
+					/*printk("IRQ_INPROGRESS detected for irq %d, disabling - %s disabled\n",
+						irq, disabled ? "already" : "not yet"); */
+					fp->sr = (((fp->sr) & (~0x700))+0x200);
+					disabled = 1;
+#endif
+					goto iirq;
+				}
+				q40_state[irq] |= IRQ_INPROGRESS;
+				do_IRQ(irq, fp);
+				q40_state[irq] &= ~IRQ_INPROGRESS;
+
+				/* naively enable everything, if that fails than    */
+				/* this function will be reentered immediately thus */
+				/* getting another chance to disable the IRQ        */
+
+				if (disabled) {
+#ifdef IP_USE_DISABLE
+					if (irq > 4) {
+						disabled = 0;
+						enable_irq(irq);
+					}
+#else
+					disabled = 0;
+					/*printk("reenabling irq %d\n", irq); */
+#endif
+				}
+// used to do 'goto repeat;' here, this delayed bh processing too long
+				return;
+			}
+		}
+		if (mer && ccleirq > 0 && !aliased_irq) {
+			printk("ISA interrupt from unknown source? EIRQ_REG = %x\n",mer);
+			ccleirq--;
+		}
+	}
+ iirq:
+	mir = master_inb(IIRQ_REG);
+	/* should test whether keyboard irq is really enabled, doing it in defhand */
+	if (mir & Q40_IRQ_KEYB_MASK)
+		do_IRQ(Q40_IRQ_KEYBOARD, fp);
+
+	return;
+}
+
+void q40_irq_enable(struct irq_data *data)
+{
+	unsigned int irq = data->irq;
+
+	if (irq >= 5 && irq <= 15) {
+		mext_disabled--;
+		if (mext_disabled > 0)
+			printk("q40_irq_enable : nested disable/enable\n");
+		if (mext_disabled == 0)
+			master_outb(1, EXT_ENABLE_REG);
+	}
+}
+
+
+void q40_irq_disable(struct irq_data *data)
+{
+	unsigned int irq = data->irq;
+
+	/* disable ISA iqs : only do something if the driver has been
+	 * verified to be Q40 "compatible" - right now IDE, NE2K
+	 * Any driver should not attempt to sleep across disable_irq !!
+	 */
+
+	if (irq >= 5 && irq <= 15) {
+		master_outb(0, EXT_ENABLE_REG);
+		mext_disabled++;
+		if (mext_disabled > 1)
+			printk("disable_irq nesting count %d\n",mext_disabled);
+	}
+}