Initial revision

cpu/mpc8xx/interrupts.c

+/*
+ * (C) Copyright 2000-2002
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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
+ */
+
+#include <common.h>
+#include <watchdog.h>
+#include <mpc8xx.h>
+#include <mpc8xx_irq.h>
+#include <asm/processor.h>
+#include <commproc.h>
+
+/****************************************************************************/
+
+unsigned decrementer_count;		/* count value for 1e6/HZ microseconds */
+
+/****************************************************************************/
+
+/*
+ * CPM interrupt vector functions.
+ */
+struct	cpm_action {
+	 interrupt_handler_t *handler;
+	 void *arg;
+};
+
+static struct cpm_action cpm_vecs[CPMVEC_NR];
+
+static void cpm_interrupt_init (void);
+static void cpm_interrupt(int irq, struct pt_regs * regs);
+
+/****************************************************************************/
+
+static __inline__ unsigned long get_msr(void)
+{
+    unsigned long msr;
+
+    asm volatile("mfmsr %0" : "=r" (msr) :);
+    return msr;
+}
+
+static __inline__ void set_msr(unsigned long msr)
+{
+    asm volatile("mtmsr %0" : : "r" (msr));
+}
+
+static __inline__ unsigned long get_dec(void)
+{
+    unsigned long val;
+
+    asm volatile("mfdec %0" : "=r" (val) :);
+    return val;
+}
+
+
+static __inline__ void set_dec(unsigned long val)
+{
+    asm volatile("mtdec %0" : : "r" (val));
+}
+
+
+void enable_interrupts (void)
+{
+	set_msr (get_msr() | MSR_EE);
+}
+
+/* returns flag if MSR_EE was set before */
+int disable_interrupts (void)
+{
+	ulong msr = get_msr();
+	set_msr (msr & ~MSR_EE);
+	return ((msr & MSR_EE) != 0);
+}
+
+/****************************************************************************/
+
+int interrupt_init(void)
+{
+	volatile immap_t *immr = (immap_t *)CFG_IMMR;
+
+	decrementer_count = get_tbclk() / CFG_HZ;
+
+	cpm_interrupt_init();
+
+	/* disable all interrupts except for the CPM interrupt */
+	immr->im_siu_conf.sc_simask = 1 << (31-CPM_INTERRUPT);
+
+	set_dec (decrementer_count);
+
+	set_msr (get_msr() | MSR_EE);
+
+	return (0);
+}
+
+/****************************************************************************/
+
+/*
+ * Handle external interrupts
+ */
+void external_interrupt(struct pt_regs *regs)
+{
+	volatile immap_t *immr = (immap_t *)CFG_IMMR;
+	int	irq;
+	ulong	simask, newmask;
+	ulong	vec, v_bit;
+
+	/*
+	 * read the SIVEC register and shift the bits down
+	 * to get the irq number
+	 */
+	vec = immr->im_siu_conf.sc_sivec;
+	irq = vec >> 26;
+	v_bit = 0x80000000UL >> irq;
+
+	/*
+	 * Read Interrupt Mask Register and Mask Interrupts
+	 */
+	simask = immr->im_siu_conf.sc_simask;
+	newmask = simask & (~(0xFFFF0000 >> irq));
+	immr->im_siu_conf.sc_simask = newmask;
+
+	if (!(irq & 0x1)) {			/* External Interrupt ?		*/
+		ulong siel;
+		/*
+		 * Read Interrupt Edge/Level Register
+		 */
+		siel = immr->im_siu_conf.sc_siel;
+
+		if (siel & v_bit) {		/* edge triggered interrupt ?	*/
+			/*
+			 * Rewrite SIPEND Register to clear interrupt
+			 */
+			immr->im_siu_conf.sc_sipend = v_bit;
+		}
+	}
+
+	switch (irq) {
+	case CPM_INTERRUPT:
+		cpm_interrupt (irq, regs);
+		break;
+	default:
+		printf ("\nBogus External Interrupt IRQ %d Vector %ld\n",
+			irq, vec);
+		/* turn off the bogus interrupt to avoid it from now */
+		simask &= ~v_bit;
+		break;
+	}
+
+	/*
+	 * Re-Enable old Interrupt Mask
+	 */
+	immr->im_siu_conf.sc_simask = simask;
+}
+
+/****************************************************************************/
+
+/*
+ * CPM interrupt handler
+ */
+static void
+cpm_interrupt(int irq, struct pt_regs * regs)
+{
+	volatile immap_t *immr = (immap_t *)CFG_IMMR;
+	uint	vec;
+
+	/*
+	 * Get the vector by setting the ACK bit
+	 * and then reading the register.
+	 */
+	immr->im_cpic.cpic_civr = 1;
+	vec = immr->im_cpic.cpic_civr;
+	vec >>= 11;
+
+	if (cpm_vecs[vec].handler != NULL) {
+		(*cpm_vecs[vec].handler)(cpm_vecs[vec].arg);
+	} else {
+		immr->im_cpic.cpic_cimr &= ~(1 << vec);
+		printf ("Masking bogus CPM interrupt vector 0x%x\n", vec);
+	}
+	/*
+	 * After servicing the interrupt, we have to remove the status indicator.
+	 */
+	immr->im_cpic.cpic_cisr |= (1 << vec);
+}
+
+/*
+ * The CPM can generate the error interrupt when there is a race
+ * condition between generating and masking interrupts. All we have
+ * to do is ACK it and return. This is a no-op function so we don't
+ * need any special tests in the interrupt handler.
+ */
+static void
+cpm_error_interrupt (void *dummy)
+{
+}
+
+/****************************************************************************/
+
+/*
+ * Install and free a CPM interrupt handler.
+ */
+
+void
+irq_install_handler(int vec, interrupt_handler_t *handler, void *arg)
+{
+	volatile immap_t *immr = (immap_t *)CFG_IMMR;
+
+	if (cpm_vecs[vec].handler != NULL) {
+		printf ("CPM interrupt 0x%x replacing 0x%x\n",
+			(uint)handler, (uint)cpm_vecs[vec].handler);
+	}
+	cpm_vecs[vec].handler = handler;
+	cpm_vecs[vec].arg     = arg;
+	immr->im_cpic.cpic_cimr |= (1 << vec);
+#if 0
+	printf ("Install CPM interrupt for vector %d ==> %p\n", vec, handler);
+#endif
+}
+
+void
+irq_free_handler(int vec)
+{
+	volatile immap_t *immr = (immap_t *)CFG_IMMR;
+#if 0
+	printf ("Free CPM interrupt for vector %d ==> %p\n",
+		vec, cpm_vecs[vec].handler);
+#endif
+	immr->im_cpic.cpic_cimr &= ~(1 << vec);
+	cpm_vecs[vec].handler = NULL;
+	cpm_vecs[vec].arg     = NULL;
+}
+
+/****************************************************************************/
+
+static void
+cpm_interrupt_init (void)
+{
+	volatile immap_t *immr = (immap_t *)CFG_IMMR;
+
+	/*
+	 * Initialize the CPM interrupt controller.
+	 */
+
+	immr->im_cpic.cpic_cicr =
+		( CICR_SCD_SCC4 |
+		  CICR_SCC_SCC3 |
+		  CICR_SCB_SCC2 |
+		  CICR_SCA_SCC1 ) | ((CPM_INTERRUPT/2) << 13) | CICR_HP_MASK;
+
+	immr->im_cpic.cpic_cimr = 0;
+
+	/*
+	 * Install the error handler.
+	 */
+	irq_install_handler(CPMVEC_ERROR, cpm_error_interrupt, NULL);
+
+	immr->im_cpic.cpic_cicr |= CICR_IEN;
+}
+
+/****************************************************************************/
+
+volatile ulong timestamp = 0;
+
+/*
+ * timer_interrupt - gets called when the decrementer overflows,
+ * with interrupts disabled.
+ * Trivial implementation - no need to be really accurate.
+ */
+void timer_interrupt(struct pt_regs *regs)
+{
+	volatile immap_t *immr = (immap_t *)CFG_IMMR;
+#ifdef CONFIG_STATUS_LED
+    	extern void status_led_tick (ulong);
+#endif
+#if 0
+	printf ("*** Timer Interrupt *** ");
+#endif
+	/* Reset Timer Expired and Timers Interrupt Status */
+	immr->im_clkrstk.cark_plprcrk = KAPWR_KEY;
+	__asm__("nop");
+	immr->im_clkrst.car_plprcr |= PLPRCR_TEXPS | PLPRCR_TMIST;
+	/* Restore Decrementer Count */
+	set_dec (decrementer_count);
+
+	timestamp++;
+
+#ifdef CONFIG_STATUS_LED
+	status_led_tick (timestamp);
+#endif	/* CONFIG_STATUS_LED */
+
+#if defined(CONFIG_WATCHDOG) || defined(CFG_CMA_LCD_HEARTBEAT)
+
+
+	/*
+	 * The shortest watchdog period of all boards (except LWMON)
+	 * is approx. 1 sec, thus re-trigger watchdog at least
+	 * every 500 ms = CFG_HZ / 2
+	 */
+#ifndef CONFIG_LWMON
+	if ((timestamp % (CFG_HZ / 2)) == 0) {
+#else
+	if ((timestamp % (CFG_HZ / 20)) == 0) {
+#endif
+
+#if defined(CFG_CMA_LCD_HEARTBEAT)
+		extern void lcd_heartbeat(void);
+		lcd_heartbeat();
+#endif /* CFG_CMA_LCD_HEARTBEAT */
+
+#if defined(CONFIG_WATCHDOG)
+		reset_8xx_watchdog(immr);
+#endif /* CONFIG_WATCHDOG */
+
+	}
+
+#endif /* CONFIG_WATCHDOG || CFG_CMA_LCD_HEARTBEAT */
+}
+
+/****************************************************************************/
+
+void reset_timer (void)
+{
+	timestamp = 0;
+}
+
+ulong get_timer (ulong base)
+{
+	return (timestamp - base);
+}
+
+void set_timer (ulong t)
+{
+	timestamp = t;
+}
+
+/****************************************************************************/