patch-2.4.25 linux-2.4.25/arch/ppc/kernel/m8xx_wdt.c

• Lines: 111
• Date: 2004-02-18 05:36:30.000000000 -0800
• Orig file: linux-2.4.24/arch/ppc/kernel/m8xx_wdt.c
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.24/arch/ppc/kernel/m8xx_wdt.c linux-2.4.25/arch/ppc/kernel/m8xx_wdt.c
@@ -0,0 +1,110 @@
+/*
+ * m8xx_wdt.c - MPC8xx watchdog driver
+ *
+ * Copyright (C) 2002 Florian Schirmer <jolt@tuxbox.org>
+ *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <asm/8xx_immap.h>
+
+static int wdt_timeout;
+
+void
+m8xx_wdt_reset(void)
+{
+	volatile immap_t *imap = (volatile immap_t *) IMAP_ADDR;
+
+	imap->im_siu_conf.sc_swsr = 0x556c;	/* write magic1 */
+	imap->im_siu_conf.sc_swsr = 0xaa39;	/* write magic2 */
+}
+
+static void
+m8xx_wdt_interrupt(int irq, void *dev, struct pt_regs *regs)
+{
+	volatile immap_t *imap = (volatile immap_t *) IMAP_ADDR;
+
+	m8xx_wdt_reset();
+
+	imap->im_sit.sit_piscr |= PISCR_PS;	/* clear irq */
+}
+
+void __init
+m8xx_wdt_handler_install(bd_t * binfo)
+{
+	volatile immap_t *imap = (volatile immap_t *) IMAP_ADDR;
+	u32 pitc;
+	u32 sypcr;
+	u32 pitrtclk;
+
+	sypcr = imap->im_siu_conf.sc_sypcr;
+
+	if (!(sypcr & 0x04)) {
+		printk(KERN_NOTICE "m8xx_wdt: wdt disabled (SYPCR: 0x%08X)\n",
+		       sypcr);
+		return;
+	}
+
+	m8xx_wdt_reset();
+
+	printk(KERN_NOTICE
+	       "m8xx_wdt: active wdt found (SWTC: 0x%04X, SWP: 0x%01X)\n",
+	       (sypcr >> 16), sypcr & 0x01);
+
+	wdt_timeout = (sypcr >> 16) & 0xFFFF;
+
+	if (!wdt_timeout)
+		wdt_timeout = 0xFFFF;
+
+	if (sypcr & 0x01)
+		wdt_timeout *= 2048;
+
+	/*
+	 * Fire trigger if half of the wdt ticked down 
+	 */
+
+	if (imap->im_sit.sit_rtcsc & RTCSC_38K)
+		pitrtclk = 9600;
+	else
+		pitrtclk = 8192;
+
+	if ((wdt_timeout) > (UINT_MAX / pitrtclk))
+		pitc = wdt_timeout / binfo->bi_intfreq * pitrtclk / 2;
+	else
+		pitc = pitrtclk * wdt_timeout / binfo->bi_intfreq / 2;
+
+	imap->im_sit.sit_pitc = pitc << 16;
+	imap->im_sit.sit_piscr =
+	    (mk_int_int_mask(PIT_INTERRUPT) << 8) | PISCR_PIE | PISCR_PTE;
+
+	if (request_irq(PIT_INTERRUPT, m8xx_wdt_interrupt, 0, "watchdog", NULL))
+		panic("m8xx_wdt: could not allocate watchdog irq!");
+
+	printk(KERN_NOTICE
+	       "m8xx_wdt: keep-alive trigger installed (PITC: 0x%04X)\n", pitc);
+
+	wdt_timeout /= binfo->bi_intfreq;
+}
+
+int
+m8xx_wdt_get_timeout(void)
+{
+	return wdt_timeout;
+}