patch-2.4.20 linux-2.4.20/arch/parisc/kernel/power.c

• Lines: 378
• Date: Thu Nov 28 15:53:10 2002
• Orig file: linux-2.4.19/arch/parisc/kernel/power.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.19/arch/parisc/kernel/power.c linux-2.4.20/arch/parisc/kernel/power.c
@@ -0,0 +1,377 @@
+/*
+ * linux/arch/parisc/kernel/power.c
+ * HP PARISC soft power switch support driver
+ *
+ * Copyright (c) 2001-2002 Helge Deller <deller@gmx.de>
+ * All rights reserved.
+ *
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions, and the following disclaimer,
+ *    without modification.
+ * 2. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL").
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ *
+ *
+ * 
+ *  HINT:
+ *  Support of the soft power switch button may be enabled or disabled at
+ *  runtime through the "/proc/sys/kernel/power" procfs entry.
+ */ 
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/proc_fs.h>
+#include <linux/ctype.h>
+
+#include <asm/gsc.h>
+#include <asm/pdc.h>
+#include <asm/irq.h>
+#include <asm/io.h>
+#include <asm/led.h>
+#include <asm/led.h>
+#include <asm/uaccess.h>
+
+
+#ifdef DEBUG
+# define DPRINTK(x) printk x
+#else
+# define DPRINTK(x) do { } while (0)
+#endif
+
+
+/* filename in /proc which can be used to enable/disable the power switch */
+#define SYSCTL_FILENAME		"sys/kernel/power"
+
+
+#define DIAG_CODE(code)		(0x14000000 + ((code)<<5))
+
+/* this will go to processor.h or any other place... */
+/* taken from PCXL ERS page 82 */
+#define MFCPU_X(rDiagReg, t_ch, t_th, code) \
+	(DIAG_CODE(code) + ((rDiagReg)<<21) + ((t_ch)<<16) + ((t_th)<<0) )
+	
+#define MTCPU(dr, gr)		MFCPU_X(dr, gr,  0, 0x12)       /* move value of gr to dr[dr] */
+#define MFCPU_C(dr, gr)		MFCPU_X(dr, gr,  0, 0x30)	/* for dr0 and dr8 only ! */
+#define MFCPU_T(dr, gr)		MFCPU_X(dr,  0, gr, 0xa0)	/* all dr except dr0 and dr8 */
+	
+#define __getDIAG(dr) ( { 			\
+        register unsigned long __res asm("r28");\
+	 __asm__ __volatile__ (			\
+		".word %1\n nop\n" : "=&r" (__res) : "i" (MFCPU_T(dr,28)) \
+	);					\
+	__res;					\
+} )
+
+
+static void deferred_poweroff(void *dummy)
+{
+	extern int cad_pid;	/* from kernel/sys.c */
+	if (kill_proc(cad_pid, SIGINT, 1)) {
+		/* just in case killing init process failed */
+		machine_power_off();
+	}
+}
+
+/*
+ * This function gets called from interrupt context.
+ * As it's called within an interrupt, it wouldn't sync if we don't
+ * use schedule_task().
+ */
+
+static void poweroff(void)
+{
+	static int powering_off;
+	static struct tq_struct poweroff_tq = {
+		routine: deferred_poweroff,
+	};
+
+	if (powering_off)
+		return;
+
+	powering_off++;
+	schedule_task(&poweroff_tq);
+}
+
+
+/* local time-counter for shutdown */
+static int shutdown_timer;
+
+/* check, give feedback and start shutdown after one second */
+static void process_shutdown(void)
+{
+	if (shutdown_timer == 0)
+		DPRINTK((KERN_INFO "Shutdown requested...\n"));
+
+	shutdown_timer++;
+	
+	/* wait until the button was pressed for 1 second */
+	if (shutdown_timer == HZ) {
+		static char msg[] = "Shutting down...";
+		DPRINTK((KERN_INFO "%s\n", msg));
+#ifdef CONFIG_CHASSIS_LCD_LED
+		lcd_print(msg);
+#endif
+		poweroff();
+	}
+}
+
+
+/* main power switch tasklet struct (scheduled from time.c) */
+DECLARE_TASKLET_DISABLED(power_tasklet, NULL, 0);
+
+/* soft power switch enabled/disabled */
+#ifdef CONFIG_PROC_FS
+static int pwrsw_enabled = 1;
+#else
+#define pwrsw_enabled (1)
+#endif
+
+/*
+ * On gecko style machines (e.g. 712/xx and 715/xx) 
+ * the power switch status is stored in Bit 0 ("the highest bit")
+ * of CPU diagnose register 25.
+ * 
+ */
+static void gecko_tasklet_func(unsigned long unused)
+{
+	if (!pwrsw_enabled)
+		return;
+
+	if (__getDIAG(25) & 0x80000000) {
+		/* power switch button not pressed or released again */
+		/* Warning: Some machines do never reset this DIAG flag! */
+		shutdown_timer = 0;
+	} else {
+		process_shutdown();
+	}
+}
+
+
+
+/*
+ * Check the power switch status which is read from the
+ * real I/O location at soft_power_reg.
+ * Bit 31 ("the lowest bit) is the status of the power switch.
+ */
+
+static void polling_tasklet_func(unsigned long soft_power_reg)
+{
+        unsigned long current_status;
+	
+	if (!pwrsw_enabled)
+		return;
+
+	current_status = gsc_readl(soft_power_reg);
+	if (current_status & 0x1) {
+		/* power switch button not pressed */
+		shutdown_timer = 0;
+	} else {
+		process_shutdown();
+	}
+}
+
+
+/*
+ * powerfail interruption handler (irq IRQ_FROM_REGION(CPU_IRQ_REGION)+2) 
+ */
+#if 0
+static void powerfail_interrupt(int code, void *x, struct pt_regs *regs)
+{
+	printk(KERN_CRIT "POWERFAIL INTERRUPTION !\n");
+	poweroff();
+}
+#endif
+
+
+
+
+/* 
+ * /proc filesystem support 
+ */
+
+#ifdef CONFIG_SYSCTL
+static int power_proc_read(char *page, char **start, off_t off, int count, 
+	int *eof, void *data)
+{
+	char *out = page;
+	int len;
+
+	out += sprintf(out, "Software power switch support: ");
+	out += sprintf(out, pwrsw_enabled ? "enabled (1)" : "disabled (0)" );
+	out += sprintf(out, "\n");
+
+	len = out - page - off;
+	if (len < count) {
+		*eof = 1;
+		if (len <= 0) return 0;
+	} else {
+		len = count;
+	}
+	*start = page + off;
+	return len;
+}
+
+static int power_proc_write(struct file *file, const char *buf, 
+	unsigned long count, void *data)
+{
+	char *cur, lbuf[count];
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
+
+	memset(lbuf, 0, count);
+
+	copy_from_user(lbuf, buf, count);
+	cur = lbuf;
+
+	/* skip initial spaces */
+	while (*cur && isspace(*cur))
+		cur++;
+
+	switch (*cur) {
+	case '0':	pwrsw_enabled = 0;
+			break;
+	case '1':	pwrsw_enabled = 1;
+			break;
+	default:	printk(KERN_CRIT "/proc/" SYSCTL_FILENAME 
+					": Parse error: only '0' or '1' allowed!\n");
+			return -EINVAL;
+	} /* switch() */
+
+	return count;
+}
+
+static struct proc_dir_entry *ent;
+
+static void __init power_create_procfs(void)
+{
+	if (!power_tasklet.func)
+		return;
+	
+	ent = create_proc_entry(SYSCTL_FILENAME, S_IFREG|S_IRUGO|S_IWUSR, 0);
+	if (!ent) return;
+	
+	ent->nlink = 1;
+	ent->read_proc = power_proc_read;
+	ent->write_proc = power_proc_write;
+	ent->owner = THIS_MODULE;
+}
+
+static void __exit power_remove_procfs(void)
+{
+	remove_proc_entry(SYSCTL_FILENAME, NULL);
+}
+
+#else
+#define power_create_procfs()	do { } while (0)
+#define power_remove_procfs()	do { } while (0)
+#endif	/* CONFIG_SYSCTL */
+
+
+
+/* parisc_panic_event() is called by the panic handler.
+ * As soon as a panic occurs, our tasklets above will not be
+ * executed any longer. This function then re-enables the 
+ * soft-power switch and allows the user to switch off the system
+ */
+static int parisc_panic_event(struct notifier_block *this,
+		unsigned long event, void *ptr)
+{
+	/* re-enable the soft-power switch */
+	pdc_soft_power_button(0);
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block parisc_panic_block = {
+	notifier_call: parisc_panic_event,
+	priority: INT_MAX,
+};
+
+
+static int __init power_init(void)
+{
+	unsigned long ret;
+	unsigned long soft_power_reg = 0;
+
+#if 0
+	request_irq( IRQ_FROM_REGION(CPU_IRQ_REGION)+2, &powerfail_interrupt,
+		0, "powerfail", NULL);
+#endif
+
+	/* enable the soft power switch if possible */
+	ret = pdc_soft_power_info(&soft_power_reg);
+	if (ret == PDC_OK)
+		ret = pdc_soft_power_button(1);
+	if (ret != PDC_OK)
+		soft_power_reg = -1UL;
+	
+	switch (soft_power_reg) {
+	case 0:		printk(KERN_INFO "Gecko-style soft power switch enabled.\n");
+			power_tasklet.func = gecko_tasklet_func;
+			break;
+			
+	case -1UL:	printk(KERN_INFO "Soft power switch support not available.\n");
+			return -ENODEV;
+	
+	default:	printk(KERN_INFO "Soft power switch enabled, polling @ 0x%08lx.\n",
+				soft_power_reg);
+			power_tasklet.data = soft_power_reg;
+			power_tasklet.func = polling_tasklet_func;
+	}
+
+	/* Register a call for panic conditions. */
+	notifier_chain_register(&panic_notifier_list, &parisc_panic_block);
+
+	power_create_procfs();
+	tasklet_enable(&power_tasklet);
+
+	return 0;
+}
+
+static void __exit power_exit(void)
+{
+	if (!power_tasklet.func)
+		return;
+
+	tasklet_disable(&power_tasklet);
+	notifier_chain_unregister(&panic_notifier_list, &parisc_panic_block);
+	power_remove_procfs();
+	power_tasklet.func = NULL;
+	pdc_soft_power_button(0);
+}
+
+module_init(power_init);
+module_exit(power_exit);
+
+
+MODULE_AUTHOR("Helge Deller");
+MODULE_DESCRIPTION("Soft power switch driver");
+MODULE_LICENSE("Dual BSD/GPL");
+
+
+EXPORT_NO_SYMBOLS;
+