Initial import

1 files changed, 255 insertions, 0 deletions

diff --git a/drivers/parisc/power.c b/drivers/parisc/power.c
new file mode 100644
index 000000000..ef31b7740
--- /dev/null
+++ b/drivers/parisc/power.c
@@ -0,0 +1,255 @@
+/*
+ * linux/drivers/parisc/power.c
+ * HP PARISC soft power switch support driver
+ *
+ * Copyright (c) 2001-2007 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/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/sched.h>
+#include <linux/kthread.h>
+#include <linux/pm.h>
+
+#include <asm/pdc.h>
+#include <asm/io.h>
+#include <asm/led.h>
+
+#define DRIVER_NAME  "powersw"
+#define KTHREAD_NAME "kpowerswd"
+
+/* how often should the power button be polled ? */
+#define POWERSWITCH_POLL_PER_SEC 2
+
+/* how long does the power button needs to be down until we react ? */
+#define POWERSWITCH_DOWN_SEC 2
+
+/* assembly code to access special registers */
+/* taken from PCXL ERS page 82 */
+#define DIAG_CODE(code)		(0x14000000 + ((code)<<5))
+
+#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" : "=&r" (__res) : "i" (MFCPU_T(dr,28) ) \
+	);					\
+	__res;					\
+} )
+
+/* local shutdown counter */
+static int shutdown_timer __read_mostly;
+
+/* check, give feedback and start shutdown after one second */
+static void process_shutdown(void)
+{
+	if (shutdown_timer == 0)
+		printk(KERN_ALERT KTHREAD_NAME ": Shutdown requested...\n");
+
+	shutdown_timer++;
+	
+	/* wait until the button was pressed for 1 second */
+	if (shutdown_timer == (POWERSWITCH_DOWN_SEC*POWERSWITCH_POLL_PER_SEC)) {
+		static const char msg[] = "Shutting down...";
+		printk(KERN_INFO KTHREAD_NAME ": %s\n", msg);
+		lcd_print(msg);
+
+		/* send kill signal */
+		if (kill_cad_pid(SIGINT, 1)) {
+			/* just in case killing init process failed */
+			if (pm_power_off)
+				pm_power_off();
+		}
+	}
+}
+
+
+/* main power switch task struct */
+static struct task_struct *power_task;
+
+/* filename in /proc which can be used to enable/disable the power switch */
+#define SYSCTL_FILENAME	"sys/kernel/power"
+
+/* soft power switch enabled/disabled */
+int pwrsw_enabled __read_mostly = 1;
+
+/* main kernel thread worker. It polls the button state */
+static int kpowerswd(void *param)
+{
+	__set_current_state(TASK_RUNNING);
+
+	do {
+		int button_not_pressed;
+		unsigned long soft_power_reg = (unsigned long) param;
+
+		schedule_timeout_interruptible(pwrsw_enabled ? HZ : HZ/POWERSWITCH_POLL_PER_SEC);
+
+		if (unlikely(!pwrsw_enabled))
+			continue;
+
+		if (soft_power_reg) {
+			/*
+			 * Non-Gecko-style machines:
+			 * 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.
+			 * This bit is "1" if the button is NOT pressed.
+			 */
+			button_not_pressed = (gsc_readl(soft_power_reg) & 0x1);
+		} else {
+			/*
+			 * 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.
+			 * Warning: Some machines never reset the DIAG flag, even if
+			 * the button has been released again.
+			 */
+			button_not_pressed = (__getDIAG(25) & 0x80000000);
+		}
+
+		if (likely(button_not_pressed)) {
+			if (unlikely(shutdown_timer && /* avoid writing if not necessary */
+				shutdown_timer < (POWERSWITCH_DOWN_SEC*POWERSWITCH_POLL_PER_SEC))) {
+				shutdown_timer = 0;
+				printk(KERN_INFO KTHREAD_NAME ": Shutdown request aborted.\n");
+			}
+		} else
+			process_shutdown();
+
+
+	} while (!kthread_should_stop());
+
+	return 0;
+}
+
+
+/*
+ * powerfail interruption handler (irq IRQ_FROM_REGION(CPU_IRQ_REGION)+2) 
+ */
+#if 0
+static void powerfail_interrupt(int code, void *x)
+{
+	printk(KERN_CRIT "POWERFAIL INTERRUPTION !\n");
+	poweroff();
+}
+#endif
+
+
+
+
+/* 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;
+
+#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 DRIVER_NAME ": Gecko-style soft power switch enabled.\n");
+			break;
+			
+	case -1UL:	printk(KERN_INFO DRIVER_NAME ": Soft power switch support not available.\n");
+			return -ENODEV;
+	
+	default:	printk(KERN_INFO DRIVER_NAME ": Soft power switch at 0x%08lx enabled.\n",
+				soft_power_reg);
+	}
+
+	power_task = kthread_run(kpowerswd, (void*)soft_power_reg, KTHREAD_NAME);
+	if (IS_ERR(power_task)) {
+		printk(KERN_ERR DRIVER_NAME ": thread creation failed.  Driver not loaded.\n");
+		pdc_soft_power_button(0);
+		return -EIO;
+	}
+
+	/* Register a call for panic conditions. */
+	atomic_notifier_chain_register(&panic_notifier_list,
+			&parisc_panic_block);
+
+	return 0;
+}
+
+static void __exit power_exit(void)
+{
+	kthread_stop(power_task);
+
+	atomic_notifier_chain_unregister(&panic_notifier_list,
+			&parisc_panic_block);
+
+	pdc_soft_power_button(0);
+}
+
+arch_initcall(power_init);
+module_exit(power_exit);
+
+
+MODULE_AUTHOR("Helge Deller <deller@gmx.de>");
+MODULE_DESCRIPTION("Soft power switch driver");
+MODULE_LICENSE("Dual BSD/GPL");