--- /dev/null
+/*
+ * 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");
Code Review / kvmfornfv.git / blobdiff