diff options
Diffstat (limited to 'drivers/parisc/power.c')
| -rw-r--r-- | drivers/parisc/power.c | 273 |
1 files changed, 273 insertions, 0 deletions
diff --git a/drivers/parisc/power.c b/drivers/parisc/power.c new file mode 100644 index 0000000000..498bae2e34 --- /dev/null +++ b/drivers/parisc/power.c @@ -0,0 +1,273 @@ +/* + * 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/panic_notifier.h> +#include <linux/reboot.h> +#include <linux/sched/signal.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 */ + machine_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. We rely in pdc_soft_power_button_panic() + * since this version spin_trylocks (instead of regular + * spinlock), preventing deadlocks on panic path. + */ +static int parisc_panic_event(struct notifier_block *this, + unsigned long event, void *ptr) +{ + /* re-enable the soft-power switch */ + pdc_soft_power_button_panic(0); + return NOTIFY_DONE; +} + +static struct notifier_block parisc_panic_block = { + .notifier_call = parisc_panic_event, + .priority = INT_MAX, +}; + +/* qemu soft power-off function */ +static int qemu_power_off(struct sys_off_data *data) +{ + /* this turns the system off via SeaBIOS */ + gsc_writel(0, (unsigned long) data->cb_data); + pdc_soft_power_button(1); + return NOTIFY_DONE; +} + +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 = NULL; + if (running_on_qemu && soft_power_reg) + register_sys_off_handler(SYS_OFF_MODE_POWER_OFF, SYS_OFF_PRIO_DEFAULT, + qemu_power_off, (void *)soft_power_reg); + if (!running_on_qemu || 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"); |