1 /* 2 * linux/arch/parisc/kernel/power.c 3 * HP PARISC soft power switch support driver 4 * 5 * Copyright (c) 2001-2005 Helge Deller <deller@gmx.de> 6 * All rights reserved. 7 * 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions, and the following disclaimer, 14 * without modification. 15 * 2. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 18 * Alternatively, this software may be distributed under the terms of the 19 * GNU General Public License ("GPL"). 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR 25 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * 31 * 32 * 33 * HINT: 34 * Support of the soft power switch button may be enabled or disabled at 35 * runtime through the "/proc/sys/kernel/power" procfs entry. 36 */ 37 38 #include <linux/module.h> 39 #include <linux/init.h> 40 #include <linux/kernel.h> 41 #include <linux/string.h> 42 #include <linux/notifier.h> 43 #include <linux/reboot.h> 44 #include <linux/sched.h> 45 #include <linux/interrupt.h> 46 #include <linux/workqueue.h> 47 48 #include <asm/pdc.h> 49 #include <asm/io.h> 50 #include <asm/led.h> 51 #include <asm/uaccess.h> 52 53 54 #ifdef DEBUG 55 # define DPRINTK(x...) printk(x) 56 #else 57 # define DPRINTK(x...) 58 #endif 59 60 61 /* filename in /proc which can be used to enable/disable the power switch */ 62 #define SYSCTL_FILENAME "sys/kernel/power" 63 64 65 #define DIAG_CODE(code) (0x14000000 + ((code)<<5)) 66 67 /* this will go to processor.h or any other place... */ 68 /* taken from PCXL ERS page 82 */ 69 #define MFCPU_X(rDiagReg, t_ch, t_th, code) \ 70 (DIAG_CODE(code) + ((rDiagReg)<<21) + ((t_ch)<<16) + ((t_th)<<0) ) 71 72 #define MTCPU(dr, gr) MFCPU_X(dr, gr, 0, 0x12) /* move value of gr to dr[dr] */ 73 #define MFCPU_C(dr, gr) MFCPU_X(dr, gr, 0, 0x30) /* for dr0 and dr8 only ! */ 74 #define MFCPU_T(dr, gr) MFCPU_X(dr, 0, gr, 0xa0) /* all dr except dr0 and dr8 */ 75 76 #define __getDIAG(dr) ( { \ 77 register unsigned long __res asm("r28");\ 78 __asm__ __volatile__ ( \ 79 ".word %1\n nop\n" : "=&r" (__res) : "i" (MFCPU_T(dr,28)) \ 80 ); \ 81 __res; \ 82 } ) 83 84 85 static void deferred_poweroff(void *dummy) 86 { 87 extern int cad_pid; /* from kernel/sys.c */ 88 if (kill_proc(cad_pid, SIGINT, 1)) { 89 /* just in case killing init process failed */ 90 machine_power_off(); 91 } 92 } 93 94 /* 95 * This function gets called from interrupt context. 96 * As it's called within an interrupt, it wouldn't sync if we don't 97 * use schedule_work(). 98 */ 99 100 static DECLARE_WORK(poweroff_work, deferred_poweroff, NULL); 101 102 static void poweroff(void) 103 { 104 static int powering_off __read_mostly; 105 106 if (powering_off) 107 return; 108 109 powering_off++; 110 schedule_work(&poweroff_work); 111 } 112 113 114 /* local time-counter for shutdown */ 115 static int shutdown_timer __read_mostly; 116 117 /* check, give feedback and start shutdown after one second */ 118 static void process_shutdown(void) 119 { 120 if (shutdown_timer == 0) 121 DPRINTK(KERN_INFO "Shutdown requested...\n"); 122 123 shutdown_timer++; 124 125 /* wait until the button was pressed for 1 second */ 126 if (shutdown_timer == HZ) { 127 #if defined (DEBUG) || defined(CONFIG_CHASSIS_LCD_LED) 128 static char msg[] = "Shutting down..."; 129 #endif 130 DPRINTK(KERN_INFO "%s\n", msg); 131 lcd_print(msg); 132 poweroff(); 133 } 134 } 135 136 137 /* main power switch tasklet struct (scheduled from time.c) */ 138 DECLARE_TASKLET_DISABLED(power_tasklet, NULL, 0); 139 140 /* soft power switch enabled/disabled */ 141 int pwrsw_enabled __read_mostly = 1; 142 143 /* 144 * On gecko style machines (e.g. 712/xx and 715/xx) 145 * the power switch status is stored in Bit 0 ("the highest bit") 146 * of CPU diagnose register 25. 147 * 148 */ 149 static void gecko_tasklet_func(unsigned long unused) 150 { 151 if (unlikely(!pwrsw_enabled)) 152 return; 153 154 if (__getDIAG(25) & 0x80000000) { 155 /* power switch button not pressed or released again */ 156 /* Warning: Some machines do never reset this DIAG flag! */ 157 shutdown_timer = 0; 158 } else { 159 process_shutdown(); 160 } 161 } 162 163 164 165 /* 166 * Check the power switch status which is read from the 167 * real I/O location at soft_power_reg. 168 * Bit 31 ("the lowest bit) is the status of the power switch. 169 */ 170 171 static void polling_tasklet_func(unsigned long soft_power_reg) 172 { 173 unsigned long current_status; 174 175 if (unlikely(!pwrsw_enabled)) 176 return; 177 178 current_status = gsc_readl(soft_power_reg); 179 if (current_status & 0x1) { 180 /* power switch button not pressed */ 181 shutdown_timer = 0; 182 } else { 183 process_shutdown(); 184 } 185 } 186 187 188 /* 189 * powerfail interruption handler (irq IRQ_FROM_REGION(CPU_IRQ_REGION)+2) 190 */ 191 #if 0 192 static void powerfail_interrupt(int code, void *x, struct pt_regs *regs) 193 { 194 printk(KERN_CRIT "POWERFAIL INTERRUPTION !\n"); 195 poweroff(); 196 } 197 #endif 198 199 200 201 202 /* parisc_panic_event() is called by the panic handler. 203 * As soon as a panic occurs, our tasklets above will not be 204 * executed any longer. This function then re-enables the 205 * soft-power switch and allows the user to switch off the system 206 */ 207 static int parisc_panic_event(struct notifier_block *this, 208 unsigned long event, void *ptr) 209 { 210 /* re-enable the soft-power switch */ 211 pdc_soft_power_button(0); 212 return NOTIFY_DONE; 213 } 214 215 static struct notifier_block parisc_panic_block = { 216 .notifier_call = parisc_panic_event, 217 .priority = INT_MAX, 218 }; 219 220 221 static int __init power_init(void) 222 { 223 unsigned long ret; 224 unsigned long soft_power_reg = 0; 225 226 #if 0 227 request_irq( IRQ_FROM_REGION(CPU_IRQ_REGION)+2, &powerfail_interrupt, 228 0, "powerfail", NULL); 229 #endif 230 231 /* enable the soft power switch if possible */ 232 ret = pdc_soft_power_info(&soft_power_reg); 233 if (ret == PDC_OK) 234 ret = pdc_soft_power_button(1); 235 if (ret != PDC_OK) 236 soft_power_reg = -1UL; 237 238 switch (soft_power_reg) { 239 case 0: printk(KERN_INFO "Gecko-style soft power switch enabled.\n"); 240 power_tasklet.func = gecko_tasklet_func; 241 break; 242 243 case -1UL: printk(KERN_INFO "Soft power switch support not available.\n"); 244 return -ENODEV; 245 246 default: printk(KERN_INFO "Soft power switch enabled, polling @ 0x%08lx.\n", 247 soft_power_reg); 248 power_tasklet.data = soft_power_reg; 249 power_tasklet.func = polling_tasklet_func; 250 } 251 252 /* Register a call for panic conditions. */ 253 atomic_notifier_chain_register(&panic_notifier_list, 254 &parisc_panic_block); 255 256 tasklet_enable(&power_tasklet); 257 258 return 0; 259 } 260 261 static void __exit power_exit(void) 262 { 263 if (!power_tasklet.func) 264 return; 265 266 tasklet_disable(&power_tasklet); 267 atomic_notifier_chain_unregister(&panic_notifier_list, 268 &parisc_panic_block); 269 power_tasklet.func = NULL; 270 pdc_soft_power_button(0); 271 } 272 273 module_init(power_init); 274 module_exit(power_exit); 275 276 277 MODULE_AUTHOR("Helge Deller"); 278 MODULE_DESCRIPTION("Soft power switch driver"); 279 MODULE_LICENSE("Dual BSD/GPL"); 280