1 /* 2 * linux/arch/parisc/kernel/power.c 3 * HP PARISC soft power switch support driver 4 * 5 * Copyright (c) 2001-2002 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/config.h> 39 #include <linux/module.h> 40 #include <linux/init.h> 41 #include <linux/kernel.h> 42 #include <linux/string.h> 43 #include <linux/notifier.h> 44 #include <linux/reboot.h> 45 #include <linux/sched.h> 46 #include <linux/interrupt.h> 47 #include <linux/workqueue.h> 48 49 #include <asm/pdc.h> 50 #include <asm/io.h> 51 #include <asm/led.h> 52 #include <asm/uaccess.h> 53 54 55 #ifdef DEBUG 56 # define DPRINTK(x...) printk(x) 57 #else 58 # define DPRINTK(x...) 59 #endif 60 61 62 /* filename in /proc which can be used to enable/disable the power switch */ 63 #define SYSCTL_FILENAME "sys/kernel/power" 64 65 66 #define DIAG_CODE(code) (0x14000000 + ((code)<<5)) 67 68 /* this will go to processor.h or any other place... */ 69 /* taken from PCXL ERS page 82 */ 70 #define MFCPU_X(rDiagReg, t_ch, t_th, code) \ 71 (DIAG_CODE(code) + ((rDiagReg)<<21) + ((t_ch)<<16) + ((t_th)<<0) ) 72 73 #define MTCPU(dr, gr) MFCPU_X(dr, gr, 0, 0x12) /* move value of gr to dr[dr] */ 74 #define MFCPU_C(dr, gr) MFCPU_X(dr, gr, 0, 0x30) /* for dr0 and dr8 only ! */ 75 #define MFCPU_T(dr, gr) MFCPU_X(dr, 0, gr, 0xa0) /* all dr except dr0 and dr8 */ 76 77 #define __getDIAG(dr) ( { \ 78 register unsigned long __res asm("r28");\ 79 __asm__ __volatile__ ( \ 80 ".word %1\n nop\n" : "=&r" (__res) : "i" (MFCPU_T(dr,28)) \ 81 ); \ 82 __res; \ 83 } ) 84 85 86 static void deferred_poweroff(void *dummy) 87 { 88 extern int cad_pid; /* from kernel/sys.c */ 89 if (kill_proc(cad_pid, SIGINT, 1)) { 90 /* just in case killing init process failed */ 91 machine_power_off(); 92 } 93 } 94 95 /* 96 * This function gets called from interrupt context. 97 * As it's called within an interrupt, it wouldn't sync if we don't 98 * use schedule_work(). 99 */ 100 101 static DECLARE_WORK(poweroff_work, deferred_poweroff, NULL); 102 103 static void poweroff(void) 104 { 105 static int powering_off; 106 107 if (powering_off) 108 return; 109 110 powering_off++; 111 schedule_work(&poweroff_work); 112 } 113 114 115 /* local time-counter for shutdown */ 116 static int shutdown_timer; 117 118 /* check, give feedback and start shutdown after one second */ 119 static void process_shutdown(void) 120 { 121 if (shutdown_timer == 0) 122 DPRINTK(KERN_INFO "Shutdown requested...\n"); 123 124 shutdown_timer++; 125 126 /* wait until the button was pressed for 1 second */ 127 if (shutdown_timer == HZ) { 128 #if defined (DEBUG) || defined(CONFIG_CHASSIS_LCD_LED) 129 static char msg[] = "Shutting down..."; 130 #endif 131 DPRINTK(KERN_INFO "%s\n", msg); 132 lcd_print(msg); 133 poweroff(); 134 } 135 } 136 137 138 /* main power switch tasklet struct (scheduled from time.c) */ 139 DECLARE_TASKLET_DISABLED(power_tasklet, NULL, 0); 140 141 /* soft power switch enabled/disabled */ 142 int pwrsw_enabled = 1; 143 144 /* 145 * On gecko style machines (e.g. 712/xx and 715/xx) 146 * the power switch status is stored in Bit 0 ("the highest bit") 147 * of CPU diagnose register 25. 148 * 149 */ 150 static void gecko_tasklet_func(unsigned long unused) 151 { 152 if (!pwrsw_enabled) 153 return; 154 155 if (__getDIAG(25) & 0x80000000) { 156 /* power switch button not pressed or released again */ 157 /* Warning: Some machines do never reset this DIAG flag! */ 158 shutdown_timer = 0; 159 } else { 160 process_shutdown(); 161 } 162 } 163 164 165 166 /* 167 * Check the power switch status which is read from the 168 * real I/O location at soft_power_reg. 169 * Bit 31 ("the lowest bit) is the status of the power switch. 170 */ 171 172 static void polling_tasklet_func(unsigned long soft_power_reg) 173 { 174 unsigned long current_status; 175 176 if (!pwrsw_enabled) 177 return; 178 179 current_status = gsc_readl(soft_power_reg); 180 if (current_status & 0x1) { 181 /* power switch button not pressed */ 182 shutdown_timer = 0; 183 } else { 184 process_shutdown(); 185 } 186 } 187 188 189 /* 190 * powerfail interruption handler (irq IRQ_FROM_REGION(CPU_IRQ_REGION)+2) 191 */ 192 #if 0 193 static void powerfail_interrupt(int code, void *x, struct pt_regs *regs) 194 { 195 printk(KERN_CRIT "POWERFAIL INTERRUPTION !\n"); 196 poweroff(); 197 } 198 #endif 199 200 201 202 203 /* parisc_panic_event() is called by the panic handler. 204 * As soon as a panic occurs, our tasklets above will not be 205 * executed any longer. This function then re-enables the 206 * soft-power switch and allows the user to switch off the system 207 */ 208 static int parisc_panic_event(struct notifier_block *this, 209 unsigned long event, void *ptr) 210 { 211 /* re-enable the soft-power switch */ 212 pdc_soft_power_button(0); 213 return NOTIFY_DONE; 214 } 215 216 static struct notifier_block parisc_panic_block = { 217 .notifier_call = parisc_panic_event, 218 .priority = INT_MAX, 219 }; 220 221 222 static int __init power_init(void) 223 { 224 unsigned long ret; 225 unsigned long soft_power_reg = 0; 226 227 #if 0 228 request_irq( IRQ_FROM_REGION(CPU_IRQ_REGION)+2, &powerfail_interrupt, 229 0, "powerfail", NULL); 230 #endif 231 232 /* enable the soft power switch if possible */ 233 ret = pdc_soft_power_info(&soft_power_reg); 234 if (ret == PDC_OK) 235 ret = pdc_soft_power_button(1); 236 if (ret != PDC_OK) 237 soft_power_reg = -1UL; 238 239 switch (soft_power_reg) { 240 case 0: printk(KERN_INFO "Gecko-style soft power switch enabled.\n"); 241 power_tasklet.func = gecko_tasklet_func; 242 break; 243 244 case -1UL: printk(KERN_INFO "Soft power switch support not available.\n"); 245 return -ENODEV; 246 247 default: printk(KERN_INFO "Soft power switch enabled, polling @ 0x%08lx.\n", 248 soft_power_reg); 249 power_tasklet.data = soft_power_reg; 250 power_tasklet.func = polling_tasklet_func; 251 } 252 253 /* Register a call for panic conditions. */ 254 notifier_chain_register(&panic_notifier_list, &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 notifier_chain_unregister(&panic_notifier_list, &parisc_panic_block); 268 power_tasklet.func = NULL; 269 pdc_soft_power_button(0); 270 } 271 272 module_init(power_init); 273 module_exit(power_exit); 274 275 276 MODULE_AUTHOR("Helge Deller"); 277 MODULE_DESCRIPTION("Soft power switch driver"); 278 MODULE_LICENSE("Dual BSD/GPL"); 279