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1/*
2 * linux/drivers/parisc/power.c
3 * HP PARISC soft power switch support driver
4 *
5 * Copyright (c) 2001-2007 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 * HINT:
33 * Support of the soft power switch button may be enabled or disabled at
34 * runtime through the "/proc/sys/kernel/power" procfs entry.
35 */
36
37#include <linux/module.h>
38#include <linux/init.h>
39#include <linux/kernel.h>
40#include <linux/notifier.h>
41#include <linux/reboot.h>
42#include <linux/sched.h>
43#include <linux/kthread.h>
44#include <linux/pm.h>
45
46#include <asm/pdc.h>
47#include <asm/io.h>
48#include <asm/led.h>
49
50#define DRIVER_NAME "powersw"
51#define KTHREAD_NAME "kpowerswd"
52
53/* how often should the power button be polled ? */
54#define POWERSWITCH_POLL_PER_SEC 2
55
56/* how long does the power button needs to be down until we react ? */
57#define POWERSWITCH_DOWN_SEC 2
58
59/* assembly code to access special registers */
60/* taken from PCXL ERS page 82 */
61#define DIAG_CODE(code) (0x14000000 + ((code)<<5))
62
63#define MFCPU_X(rDiagReg, t_ch, t_th, code) \
64 (DIAG_CODE(code) + ((rDiagReg)<<21) + ((t_ch)<<16) + ((t_th)<<0) )
65
66#define MTCPU(dr, gr) MFCPU_X(dr, gr, 0, 0x12) /* move value of gr to dr[dr] */
67#define MFCPU_C(dr, gr) MFCPU_X(dr, gr, 0, 0x30) /* for dr0 and dr8 only ! */
68#define MFCPU_T(dr, gr) MFCPU_X(dr, 0, gr, 0xa0) /* all dr except dr0 and dr8 */
69
70#define __getDIAG(dr) ( { \
71 register unsigned long __res asm("r28");\
72 __asm__ __volatile__ ( \
73 ".word %1" : "=&r" (__res) : "i" (MFCPU_T(dr,28) ) \
74 ); \
75 __res; \
76} )
77
78/* local shutdown counter */
79static int shutdown_timer __read_mostly;
80
81/* check, give feedback and start shutdown after one second */
82static void process_shutdown(void)
83{
84 if (shutdown_timer == 0)
85 printk(KERN_ALERT KTHREAD_NAME ": Shutdown requested...\n");
86
87 shutdown_timer++;
88
89 /* wait until the button was pressed for 1 second */
90 if (shutdown_timer == (POWERSWITCH_DOWN_SEC*POWERSWITCH_POLL_PER_SEC)) {
91 static const char msg[] = "Shutting down...";
92 printk(KERN_INFO KTHREAD_NAME ": %s\n", msg);
93 lcd_print(msg);
94
95 /* send kill signal */
96 if (kill_cad_pid(SIGINT, 1)) {
97 /* just in case killing init process failed */
98 if (pm_power_off)
99 pm_power_off();
100 }
101 }
102}
103
104
105/* main power switch task struct */
106static struct task_struct *power_task;
107
108/* filename in /proc which can be used to enable/disable the power switch */
109#define SYSCTL_FILENAME "sys/kernel/power"
110
111/* soft power switch enabled/disabled */
112int pwrsw_enabled __read_mostly = 1;
113
114/* main kernel thread worker. It polls the button state */
115static int kpowerswd(void *param)
116{
117 __set_current_state(TASK_RUNNING);
118
119 do {
120 int button_not_pressed;
121 unsigned long soft_power_reg = (unsigned long) param;
122
123 schedule_timeout_interruptible(pwrsw_enabled ? HZ : HZ/POWERSWITCH_POLL_PER_SEC);
124
125 if (unlikely(!pwrsw_enabled))
126 continue;
127
128 if (soft_power_reg) {
129 /*
130 * Non-Gecko-style machines:
131 * Check the power switch status which is read from the
132 * real I/O location at soft_power_reg.
133 * Bit 31 ("the lowest bit) is the status of the power switch.
134 * This bit is "1" if the button is NOT pressed.
135 */
136 button_not_pressed = (gsc_readl(soft_power_reg) & 0x1);
137 } else {
138 /*
139 * On gecko style machines (e.g. 712/xx and 715/xx)
140 * the power switch status is stored in Bit 0 ("the highest bit")
141 * of CPU diagnose register 25.
142 * Warning: Some machines never reset the DIAG flag, even if
143 * the button has been released again.
144 */
145 button_not_pressed = (__getDIAG(25) & 0x80000000);
146 }
147
148 if (likely(button_not_pressed)) {
149 if (unlikely(shutdown_timer && /* avoid writing if not necessary */
150 shutdown_timer < (POWERSWITCH_DOWN_SEC*POWERSWITCH_POLL_PER_SEC))) {
151 shutdown_timer = 0;
152 printk(KERN_INFO KTHREAD_NAME ": Shutdown request aborted.\n");
153 }
154 } else
155 process_shutdown();
156
157
158 } while (!kthread_should_stop());
159
160 return 0;
161}
162
163
164/*
165 * powerfail interruption handler (irq IRQ_FROM_REGION(CPU_IRQ_REGION)+2)
166 */
167#if 0
168static void powerfail_interrupt(int code, void *x)
169{
170 printk(KERN_CRIT "POWERFAIL INTERRUPTION !\n");
171 poweroff();
172}
173#endif
174
175
176
177
178/* parisc_panic_event() is called by the panic handler.
179 * As soon as a panic occurs, our tasklets above will not be
180 * executed any longer. This function then re-enables the
181 * soft-power switch and allows the user to switch off the system
182 */
183static int parisc_panic_event(struct notifier_block *this,
184 unsigned long event, void *ptr)
185{
186 /* re-enable the soft-power switch */
187 pdc_soft_power_button(0);
188 return NOTIFY_DONE;
189}
190
191static struct notifier_block parisc_panic_block = {
192 .notifier_call = parisc_panic_event,
193 .priority = INT_MAX,
194};
195
196
197static int __init power_init(void)
198{
199 unsigned long ret;
200 unsigned long soft_power_reg;
201
202#if 0
203 request_irq( IRQ_FROM_REGION(CPU_IRQ_REGION)+2, &powerfail_interrupt,
204 0, "powerfail", NULL);
205#endif
206
207 /* enable the soft power switch if possible */
208 ret = pdc_soft_power_info(&soft_power_reg);
209 if (ret == PDC_OK)
210 ret = pdc_soft_power_button(1);
211 if (ret != PDC_OK)
212 soft_power_reg = -1UL;
213
214 switch (soft_power_reg) {
215 case 0: printk(KERN_INFO DRIVER_NAME ": Gecko-style soft power switch enabled.\n");
216 break;
217
218 case -1UL: printk(KERN_INFO DRIVER_NAME ": Soft power switch support not available.\n");
219 return -ENODEV;
220
221 default: printk(KERN_INFO DRIVER_NAME ": Soft power switch at 0x%08lx enabled.\n",
222 soft_power_reg);
223 }
224
225 power_task = kthread_run(kpowerswd, (void*)soft_power_reg, KTHREAD_NAME);
226 if (IS_ERR(power_task)) {
227 printk(KERN_ERR DRIVER_NAME ": thread creation failed. Driver not loaded.\n");
228 pdc_soft_power_button(0);
229 return -EIO;
230 }
231
232 /* Register a call for panic conditions. */
233 atomic_notifier_chain_register(&panic_notifier_list,
234 &parisc_panic_block);
235
236 return 0;
237}
238
239static void __exit power_exit(void)
240{
241 kthread_stop(power_task);
242
243 atomic_notifier_chain_unregister(&panic_notifier_list,
244 &parisc_panic_block);
245
246 pdc_soft_power_button(0);
247}
248
249arch_initcall(power_init);
250module_exit(power_exit);
251
252
253MODULE_AUTHOR("Helge Deller <deller@gmx.de>");
254MODULE_DESCRIPTION("Soft power switch driver");
255MODULE_LICENSE("Dual BSD/GPL");
1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * HP PARISC soft power switch driver
4 *
5 * Copyright (c) 2001-2023 Helge Deller <deller@gmx.de>
6 *
7 * HINT:
8 * Support of the soft power switch button may be enabled or disabled at
9 * runtime through the "/proc/sys/kernel/power" procfs entry.
10 */
11
12#include <linux/module.h>
13#include <linux/init.h>
14#include <linux/kernel.h>
15#include <linux/panic_notifier.h>
16#include <linux/reboot.h>
17#include <linux/sched/signal.h>
18#include <linux/kthread.h>
19#include <linux/pm.h>
20
21#include <asm/pdc.h>
22#include <asm/io.h>
23#include <asm/led.h>
24
25#define DRIVER_NAME "powersw"
26#define KTHREAD_NAME "kpowerswd"
27
28/* how often should the power button be polled ? */
29#define POWERSWITCH_POLL_PER_SEC 2
30
31/* how long does the power button needs to be down until we react ? */
32#define POWERSWITCH_DOWN_SEC 2
33
34/* assembly code to access special registers */
35/* taken from PCXL ERS page 82 */
36#define DIAG_CODE(code) (0x14000000 + ((code)<<5))
37
38#define MFCPU_X(rDiagReg, t_ch, t_th, code) \
39 (DIAG_CODE(code) + ((rDiagReg)<<21) + ((t_ch)<<16) + ((t_th)<<0) )
40
41#define MTCPU(dr, gr) MFCPU_X(dr, gr, 0, 0x12) /* move value of gr to dr[dr] */
42#define MFCPU_C(dr, gr) MFCPU_X(dr, gr, 0, 0x30) /* for dr0 and dr8 only ! */
43#define MFCPU_T(dr, gr) MFCPU_X(dr, 0, gr, 0xa0) /* all dr except dr0 and dr8 */
44
45#define __getDIAG(dr) ( { \
46 register unsigned long __res asm("r28");\
47 __asm__ __volatile__ ( \
48 ".word %1" : "=&r" (__res) : "i" (MFCPU_T(dr,28) ) \
49 ); \
50 __res; \
51} )
52
53/* local shutdown counter */
54static int shutdown_timer __read_mostly;
55
56/* check, give feedback and start shutdown after one second */
57static void process_shutdown(void)
58{
59 if (shutdown_timer == 0)
60 printk(KERN_ALERT KTHREAD_NAME ": Shutdown requested...\n");
61
62 shutdown_timer++;
63
64 /* wait until the button was pressed for 1 second */
65 if (shutdown_timer == (POWERSWITCH_DOWN_SEC*POWERSWITCH_POLL_PER_SEC)) {
66 static const char msg[] = "Shutting down...";
67 printk(KERN_INFO KTHREAD_NAME ": %s\n", msg);
68 lcd_print(msg);
69
70 /* send kill signal */
71 if (kill_cad_pid(SIGINT, 1)) {
72 /* just in case killing init process failed */
73 machine_power_off();
74 }
75 }
76}
77
78
79/* main power switch task struct */
80static struct task_struct *power_task;
81
82/* filename in /proc which can be used to enable/disable the power switch */
83#define SYSCTL_FILENAME "sys/kernel/power"
84
85/* soft power switch enabled/disabled */
86int pwrsw_enabled __read_mostly = 1;
87
88/* main kernel thread worker. It polls the button state */
89static int kpowerswd(void *param)
90{
91 __set_current_state(TASK_RUNNING);
92
93 do {
94 int button_not_pressed;
95 unsigned long soft_power_reg = (unsigned long) param;
96
97 schedule_timeout_interruptible(pwrsw_enabled ? HZ : HZ/POWERSWITCH_POLL_PER_SEC);
98
99 if (unlikely(!pwrsw_enabled))
100 continue;
101
102 if (soft_power_reg) {
103 /*
104 * Non-Gecko-style machines:
105 * Check the power switch status which is read from the
106 * real I/O location at soft_power_reg.
107 * Bit 31 ("the lowest bit) is the status of the power switch.
108 * This bit is "1" if the button is NOT pressed.
109 */
110 button_not_pressed = (gsc_readl(soft_power_reg) & 0x1);
111 } else {
112 /*
113 * On gecko style machines (e.g. 712/xx and 715/xx)
114 * the power switch status is stored in Bit 0 ("the highest bit")
115 * of CPU diagnose register 25.
116 * Warning: Some machines never reset the DIAG flag, even if
117 * the button has been released again.
118 */
119 button_not_pressed = (__getDIAG(25) & 0x80000000);
120 }
121
122 if (likely(button_not_pressed)) {
123 if (unlikely(shutdown_timer && /* avoid writing if not necessary */
124 shutdown_timer < (POWERSWITCH_DOWN_SEC*POWERSWITCH_POLL_PER_SEC))) {
125 shutdown_timer = 0;
126 printk(KERN_INFO KTHREAD_NAME ": Shutdown request aborted.\n");
127 }
128 } else
129 process_shutdown();
130
131
132 } while (!kthread_should_stop());
133
134 return 0;
135}
136
137
138/*
139 * powerfail interruption handler (irq IRQ_FROM_REGION(CPU_IRQ_REGION)+2)
140 */
141#if 0
142static void powerfail_interrupt(int code, void *x)
143{
144 printk(KERN_CRIT "POWERFAIL INTERRUPTION !\n");
145 poweroff();
146}
147#endif
148
149
150
151
152/*
153 * parisc_panic_event() is called by the panic handler.
154 *
155 * As soon as a panic occurs, our tasklets above will not
156 * be executed any longer. This function then re-enables
157 * the soft-power switch and allows the user to switch off
158 * the system. We rely in pdc_soft_power_button_panic()
159 * since this version spin_trylocks (instead of regular
160 * spinlock), preventing deadlocks on panic path.
161 */
162static int parisc_panic_event(struct notifier_block *this,
163 unsigned long event, void *ptr)
164{
165 /* re-enable the soft-power switch */
166 pdc_soft_power_button_panic(0);
167 return NOTIFY_DONE;
168}
169
170static struct notifier_block parisc_panic_block = {
171 .notifier_call = parisc_panic_event,
172 .priority = INT_MAX,
173};
174
175/* qemu soft power-off function */
176static int qemu_power_off(struct sys_off_data *data)
177{
178 /* this turns the system off via SeaBIOS */
179 gsc_writel(0, (unsigned long) data->cb_data);
180 pdc_soft_power_button(1);
181 return NOTIFY_DONE;
182}
183
184static int __init power_init(void)
185{
186 unsigned long ret;
187 unsigned long soft_power_reg;
188
189#if 0
190 request_irq( IRQ_FROM_REGION(CPU_IRQ_REGION)+2, &powerfail_interrupt,
191 0, "powerfail", NULL);
192#endif
193
194 /* enable the soft power switch if possible */
195 ret = pdc_soft_power_info(&soft_power_reg);
196 if (ret == PDC_OK)
197 ret = pdc_soft_power_button(1);
198 if (ret != PDC_OK)
199 soft_power_reg = -1UL;
200
201 switch (soft_power_reg) {
202 case 0: printk(KERN_INFO DRIVER_NAME ": Gecko-style soft power switch enabled.\n");
203 break;
204
205 case -1UL: printk(KERN_INFO DRIVER_NAME ": Soft power switch support not available.\n");
206 return -ENODEV;
207
208 default: printk(KERN_INFO DRIVER_NAME ": Soft power switch at 0x%08lx enabled.\n",
209 soft_power_reg);
210 }
211
212 power_task = NULL;
213 if (running_on_qemu && soft_power_reg)
214 register_sys_off_handler(SYS_OFF_MODE_POWER_OFF, SYS_OFF_PRIO_DEFAULT,
215 qemu_power_off, (void *)soft_power_reg);
216 if (!running_on_qemu || soft_power_reg)
217 power_task = kthread_run(kpowerswd, (void*)soft_power_reg,
218 KTHREAD_NAME);
219 if (IS_ERR(power_task)) {
220 printk(KERN_ERR DRIVER_NAME ": thread creation failed. Driver not loaded.\n");
221 pdc_soft_power_button(0);
222 return -EIO;
223 }
224
225 /* Register a call for panic conditions. */
226 atomic_notifier_chain_register(&panic_notifier_list,
227 &parisc_panic_block);
228
229 return 0;
230}
231
232static void __exit power_exit(void)
233{
234 kthread_stop(power_task);
235
236 atomic_notifier_chain_unregister(&panic_notifier_list,
237 &parisc_panic_block);
238
239 pdc_soft_power_button(0);
240}
241
242arch_initcall(power_init);
243module_exit(power_exit);
244
245
246MODULE_AUTHOR("Helge Deller <deller@gmx.de>");
247MODULE_DESCRIPTION("Soft power switch driver");
248MODULE_LICENSE("Dual BSD/GPL");