1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * pmu.c, Power Management Unit routines for NEC VR4100 series.
4 *
5 * Copyright (C) 2003-2007 Yoichi Yuasa <yuasa@linux-mips.org>
6 */
7 #include <linux/cpu.h>
8 #include <linux/errno.h>
9 #include <linux/init.h>
10 #include <linux/ioport.h>
11 #include <linux/kernel.h>
12 #include <linux/pm.h>
13 #include <linux/sched.h>
14 #include <linux/types.h>
15
16 #include <asm/cacheflush.h>
17 #include <asm/cpu.h>
18 #include <asm/idle.h>
19 #include <asm/io.h>
20 #include <asm/processor.h>
21 #include <asm/reboot.h>
22
23 #define PMU_TYPE1_BASE 0x0b0000a0UL
24 #define PMU_TYPE1_SIZE 0x0eUL
25
26 #define PMU_TYPE2_BASE 0x0f0000c0UL
27 #define PMU_TYPE2_SIZE 0x10UL
28
29 #define PMUCNT2REG 0x06
30 #define SOFTRST 0x0010
31
32 static void __iomem *pmu_base;
33
34 #define pmu_read(offset) readw(pmu_base + (offset))
35 #define pmu_write(offset, value) writew((value), pmu_base + (offset))
36
vr41xx_cpu_wait(void)37 static void __cpuidle vr41xx_cpu_wait(void)
38 {
39 local_irq_disable();
40 if (!need_resched())
41 /*
42 * "standby" sets IE bit of the CP0_STATUS to 1.
43 */
44 __asm__("standby;\n");
45 else
46 local_irq_enable();
47 }
48
software_reset(void)49 static inline void software_reset(void)
50 {
51 uint16_t pmucnt2;
52
53 switch (current_cpu_type()) {
54 case CPU_VR4122:
55 case CPU_VR4131:
56 case CPU_VR4133:
57 pmucnt2 = pmu_read(PMUCNT2REG);
58 pmucnt2 |= SOFTRST;
59 pmu_write(PMUCNT2REG, pmucnt2);
60 break;
61 default:
62 set_c0_status(ST0_BEV | ST0_ERL);
63 change_c0_config(CONF_CM_CMASK, CONF_CM_UNCACHED);
64 __flush_cache_all();
65 write_c0_wired(0);
66 __asm__("jr %0"::"r"(0xbfc00000));
67 break;
68 }
69 }
70
vr41xx_restart(char * command)71 static void vr41xx_restart(char *command)
72 {
73 local_irq_disable();
74 software_reset();
75 while (1) ;
76 }
77
vr41xx_halt(void)78 static void vr41xx_halt(void)
79 {
80 local_irq_disable();
81 printk(KERN_NOTICE "\nYou can turn off the power supply\n");
82 __asm__("hibernate;\n");
83 }
84
vr41xx_pmu_init(void)85 static int __init vr41xx_pmu_init(void)
86 {
87 unsigned long start, size;
88
89 switch (current_cpu_type()) {
90 case CPU_VR4111:
91 case CPU_VR4121:
92 start = PMU_TYPE1_BASE;
93 size = PMU_TYPE1_SIZE;
94 break;
95 case CPU_VR4122:
96 case CPU_VR4131:
97 case CPU_VR4133:
98 start = PMU_TYPE2_BASE;
99 size = PMU_TYPE2_SIZE;
100 break;
101 default:
102 printk("Unexpected CPU of NEC VR4100 series\n");
103 return -ENODEV;
104 }
105
106 if (request_mem_region(start, size, "PMU") == NULL)
107 return -EBUSY;
108
109 pmu_base = ioremap(start, size);
110 if (pmu_base == NULL) {
111 release_mem_region(start, size);
112 return -EBUSY;
113 }
114
115 cpu_wait = vr41xx_cpu_wait;
116 _machine_restart = vr41xx_restart;
117 _machine_halt = vr41xx_halt;
118 pm_power_off = vr41xx_halt;
119
120 return 0;
121 }
122
123 core_initcall(vr41xx_pmu_init);
124