1 /*
2 * pmu.c, Power Management Unit routines for NEC VR4100 series.
3 *
4 * Copyright (C) 2003-2007 Yoichi Yuasa <yuasa@linux-mips.org>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 */
20 #include <linux/errno.h>
21 #include <linux/init.h>
22 #include <linux/ioport.h>
23 #include <linux/kernel.h>
24 #include <linux/pm.h>
25 #include <linux/sched.h>
26 #include <linux/types.h>
27
28 #include <asm/cacheflush.h>
29 #include <asm/cpu.h>
30 #include <asm/idle.h>
31 #include <asm/io.h>
32 #include <asm/processor.h>
33 #include <asm/reboot.h>
34
35 #define PMU_TYPE1_BASE 0x0b0000a0UL
36 #define PMU_TYPE1_SIZE 0x0eUL
37
38 #define PMU_TYPE2_BASE 0x0f0000c0UL
39 #define PMU_TYPE2_SIZE 0x10UL
40
41 #define PMUCNT2REG 0x06
42 #define SOFTRST 0x0010
43
44 static void __iomem *pmu_base;
45
46 #define pmu_read(offset) readw(pmu_base + (offset))
47 #define pmu_write(offset, value) writew((value), pmu_base + (offset))
48
vr41xx_cpu_wait(void)49 static void vr41xx_cpu_wait(void)
50 {
51 local_irq_disable();
52 if (!need_resched())
53 /*
54 * "standby" sets IE bit of the CP0_STATUS to 1.
55 */
56 __asm__("standby;\n");
57 else
58 local_irq_enable();
59 }
60
software_reset(void)61 static inline void software_reset(void)
62 {
63 uint16_t pmucnt2;
64
65 switch (current_cpu_type()) {
66 case CPU_VR4122:
67 case CPU_VR4131:
68 case CPU_VR4133:
69 pmucnt2 = pmu_read(PMUCNT2REG);
70 pmucnt2 |= SOFTRST;
71 pmu_write(PMUCNT2REG, pmucnt2);
72 break;
73 default:
74 set_c0_status(ST0_BEV | ST0_ERL);
75 change_c0_config(CONF_CM_CMASK, CONF_CM_UNCACHED);
76 flush_cache_all();
77 write_c0_wired(0);
78 __asm__("jr %0"::"r"(0xbfc00000));
79 break;
80 }
81 }
82
vr41xx_restart(char * command)83 static void vr41xx_restart(char *command)
84 {
85 local_irq_disable();
86 software_reset();
87 while (1) ;
88 }
89
vr41xx_halt(void)90 static void vr41xx_halt(void)
91 {
92 local_irq_disable();
93 printk(KERN_NOTICE "\nYou can turn off the power supply\n");
94 __asm__("hibernate;\n");
95 }
96
vr41xx_pmu_init(void)97 static int __init vr41xx_pmu_init(void)
98 {
99 unsigned long start, size;
100
101 switch (current_cpu_type()) {
102 case CPU_VR4111:
103 case CPU_VR4121:
104 start = PMU_TYPE1_BASE;
105 size = PMU_TYPE1_SIZE;
106 break;
107 case CPU_VR4122:
108 case CPU_VR4131:
109 case CPU_VR4133:
110 start = PMU_TYPE2_BASE;
111 size = PMU_TYPE2_SIZE;
112 break;
113 default:
114 printk("Unexpected CPU of NEC VR4100 series\n");
115 return -ENODEV;
116 }
117
118 if (request_mem_region(start, size, "PMU") == NULL)
119 return -EBUSY;
120
121 pmu_base = ioremap(start, size);
122 if (pmu_base == NULL) {
123 release_mem_region(start, size);
124 return -EBUSY;
125 }
126
127 cpu_wait = vr41xx_cpu_wait;
128 _machine_restart = vr41xx_restart;
129 _machine_halt = vr41xx_halt;
130 pm_power_off = vr41xx_halt;
131
132 return 0;
133 }
134
135 core_initcall(vr41xx_pmu_init);
136