1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Copyright (C) 2006-2007 PA Semi, Inc
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Maintained by: Olof Johansson <olof@lixom.net>
6*4882a593Smuzhiyun */
7*4882a593Smuzhiyun
8*4882a593Smuzhiyun #undef DEBUG
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun #include <linux/kernel.h>
11*4882a593Smuzhiyun #include <linux/string.h>
12*4882a593Smuzhiyun #include <linux/irq.h>
13*4882a593Smuzhiyun
14*4882a593Smuzhiyun #include <asm/machdep.h>
15*4882a593Smuzhiyun #include <asm/reg.h>
16*4882a593Smuzhiyun #include <asm/smp.h>
17*4882a593Smuzhiyun
18*4882a593Smuzhiyun #include "pasemi.h"
19*4882a593Smuzhiyun
20*4882a593Smuzhiyun struct sleep_mode {
21*4882a593Smuzhiyun char *name;
22*4882a593Smuzhiyun void (*entry)(void);
23*4882a593Smuzhiyun };
24*4882a593Smuzhiyun
25*4882a593Smuzhiyun static struct sleep_mode modes[] = {
26*4882a593Smuzhiyun { .name = "spin", .entry = &idle_spin },
27*4882a593Smuzhiyun { .name = "doze", .entry = &idle_doze },
28*4882a593Smuzhiyun };
29*4882a593Smuzhiyun
30*4882a593Smuzhiyun static int current_mode = 0;
31*4882a593Smuzhiyun
pasemi_system_reset_exception(struct pt_regs * regs)32*4882a593Smuzhiyun static int pasemi_system_reset_exception(struct pt_regs *regs)
33*4882a593Smuzhiyun {
34*4882a593Smuzhiyun /* If we were woken up from power savings, we need to return
35*4882a593Smuzhiyun * to the calling function, since nip is not saved across
36*4882a593Smuzhiyun * all modes.
37*4882a593Smuzhiyun */
38*4882a593Smuzhiyun
39*4882a593Smuzhiyun if (regs->msr & SRR1_WAKEMASK)
40*4882a593Smuzhiyun regs->nip = regs->link;
41*4882a593Smuzhiyun
42*4882a593Smuzhiyun switch (regs->msr & SRR1_WAKEMASK) {
43*4882a593Smuzhiyun case SRR1_WAKEDEC:
44*4882a593Smuzhiyun set_dec(1);
45*4882a593Smuzhiyun case SRR1_WAKEEE:
46*4882a593Smuzhiyun /*
47*4882a593Smuzhiyun * Handle these when interrupts get re-enabled and we take
48*4882a593Smuzhiyun * them as regular exceptions. We are in an NMI context
49*4882a593Smuzhiyun * and can't handle these here.
50*4882a593Smuzhiyun */
51*4882a593Smuzhiyun break;
52*4882a593Smuzhiyun default:
53*4882a593Smuzhiyun /* do system reset */
54*4882a593Smuzhiyun return 0;
55*4882a593Smuzhiyun }
56*4882a593Smuzhiyun
57*4882a593Smuzhiyun /* Set higher astate since we come out of power savings at 0 */
58*4882a593Smuzhiyun restore_astate(hard_smp_processor_id());
59*4882a593Smuzhiyun
60*4882a593Smuzhiyun /* everything handled */
61*4882a593Smuzhiyun regs->msr |= MSR_RI;
62*4882a593Smuzhiyun return 1;
63*4882a593Smuzhiyun }
64*4882a593Smuzhiyun
pasemi_idle_init(void)65*4882a593Smuzhiyun static int __init pasemi_idle_init(void)
66*4882a593Smuzhiyun {
67*4882a593Smuzhiyun #ifndef CONFIG_PPC_PASEMI_CPUFREQ
68*4882a593Smuzhiyun pr_warn("No cpufreq driver, powersavings modes disabled\n");
69*4882a593Smuzhiyun current_mode = 0;
70*4882a593Smuzhiyun #endif
71*4882a593Smuzhiyun
72*4882a593Smuzhiyun ppc_md.system_reset_exception = pasemi_system_reset_exception;
73*4882a593Smuzhiyun ppc_md.power_save = modes[current_mode].entry;
74*4882a593Smuzhiyun pr_info("Using PA6T idle loop (%s)\n", modes[current_mode].name);
75*4882a593Smuzhiyun
76*4882a593Smuzhiyun return 0;
77*4882a593Smuzhiyun }
78*4882a593Smuzhiyun machine_late_initcall(pasemi, pasemi_idle_init);
79*4882a593Smuzhiyun
idle_param(char * p)80*4882a593Smuzhiyun static int __init idle_param(char *p)
81*4882a593Smuzhiyun {
82*4882a593Smuzhiyun int i;
83*4882a593Smuzhiyun for (i = 0; i < ARRAY_SIZE(modes); i++) {
84*4882a593Smuzhiyun if (!strcmp(modes[i].name, p)) {
85*4882a593Smuzhiyun current_mode = i;
86*4882a593Smuzhiyun break;
87*4882a593Smuzhiyun }
88*4882a593Smuzhiyun }
89*4882a593Smuzhiyun return 0;
90*4882a593Smuzhiyun }
91*4882a593Smuzhiyun
92*4882a593Smuzhiyun early_param("idle", idle_param);
93