1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Support for power management features of the OLPC XO-1 laptop
4 *
5 * Copyright (C) 2010 Andres Salomon <dilinger@queued.net>
6 * Copyright (C) 2010 One Laptop per Child
7 * Copyright (C) 2006 Red Hat, Inc.
8 * Copyright (C) 2006 Advanced Micro Devices, Inc.
9 */
10
11#include <linux/cs5535.h>
12#include <linux/platform_device.h>
13#include <linux/export.h>
14#include <linux/pm.h>
15#include <linux/suspend.h>
16#include <linux/olpc-ec.h>
17
18#include <asm/io.h>
19#include <asm/olpc.h>
20
21#define DRV_NAME "olpc-xo1-pm"
22
23static unsigned long acpi_base;
24static unsigned long pms_base;
25
26static u16 wakeup_mask = CS5536_PM_PWRBTN;
27
28static struct {
29 unsigned long address;
30 unsigned short segment;
31} ofw_bios_entry = { 0xF0000 + PAGE_OFFSET, __KERNEL_CS };
32
33/* Set bits in the wakeup mask */
34void olpc_xo1_pm_wakeup_set(u16 value)
35{
36 wakeup_mask |= value;
37}
38EXPORT_SYMBOL_GPL(olpc_xo1_pm_wakeup_set);
39
40/* Clear bits in the wakeup mask */
41void olpc_xo1_pm_wakeup_clear(u16 value)
42{
43 wakeup_mask &= ~value;
44}
45EXPORT_SYMBOL_GPL(olpc_xo1_pm_wakeup_clear);
46
47static int xo1_power_state_enter(suspend_state_t pm_state)
48{
49 unsigned long saved_sci_mask;
50
51 /* Only STR is supported */
52 if (pm_state != PM_SUSPEND_MEM)
53 return -EINVAL;
54
55 /*
56 * Save SCI mask (this gets lost since PM1_EN is used as a mask for
57 * wakeup events, which is not necessarily the same event set)
58 */
59 saved_sci_mask = inl(port: acpi_base + CS5536_PM1_STS);
60 saved_sci_mask &= 0xffff0000;
61
62 /* Save CPU state */
63 do_olpc_suspend_lowlevel();
64
65 /* Resume path starts here */
66
67 /* Restore SCI mask (using dword access to CS5536_PM1_EN) */
68 outl(value: saved_sci_mask, port: acpi_base + CS5536_PM1_STS);
69
70 return 0;
71}
72
73asmlinkage __visible int xo1_do_sleep(u8 sleep_state)
74{
75 void *pgd_addr = __va(read_cr3_pa());
76
77 /* Program wakeup mask (using dword access to CS5536_PM1_EN) */
78 outl(value: wakeup_mask << 16, port: acpi_base + CS5536_PM1_STS);
79
80 __asm__("movl %0,%%eax" : : "r" (pgd_addr));
81 __asm__("call *(%%edi); cld"
82 : : "D" (&ofw_bios_entry));
83 __asm__("movb $0x34, %al\n\t"
84 "outb %al, $0x70\n\t"
85 "movb $0x30, %al\n\t"
86 "outb %al, $0x71\n\t");
87 return 0;
88}
89
90static void xo1_power_off(void)
91{
92 printk(KERN_INFO "OLPC XO-1 power off sequence...\n");
93
94 /* Enable all of these controls with 0 delay */
95 outl(value: 0x40000000, port: pms_base + CS5536_PM_SCLK);
96 outl(value: 0x40000000, port: pms_base + CS5536_PM_IN_SLPCTL);
97 outl(value: 0x40000000, port: pms_base + CS5536_PM_WKXD);
98 outl(value: 0x40000000, port: pms_base + CS5536_PM_WKD);
99
100 /* Clear status bits (possibly unnecessary) */
101 outl(value: 0x0002ffff, port: pms_base + CS5536_PM_SSC);
102 outl(value: 0xffffffff, port: acpi_base + CS5536_PM_GPE0_STS);
103
104 /* Write SLP_EN bit to start the machinery */
105 outl(value: 0x00002000, port: acpi_base + CS5536_PM1_CNT);
106}
107
108static int xo1_power_state_valid(suspend_state_t pm_state)
109{
110 /* suspend-to-RAM only */
111 return pm_state == PM_SUSPEND_MEM;
112}
113
114static const struct platform_suspend_ops xo1_suspend_ops = {
115 .valid = xo1_power_state_valid,
116 .enter = xo1_power_state_enter,
117};
118
119static int xo1_pm_probe(struct platform_device *pdev)
120{
121 struct resource *res;
122
123 /* don't run on non-XOs */
124 if (!machine_is_olpc())
125 return -ENODEV;
126
127 res = platform_get_resource(pdev, IORESOURCE_IO, 0);
128 if (!res) {
129 dev_err(&pdev->dev, "can't fetch device resource info\n");
130 return -EIO;
131 }
132 if (strcmp(pdev->name, "cs5535-pms") == 0)
133 pms_base = res->start;
134 else if (strcmp(pdev->name, "olpc-xo1-pm-acpi") == 0)
135 acpi_base = res->start;
136
137 /* If we have both addresses, we can override the poweroff hook */
138 if (pms_base && acpi_base) {
139 suspend_set_ops(ops: &xo1_suspend_ops);
140 pm_power_off = xo1_power_off;
141 printk(KERN_INFO "OLPC XO-1 support registered\n");
142 }
143
144 return 0;
145}
146
147static void xo1_pm_remove(struct platform_device *pdev)
148{
149 if (strcmp(pdev->name, "cs5535-pms") == 0)
150 pms_base = 0;
151 else if (strcmp(pdev->name, "olpc-xo1-pm-acpi") == 0)
152 acpi_base = 0;
153
154 pm_power_off = NULL;
155}
156
157static struct platform_driver cs5535_pms_driver = {
158 .driver = {
159 .name = "cs5535-pms",
160 },
161 .probe = xo1_pm_probe,
162 .remove = xo1_pm_remove,
163};
164
165static struct platform_driver cs5535_acpi_driver = {
166 .driver = {
167 .name = "olpc-xo1-pm-acpi",
168 },
169 .probe = xo1_pm_probe,
170 .remove = xo1_pm_remove,
171};
172
173static int __init xo1_pm_init(void)
174{
175 int r;
176
177 r = platform_driver_register(&cs5535_pms_driver);
178 if (r)
179 return r;
180
181 r = platform_driver_register(&cs5535_acpi_driver);
182 if (r)
183 platform_driver_unregister(&cs5535_pms_driver);
184
185 return r;
186}
187arch_initcall(xo1_pm_init);
188

source code of linux/arch/x86/platform/olpc/olpc-xo1-pm.c