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(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(saved_sci_mask, 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(wakeup_mask << 16, 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(0x40000000, pms_base + CS5536_PM_SCLK);
96	outl(0x40000000, pms_base + CS5536_PM_IN_SLPCTL);
97	outl(0x40000000, pms_base + CS5536_PM_WKXD);
98	outl(0x40000000, pms_base + CS5536_PM_WKD);
99
100	/* Clear status bits (possibly unnecessary) */
101	outl(0x0002ffff, pms_base  + CS5536_PM_SSC);
102	outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);
103
104	/* Write SLP_EN bit to start the machinery */
105	outl(0x00002000, 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(&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 int 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	return 0;
156}
157
158static struct platform_driver cs5535_pms_driver = {
159	.driver = {
160		.name = "cs5535-pms",
161	},
162	.probe = xo1_pm_probe,
163	.remove = xo1_pm_remove,
164};
165
166static struct platform_driver cs5535_acpi_driver = {
167	.driver = {
168		.name = "olpc-xo1-pm-acpi",
169	},
170	.probe = xo1_pm_probe,
171	.remove = xo1_pm_remove,
172};
173
174static int __init xo1_pm_init(void)
175{
176	int r;
177
178	r = platform_driver_register(&cs5535_pms_driver);
179	if (r)
180		return r;
181
182	r = platform_driver_register(&cs5535_acpi_driver);
183	if (r)
184		platform_driver_unregister(&cs5535_pms_driver);
185
186	return r;
187}
188arch_initcall(xo1_pm_init);
189