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/mfd/core.h>
16 #include <linux/suspend.h>
17 #include <linux/olpc-ec.h>
18
19 #include <asm/io.h>
20 #include <asm/olpc.h>
21
22 #define DRV_NAME "olpc-xo1-pm"
23
24 static unsigned long acpi_base;
25 static unsigned long pms_base;
26
27 static u16 wakeup_mask = CS5536_PM_PWRBTN;
28
29 static struct {
30 unsigned long address;
31 unsigned short segment;
32 } ofw_bios_entry = { 0xF0000 + PAGE_OFFSET, __KERNEL_CS };
33
34 /* Set bits in the wakeup mask */
olpc_xo1_pm_wakeup_set(u16 value)35 void olpc_xo1_pm_wakeup_set(u16 value)
36 {
37 wakeup_mask |= value;
38 }
39 EXPORT_SYMBOL_GPL(olpc_xo1_pm_wakeup_set);
40
41 /* Clear bits in the wakeup mask */
olpc_xo1_pm_wakeup_clear(u16 value)42 void olpc_xo1_pm_wakeup_clear(u16 value)
43 {
44 wakeup_mask &= ~value;
45 }
46 EXPORT_SYMBOL_GPL(olpc_xo1_pm_wakeup_clear);
47
xo1_power_state_enter(suspend_state_t pm_state)48 static int xo1_power_state_enter(suspend_state_t pm_state)
49 {
50 unsigned long saved_sci_mask;
51
52 /* Only STR is supported */
53 if (pm_state != PM_SUSPEND_MEM)
54 return -EINVAL;
55
56 /*
57 * Save SCI mask (this gets lost since PM1_EN is used as a mask for
58 * wakeup events, which is not necessarily the same event set)
59 */
60 saved_sci_mask = inl(acpi_base + CS5536_PM1_STS);
61 saved_sci_mask &= 0xffff0000;
62
63 /* Save CPU state */
64 do_olpc_suspend_lowlevel();
65
66 /* Resume path starts here */
67
68 /* Restore SCI mask (using dword access to CS5536_PM1_EN) */
69 outl(saved_sci_mask, acpi_base + CS5536_PM1_STS);
70
71 return 0;
72 }
73
xo1_do_sleep(u8 sleep_state)74 asmlinkage __visible int xo1_do_sleep(u8 sleep_state)
75 {
76 void *pgd_addr = __va(read_cr3_pa());
77
78 /* Program wakeup mask (using dword access to CS5536_PM1_EN) */
79 outl(wakeup_mask << 16, acpi_base + CS5536_PM1_STS);
80
81 __asm__("movl %0,%%eax" : : "r" (pgd_addr));
82 __asm__("call *(%%edi); cld"
83 : : "D" (&ofw_bios_entry));
84 __asm__("movb $0x34, %al\n\t"
85 "outb %al, $0x70\n\t"
86 "movb $0x30, %al\n\t"
87 "outb %al, $0x71\n\t");
88 return 0;
89 }
90
xo1_power_off(void)91 static void xo1_power_off(void)
92 {
93 printk(KERN_INFO "OLPC XO-1 power off sequence...\n");
94
95 /* Enable all of these controls with 0 delay */
96 outl(0x40000000, pms_base + CS5536_PM_SCLK);
97 outl(0x40000000, pms_base + CS5536_PM_IN_SLPCTL);
98 outl(0x40000000, pms_base + CS5536_PM_WKXD);
99 outl(0x40000000, pms_base + CS5536_PM_WKD);
100
101 /* Clear status bits (possibly unnecessary) */
102 outl(0x0002ffff, pms_base + CS5536_PM_SSC);
103 outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);
104
105 /* Write SLP_EN bit to start the machinery */
106 outl(0x00002000, acpi_base + CS5536_PM1_CNT);
107 }
108
xo1_power_state_valid(suspend_state_t pm_state)109 static int xo1_power_state_valid(suspend_state_t pm_state)
110 {
111 /* suspend-to-RAM only */
112 return pm_state == PM_SUSPEND_MEM;
113 }
114
115 static const struct platform_suspend_ops xo1_suspend_ops = {
116 .valid = xo1_power_state_valid,
117 .enter = xo1_power_state_enter,
118 };
119
xo1_pm_probe(struct platform_device * pdev)120 static int xo1_pm_probe(struct platform_device *pdev)
121 {
122 struct resource *res;
123 int err;
124
125 /* don't run on non-XOs */
126 if (!machine_is_olpc())
127 return -ENODEV;
128
129 err = mfd_cell_enable(pdev);
130 if (err)
131 return err;
132
133 res = platform_get_resource(pdev, IORESOURCE_IO, 0);
134 if (!res) {
135 dev_err(&pdev->dev, "can't fetch device resource info\n");
136 return -EIO;
137 }
138 if (strcmp(pdev->name, "cs5535-pms") == 0)
139 pms_base = res->start;
140 else if (strcmp(pdev->name, "olpc-xo1-pm-acpi") == 0)
141 acpi_base = res->start;
142
143 /* If we have both addresses, we can override the poweroff hook */
144 if (pms_base && acpi_base) {
145 suspend_set_ops(&xo1_suspend_ops);
146 pm_power_off = xo1_power_off;
147 printk(KERN_INFO "OLPC XO-1 support registered\n");
148 }
149
150 return 0;
151 }
152
xo1_pm_remove(struct platform_device * pdev)153 static int xo1_pm_remove(struct platform_device *pdev)
154 {
155 mfd_cell_disable(pdev);
156
157 if (strcmp(pdev->name, "cs5535-pms") == 0)
158 pms_base = 0;
159 else if (strcmp(pdev->name, "olpc-xo1-pm-acpi") == 0)
160 acpi_base = 0;
161
162 pm_power_off = NULL;
163 return 0;
164 }
165
166 static struct platform_driver cs5535_pms_driver = {
167 .driver = {
168 .name = "cs5535-pms",
169 },
170 .probe = xo1_pm_probe,
171 .remove = xo1_pm_remove,
172 };
173
174 static struct platform_driver cs5535_acpi_driver = {
175 .driver = {
176 .name = "olpc-xo1-pm-acpi",
177 },
178 .probe = xo1_pm_probe,
179 .remove = xo1_pm_remove,
180 };
181
xo1_pm_init(void)182 static int __init xo1_pm_init(void)
183 {
184 int r;
185
186 r = platform_driver_register(&cs5535_pms_driver);
187 if (r)
188 return r;
189
190 r = platform_driver_register(&cs5535_acpi_driver);
191 if (r)
192 platform_driver_unregister(&cs5535_pms_driver);
193
194 return r;
195 }
196 arch_initcall(xo1_pm_init);
197
