olpc-xo1-pm.c

  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 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);