1/*
  2 * Support for power management features of the OLPC XO-1 laptop
  3 *
  4 * Copyright (C) 2010 Andres Salomon <dilinger@queued.net>
  5 * Copyright (C) 2010 One Laptop per Child
  6 * Copyright (C) 2006 Red Hat, Inc.
  7 * Copyright (C) 2006 Advanced Micro Devices, Inc.
  8 *
  9 * This program is free software; you can redistribute it and/or modify
 10 * it under the terms of the GNU General Public License as published by
 11 * the Free Software Foundation; either version 2 of the License, or
 12 * (at your option) any later version.
 13 */
 14
 15#include <linux/cs5535.h>
 16#include <linux/platform_device.h>
 17#include <linux/export.h>
 18#include <linux/pm.h>
 19#include <linux/mfd/core.h>
 20#include <linux/suspend.h>
 21
 22#include <asm/io.h>
 23#include <asm/olpc.h>
 24
 25#define DRV_NAME "olpc-xo1-pm"
 26
 27static unsigned long acpi_base;
 28static unsigned long pms_base;
 29
 30static u16 wakeup_mask = CS5536_PM_PWRBTN;
 31
 32static struct {
 33	unsigned long address;
 34	unsigned short segment;
 35} ofw_bios_entry = { 0xF0000 + PAGE_OFFSET, __KERNEL_CS };
 36
 37/* Set bits in the wakeup mask */
 38void olpc_xo1_pm_wakeup_set(u16 value)
 39{
 40	wakeup_mask |= value;
 41}
 42EXPORT_SYMBOL_GPL(olpc_xo1_pm_wakeup_set);
 43
 44/* Clear bits in the wakeup mask */
 45void olpc_xo1_pm_wakeup_clear(u16 value)
 46{
 47	wakeup_mask &= ~value;
 48}
 49EXPORT_SYMBOL_GPL(olpc_xo1_pm_wakeup_clear);
 50
 51static int xo1_power_state_enter(suspend_state_t pm_state)
 52{
 53	unsigned long saved_sci_mask;
 54	int r;
 55
 56	/* Only STR is supported */
 57	if (pm_state != PM_SUSPEND_MEM)
 58		return -EINVAL;
 59
 60	r = olpc_ec_cmd(EC_SET_SCI_INHIBIT, NULL, 0, NULL, 0);
 61	if (r)
 62		return r;
 63
 64	/*
 65	 * Save SCI mask (this gets lost since PM1_EN is used as a mask for
 66	 * wakeup events, which is not necessarily the same event set)
 67	 */
 68	saved_sci_mask = inl(acpi_base + CS5536_PM1_STS);
 69	saved_sci_mask &= 0xffff0000;
 70
 71	/* Save CPU state */
 72	do_olpc_suspend_lowlevel();
 73
 74	/* Resume path starts here */
 75
 76	/* Restore SCI mask (using dword access to CS5536_PM1_EN) */
 77	outl(saved_sci_mask, acpi_base + CS5536_PM1_STS);
 78
 79	/* Tell the EC to stop inhibiting SCIs */
 80	olpc_ec_cmd(EC_SET_SCI_INHIBIT_RELEASE, NULL, 0, NULL, 0);
 81
 82	/*
 83	 * Tell the wireless module to restart USB communication.
 84	 * Must be done twice.
 85	 */
 86	olpc_ec_cmd(EC_WAKE_UP_WLAN, NULL, 0, NULL, 0);
 87	olpc_ec_cmd(EC_WAKE_UP_WLAN, NULL, 0, NULL, 0);
 88
 89	return 0;
 90}
 91
 92asmlinkage int xo1_do_sleep(u8 sleep_state)
 93{
 94	void *pgd_addr = __va(read_cr3());
 95
 96	/* Program wakeup mask (using dword access to CS5536_PM1_EN) */
 97	outl(wakeup_mask << 16, acpi_base + CS5536_PM1_STS);
 98
 99	__asm__("movl %0,%%eax" : : "r" (pgd_addr));
100	__asm__("call *(%%edi); cld"
101		: : "D" (&ofw_bios_entry));
102	__asm__("movb $0x34, %al\n\t"
103		"outb %al, $0x70\n\t"
104		"movb $0x30, %al\n\t"
105		"outb %al, $0x71\n\t");
106	return 0;
107}
108
109static void xo1_power_off(void)
110{
111	printk(KERN_INFO "OLPC XO-1 power off sequence...\n");
112
113	/* Enable all of these controls with 0 delay */
114	outl(0x40000000, pms_base + CS5536_PM_SCLK);
115	outl(0x40000000, pms_base + CS5536_PM_IN_SLPCTL);
116	outl(0x40000000, pms_base + CS5536_PM_WKXD);
117	outl(0x40000000, pms_base + CS5536_PM_WKD);
118
119	/* Clear status bits (possibly unnecessary) */
120	outl(0x0002ffff, pms_base  + CS5536_PM_SSC);
121	outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);
122
123	/* Write SLP_EN bit to start the machinery */
124	outl(0x00002000, acpi_base + CS5536_PM1_CNT);
125}
126
127static int xo1_power_state_valid(suspend_state_t pm_state)
128{
129	/* suspend-to-RAM only */
130	return pm_state == PM_SUSPEND_MEM;
131}
132
133static const struct platform_suspend_ops xo1_suspend_ops = {
134	.valid = xo1_power_state_valid,
135	.enter = xo1_power_state_enter,
136};
137
138static int __devinit xo1_pm_probe(struct platform_device *pdev)
139{
140	struct resource *res;
141	int err;
142
143	/* don't run on non-XOs */
144	if (!machine_is_olpc())
145		return -ENODEV;
146
147	err = mfd_cell_enable(pdev);
148	if (err)
149		return err;
150
151	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
152	if (!res) {
153		dev_err(&pdev->dev, "can't fetch device resource info\n");
154		return -EIO;
155	}
156	if (strcmp(pdev->name, "cs5535-pms") == 0)
157		pms_base = res->start;
158	else if (strcmp(pdev->name, "olpc-xo1-pm-acpi") == 0)
159		acpi_base = res->start;
160
161	/* If we have both addresses, we can override the poweroff hook */
162	if (pms_base && acpi_base) {
163		suspend_set_ops(&xo1_suspend_ops);
164		pm_power_off = xo1_power_off;
165		printk(KERN_INFO "OLPC XO-1 support registered\n");
166	}
167
168	return 0;
169}
170
171static int __devexit xo1_pm_remove(struct platform_device *pdev)
172{
173	mfd_cell_disable(pdev);
174
175	if (strcmp(pdev->name, "cs5535-pms") == 0)
176		pms_base = 0;
177	else if (strcmp(pdev->name, "olpc-xo1-pm-acpi") == 0)
178		acpi_base = 0;
179
180	pm_power_off = NULL;
181	return 0;
182}
183
184static struct platform_driver cs5535_pms_driver = {
185	.driver = {
186		.name = "cs5535-pms",
187		.owner = THIS_MODULE,
188	},
189	.probe = xo1_pm_probe,
190	.remove = __devexit_p(xo1_pm_remove),
191};
192
193static struct platform_driver cs5535_acpi_driver = {
194	.driver = {
195		.name = "olpc-xo1-pm-acpi",
196		.owner = THIS_MODULE,
197	},
198	.probe = xo1_pm_probe,
199	.remove = __devexit_p(xo1_pm_remove),
200};
201
202static int __init xo1_pm_init(void)
203{
204	int r;
205
206	r = platform_driver_register(&cs5535_pms_driver);
207	if (r)
208		return r;
209
210	r = platform_driver_register(&cs5535_acpi_driver);
211	if (r)
212		platform_driver_unregister(&cs5535_pms_driver);
213
214	return r;
215}
216arch_initcall(xo1_pm_init);