1/*
2 * Support for OLPC XO-1.5 System Control Interrupts (SCI)
3 *
4 * Copyright (C) 2009-2010 One Laptop per Child
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 */
11
12#include <linux/device.h>
13#include <linux/slab.h>
14#include <linux/workqueue.h>
15#include <linux/power_supply.h>
16#include <linux/olpc-ec.h>
17
18#include <linux/acpi.h>
19#include <asm/olpc.h>
20
21#define DRV_NAME			"olpc-xo15-sci"
22#define PFX				DRV_NAME ": "
23#define XO15_SCI_CLASS			DRV_NAME
24#define XO15_SCI_DEVICE_NAME		"OLPC XO-1.5 SCI"
25
26static unsigned long			xo15_sci_gpe;
27static bool				lid_wake_on_close;
28
29/*
30 * The normal ACPI LID wakeup behavior is wake-on-open, but not
31 * wake-on-close. This is implemented as standard by the XO-1.5 DSDT.
32 *
33 * We provide here a sysfs attribute that will additionally enable
34 * wake-on-close behavior. This is useful (e.g.) when we oportunistically
35 * suspend with the display running; if the lid is then closed, we want to
36 * wake up to turn the display off.
37 *
38 * This is controlled through a custom method in the XO-1.5 DSDT.
39 */
40static int set_lid_wake_behavior(bool wake_on_close)
41{
42	acpi_status status;
43
44	status = acpi_execute_simple_method(NULL, "\\_SB.PCI0.LID.LIDW", wake_on_close);
45	if (ACPI_FAILURE(status)) {
46		pr_warning(PFX "failed to set lid behavior\n");
47		return 1;
48	}
49
50	lid_wake_on_close = wake_on_close;
51
52	return 0;
53}
54
55static ssize_t
56lid_wake_on_close_show(struct kobject *s, struct kobj_attribute *attr, char *buf)
57{
58	return sprintf(buf, "%u\n", lid_wake_on_close);
59}
60
61static ssize_t lid_wake_on_close_store(struct kobject *s,
62				       struct kobj_attribute *attr,
63				       const char *buf, size_t n)
64{
65	unsigned int val;
66
67	if (sscanf(buf, "%u", &val) != 1)
68		return -EINVAL;
69
70	set_lid_wake_behavior(!!val);
71
72	return n;
73}
74
75static struct kobj_attribute lid_wake_on_close_attr =
76	__ATTR(lid_wake_on_close, 0644,
77	       lid_wake_on_close_show,
78	       lid_wake_on_close_store);
79
80static void battery_status_changed(void)
81{
82	struct power_supply *psy = power_supply_get_by_name("olpc-battery");
83
84	if (psy) {
85		power_supply_changed(psy);
86		power_supply_put(psy);
87	}
88}
89
90static void ac_status_changed(void)
91{
92	struct power_supply *psy = power_supply_get_by_name("olpc-ac");
93
94	if (psy) {
95		power_supply_changed(psy);
96		power_supply_put(psy);
97	}
98}
99
100static void process_sci_queue(void)
101{
102	u16 data;
103	int r;
104
105	do {
106		r = olpc_ec_sci_query(&data);
107		if (r || !data)
108			break;
109
110		pr_debug(PFX "SCI 0x%x received\n", data);
111
112		switch (data) {
113		case EC_SCI_SRC_BATERR:
114		case EC_SCI_SRC_BATSOC:
115		case EC_SCI_SRC_BATTERY:
116		case EC_SCI_SRC_BATCRIT:
117			battery_status_changed();
118			break;
119		case EC_SCI_SRC_ACPWR:
120			ac_status_changed();
121			break;
122		}
123	} while (data);
124
125	if (r)
126		pr_err(PFX "Failed to clear SCI queue");
127}
128
129static void process_sci_queue_work(struct work_struct *work)
130{
131	process_sci_queue();
132}
133
134static DECLARE_WORK(sci_work, process_sci_queue_work);
135
136static u32 xo15_sci_gpe_handler(acpi_handle gpe_device, u32 gpe, void *context)
137{
138	schedule_work(&sci_work);
139	return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
140}
141
142static int xo15_sci_add(struct acpi_device *device)
143{
144	unsigned long long tmp;
145	acpi_status status;
146	int r;
147
148	if (!device)
149		return -EINVAL;
150
151	strcpy(acpi_device_name(device), XO15_SCI_DEVICE_NAME);
152	strcpy(acpi_device_class(device), XO15_SCI_CLASS);
153
154	/* Get GPE bit assignment (EC events). */
155	status = acpi_evaluate_integer(device->handle, "_GPE", NULL, &tmp);
156	if (ACPI_FAILURE(status))
157		return -EINVAL;
158
159	xo15_sci_gpe = tmp;
160	status = acpi_install_gpe_handler(NULL, xo15_sci_gpe,
161					  ACPI_GPE_EDGE_TRIGGERED,
162					  xo15_sci_gpe_handler, device);
163	if (ACPI_FAILURE(status))
164		return -ENODEV;
165
166	dev_info(&device->dev, "Initialized, GPE = 0x%lx\n", xo15_sci_gpe);
167
168	r = sysfs_create_file(&device->dev.kobj, &lid_wake_on_close_attr.attr);
169	if (r)
170		goto err_sysfs;
171
172	/* Flush queue, and enable all SCI events */
173	process_sci_queue();
174	olpc_ec_mask_write(EC_SCI_SRC_ALL);
175
176	acpi_enable_gpe(NULL, xo15_sci_gpe);
177
178	/* Enable wake-on-EC */
179	if (device->wakeup.flags.valid)
180		device_init_wakeup(&device->dev, true);
181
182	return 0;
183
184err_sysfs:
185	acpi_remove_gpe_handler(NULL, xo15_sci_gpe, xo15_sci_gpe_handler);
186	cancel_work_sync(&sci_work);
187	return r;
188}
189
190static int xo15_sci_remove(struct acpi_device *device)
191{
192	acpi_disable_gpe(NULL, xo15_sci_gpe);
193	acpi_remove_gpe_handler(NULL, xo15_sci_gpe, xo15_sci_gpe_handler);
194	cancel_work_sync(&sci_work);
195	sysfs_remove_file(&device->dev.kobj, &lid_wake_on_close_attr.attr);
196	return 0;
197}
198
199static int xo15_sci_resume(struct device *dev)
200{
201	/* Enable all EC events */
202	olpc_ec_mask_write(EC_SCI_SRC_ALL);
203
204	/* Power/battery status might have changed */
205	battery_status_changed();
206	ac_status_changed();
207
208	return 0;
209}
210
211static SIMPLE_DEV_PM_OPS(xo15_sci_pm, NULL, xo15_sci_resume);
212
213static const struct acpi_device_id xo15_sci_device_ids[] = {
214	{"XO15EC", 0},
215	{"", 0},
216};
217
218static struct acpi_driver xo15_sci_drv = {
219	.name = DRV_NAME,
220	.class = XO15_SCI_CLASS,
221	.ids = xo15_sci_device_ids,
222	.ops = {
223		.add = xo15_sci_add,
224		.remove = xo15_sci_remove,
225	},
226	.drv.pm = &xo15_sci_pm,
227};
228
229static int __init xo15_sci_init(void)
230{
231	return acpi_bus_register_driver(&xo15_sci_drv);
232}
233device_initcall(xo15_sci_init);
234