1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Support for OLPC XO-1.5 System Control Interrupts (SCI)
4 *
5 * Copyright (C) 2009-2010 One Laptop per Child
6 */
7
8#include <linux/device.h>
9#include <linux/slab.h>
10#include <linux/workqueue.h>
11#include <linux/power_supply.h>
12#include <linux/olpc-ec.h>
13
14#include <linux/acpi.h>
15#include <asm/olpc.h>
16
17#define DRV_NAME			"olpc-xo15-sci"
18#define PFX				DRV_NAME ": "
19#define XO15_SCI_CLASS			DRV_NAME
20#define XO15_SCI_DEVICE_NAME		"OLPC XO-1.5 SCI"
21
22static unsigned long			xo15_sci_gpe;
23static bool				lid_wake_on_close;
24
25/*
26 * The normal ACPI LID wakeup behavior is wake-on-open, but not
27 * wake-on-close. This is implemented as standard by the XO-1.5 DSDT.
28 *
29 * We provide here a sysfs attribute that will additionally enable
30 * wake-on-close behavior. This is useful (e.g.) when we opportunistically
31 * suspend with the display running; if the lid is then closed, we want to
32 * wake up to turn the display off.
33 *
34 * This is controlled through a custom method in the XO-1.5 DSDT.
35 */
36static int set_lid_wake_behavior(bool wake_on_close)
37{
38	acpi_status status;
39
40	status = acpi_execute_simple_method(NULL, "\\_SB.PCI0.LID.LIDW", wake_on_close);
41	if (ACPI_FAILURE(status)) {
42		pr_warn(PFX "failed to set lid behavior\n");
43		return 1;
44	}
45
46	lid_wake_on_close = wake_on_close;
47
48	return 0;
49}
50
51static ssize_t
52lid_wake_on_close_show(struct kobject *s, struct kobj_attribute *attr, char *buf)
53{
54	return sprintf(buf, "%u\n", lid_wake_on_close);
55}
56
57static ssize_t lid_wake_on_close_store(struct kobject *s,
58				       struct kobj_attribute *attr,
59				       const char *buf, size_t n)
60{
61	unsigned int val;
62
63	if (sscanf(buf, "%u", &val) != 1)
64		return -EINVAL;
65
66	set_lid_wake_behavior(!!val);
67
68	return n;
69}
70
71static struct kobj_attribute lid_wake_on_close_attr =
72	__ATTR(lid_wake_on_close, 0644,
73	       lid_wake_on_close_show,
74	       lid_wake_on_close_store);
75
76static void battery_status_changed(void)
77{
78	struct power_supply *psy = power_supply_get_by_name("olpc_battery");
79
80	if (psy) {
81		power_supply_changed(psy);
82		power_supply_put(psy);
83	}
84}
85
86static void ac_status_changed(void)
87{
88	struct power_supply *psy = power_supply_get_by_name("olpc_ac");
89
90	if (psy) {
91		power_supply_changed(psy);
92		power_supply_put(psy);
93	}
94}
95
96static void process_sci_queue(void)
97{
98	u16 data;
99	int r;
100
101	do {
102		r = olpc_ec_sci_query(&data);
103		if (r || !data)
104			break;
105
106		pr_debug(PFX "SCI 0x%x received\n", data);
107
108		switch (data) {
109		case EC_SCI_SRC_BATERR:
110		case EC_SCI_SRC_BATSOC:
111		case EC_SCI_SRC_BATTERY:
112		case EC_SCI_SRC_BATCRIT:
113			battery_status_changed();
114			break;
115		case EC_SCI_SRC_ACPWR:
116			ac_status_changed();
117			break;
118		}
119	} while (data);
120
121	if (r)
122		pr_err(PFX "Failed to clear SCI queue");
123}
124
125static void process_sci_queue_work(struct work_struct *work)
126{
127	process_sci_queue();
128}
129
130static DECLARE_WORK(sci_work, process_sci_queue_work);
131
132static u32 xo15_sci_gpe_handler(acpi_handle gpe_device, u32 gpe, void *context)
133{
134	schedule_work(&sci_work);
135	return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
136}
137
138static int xo15_sci_add(struct acpi_device *device)
139{
140	unsigned long long tmp;
141	acpi_status status;
142	int r;
143
144	if (!device)
145		return -EINVAL;
146
147	strcpy(acpi_device_name(device), XO15_SCI_DEVICE_NAME);
148	strcpy(acpi_device_class(device), XO15_SCI_CLASS);
149
150	/* Get GPE bit assignment (EC events). */
151	status = acpi_evaluate_integer(device->handle, "_GPE", NULL, &tmp);
152	if (ACPI_FAILURE(status))
153		return -EINVAL;
154
155	xo15_sci_gpe = tmp;
156	status = acpi_install_gpe_handler(NULL, xo15_sci_gpe,
157					  ACPI_GPE_EDGE_TRIGGERED,
158					  xo15_sci_gpe_handler, device);
159	if (ACPI_FAILURE(status))
160		return -ENODEV;
161
162	dev_info(&device->dev, "Initialized, GPE = 0x%lx\n", xo15_sci_gpe);
163
164	r = sysfs_create_file(&device->dev.kobj, &lid_wake_on_close_attr.attr);
165	if (r)
166		goto err_sysfs;
167
168	/* Flush queue, and enable all SCI events */
169	process_sci_queue();
170	olpc_ec_mask_write(EC_SCI_SRC_ALL);
171
172	acpi_enable_gpe(NULL, xo15_sci_gpe);
173
174	/* Enable wake-on-EC */
175	if (device->wakeup.flags.valid)
176		device_init_wakeup(&device->dev, true);
177
178	return 0;
179
180err_sysfs:
181	acpi_remove_gpe_handler(NULL, xo15_sci_gpe, xo15_sci_gpe_handler);
182	cancel_work_sync(&sci_work);
183	return r;
184}
185
186static void xo15_sci_remove(struct acpi_device *device)
187{
188	acpi_disable_gpe(NULL, xo15_sci_gpe);
189	acpi_remove_gpe_handler(NULL, xo15_sci_gpe, xo15_sci_gpe_handler);
190	cancel_work_sync(&sci_work);
191	sysfs_remove_file(&device->dev.kobj, &lid_wake_on_close_attr.attr);
192}
193
194#ifdef CONFIG_PM_SLEEP
195static int xo15_sci_resume(struct device *dev)
196{
197	/* Enable all EC events */
198	olpc_ec_mask_write(EC_SCI_SRC_ALL);
199
200	/* Power/battery status might have changed */
201	battery_status_changed();
202	ac_status_changed();
203
204	return 0;
205}
206#endif
207
208static SIMPLE_DEV_PM_OPS(xo15_sci_pm, NULL, xo15_sci_resume);
209
210static const struct acpi_device_id xo15_sci_device_ids[] = {
211	{"XO15EC", 0},
212	{"", 0},
213};
214
215static struct acpi_driver xo15_sci_drv = {
216	.name = DRV_NAME,
217	.class = XO15_SCI_CLASS,
218	.ids = xo15_sci_device_ids,
219	.ops = {
220		.add = xo15_sci_add,
221		.remove = xo15_sci_remove,
222	},
223	.drv.pm = &xo15_sci_pm,
224};
225
226static int __init xo15_sci_init(void)
227{
228	return acpi_bus_register_driver(&xo15_sci_drv);
229}
230device_initcall(xo15_sci_init);
231