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 
22 static unsigned long			xo15_sci_gpe;
23 static 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 oportunistically
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  */
36 static 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 
51 static ssize_t
52 lid_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 
57 static 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 
71 static 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 
76 static 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 
86 static 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 
96 static 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 
125 static void process_sci_queue_work(struct work_struct *work)
126 {
127 	process_sci_queue();
128 }
129 
130 static DECLARE_WORK(sci_work, process_sci_queue_work);
131 
132 static 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 
138 static 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 
180 err_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 
186 static int 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 	return 0;
193 }
194 
195 #ifdef CONFIG_PM_SLEEP
196 static int xo15_sci_resume(struct device *dev)
197 {
198 	/* Enable all EC events */
199 	olpc_ec_mask_write(EC_SCI_SRC_ALL);
200 
201 	/* Power/battery status might have changed */
202 	battery_status_changed();
203 	ac_status_changed();
204 
205 	return 0;
206 }
207 #endif
208 
209 static SIMPLE_DEV_PM_OPS(xo15_sci_pm, NULL, xo15_sci_resume);
210 
211 static const struct acpi_device_id xo15_sci_device_ids[] = {
212 	{"XO15EC", 0},
213 	{"", 0},
214 };
215 
216 static struct acpi_driver xo15_sci_drv = {
217 	.name = DRV_NAME,
218 	.class = XO15_SCI_CLASS,
219 	.ids = xo15_sci_device_ids,
220 	.ops = {
221 		.add = xo15_sci_add,
222 		.remove = xo15_sci_remove,
223 	},
224 	.drv.pm = &xo15_sci_pm,
225 };
226 
227 static int __init xo15_sci_init(void)
228 {
229 	return acpi_bus_register_driver(&xo15_sci_drv);
230 }
231 device_initcall(xo15_sci_init);
232