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 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 */
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 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
195 static 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
208 static SIMPLE_DEV_PM_OPS(xo15_sci_pm, NULL, xo15_sci_resume);
209
210 static const struct acpi_device_id xo15_sci_device_ids[] = {
211 {"XO15EC", 0},
212 {"", 0},
213 };
214
215 static 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
226 static int __init xo15_sci_init(void)
227 {
228 return acpi_bus_register_driver(&xo15_sci_drv);
229 }
230 device_initcall(xo15_sci_init);
231
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