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, method: "\\_SB.PCI0.LID.LIDW", arg: 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, fmt: "%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(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(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(sci_value: &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(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(handle: device->handle, pathname: "_GPE", NULL, data: &tmp);
152 if (ACPI_FAILURE(status))
153 return -EINVAL;
154
155 xo15_sci_gpe = tmp;
156 status = acpi_install_gpe_handler(NULL, gpe_number: xo15_sci_gpe,
157 ACPI_GPE_EDGE_TRIGGERED,
158 address: xo15_sci_gpe_handler, context: 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(kobj: &device->dev.kobj, attr: &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, gpe_number: xo15_sci_gpe);
173
174 /* Enable wake-on-EC */
175 if (device->wakeup.flags.valid)
176 device_init_wakeup(dev: &device->dev, enable: true);
177
178 return 0;
179
180err_sysfs:
181 acpi_remove_gpe_handler(NULL, gpe_number: xo15_sci_gpe, address: xo15_sci_gpe_handler);
182 cancel_work_sync(work: &sci_work);
183 return r;
184}
185
186static void xo15_sci_remove(struct acpi_device *device)
187{
188 acpi_disable_gpe(NULL, gpe_number: xo15_sci_gpe);
189 acpi_remove_gpe_handler(NULL, gpe_number: xo15_sci_gpe, address: xo15_sci_gpe_handler);
190 cancel_work_sync(work: &sci_work);
191 sysfs_remove_file(kobj: &device->dev.kobj, attr: &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(driver: &xo15_sci_drv);
229}
230device_initcall(xo15_sci_init);
231

source code of linux/arch/x86/platform/olpc/olpc-xo15-sci.c