1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
|
// SPDX-License-Identifier: GPL-2.0+
/*
* AC driver for 7th-generation Microsoft Surface devices via Surface System
* Aggregator Module (SSAM).
*
* Copyright (C) 2019-2021 Maximilian Luz <luzmaximilian@gmail.com>
*/
#include <asm/unaligned.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/power_supply.h>
#include <linux/types.h>
#include <linux/surface_aggregator/device.h>
/* -- SAM interface. -------------------------------------------------------- */
enum sam_event_cid_bat {
SAM_EVENT_CID_BAT_ADP = 0x17,
};
enum sam_battery_sta {
SAM_BATTERY_STA_OK = 0x0f,
SAM_BATTERY_STA_PRESENT = 0x10,
};
/* Get battery status (_STA). */
SSAM_DEFINE_SYNC_REQUEST_CL_R(ssam_bat_get_sta, __le32, {
.target_category = SSAM_SSH_TC_BAT,
.command_id = 0x01,
});
/* Get platform power source for battery (_PSR / DPTF PSRC). */
SSAM_DEFINE_SYNC_REQUEST_CL_R(ssam_bat_get_psrc, __le32, {
.target_category = SSAM_SSH_TC_BAT,
.command_id = 0x0d,
});
/* -- Device structures. ---------------------------------------------------- */
struct spwr_psy_properties {
const char *name;
struct ssam_event_registry registry;
};
struct spwr_ac_device {
struct ssam_device *sdev;
char name[32];
struct power_supply *psy;
struct power_supply_desc psy_desc;
struct ssam_event_notifier notif;
struct mutex lock; /* Guards access to state below. */
__le32 state;
};
/* -- State management. ----------------------------------------------------- */
static int spwr_ac_update_unlocked(struct spwr_ac_device *ac)
{
__le32 old = ac->state;
int status;
lockdep_assert_held(&ac->lock);
status = ssam_retry(ssam_bat_get_psrc, ac->sdev, &ac->state);
if (status < 0)
return status;
return old != ac->state;
}
static int spwr_ac_update(struct spwr_ac_device *ac)
{
int status;
mutex_lock(&ac->lock);
status = spwr_ac_update_unlocked(ac);
mutex_unlock(&ac->lock);
return status;
}
static int spwr_ac_recheck(struct spwr_ac_device *ac)
{
int status;
status = spwr_ac_update(ac);
if (status > 0)
power_supply_changed(ac->psy);
return status >= 0 ? 0 : status;
}
static u32 spwr_notify_ac(struct ssam_event_notifier *nf, const struct ssam_event *event)
{
struct spwr_ac_device *ac;
int status;
ac = container_of(nf, struct spwr_ac_device, notif);
dev_dbg(&ac->sdev->dev, "power event (cid = %#04x, iid = %#04x, tid = %#04x)\n",
event->command_id, event->instance_id, event->target_id);
/*
* Allow events of all targets/instances here. Global adapter status
* seems to be handled via target=1 and instance=1, but events are
* reported on all targets/instances in use.
*
* While it should be enough to just listen on 1/1, listen everywhere to
* make sure we don't miss anything.
*/
switch (event->command_id) {
case SAM_EVENT_CID_BAT_ADP:
status = spwr_ac_recheck(ac);
return ssam_notifier_from_errno(status) | SSAM_NOTIF_HANDLED;
default:
return 0;
}
}
/* -- Properties. ----------------------------------------------------------- */
static const enum power_supply_property spwr_ac_props[] = {
POWER_SUPPLY_PROP_ONLINE,
};
static int spwr_ac_get_property(struct power_supply *psy, enum power_supply_property psp,
union power_supply_propval *val)
{
struct spwr_ac_device *ac = power_supply_get_drvdata(psy);
int status;
mutex_lock(&ac->lock);
status = spwr_ac_update_unlocked(ac);
if (status)
goto out;
switch (psp) {
case POWER_SUPPLY_PROP_ONLINE:
val->intval = !!le32_to_cpu(ac->state);
break;
default:
status = -EINVAL;
goto out;
}
out:
mutex_unlock(&ac->lock);
return status;
}
/* -- Device setup. --------------------------------------------------------- */
static char *battery_supplied_to[] = {
"BAT1",
"BAT2",
};
static void spwr_ac_init(struct spwr_ac_device *ac, struct ssam_device *sdev,
struct ssam_event_registry registry, const char *name)
{
mutex_init(&ac->lock);
strscpy(ac->name, name, sizeof(ac->name));
ac->sdev = sdev;
ac->notif.base.priority = 1;
ac->notif.base.fn = spwr_notify_ac;
ac->notif.event.reg = registry;
ac->notif.event.id.target_category = sdev->uid.category;
ac->notif.event.id.instance = 0;
ac->notif.event.mask = SSAM_EVENT_MASK_NONE;
ac->notif.event.flags = SSAM_EVENT_SEQUENCED;
ac->psy_desc.name = ac->name;
ac->psy_desc.type = POWER_SUPPLY_TYPE_MAINS;
ac->psy_desc.properties = spwr_ac_props;
ac->psy_desc.num_properties = ARRAY_SIZE(spwr_ac_props);
ac->psy_desc.get_property = spwr_ac_get_property;
}
static int spwr_ac_register(struct spwr_ac_device *ac)
{
struct power_supply_config psy_cfg = {};
__le32 sta;
int status;
/* Make sure the device is there and functioning properly. */
status = ssam_retry(ssam_bat_get_sta, ac->sdev, &sta);
if (status)
return status;
if ((le32_to_cpu(sta) & SAM_BATTERY_STA_OK) != SAM_BATTERY_STA_OK)
return -ENODEV;
psy_cfg.drv_data = ac;
psy_cfg.supplied_to = battery_supplied_to;
psy_cfg.num_supplicants = ARRAY_SIZE(battery_supplied_to);
ac->psy = devm_power_supply_register(&ac->sdev->dev, &ac->psy_desc, &psy_cfg);
if (IS_ERR(ac->psy))
return PTR_ERR(ac->psy);
return ssam_device_notifier_register(ac->sdev, &ac->notif);
}
/* -- Driver setup. --------------------------------------------------------- */
static int __maybe_unused surface_ac_resume(struct device *dev)
{
return spwr_ac_recheck(dev_get_drvdata(dev));
}
static SIMPLE_DEV_PM_OPS(surface_ac_pm_ops, NULL, surface_ac_resume);
static int surface_ac_probe(struct ssam_device *sdev)
{
const struct spwr_psy_properties *p;
struct spwr_ac_device *ac;
p = ssam_device_get_match_data(sdev);
if (!p)
return -ENODEV;
ac = devm_kzalloc(&sdev->dev, sizeof(*ac), GFP_KERNEL);
if (!ac)
return -ENOMEM;
spwr_ac_init(ac, sdev, p->registry, p->name);
ssam_device_set_drvdata(sdev, ac);
return spwr_ac_register(ac);
}
static void surface_ac_remove(struct ssam_device *sdev)
{
struct spwr_ac_device *ac = ssam_device_get_drvdata(sdev);
ssam_device_notifier_unregister(sdev, &ac->notif);
}
static const struct spwr_psy_properties spwr_psy_props_adp1 = {
.name = "ADP1",
.registry = SSAM_EVENT_REGISTRY_SAM,
};
static const struct ssam_device_id surface_ac_match[] = {
{ SSAM_SDEV(BAT, SAM, 0x01, 0x01), (unsigned long)&spwr_psy_props_adp1 },
{ },
};
MODULE_DEVICE_TABLE(ssam, surface_ac_match);
static struct ssam_device_driver surface_ac_driver = {
.probe = surface_ac_probe,
.remove = surface_ac_remove,
.match_table = surface_ac_match,
.driver = {
.name = "surface_ac",
.pm = &surface_ac_pm_ops,
.probe_type = PROBE_PREFER_ASYNCHRONOUS,
},
};
module_ssam_device_driver(surface_ac_driver);
MODULE_AUTHOR("Maximilian Luz <luzmaximilian@gmail.com>");
MODULE_DESCRIPTION("AC driver for Surface System Aggregator Module");
MODULE_LICENSE("GPL");
|
