1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * ChromeOS EC multi-function device |
4 | * |
5 | * Copyright (C) 2012 Google, Inc |
6 | * |
7 | * The ChromeOS EC multi function device is used to mux all the requests |
8 | * to the EC device for its multiple features: keyboard controller, |
9 | * battery charging and regulator control, firmware update. |
10 | */ |
11 | |
12 | #include <linux/interrupt.h> |
13 | #include <linux/module.h> |
14 | #include <linux/of_platform.h> |
15 | #include <linux/platform_device.h> |
16 | #include <linux/platform_data/cros_ec_commands.h> |
17 | #include <linux/platform_data/cros_ec_proto.h> |
18 | #include <linux/slab.h> |
19 | #include <linux/suspend.h> |
20 | |
21 | #include "cros_ec.h" |
22 | |
23 | static struct cros_ec_platform ec_p = { |
24 | .ec_name = CROS_EC_DEV_NAME, |
25 | .cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_EC_INDEX), |
26 | }; |
27 | |
28 | static struct cros_ec_platform pd_p = { |
29 | .ec_name = CROS_EC_DEV_PD_NAME, |
30 | .cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX), |
31 | }; |
32 | |
33 | /** |
34 | * cros_ec_irq_handler() - top half part of the interrupt handler |
35 | * @irq: IRQ id |
36 | * @data: (ec_dev) Device with events to process. |
37 | * |
38 | * Return: Wakeup the bottom half |
39 | */ |
40 | static irqreturn_t cros_ec_irq_handler(int irq, void *data) |
41 | { |
42 | struct cros_ec_device *ec_dev = data; |
43 | |
44 | ec_dev->last_event_time = cros_ec_get_time_ns(); |
45 | |
46 | return IRQ_WAKE_THREAD; |
47 | } |
48 | |
49 | /** |
50 | * cros_ec_handle_event() - process and forward pending events on EC |
51 | * @ec_dev: Device with events to process. |
52 | * |
53 | * Call this function in a loop when the kernel is notified that the EC has |
54 | * pending events. |
55 | * |
56 | * Return: true if more events are still pending and this function should be |
57 | * called again. |
58 | */ |
59 | static bool cros_ec_handle_event(struct cros_ec_device *ec_dev) |
60 | { |
61 | bool wake_event; |
62 | bool ec_has_more_events; |
63 | int ret; |
64 | |
65 | ret = cros_ec_get_next_event(ec_dev, wake_event: &wake_event, has_more_events: &ec_has_more_events); |
66 | |
67 | /* |
68 | * Signal only if wake host events or any interrupt if |
69 | * cros_ec_get_next_event() returned an error (default value for |
70 | * wake_event is true) |
71 | */ |
72 | if (wake_event && device_may_wakeup(dev: ec_dev->dev)) |
73 | pm_wakeup_event(dev: ec_dev->dev, msec: 0); |
74 | |
75 | if (ret > 0) |
76 | blocking_notifier_call_chain(nh: &ec_dev->event_notifier, |
77 | val: 0, v: ec_dev); |
78 | |
79 | return ec_has_more_events; |
80 | } |
81 | |
82 | /** |
83 | * cros_ec_irq_thread() - bottom half part of the interrupt handler |
84 | * @irq: IRQ id |
85 | * @data: (ec_dev) Device with events to process. |
86 | * |
87 | * Return: Interrupt handled. |
88 | */ |
89 | irqreturn_t cros_ec_irq_thread(int irq, void *data) |
90 | { |
91 | struct cros_ec_device *ec_dev = data; |
92 | bool ec_has_more_events; |
93 | |
94 | do { |
95 | ec_has_more_events = cros_ec_handle_event(ec_dev); |
96 | } while (ec_has_more_events); |
97 | |
98 | return IRQ_HANDLED; |
99 | } |
100 | EXPORT_SYMBOL(cros_ec_irq_thread); |
101 | |
102 | static int cros_ec_sleep_event(struct cros_ec_device *ec_dev, u8 sleep_event) |
103 | { |
104 | int ret; |
105 | struct { |
106 | struct cros_ec_command msg; |
107 | union { |
108 | struct ec_params_host_sleep_event req0; |
109 | struct ec_params_host_sleep_event_v1 req1; |
110 | struct ec_response_host_sleep_event_v1 resp1; |
111 | } u; |
112 | } __packed buf; |
113 | |
114 | memset(&buf, 0, sizeof(buf)); |
115 | |
116 | if (ec_dev->host_sleep_v1) { |
117 | buf.u.req1.sleep_event = sleep_event; |
118 | buf.u.req1.suspend_params.sleep_timeout_ms = |
119 | ec_dev->suspend_timeout_ms; |
120 | |
121 | buf.msg.outsize = sizeof(buf.u.req1); |
122 | if ((sleep_event == HOST_SLEEP_EVENT_S3_RESUME) || |
123 | (sleep_event == HOST_SLEEP_EVENT_S0IX_RESUME)) |
124 | buf.msg.insize = sizeof(buf.u.resp1); |
125 | |
126 | buf.msg.version = 1; |
127 | |
128 | } else { |
129 | buf.u.req0.sleep_event = sleep_event; |
130 | buf.msg.outsize = sizeof(buf.u.req0); |
131 | } |
132 | |
133 | buf.msg.command = EC_CMD_HOST_SLEEP_EVENT; |
134 | |
135 | ret = cros_ec_cmd_xfer_status(ec_dev, msg: &buf.msg); |
136 | /* Report failure to transition to system wide suspend with a warning. */ |
137 | if (ret >= 0 && ec_dev->host_sleep_v1 && |
138 | (sleep_event == HOST_SLEEP_EVENT_S0IX_RESUME || |
139 | sleep_event == HOST_SLEEP_EVENT_S3_RESUME)) { |
140 | ec_dev->last_resume_result = |
141 | buf.u.resp1.resume_response.sleep_transitions; |
142 | |
143 | WARN_ONCE(buf.u.resp1.resume_response.sleep_transitions & |
144 | EC_HOST_RESUME_SLEEP_TIMEOUT, |
145 | "EC detected sleep transition timeout. Total sleep transitions: %d" , |
146 | buf.u.resp1.resume_response.sleep_transitions & |
147 | EC_HOST_RESUME_SLEEP_TRANSITIONS_MASK); |
148 | } |
149 | |
150 | return ret; |
151 | } |
152 | |
153 | static int cros_ec_ready_event(struct notifier_block *nb, |
154 | unsigned long queued_during_suspend, |
155 | void *_notify) |
156 | { |
157 | struct cros_ec_device *ec_dev = container_of(nb, struct cros_ec_device, |
158 | notifier_ready); |
159 | u32 host_event = cros_ec_get_host_event(ec_dev); |
160 | |
161 | if (host_event & EC_HOST_EVENT_MASK(EC_HOST_EVENT_INTERFACE_READY)) { |
162 | mutex_lock(&ec_dev->lock); |
163 | cros_ec_query_all(ec_dev); |
164 | mutex_unlock(lock: &ec_dev->lock); |
165 | return NOTIFY_OK; |
166 | } |
167 | |
168 | return NOTIFY_DONE; |
169 | } |
170 | |
171 | /** |
172 | * cros_ec_register() - Register a new ChromeOS EC, using the provided info. |
173 | * @ec_dev: Device to register. |
174 | * |
175 | * Before calling this, allocate a pointer to a new device and then fill |
176 | * in all the fields up to the --private-- marker. |
177 | * |
178 | * Return: 0 on success or negative error code. |
179 | */ |
180 | int cros_ec_register(struct cros_ec_device *ec_dev) |
181 | { |
182 | struct device *dev = ec_dev->dev; |
183 | int err = 0; |
184 | |
185 | BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->event_notifier); |
186 | BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->panic_notifier); |
187 | |
188 | ec_dev->max_request = sizeof(struct ec_params_hello); |
189 | ec_dev->max_response = sizeof(struct ec_response_get_protocol_info); |
190 | ec_dev->max_passthru = 0; |
191 | ec_dev->ec = NULL; |
192 | ec_dev->pd = NULL; |
193 | ec_dev->suspend_timeout_ms = EC_HOST_SLEEP_TIMEOUT_DEFAULT; |
194 | |
195 | ec_dev->din = devm_kzalloc(dev, size: ec_dev->din_size, GFP_KERNEL); |
196 | if (!ec_dev->din) |
197 | return -ENOMEM; |
198 | |
199 | ec_dev->dout = devm_kzalloc(dev, size: ec_dev->dout_size, GFP_KERNEL); |
200 | if (!ec_dev->dout) |
201 | return -ENOMEM; |
202 | |
203 | lockdep_register_key(key: &ec_dev->lockdep_key); |
204 | mutex_init(&ec_dev->lock); |
205 | lockdep_set_class(&ec_dev->lock, &ec_dev->lockdep_key); |
206 | |
207 | err = cros_ec_query_all(ec_dev); |
208 | if (err) { |
209 | dev_err(dev, "Cannot identify the EC: error %d\n" , err); |
210 | goto exit; |
211 | } |
212 | |
213 | if (ec_dev->irq > 0) { |
214 | err = devm_request_threaded_irq(dev, irq: ec_dev->irq, |
215 | handler: cros_ec_irq_handler, |
216 | thread_fn: cros_ec_irq_thread, |
217 | IRQF_TRIGGER_LOW | IRQF_ONESHOT, |
218 | devname: "chromeos-ec" , dev_id: ec_dev); |
219 | if (err) { |
220 | dev_err(dev, "Failed to request IRQ %d: %d\n" , |
221 | ec_dev->irq, err); |
222 | goto exit; |
223 | } |
224 | } |
225 | |
226 | /* Register a platform device for the main EC instance */ |
227 | ec_dev->ec = platform_device_register_data(parent: ec_dev->dev, name: "cros-ec-dev" , |
228 | PLATFORM_DEVID_AUTO, data: &ec_p, |
229 | size: sizeof(struct cros_ec_platform)); |
230 | if (IS_ERR(ptr: ec_dev->ec)) { |
231 | dev_err(ec_dev->dev, |
232 | "Failed to create CrOS EC platform device\n" ); |
233 | err = PTR_ERR(ptr: ec_dev->ec); |
234 | goto exit; |
235 | } |
236 | |
237 | if (ec_dev->max_passthru) { |
238 | /* |
239 | * Register a platform device for the PD behind the main EC. |
240 | * We make the following assumptions: |
241 | * - behind an EC, we have a pd |
242 | * - only one device added. |
243 | * - the EC is responsive at init time (it is not true for a |
244 | * sensor hub). |
245 | */ |
246 | ec_dev->pd = platform_device_register_data(parent: ec_dev->dev, |
247 | name: "cros-ec-dev" , |
248 | PLATFORM_DEVID_AUTO, data: &pd_p, |
249 | size: sizeof(struct cros_ec_platform)); |
250 | if (IS_ERR(ptr: ec_dev->pd)) { |
251 | dev_err(ec_dev->dev, |
252 | "Failed to create CrOS PD platform device\n" ); |
253 | err = PTR_ERR(ptr: ec_dev->pd); |
254 | goto exit; |
255 | } |
256 | } |
257 | |
258 | if (IS_ENABLED(CONFIG_OF) && dev->of_node) { |
259 | err = devm_of_platform_populate(dev); |
260 | if (err) { |
261 | dev_err(dev, "Failed to register sub-devices\n" ); |
262 | goto exit; |
263 | } |
264 | } |
265 | |
266 | /* |
267 | * Clear sleep event - this will fail harmlessly on platforms that |
268 | * don't implement the sleep event host command. |
269 | */ |
270 | err = cros_ec_sleep_event(ec_dev, sleep_event: 0); |
271 | if (err < 0) |
272 | dev_dbg(ec_dev->dev, "Error %d clearing sleep event to ec\n" , |
273 | err); |
274 | |
275 | if (ec_dev->mkbp_event_supported) { |
276 | /* |
277 | * Register the notifier for EC_HOST_EVENT_INTERFACE_READY |
278 | * event. |
279 | */ |
280 | ec_dev->notifier_ready.notifier_call = cros_ec_ready_event; |
281 | err = blocking_notifier_chain_register(nh: &ec_dev->event_notifier, |
282 | nb: &ec_dev->notifier_ready); |
283 | if (err) |
284 | goto exit; |
285 | } |
286 | |
287 | dev_info(dev, "Chrome EC device registered\n" ); |
288 | |
289 | /* |
290 | * Unlock EC that may be waiting for AP to process MKBP events. |
291 | * If the AP takes to long to answer, the EC would stop sending events. |
292 | */ |
293 | if (ec_dev->mkbp_event_supported) |
294 | cros_ec_irq_thread(0, ec_dev); |
295 | |
296 | return 0; |
297 | exit: |
298 | platform_device_unregister(ec_dev->ec); |
299 | platform_device_unregister(ec_dev->pd); |
300 | mutex_destroy(lock: &ec_dev->lock); |
301 | lockdep_unregister_key(key: &ec_dev->lockdep_key); |
302 | return err; |
303 | } |
304 | EXPORT_SYMBOL(cros_ec_register); |
305 | |
306 | /** |
307 | * cros_ec_unregister() - Remove a ChromeOS EC. |
308 | * @ec_dev: Device to unregister. |
309 | * |
310 | * Call this to deregister a ChromeOS EC, then clean up any private data. |
311 | * |
312 | * Return: 0 on success or negative error code. |
313 | */ |
314 | void cros_ec_unregister(struct cros_ec_device *ec_dev) |
315 | { |
316 | platform_device_unregister(ec_dev->pd); |
317 | platform_device_unregister(ec_dev->ec); |
318 | mutex_destroy(lock: &ec_dev->lock); |
319 | lockdep_unregister_key(key: &ec_dev->lockdep_key); |
320 | } |
321 | EXPORT_SYMBOL(cros_ec_unregister); |
322 | |
323 | #ifdef CONFIG_PM_SLEEP |
324 | static void cros_ec_send_suspend_event(struct cros_ec_device *ec_dev) |
325 | { |
326 | int ret; |
327 | u8 sleep_event; |
328 | |
329 | sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ? |
330 | HOST_SLEEP_EVENT_S3_SUSPEND : |
331 | HOST_SLEEP_EVENT_S0IX_SUSPEND; |
332 | |
333 | ret = cros_ec_sleep_event(ec_dev, sleep_event); |
334 | if (ret < 0) |
335 | dev_dbg(ec_dev->dev, "Error %d sending suspend event to ec\n" , |
336 | ret); |
337 | } |
338 | |
339 | /** |
340 | * cros_ec_suspend_prepare() - Handle a suspend prepare operation for the ChromeOS EC device. |
341 | * @ec_dev: Device to suspend. |
342 | * |
343 | * This can be called by drivers to handle a suspend prepare stage of suspend. |
344 | * |
345 | * Return: 0 always. |
346 | */ |
347 | int cros_ec_suspend_prepare(struct cros_ec_device *ec_dev) |
348 | { |
349 | cros_ec_send_suspend_event(ec_dev); |
350 | return 0; |
351 | } |
352 | EXPORT_SYMBOL(cros_ec_suspend_prepare); |
353 | |
354 | static void cros_ec_disable_irq(struct cros_ec_device *ec_dev) |
355 | { |
356 | struct device *dev = ec_dev->dev; |
357 | if (device_may_wakeup(dev)) |
358 | ec_dev->wake_enabled = !enable_irq_wake(irq: ec_dev->irq); |
359 | else |
360 | ec_dev->wake_enabled = false; |
361 | |
362 | disable_irq(irq: ec_dev->irq); |
363 | ec_dev->suspended = true; |
364 | } |
365 | |
366 | /** |
367 | * cros_ec_suspend_late() - Handle a suspend late operation for the ChromeOS EC device. |
368 | * @ec_dev: Device to suspend. |
369 | * |
370 | * This can be called by drivers to handle a suspend late stage of suspend. |
371 | * |
372 | * Return: 0 always. |
373 | */ |
374 | int cros_ec_suspend_late(struct cros_ec_device *ec_dev) |
375 | { |
376 | cros_ec_disable_irq(ec_dev); |
377 | return 0; |
378 | } |
379 | EXPORT_SYMBOL(cros_ec_suspend_late); |
380 | |
381 | /** |
382 | * cros_ec_suspend() - Handle a suspend operation for the ChromeOS EC device. |
383 | * @ec_dev: Device to suspend. |
384 | * |
385 | * This can be called by drivers to handle a suspend event. |
386 | * |
387 | * Return: 0 always. |
388 | */ |
389 | int cros_ec_suspend(struct cros_ec_device *ec_dev) |
390 | { |
391 | cros_ec_send_suspend_event(ec_dev); |
392 | cros_ec_disable_irq(ec_dev); |
393 | return 0; |
394 | } |
395 | EXPORT_SYMBOL(cros_ec_suspend); |
396 | |
397 | static void cros_ec_report_events_during_suspend(struct cros_ec_device *ec_dev) |
398 | { |
399 | bool wake_event; |
400 | |
401 | while (ec_dev->mkbp_event_supported && |
402 | cros_ec_get_next_event(ec_dev, wake_event: &wake_event, NULL) > 0) { |
403 | blocking_notifier_call_chain(nh: &ec_dev->event_notifier, |
404 | val: 1, v: ec_dev); |
405 | |
406 | if (wake_event && device_may_wakeup(dev: ec_dev->dev)) |
407 | pm_wakeup_event(dev: ec_dev->dev, msec: 0); |
408 | } |
409 | } |
410 | |
411 | static void cros_ec_send_resume_event(struct cros_ec_device *ec_dev) |
412 | { |
413 | int ret; |
414 | u8 sleep_event; |
415 | |
416 | sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ? |
417 | HOST_SLEEP_EVENT_S3_RESUME : |
418 | HOST_SLEEP_EVENT_S0IX_RESUME; |
419 | |
420 | ret = cros_ec_sleep_event(ec_dev, sleep_event); |
421 | if (ret < 0) |
422 | dev_dbg(ec_dev->dev, "Error %d sending resume event to ec\n" , |
423 | ret); |
424 | } |
425 | |
426 | /** |
427 | * cros_ec_resume_complete() - Handle a resume complete operation for the ChromeOS EC device. |
428 | * @ec_dev: Device to resume. |
429 | * |
430 | * This can be called by drivers to handle a resume complete stage of resume. |
431 | */ |
432 | void cros_ec_resume_complete(struct cros_ec_device *ec_dev) |
433 | { |
434 | cros_ec_send_resume_event(ec_dev); |
435 | } |
436 | EXPORT_SYMBOL(cros_ec_resume_complete); |
437 | |
438 | static void cros_ec_enable_irq(struct cros_ec_device *ec_dev) |
439 | { |
440 | ec_dev->suspended = false; |
441 | enable_irq(irq: ec_dev->irq); |
442 | |
443 | if (ec_dev->wake_enabled) |
444 | disable_irq_wake(irq: ec_dev->irq); |
445 | |
446 | /* |
447 | * Let the mfd devices know about events that occur during |
448 | * suspend. This way the clients know what to do with them. |
449 | */ |
450 | cros_ec_report_events_during_suspend(ec_dev); |
451 | } |
452 | |
453 | /** |
454 | * cros_ec_resume_early() - Handle a resume early operation for the ChromeOS EC device. |
455 | * @ec_dev: Device to resume. |
456 | * |
457 | * This can be called by drivers to handle a resume early stage of resume. |
458 | * |
459 | * Return: 0 always. |
460 | */ |
461 | int cros_ec_resume_early(struct cros_ec_device *ec_dev) |
462 | { |
463 | cros_ec_enable_irq(ec_dev); |
464 | return 0; |
465 | } |
466 | EXPORT_SYMBOL(cros_ec_resume_early); |
467 | |
468 | /** |
469 | * cros_ec_resume() - Handle a resume operation for the ChromeOS EC device. |
470 | * @ec_dev: Device to resume. |
471 | * |
472 | * This can be called by drivers to handle a resume event. |
473 | * |
474 | * Return: 0 always. |
475 | */ |
476 | int cros_ec_resume(struct cros_ec_device *ec_dev) |
477 | { |
478 | cros_ec_enable_irq(ec_dev); |
479 | cros_ec_send_resume_event(ec_dev); |
480 | return 0; |
481 | } |
482 | EXPORT_SYMBOL(cros_ec_resume); |
483 | |
484 | #endif |
485 | |
486 | MODULE_LICENSE("GPL" ); |
487 | MODULE_DESCRIPTION("ChromeOS EC core driver" ); |
488 | |