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/cleanup.h>
13#include <linux/interrupt.h>
14#include <linux/module.h>
15#include <linux/of_platform.h>
16#include <linux/platform_device.h>
17#include <linux/platform_data/cros_ec_commands.h>
18#include <linux/platform_data/cros_ec_proto.h>
19#include <linux/slab.h>
20#include <linux/suspend.h>
21
22#include "cros_ec.h"
23
24static struct cros_ec_platform ec_p = {
25 .ec_name = CROS_EC_DEV_NAME,
26 .cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_EC_INDEX),
27};
28
29static struct cros_ec_platform pd_p = {
30 .ec_name = CROS_EC_DEV_PD_NAME,
31 .cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX),
32};
33
34static void cros_ec_device_free(void *data)
35{
36 struct cros_ec_device *ec_dev = data;
37
38 mutex_destroy(lock: &ec_dev->lock);
39 lockdep_unregister_key(key: &ec_dev->lockdep_key);
40}
41
42struct cros_ec_device *cros_ec_device_alloc(struct device *dev)
43{
44 struct cros_ec_device *ec_dev;
45
46 ec_dev = devm_kzalloc(dev, size: sizeof(*ec_dev), GFP_KERNEL);
47 if (!ec_dev)
48 return NULL;
49
50 ec_dev->din_size = sizeof(struct ec_host_response) +
51 sizeof(struct ec_response_get_protocol_info) +
52 EC_MAX_RESPONSE_OVERHEAD;
53 ec_dev->dout_size = sizeof(struct ec_host_request) +
54 sizeof(struct ec_params_rwsig_action) +
55 EC_MAX_REQUEST_OVERHEAD;
56
57 ec_dev->din = devm_kzalloc(dev, size: ec_dev->din_size, GFP_KERNEL);
58 if (!ec_dev->din)
59 return NULL;
60
61 ec_dev->dout = devm_kzalloc(dev, size: ec_dev->dout_size, GFP_KERNEL);
62 if (!ec_dev->dout)
63 return NULL;
64
65 ec_dev->dev = dev;
66 ec_dev->max_response = sizeof(struct ec_response_get_protocol_info);
67 ec_dev->max_request = sizeof(struct ec_params_rwsig_action);
68 ec_dev->suspend_timeout_ms = EC_HOST_SLEEP_TIMEOUT_DEFAULT;
69
70 BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->event_notifier);
71 BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->panic_notifier);
72
73 lockdep_register_key(key: &ec_dev->lockdep_key);
74 mutex_init(&ec_dev->lock);
75 lockdep_set_class(&ec_dev->lock, &ec_dev->lockdep_key);
76
77 if (devm_add_action_or_reset(dev, cros_ec_device_free, ec_dev))
78 return NULL;
79
80 return ec_dev;
81}
82EXPORT_SYMBOL(cros_ec_device_alloc);
83
84/**
85 * cros_ec_irq_handler() - top half part of the interrupt handler
86 * @irq: IRQ id
87 * @data: (ec_dev) Device with events to process.
88 *
89 * Return: Wakeup the bottom half
90 */
91static irqreturn_t cros_ec_irq_handler(int irq, void *data)
92{
93 struct cros_ec_device *ec_dev = data;
94
95 ec_dev->last_event_time = cros_ec_get_time_ns();
96
97 return IRQ_WAKE_THREAD;
98}
99
100/**
101 * cros_ec_handle_event() - process and forward pending events on EC
102 * @ec_dev: Device with events to process.
103 *
104 * Call this function in a loop when the kernel is notified that the EC has
105 * pending events.
106 *
107 * Return: true if more events are still pending and this function should be
108 * called again.
109 */
110static bool cros_ec_handle_event(struct cros_ec_device *ec_dev)
111{
112 bool wake_event;
113 bool ec_has_more_events;
114 int ret;
115
116 ret = cros_ec_get_next_event(ec_dev, wake_event: &wake_event, has_more_events: &ec_has_more_events);
117
118 /*
119 * Signal only if wake host events or any interrupt if
120 * cros_ec_get_next_event() returned an error (default value for
121 * wake_event is true)
122 */
123 if (wake_event && device_may_wakeup(dev: ec_dev->dev))
124 pm_wakeup_event(dev: ec_dev->dev, msec: 0);
125
126 if (ret > 0)
127 blocking_notifier_call_chain(nh: &ec_dev->event_notifier,
128 val: 0, v: ec_dev);
129
130 return ec_has_more_events;
131}
132
133/**
134 * cros_ec_irq_thread() - bottom half part of the interrupt handler
135 * @irq: IRQ id
136 * @data: (ec_dev) Device with events to process.
137 *
138 * Return: Interrupt handled.
139 */
140irqreturn_t cros_ec_irq_thread(int irq, void *data)
141{
142 struct cros_ec_device *ec_dev = data;
143 bool ec_has_more_events;
144
145 do {
146 ec_has_more_events = cros_ec_handle_event(ec_dev);
147 } while (ec_has_more_events);
148
149 return IRQ_HANDLED;
150}
151EXPORT_SYMBOL(cros_ec_irq_thread);
152
153static int cros_ec_sleep_event(struct cros_ec_device *ec_dev, u8 sleep_event)
154{
155 int ret;
156 TRAILING_OVERLAP(struct cros_ec_command, msg, data,
157 union {
158 struct ec_params_host_sleep_event req0;
159 struct ec_params_host_sleep_event_v1 req1;
160 struct ec_response_host_sleep_event_v1 resp1;
161 } u;
162 ) __packed buf;
163
164 memset(&buf, 0, sizeof(buf));
165
166 if (ec_dev->host_sleep_v1) {
167 buf.u.req1.sleep_event = sleep_event;
168 buf.u.req1.suspend_params.sleep_timeout_ms =
169 ec_dev->suspend_timeout_ms;
170
171 buf.msg.outsize = sizeof(buf.u.req1);
172 if ((sleep_event == HOST_SLEEP_EVENT_S3_RESUME) ||
173 (sleep_event == HOST_SLEEP_EVENT_S0IX_RESUME))
174 buf.msg.insize = sizeof(buf.u.resp1);
175
176 buf.msg.version = 1;
177
178 } else {
179 buf.u.req0.sleep_event = sleep_event;
180 buf.msg.outsize = sizeof(buf.u.req0);
181 }
182
183 buf.msg.command = EC_CMD_HOST_SLEEP_EVENT;
184
185 ret = cros_ec_cmd_xfer_status(ec_dev, msg: &buf.msg);
186 /* Report failure to transition to system wide suspend with a warning. */
187 if (ret >= 0 && ec_dev->host_sleep_v1 &&
188 (sleep_event == HOST_SLEEP_EVENT_S0IX_RESUME ||
189 sleep_event == HOST_SLEEP_EVENT_S3_RESUME)) {
190 ec_dev->last_resume_result =
191 buf.u.resp1.resume_response.sleep_transitions;
192
193 WARN_ONCE(buf.u.resp1.resume_response.sleep_transitions &
194 EC_HOST_RESUME_SLEEP_TIMEOUT,
195 "EC detected sleep transition timeout. Total sleep transitions: %d",
196 buf.u.resp1.resume_response.sleep_transitions &
197 EC_HOST_RESUME_SLEEP_TRANSITIONS_MASK);
198 }
199
200 return ret;
201}
202
203static int cros_ec_ready_event(struct notifier_block *nb,
204 unsigned long queued_during_suspend,
205 void *_notify)
206{
207 struct cros_ec_device *ec_dev = container_of(nb, struct cros_ec_device,
208 notifier_ready);
209 u32 host_event = cros_ec_get_host_event(ec_dev);
210
211 if (host_event & EC_HOST_EVENT_MASK(EC_HOST_EVENT_INTERFACE_READY)) {
212 mutex_lock(&ec_dev->lock);
213 cros_ec_query_all(ec_dev);
214 mutex_unlock(lock: &ec_dev->lock);
215 return NOTIFY_OK;
216 }
217
218 return NOTIFY_DONE;
219}
220
221/**
222 * cros_ec_register() - Register a new ChromeOS EC, using the provided info.
223 * @ec_dev: Device to register.
224 *
225 * Before calling this, allocate a pointer to a new device and then fill
226 * in all the fields up to the --private-- marker.
227 *
228 * Return: 0 on success or negative error code.
229 */
230int cros_ec_register(struct cros_ec_device *ec_dev)
231{
232 struct device *dev = ec_dev->dev;
233 int err;
234
235 /* Send RWSIG continue to jump to RW for devices using RWSIG. */
236 err = cros_ec_rwsig_continue(ec_dev);
237 if (err)
238 dev_info(dev, "Failed to continue RWSIG: %d\n", err);
239
240 err = cros_ec_query_all(ec_dev);
241 if (err) {
242 dev_err(dev, "Cannot identify the EC: error %d\n", err);
243 goto exit;
244 }
245
246 if (ec_dev->irq > 0) {
247 err = devm_request_threaded_irq(dev, irq: ec_dev->irq,
248 handler: cros_ec_irq_handler,
249 thread_fn: cros_ec_irq_thread,
250 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
251 devname: "chromeos-ec", dev_id: ec_dev);
252 if (err) {
253 dev_err(dev, "Failed to request IRQ %d: %d\n",
254 ec_dev->irq, err);
255 goto exit;
256 }
257 }
258
259 /* Register a platform device for the main EC instance */
260 ec_dev->ec = platform_device_register_data(parent: ec_dev->dev, name: "cros-ec-dev",
261 PLATFORM_DEVID_AUTO, data: &ec_p,
262 size: sizeof(struct cros_ec_platform));
263 if (IS_ERR(ptr: ec_dev->ec)) {
264 dev_err(ec_dev->dev,
265 "Failed to create CrOS EC platform device\n");
266 err = PTR_ERR(ptr: ec_dev->ec);
267 goto exit;
268 }
269
270 if (ec_dev->max_passthru) {
271 /*
272 * Register a platform device for the PD behind the main EC.
273 * We make the following assumptions:
274 * - behind an EC, we have a pd
275 * - only one device added.
276 * - the EC is responsive at init time (it is not true for a
277 * sensor hub).
278 */
279 ec_dev->pd = platform_device_register_data(parent: ec_dev->dev,
280 name: "cros-ec-dev",
281 PLATFORM_DEVID_AUTO, data: &pd_p,
282 size: sizeof(struct cros_ec_platform));
283 if (IS_ERR(ptr: ec_dev->pd)) {
284 dev_err(ec_dev->dev,
285 "Failed to create CrOS PD platform device\n");
286 err = PTR_ERR(ptr: ec_dev->pd);
287 goto exit;
288 }
289 }
290
291 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
292 err = devm_of_platform_populate(dev);
293 if (err) {
294 dev_err(dev, "Failed to register sub-devices\n");
295 goto exit;
296 }
297 }
298
299 /*
300 * Clear sleep event - this will fail harmlessly on platforms that
301 * don't implement the sleep event host command.
302 */
303 err = cros_ec_sleep_event(ec_dev, sleep_event: 0);
304 if (err < 0)
305 dev_dbg(ec_dev->dev, "Error %d clearing sleep event to ec\n",
306 err);
307
308 if (ec_dev->mkbp_event_supported) {
309 /*
310 * Register the notifier for EC_HOST_EVENT_INTERFACE_READY
311 * event.
312 */
313 ec_dev->notifier_ready.notifier_call = cros_ec_ready_event;
314 err = blocking_notifier_chain_register(nh: &ec_dev->event_notifier,
315 nb: &ec_dev->notifier_ready);
316 if (err)
317 goto exit;
318 }
319
320 scoped_guard(mutex, &ec_dev->lock)
321 ec_dev->registered = true;
322
323 dev_info(dev, "Chrome EC device registered\n");
324
325 /*
326 * Unlock EC that may be waiting for AP to process MKBP events.
327 * If the AP takes to long to answer, the EC would stop sending events.
328 */
329 if (ec_dev->mkbp_event_supported)
330 cros_ec_irq_thread(0, ec_dev);
331
332 return 0;
333exit:
334 platform_device_unregister(ec_dev->ec);
335 platform_device_unregister(ec_dev->pd);
336 return err;
337}
338EXPORT_SYMBOL(cros_ec_register);
339
340/**
341 * cros_ec_unregister() - Remove a ChromeOS EC.
342 * @ec_dev: Device to unregister.
343 *
344 * Call this to deregister a ChromeOS EC, then clean up any private data.
345 *
346 * Return: 0 on success or negative error code.
347 */
348void cros_ec_unregister(struct cros_ec_device *ec_dev)
349{
350 scoped_guard(mutex, &ec_dev->lock)
351 ec_dev->registered = false;
352
353 if (ec_dev->mkbp_event_supported)
354 blocking_notifier_chain_unregister(nh: &ec_dev->event_notifier,
355 nb: &ec_dev->notifier_ready);
356 platform_device_unregister(ec_dev->pd);
357 platform_device_unregister(ec_dev->ec);
358}
359EXPORT_SYMBOL(cros_ec_unregister);
360
361#ifdef CONFIG_PM_SLEEP
362static void cros_ec_send_suspend_event(struct cros_ec_device *ec_dev)
363{
364 int ret;
365 u8 sleep_event;
366
367 sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ?
368 HOST_SLEEP_EVENT_S3_SUSPEND :
369 HOST_SLEEP_EVENT_S0IX_SUSPEND;
370
371 ret = cros_ec_sleep_event(ec_dev, sleep_event);
372 if (ret < 0)
373 dev_dbg(ec_dev->dev, "Error %d sending suspend event to ec\n",
374 ret);
375}
376
377/**
378 * cros_ec_suspend_prepare() - Handle a suspend prepare operation for the ChromeOS EC device.
379 * @ec_dev: Device to suspend.
380 *
381 * This can be called by drivers to handle a suspend prepare stage of suspend.
382 *
383 * Return: 0 always.
384 */
385int cros_ec_suspend_prepare(struct cros_ec_device *ec_dev)
386{
387 cros_ec_send_suspend_event(ec_dev);
388 return 0;
389}
390EXPORT_SYMBOL(cros_ec_suspend_prepare);
391
392static void cros_ec_disable_irq(struct cros_ec_device *ec_dev)
393{
394 struct device *dev = ec_dev->dev;
395 if (device_may_wakeup(dev))
396 ec_dev->wake_enabled = !enable_irq_wake(irq: ec_dev->irq);
397 else
398 ec_dev->wake_enabled = false;
399
400 disable_irq(irq: ec_dev->irq);
401 ec_dev->suspended = true;
402}
403
404/**
405 * cros_ec_suspend_late() - Handle a suspend late operation for the ChromeOS EC device.
406 * @ec_dev: Device to suspend.
407 *
408 * This can be called by drivers to handle a suspend late stage of suspend.
409 *
410 * Return: 0 always.
411 */
412int cros_ec_suspend_late(struct cros_ec_device *ec_dev)
413{
414 cros_ec_disable_irq(ec_dev);
415 return 0;
416}
417EXPORT_SYMBOL(cros_ec_suspend_late);
418
419/**
420 * cros_ec_suspend() - Handle a suspend operation for the ChromeOS EC device.
421 * @ec_dev: Device to suspend.
422 *
423 * This can be called by drivers to handle a suspend event.
424 *
425 * Return: 0 always.
426 */
427int cros_ec_suspend(struct cros_ec_device *ec_dev)
428{
429 cros_ec_suspend_prepare(ec_dev);
430 cros_ec_suspend_late(ec_dev);
431 return 0;
432}
433EXPORT_SYMBOL(cros_ec_suspend);
434
435static void cros_ec_report_events_during_suspend(struct cros_ec_device *ec_dev)
436{
437 bool wake_event;
438
439 while (ec_dev->mkbp_event_supported &&
440 cros_ec_get_next_event(ec_dev, wake_event: &wake_event, NULL) > 0) {
441 blocking_notifier_call_chain(nh: &ec_dev->event_notifier,
442 val: 1, v: ec_dev);
443
444 if (wake_event && device_may_wakeup(dev: ec_dev->dev))
445 pm_wakeup_event(dev: ec_dev->dev, msec: 0);
446 }
447}
448
449static void cros_ec_send_resume_event(struct cros_ec_device *ec_dev)
450{
451 int ret;
452 u8 sleep_event;
453
454 sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ?
455 HOST_SLEEP_EVENT_S3_RESUME :
456 HOST_SLEEP_EVENT_S0IX_RESUME;
457
458 ret = cros_ec_sleep_event(ec_dev, sleep_event);
459 if (ret < 0)
460 dev_dbg(ec_dev->dev, "Error %d sending resume event to ec\n",
461 ret);
462}
463
464/**
465 * cros_ec_resume_complete() - Handle a resume complete operation for the ChromeOS EC device.
466 * @ec_dev: Device to resume.
467 *
468 * This can be called by drivers to handle a resume complete stage of resume.
469 */
470void cros_ec_resume_complete(struct cros_ec_device *ec_dev)
471{
472 cros_ec_send_resume_event(ec_dev);
473
474 /*
475 * Let the mfd devices know about events that occur during
476 * suspend. This way the clients know what to do with them.
477 */
478 cros_ec_report_events_during_suspend(ec_dev);
479}
480EXPORT_SYMBOL(cros_ec_resume_complete);
481
482static void cros_ec_enable_irq(struct cros_ec_device *ec_dev)
483{
484 ec_dev->suspended = false;
485 enable_irq(irq: ec_dev->irq);
486
487 if (ec_dev->wake_enabled)
488 disable_irq_wake(irq: ec_dev->irq);
489}
490
491/**
492 * cros_ec_resume_early() - Handle a resume early operation for the ChromeOS EC device.
493 * @ec_dev: Device to resume.
494 *
495 * This can be called by drivers to handle a resume early stage of resume.
496 *
497 * Return: 0 always.
498 */
499int cros_ec_resume_early(struct cros_ec_device *ec_dev)
500{
501 cros_ec_enable_irq(ec_dev);
502 return 0;
503}
504EXPORT_SYMBOL(cros_ec_resume_early);
505
506/**
507 * cros_ec_resume() - Handle a resume operation for the ChromeOS EC device.
508 * @ec_dev: Device to resume.
509 *
510 * This can be called by drivers to handle a resume event.
511 *
512 * Return: 0 always.
513 */
514int cros_ec_resume(struct cros_ec_device *ec_dev)
515{
516 cros_ec_resume_early(ec_dev);
517 cros_ec_resume_complete(ec_dev);
518 return 0;
519}
520EXPORT_SYMBOL(cros_ec_resume);
521
522#endif
523
524MODULE_LICENSE("GPL");
525MODULE_DESCRIPTION("ChromeOS EC core driver");
526

source code of linux/drivers/platform/chrome/cros_ec.c