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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
23static 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
28static 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 */
40static 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 */
59static 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, &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(ec_dev->dev))
73 pm_wakeup_event(ec_dev->dev, 0);
74
75 if (ret > 0)
76 blocking_notifier_call_chain(&ec_dev->event_notifier,
77 0, 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 */
89irqreturn_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}
100EXPORT_SYMBOL(cros_ec_irq_thread);
101
102static 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, &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
153static 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(&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 */
180int 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, ec_dev->din_size, GFP_KERNEL);
196 if (!ec_dev->din)
197 return -ENOMEM;
198
199 ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
200 if (!ec_dev->dout)
201 return -ENOMEM;
202
203 lockdep_register_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, ec_dev->irq,
215 cros_ec_irq_handler,
216 cros_ec_irq_thread,
217 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
218 "chromeos-ec", 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(ec_dev->dev, "cros-ec-dev",
228 PLATFORM_DEVID_AUTO, &ec_p,
229 sizeof(struct cros_ec_platform));
230 if (IS_ERR(ec_dev->ec)) {
231 dev_err(ec_dev->dev,
232 "Failed to create CrOS EC platform device\n");
233 err = PTR_ERR(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(ec_dev->dev,
247 "cros-ec-dev",
248 PLATFORM_DEVID_AUTO, &pd_p,
249 sizeof(struct cros_ec_platform));
250 if (IS_ERR(ec_dev->pd)) {
251 dev_err(ec_dev->dev,
252 "Failed to create CrOS PD platform device\n");
253 err = PTR_ERR(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, 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(&ec_dev->event_notifier,
282 &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;
297exit:
298 platform_device_unregister(ec_dev->ec);
299 platform_device_unregister(ec_dev->pd);
300 mutex_destroy(&ec_dev->lock);
301 lockdep_unregister_key(&ec_dev->lockdep_key);
302 return err;
303}
304EXPORT_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 */
314void 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(&ec_dev->lock);
319 lockdep_unregister_key(&ec_dev->lockdep_key);
320}
321EXPORT_SYMBOL(cros_ec_unregister);
322
323#ifdef CONFIG_PM_SLEEP
324static 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 */
347int cros_ec_suspend_prepare(struct cros_ec_device *ec_dev)
348{
349 cros_ec_send_suspend_event(ec_dev);
350 return 0;
351}
352EXPORT_SYMBOL(cros_ec_suspend_prepare);
353
354static 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(ec_dev->irq);
359 else
360 ec_dev->wake_enabled = false;
361
362 disable_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 */
374int cros_ec_suspend_late(struct cros_ec_device *ec_dev)
375{
376 cros_ec_disable_irq(ec_dev);
377 return 0;
378}
379EXPORT_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 */
389int cros_ec_suspend(struct cros_ec_device *ec_dev)
390{
391 cros_ec_suspend_prepare(ec_dev);
392 cros_ec_suspend_late(ec_dev);
393 return 0;
394}
395EXPORT_SYMBOL(cros_ec_suspend);
396
397static 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, NULL) > 0) {
403 blocking_notifier_call_chain(&ec_dev->event_notifier,
404 1, ec_dev);
405
406 if (wake_event && device_may_wakeup(ec_dev->dev))
407 pm_wakeup_event(ec_dev->dev, 0);
408 }
409}
410
411static 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 */
432void cros_ec_resume_complete(struct cros_ec_device *ec_dev)
433{
434 cros_ec_send_resume_event(ec_dev);
435
436 /*
437 * Let the mfd devices know about events that occur during
438 * suspend. This way the clients know what to do with them.
439 */
440 cros_ec_report_events_during_suspend(ec_dev);
441}
442EXPORT_SYMBOL(cros_ec_resume_complete);
443
444static void cros_ec_enable_irq(struct cros_ec_device *ec_dev)
445{
446 ec_dev->suspended = false;
447 enable_irq(ec_dev->irq);
448
449 if (ec_dev->wake_enabled)
450 disable_irq_wake(ec_dev->irq);
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 */
461int cros_ec_resume_early(struct cros_ec_device *ec_dev)
462{
463 cros_ec_enable_irq(ec_dev);
464 return 0;
465}
466EXPORT_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 */
476int cros_ec_resume(struct cros_ec_device *ec_dev)
477{
478 cros_ec_resume_early(ec_dev);
479 cros_ec_resume_complete(ec_dev);
480 return 0;
481}
482EXPORT_SYMBOL(cros_ec_resume);
483
484#endif
485
486MODULE_LICENSE("GPL");
487MODULE_DESCRIPTION("ChromeOS EC core driver");