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 */
cros_ec_irq_handler(int irq,void * data)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 */
cros_ec_handle_event(struct cros_ec_device * ec_dev)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, &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 */
cros_ec_irq_thread(int irq,void * data)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
cros_ec_sleep_event(struct cros_ec_device * ec_dev,u8 sleep_event)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, &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
cros_ec_ready_event(struct notifier_block * nb,unsigned long queued_during_suspend,void * _notify)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(&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 */
cros_ec_register(struct cros_ec_device * ec_dev)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, 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;
297 exit:
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 }
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 */
cros_ec_unregister(struct cros_ec_device * ec_dev)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(&ec_dev->lock);
319 lockdep_unregister_key(&ec_dev->lockdep_key);
320 }
321 EXPORT_SYMBOL(cros_ec_unregister);
322
323 #ifdef CONFIG_PM_SLEEP
324 /**
325 * cros_ec_suspend() - Handle a suspend operation for the ChromeOS EC device.
326 * @ec_dev: Device to suspend.
327 *
328 * This can be called by drivers to handle a suspend event.
329 *
330 * Return: 0 on success or negative error code.
331 */
cros_ec_suspend(struct cros_ec_device * ec_dev)332 int cros_ec_suspend(struct cros_ec_device *ec_dev)
333 {
334 struct device *dev = ec_dev->dev;
335 int ret;
336 u8 sleep_event;
337
338 sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ?
339 HOST_SLEEP_EVENT_S3_SUSPEND :
340 HOST_SLEEP_EVENT_S0IX_SUSPEND;
341
342 ret = cros_ec_sleep_event(ec_dev, sleep_event);
343 if (ret < 0)
344 dev_dbg(ec_dev->dev, "Error %d sending suspend event to ec\n",
345 ret);
346
347 if (device_may_wakeup(dev))
348 ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq);
349 else
350 ec_dev->wake_enabled = false;
351
352 disable_irq(ec_dev->irq);
353 ec_dev->suspended = true;
354
355 return 0;
356 }
357 EXPORT_SYMBOL(cros_ec_suspend);
358
cros_ec_report_events_during_suspend(struct cros_ec_device * ec_dev)359 static void cros_ec_report_events_during_suspend(struct cros_ec_device *ec_dev)
360 {
361 bool wake_event;
362
363 while (ec_dev->mkbp_event_supported &&
364 cros_ec_get_next_event(ec_dev, &wake_event, NULL) > 0) {
365 blocking_notifier_call_chain(&ec_dev->event_notifier,
366 1, ec_dev);
367
368 if (wake_event && device_may_wakeup(ec_dev->dev))
369 pm_wakeup_event(ec_dev->dev, 0);
370 }
371 }
372
373 /**
374 * cros_ec_resume() - Handle a resume operation for the ChromeOS EC device.
375 * @ec_dev: Device to resume.
376 *
377 * This can be called by drivers to handle a resume event.
378 *
379 * Return: 0 on success or negative error code.
380 */
cros_ec_resume(struct cros_ec_device * ec_dev)381 int cros_ec_resume(struct cros_ec_device *ec_dev)
382 {
383 int ret;
384 u8 sleep_event;
385
386 ec_dev->suspended = false;
387 enable_irq(ec_dev->irq);
388
389 sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ?
390 HOST_SLEEP_EVENT_S3_RESUME :
391 HOST_SLEEP_EVENT_S0IX_RESUME;
392
393 ret = cros_ec_sleep_event(ec_dev, sleep_event);
394 if (ret < 0)
395 dev_dbg(ec_dev->dev, "Error %d sending resume event to ec\n",
396 ret);
397
398 if (ec_dev->wake_enabled)
399 disable_irq_wake(ec_dev->irq);
400
401 /*
402 * Let the mfd devices know about events that occur during
403 * suspend. This way the clients know what to do with them.
404 */
405 cros_ec_report_events_during_suspend(ec_dev);
406
407
408 return 0;
409 }
410 EXPORT_SYMBOL(cros_ec_resume);
411
412 #endif
413
414 MODULE_LICENSE("GPL");
415 MODULE_DESCRIPTION("ChromeOS EC core driver");
416
