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/of_platform.h>
13 #include <linux/interrupt.h>
14 #include <linux/slab.h>
15 #include <linux/module.h>
16 #include <linux/platform_data/cros_ec_commands.h>
17 #include <linux/platform_data/cros_ec_proto.h>
18 #include <linux/suspend.h>
19
20 #include "cros_ec.h"
21
22 #define CROS_EC_DEV_EC_INDEX 0
23 #define CROS_EC_DEV_PD_INDEX 1
24
25 static struct cros_ec_platform ec_p = {
26 .ec_name = CROS_EC_DEV_NAME,
27 .cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_EC_INDEX),
28 };
29
30 static struct cros_ec_platform pd_p = {
31 .ec_name = CROS_EC_DEV_PD_NAME,
32 .cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX),
33 };
34
ec_irq_handler(int irq,void * data)35 static irqreturn_t ec_irq_handler(int irq, void *data)
36 {
37 struct cros_ec_device *ec_dev = data;
38
39 ec_dev->last_event_time = cros_ec_get_time_ns();
40
41 return IRQ_WAKE_THREAD;
42 }
43
44 /**
45 * cros_ec_handle_event() - process and forward pending events on EC
46 * @ec_dev: Device with events to process.
47 *
48 * Call this function in a loop when the kernel is notified that the EC has
49 * pending events.
50 *
51 * Return: true if more events are still pending and this function should be
52 * called again.
53 */
cros_ec_handle_event(struct cros_ec_device * ec_dev)54 bool cros_ec_handle_event(struct cros_ec_device *ec_dev)
55 {
56 bool wake_event;
57 bool ec_has_more_events;
58 int ret;
59
60 ret = cros_ec_get_next_event(ec_dev, &wake_event, &ec_has_more_events);
61
62 /*
63 * Signal only if wake host events or any interrupt if
64 * cros_ec_get_next_event() returned an error (default value for
65 * wake_event is true)
66 */
67 if (wake_event && device_may_wakeup(ec_dev->dev))
68 pm_wakeup_event(ec_dev->dev, 0);
69
70 if (ret > 0)
71 blocking_notifier_call_chain(&ec_dev->event_notifier,
72 0, ec_dev);
73
74 return ec_has_more_events;
75 }
76 EXPORT_SYMBOL(cros_ec_handle_event);
77
ec_irq_thread(int irq,void * data)78 static irqreturn_t ec_irq_thread(int irq, void *data)
79 {
80 struct cros_ec_device *ec_dev = data;
81 bool ec_has_more_events;
82
83 do {
84 ec_has_more_events = cros_ec_handle_event(ec_dev);
85 } while (ec_has_more_events);
86
87 return IRQ_HANDLED;
88 }
89
cros_ec_sleep_event(struct cros_ec_device * ec_dev,u8 sleep_event)90 static int cros_ec_sleep_event(struct cros_ec_device *ec_dev, u8 sleep_event)
91 {
92 int ret;
93 struct {
94 struct cros_ec_command msg;
95 union {
96 struct ec_params_host_sleep_event req0;
97 struct ec_params_host_sleep_event_v1 req1;
98 struct ec_response_host_sleep_event_v1 resp1;
99 } u;
100 } __packed buf;
101
102 memset(&buf, 0, sizeof(buf));
103
104 if (ec_dev->host_sleep_v1) {
105 buf.u.req1.sleep_event = sleep_event;
106 buf.u.req1.suspend_params.sleep_timeout_ms =
107 EC_HOST_SLEEP_TIMEOUT_DEFAULT;
108
109 buf.msg.outsize = sizeof(buf.u.req1);
110 if ((sleep_event == HOST_SLEEP_EVENT_S3_RESUME) ||
111 (sleep_event == HOST_SLEEP_EVENT_S0IX_RESUME))
112 buf.msg.insize = sizeof(buf.u.resp1);
113
114 buf.msg.version = 1;
115
116 } else {
117 buf.u.req0.sleep_event = sleep_event;
118 buf.msg.outsize = sizeof(buf.u.req0);
119 }
120
121 buf.msg.command = EC_CMD_HOST_SLEEP_EVENT;
122
123 ret = cros_ec_cmd_xfer_status(ec_dev, &buf.msg);
124
125 /* For now, report failure to transition to S0ix with a warning. */
126 if (ret >= 0 && ec_dev->host_sleep_v1 &&
127 (sleep_event == HOST_SLEEP_EVENT_S0IX_RESUME)) {
128 ec_dev->last_resume_result =
129 buf.u.resp1.resume_response.sleep_transitions;
130
131 WARN_ONCE(buf.u.resp1.resume_response.sleep_transitions &
132 EC_HOST_RESUME_SLEEP_TIMEOUT,
133 "EC detected sleep transition timeout. Total slp_s0 transitions: %d",
134 buf.u.resp1.resume_response.sleep_transitions &
135 EC_HOST_RESUME_SLEEP_TRANSITIONS_MASK);
136 }
137
138 return ret;
139 }
140
cros_ec_ready_event(struct notifier_block * nb,unsigned long queued_during_suspend,void * _notify)141 static int cros_ec_ready_event(struct notifier_block *nb,
142 unsigned long queued_during_suspend,
143 void *_notify)
144 {
145 struct cros_ec_device *ec_dev = container_of(nb, struct cros_ec_device,
146 notifier_ready);
147 u32 host_event = cros_ec_get_host_event(ec_dev);
148
149 if (host_event & EC_HOST_EVENT_MASK(EC_HOST_EVENT_INTERFACE_READY)) {
150 mutex_lock(&ec_dev->lock);
151 cros_ec_query_all(ec_dev);
152 mutex_unlock(&ec_dev->lock);
153 return NOTIFY_OK;
154 }
155
156 return NOTIFY_DONE;
157 }
158
159 /**
160 * cros_ec_register() - Register a new ChromeOS EC, using the provided info.
161 * @ec_dev: Device to register.
162 *
163 * Before calling this, allocate a pointer to a new device and then fill
164 * in all the fields up to the --private-- marker.
165 *
166 * Return: 0 on success or negative error code.
167 */
cros_ec_register(struct cros_ec_device * ec_dev)168 int cros_ec_register(struct cros_ec_device *ec_dev)
169 {
170 struct device *dev = ec_dev->dev;
171 int err = 0;
172
173 BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->event_notifier);
174
175 ec_dev->max_request = sizeof(struct ec_params_hello);
176 ec_dev->max_response = sizeof(struct ec_response_get_protocol_info);
177 ec_dev->max_passthru = 0;
178
179 ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
180 if (!ec_dev->din)
181 return -ENOMEM;
182
183 ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
184 if (!ec_dev->dout)
185 return -ENOMEM;
186
187 mutex_init(&ec_dev->lock);
188
189 err = cros_ec_query_all(ec_dev);
190 if (err) {
191 dev_err(dev, "Cannot identify the EC: error %d\n", err);
192 return err;
193 }
194
195 if (ec_dev->irq > 0) {
196 err = devm_request_threaded_irq(dev, ec_dev->irq,
197 ec_irq_handler,
198 ec_irq_thread,
199 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
200 "chromeos-ec", ec_dev);
201 if (err) {
202 dev_err(dev, "Failed to request IRQ %d: %d",
203 ec_dev->irq, err);
204 return err;
205 }
206 }
207
208 /* Register a platform device for the main EC instance */
209 ec_dev->ec = platform_device_register_data(ec_dev->dev, "cros-ec-dev",
210 PLATFORM_DEVID_AUTO, &ec_p,
211 sizeof(struct cros_ec_platform));
212 if (IS_ERR(ec_dev->ec)) {
213 dev_err(ec_dev->dev,
214 "Failed to create CrOS EC platform device\n");
215 return PTR_ERR(ec_dev->ec);
216 }
217
218 if (ec_dev->max_passthru) {
219 /*
220 * Register a platform device for the PD behind the main EC.
221 * We make the following assumptions:
222 * - behind an EC, we have a pd
223 * - only one device added.
224 * - the EC is responsive at init time (it is not true for a
225 * sensor hub).
226 */
227 ec_dev->pd = platform_device_register_data(ec_dev->dev,
228 "cros-ec-dev",
229 PLATFORM_DEVID_AUTO, &pd_p,
230 sizeof(struct cros_ec_platform));
231 if (IS_ERR(ec_dev->pd)) {
232 dev_err(ec_dev->dev,
233 "Failed to create CrOS PD platform device\n");
234 platform_device_unregister(ec_dev->ec);
235 return PTR_ERR(ec_dev->pd);
236 }
237 }
238
239 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
240 err = devm_of_platform_populate(dev);
241 if (err) {
242 platform_device_unregister(ec_dev->pd);
243 platform_device_unregister(ec_dev->ec);
244 dev_err(dev, "Failed to register sub-devices\n");
245 return err;
246 }
247 }
248
249 /*
250 * Clear sleep event - this will fail harmlessly on platforms that
251 * don't implement the sleep event host command.
252 */
253 err = cros_ec_sleep_event(ec_dev, 0);
254 if (err < 0)
255 dev_dbg(ec_dev->dev, "Error %d clearing sleep event to ec",
256 err);
257
258 if (ec_dev->mkbp_event_supported) {
259 /*
260 * Register the notifier for EC_HOST_EVENT_INTERFACE_READY
261 * event.
262 */
263 ec_dev->notifier_ready.notifier_call = cros_ec_ready_event;
264 err = blocking_notifier_chain_register(&ec_dev->event_notifier,
265 &ec_dev->notifier_ready);
266 if (err)
267 return err;
268 }
269
270 dev_info(dev, "Chrome EC device registered\n");
271
272 return 0;
273 }
274 EXPORT_SYMBOL(cros_ec_register);
275
276 /**
277 * cros_ec_unregister() - Remove a ChromeOS EC.
278 * @ec_dev: Device to unregister.
279 *
280 * Call this to deregister a ChromeOS EC, then clean up any private data.
281 *
282 * Return: 0 on success or negative error code.
283 */
cros_ec_unregister(struct cros_ec_device * ec_dev)284 int cros_ec_unregister(struct cros_ec_device *ec_dev)
285 {
286 if (ec_dev->pd)
287 platform_device_unregister(ec_dev->pd);
288 platform_device_unregister(ec_dev->ec);
289
290 return 0;
291 }
292 EXPORT_SYMBOL(cros_ec_unregister);
293
294 #ifdef CONFIG_PM_SLEEP
295 /**
296 * cros_ec_suspend() - Handle a suspend operation for the ChromeOS EC device.
297 * @ec_dev: Device to suspend.
298 *
299 * This can be called by drivers to handle a suspend event.
300 *
301 * Return: 0 on success or negative error code.
302 */
cros_ec_suspend(struct cros_ec_device * ec_dev)303 int cros_ec_suspend(struct cros_ec_device *ec_dev)
304 {
305 struct device *dev = ec_dev->dev;
306 int ret;
307 u8 sleep_event;
308
309 sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ?
310 HOST_SLEEP_EVENT_S3_SUSPEND :
311 HOST_SLEEP_EVENT_S0IX_SUSPEND;
312
313 ret = cros_ec_sleep_event(ec_dev, sleep_event);
314 if (ret < 0)
315 dev_dbg(ec_dev->dev, "Error %d sending suspend event to ec",
316 ret);
317
318 if (device_may_wakeup(dev))
319 ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq);
320
321 disable_irq(ec_dev->irq);
322 ec_dev->was_wake_device = ec_dev->wake_enabled;
323 ec_dev->suspended = true;
324
325 return 0;
326 }
327 EXPORT_SYMBOL(cros_ec_suspend);
328
cros_ec_report_events_during_suspend(struct cros_ec_device * ec_dev)329 static void cros_ec_report_events_during_suspend(struct cros_ec_device *ec_dev)
330 {
331 while (ec_dev->mkbp_event_supported &&
332 cros_ec_get_next_event(ec_dev, NULL, NULL) > 0)
333 blocking_notifier_call_chain(&ec_dev->event_notifier,
334 1, ec_dev);
335 }
336
337 /**
338 * cros_ec_resume() - Handle a resume operation for the ChromeOS EC device.
339 * @ec_dev: Device to resume.
340 *
341 * This can be called by drivers to handle a resume event.
342 *
343 * Return: 0 on success or negative error code.
344 */
cros_ec_resume(struct cros_ec_device * ec_dev)345 int cros_ec_resume(struct cros_ec_device *ec_dev)
346 {
347 int ret;
348 u8 sleep_event;
349
350 ec_dev->suspended = false;
351 enable_irq(ec_dev->irq);
352
353 sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ?
354 HOST_SLEEP_EVENT_S3_RESUME :
355 HOST_SLEEP_EVENT_S0IX_RESUME;
356
357 ret = cros_ec_sleep_event(ec_dev, sleep_event);
358 if (ret < 0)
359 dev_dbg(ec_dev->dev, "Error %d sending resume event to ec",
360 ret);
361
362 if (ec_dev->wake_enabled) {
363 disable_irq_wake(ec_dev->irq);
364 ec_dev->wake_enabled = 0;
365 }
366 /*
367 * Let the mfd devices know about events that occur during
368 * suspend. This way the clients know what to do with them.
369 */
370 cros_ec_report_events_during_suspend(ec_dev);
371
372
373 return 0;
374 }
375 EXPORT_SYMBOL(cros_ec_resume);
376
377 #endif
378
379 MODULE_LICENSE("GPL");
380 MODULE_DESCRIPTION("ChromeOS EC core driver");
381