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