1 // SPDX-License-Identifier: GPL-2.0-only
3 * ChromeOS EC multi-function device
5 * Copyright (C) 2012 Google, Inc
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.
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>
22 #define CROS_EC_DEV_EC_INDEX 0
23 #define CROS_EC_DEV_PD_INDEX 1
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),
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),
36 * cros_ec_irq_handler() - top half part of the interrupt handler
38 * @data: (ec_dev) Device with events to process.
40 * Return: Wakeup the bottom half
42 static irqreturn_t cros_ec_irq_handler(int irq, void *data)
44 struct cros_ec_device *ec_dev = data;
46 ec_dev->last_event_time = cros_ec_get_time_ns();
48 return IRQ_WAKE_THREAD;
52 * cros_ec_handle_event() - process and forward pending events on EC
53 * @ec_dev: Device with events to process.
55 * Call this function in a loop when the kernel is notified that the EC has
58 * Return: true if more events are still pending and this function should be
61 static bool cros_ec_handle_event(struct cros_ec_device *ec_dev)
64 bool ec_has_more_events;
67 ret = cros_ec_get_next_event(ec_dev, &wake_event, &ec_has_more_events);
70 * Signal only if wake host events or any interrupt if
71 * cros_ec_get_next_event() returned an error (default value for
74 if (wake_event && device_may_wakeup(ec_dev->dev))
75 pm_wakeup_event(ec_dev->dev, 0);
78 blocking_notifier_call_chain(&ec_dev->event_notifier,
81 return ec_has_more_events;
85 * cros_ec_irq_thread() - bottom half part of the interrupt handler
87 * @data: (ec_dev) Device with events to process.
89 * Return: Interrupt handled.
91 irqreturn_t cros_ec_irq_thread(int irq, void *data)
93 struct cros_ec_device *ec_dev = data;
94 bool ec_has_more_events;
97 ec_has_more_events = cros_ec_handle_event(ec_dev);
98 } while (ec_has_more_events);
102 EXPORT_SYMBOL(cros_ec_irq_thread);
104 static int cros_ec_sleep_event(struct cros_ec_device *ec_dev, u8 sleep_event)
108 struct cros_ec_command msg;
110 struct ec_params_host_sleep_event req0;
111 struct ec_params_host_sleep_event_v1 req1;
112 struct ec_response_host_sleep_event_v1 resp1;
116 memset(&buf, 0, sizeof(buf));
118 if (ec_dev->host_sleep_v1) {
119 buf.u.req1.sleep_event = sleep_event;
120 buf.u.req1.suspend_params.sleep_timeout_ms =
121 EC_HOST_SLEEP_TIMEOUT_DEFAULT;
123 buf.msg.outsize = sizeof(buf.u.req1);
124 if ((sleep_event == HOST_SLEEP_EVENT_S3_RESUME) ||
125 (sleep_event == HOST_SLEEP_EVENT_S0IX_RESUME))
126 buf.msg.insize = sizeof(buf.u.resp1);
131 buf.u.req0.sleep_event = sleep_event;
132 buf.msg.outsize = sizeof(buf.u.req0);
135 buf.msg.command = EC_CMD_HOST_SLEEP_EVENT;
137 ret = cros_ec_cmd_xfer_status(ec_dev, &buf.msg);
139 /* For now, report failure to transition to S0ix with a warning. */
140 if (ret >= 0 && ec_dev->host_sleep_v1 &&
141 (sleep_event == HOST_SLEEP_EVENT_S0IX_RESUME)) {
142 ec_dev->last_resume_result =
143 buf.u.resp1.resume_response.sleep_transitions;
145 WARN_ONCE(buf.u.resp1.resume_response.sleep_transitions &
146 EC_HOST_RESUME_SLEEP_TIMEOUT,
147 "EC detected sleep transition timeout. Total slp_s0 transitions: %d",
148 buf.u.resp1.resume_response.sleep_transitions &
149 EC_HOST_RESUME_SLEEP_TRANSITIONS_MASK);
155 static int cros_ec_ready_event(struct notifier_block *nb,
156 unsigned long queued_during_suspend,
159 struct cros_ec_device *ec_dev = container_of(nb, struct cros_ec_device,
161 u32 host_event = cros_ec_get_host_event(ec_dev);
163 if (host_event & EC_HOST_EVENT_MASK(EC_HOST_EVENT_INTERFACE_READY)) {
164 mutex_lock(&ec_dev->lock);
165 cros_ec_query_all(ec_dev);
166 mutex_unlock(&ec_dev->lock);
174 * cros_ec_register() - Register a new ChromeOS EC, using the provided info.
175 * @ec_dev: Device to register.
177 * Before calling this, allocate a pointer to a new device and then fill
178 * in all the fields up to the --private-- marker.
180 * Return: 0 on success or negative error code.
182 int cros_ec_register(struct cros_ec_device *ec_dev)
184 struct device *dev = ec_dev->dev;
187 BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->event_notifier);
189 ec_dev->max_request = sizeof(struct ec_params_hello);
190 ec_dev->max_response = sizeof(struct ec_response_get_protocol_info);
191 ec_dev->max_passthru = 0;
195 ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
199 ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
203 mutex_init(&ec_dev->lock);
205 err = cros_ec_query_all(ec_dev);
207 dev_err(dev, "Cannot identify the EC: error %d\n", err);
211 if (ec_dev->irq > 0) {
212 err = devm_request_threaded_irq(dev, ec_dev->irq,
215 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
216 "chromeos-ec", ec_dev);
218 dev_err(dev, "Failed to request IRQ %d: %d\n",
224 /* Register a platform device for the main EC instance */
225 ec_dev->ec = platform_device_register_data(ec_dev->dev, "cros-ec-dev",
226 PLATFORM_DEVID_AUTO, &ec_p,
227 sizeof(struct cros_ec_platform));
228 if (IS_ERR(ec_dev->ec)) {
230 "Failed to create CrOS EC platform device\n");
231 return PTR_ERR(ec_dev->ec);
234 if (ec_dev->max_passthru) {
236 * Register a platform device for the PD behind the main EC.
237 * We make the following assumptions:
238 * - behind an EC, we have a pd
239 * - only one device added.
240 * - the EC is responsive at init time (it is not true for a
243 ec_dev->pd = platform_device_register_data(ec_dev->dev,
245 PLATFORM_DEVID_AUTO, &pd_p,
246 sizeof(struct cros_ec_platform));
247 if (IS_ERR(ec_dev->pd)) {
249 "Failed to create CrOS PD platform device\n");
250 err = PTR_ERR(ec_dev->pd);
255 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
256 err = devm_of_platform_populate(dev);
258 dev_err(dev, "Failed to register sub-devices\n");
264 * Clear sleep event - this will fail harmlessly on platforms that
265 * don't implement the sleep event host command.
267 err = cros_ec_sleep_event(ec_dev, 0);
269 dev_dbg(ec_dev->dev, "Error %d clearing sleep event to ec\n",
272 if (ec_dev->mkbp_event_supported) {
274 * Register the notifier for EC_HOST_EVENT_INTERFACE_READY
277 ec_dev->notifier_ready.notifier_call = cros_ec_ready_event;
278 err = blocking_notifier_chain_register(&ec_dev->event_notifier,
279 &ec_dev->notifier_ready);
284 dev_info(dev, "Chrome EC device registered\n");
287 * Unlock EC that may be waiting for AP to process MKBP events.
288 * If the AP takes to long to answer, the EC would stop sending events.
290 if (ec_dev->mkbp_event_supported)
291 cros_ec_irq_thread(0, ec_dev);
295 platform_device_unregister(ec_dev->ec);
296 platform_device_unregister(ec_dev->pd);
299 EXPORT_SYMBOL(cros_ec_register);
302 * cros_ec_unregister() - Remove a ChromeOS EC.
303 * @ec_dev: Device to unregister.
305 * Call this to deregister a ChromeOS EC, then clean up any private data.
307 * Return: 0 on success or negative error code.
309 void cros_ec_unregister(struct cros_ec_device *ec_dev)
312 platform_device_unregister(ec_dev->pd);
313 platform_device_unregister(ec_dev->ec);
315 EXPORT_SYMBOL(cros_ec_unregister);
317 #ifdef CONFIG_PM_SLEEP
319 * cros_ec_suspend() - Handle a suspend operation for the ChromeOS EC device.
320 * @ec_dev: Device to suspend.
322 * This can be called by drivers to handle a suspend event.
324 * Return: 0 on success or negative error code.
326 int cros_ec_suspend(struct cros_ec_device *ec_dev)
328 struct device *dev = ec_dev->dev;
332 sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ?
333 HOST_SLEEP_EVENT_S3_SUSPEND :
334 HOST_SLEEP_EVENT_S0IX_SUSPEND;
336 ret = cros_ec_sleep_event(ec_dev, sleep_event);
338 dev_dbg(ec_dev->dev, "Error %d sending suspend event to ec\n",
341 if (device_may_wakeup(dev))
342 ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq);
344 ec_dev->wake_enabled = false;
346 disable_irq(ec_dev->irq);
347 ec_dev->suspended = true;
351 EXPORT_SYMBOL(cros_ec_suspend);
353 static void cros_ec_report_events_during_suspend(struct cros_ec_device *ec_dev)
355 while (ec_dev->mkbp_event_supported &&
356 cros_ec_get_next_event(ec_dev, NULL, NULL) > 0)
357 blocking_notifier_call_chain(&ec_dev->event_notifier,
362 * cros_ec_resume() - Handle a resume operation for the ChromeOS EC device.
363 * @ec_dev: Device to resume.
365 * This can be called by drivers to handle a resume event.
367 * Return: 0 on success or negative error code.
369 int cros_ec_resume(struct cros_ec_device *ec_dev)
374 ec_dev->suspended = false;
375 enable_irq(ec_dev->irq);
377 sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ?
378 HOST_SLEEP_EVENT_S3_RESUME :
379 HOST_SLEEP_EVENT_S0IX_RESUME;
381 ret = cros_ec_sleep_event(ec_dev, sleep_event);
383 dev_dbg(ec_dev->dev, "Error %d sending resume event to ec\n",
386 if (ec_dev->wake_enabled)
387 disable_irq_wake(ec_dev->irq);
390 * Let the mfd devices know about events that occur during
391 * suspend. This way the clients know what to do with them.
393 cros_ec_report_events_during_suspend(ec_dev);
398 EXPORT_SYMBOL(cros_ec_resume);
402 MODULE_LICENSE("GPL");
403 MODULE_DESCRIPTION("ChromeOS EC core driver");