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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * ChromeOS EC multi-function device4 *5 * Copyright (C) 2012 Google, Inc6 *7 * The ChromeOS EC multi function device is used to mux all the requests8 * 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 handler35 * @irq: IRQ id36 * @data: (ec_dev) Device with events to process.37 *38 * Return: Wakeup the bottom half39 */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 EC51 * @ec_dev: Device with events to process.52 *53 * Call this function in a loop when the kernel is notified that the EC has54 * pending events.55 *56 * Return: true if more events are still pending and this function should be57 * 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 if69 * cros_ec_get_next_event() returned an error (default value for70 * 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 handler84 * @irq: IRQ id85 * @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 fill176 * 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 pd242 * - only one device added.243 * - the EC is responsive at init time (it is not true for a244 * 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 that268 * 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_READY278 * 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_SLEEP324static 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 else360 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 during438 * 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#endif485 486MODULE_LICENSE("GPL");487MODULE_DESCRIPTION("ChromeOS EC core driver");488