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 22 static 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 27 static 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 */ 39 static 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 */ 58 static 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 */ 88 irqreturn_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 } 99 EXPORT_SYMBOL(cros_ec_irq_thread); 100 101 static 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 } 151 152 static 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 */ 179 int 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 BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->panic_notifier); 186 187 ec_dev->max_request = sizeof(struct ec_params_hello); 188 ec_dev->max_response = sizeof(struct ec_response_get_protocol_info); 189 ec_dev->max_passthru = 0; 190 ec_dev->ec = NULL; 191 ec_dev->pd = NULL; 192 ec_dev->suspend_timeout_ms = EC_HOST_SLEEP_TIMEOUT_DEFAULT; 193 194 ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL); 195 if (!ec_dev->din) 196 return -ENOMEM; 197 198 ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL); 199 if (!ec_dev->dout) 200 return -ENOMEM; 201 202 lockdep_register_key(&ec_dev->lockdep_key); 203 mutex_init(&ec_dev->lock); 204 lockdep_set_class(&ec_dev->lock, &ec_dev->lockdep_key); 205 206 err = cros_ec_query_all(ec_dev); 207 if (err) { 208 dev_err(dev, "Cannot identify the EC: error %d\n", err); 209 goto destroy_mutex; 210 } 211 212 if (ec_dev->irq > 0) { 213 err = devm_request_threaded_irq(dev, ec_dev->irq, 214 cros_ec_irq_handler, 215 cros_ec_irq_thread, 216 IRQF_TRIGGER_LOW | IRQF_ONESHOT, 217 "chromeos-ec", ec_dev); 218 if (err) { 219 dev_err(dev, "Failed to request IRQ %d: %d\n", 220 ec_dev->irq, err); 221 goto destroy_mutex; 222 } 223 } 224 225 /* Register a platform device for the main EC instance */ 226 ec_dev->ec = platform_device_register_data(ec_dev->dev, "cros-ec-dev", 227 PLATFORM_DEVID_AUTO, &ec_p, 228 sizeof(struct cros_ec_platform)); 229 if (IS_ERR(ec_dev->ec)) { 230 dev_err(ec_dev->dev, 231 "Failed to create CrOS EC platform device\n"); 232 err = PTR_ERR(ec_dev->ec); 233 goto destroy_mutex; 234 } 235 236 if (ec_dev->max_passthru) { 237 /* 238 * Register a platform device for the PD behind the main EC. 239 * We make the following assumptions: 240 * - behind an EC, we have a pd 241 * - only one device added. 242 * - the EC is responsive at init time (it is not true for a 243 * sensor hub). 244 */ 245 ec_dev->pd = platform_device_register_data(ec_dev->dev, 246 "cros-ec-dev", 247 PLATFORM_DEVID_AUTO, &pd_p, 248 sizeof(struct cros_ec_platform)); 249 if (IS_ERR(ec_dev->pd)) { 250 dev_err(ec_dev->dev, 251 "Failed to create CrOS PD platform device\n"); 252 err = PTR_ERR(ec_dev->pd); 253 goto exit; 254 } 255 } 256 257 if (IS_ENABLED(CONFIG_OF) && dev->of_node) { 258 err = devm_of_platform_populate(dev); 259 if (err) { 260 dev_err(dev, "Failed to register sub-devices\n"); 261 goto exit; 262 } 263 } 264 265 /* 266 * Clear sleep event - this will fail harmlessly on platforms that 267 * don't implement the sleep event host command. 268 */ 269 err = cros_ec_sleep_event(ec_dev, 0); 270 if (err < 0) 271 dev_dbg(ec_dev->dev, "Error %d clearing sleep event to ec\n", 272 err); 273 274 if (ec_dev->mkbp_event_supported) { 275 /* 276 * Register the notifier for EC_HOST_EVENT_INTERFACE_READY 277 * event. 278 */ 279 ec_dev->notifier_ready.notifier_call = cros_ec_ready_event; 280 err = blocking_notifier_chain_register(&ec_dev->event_notifier, 281 &ec_dev->notifier_ready); 282 if (err) 283 goto exit; 284 } 285 286 dev_info(dev, "Chrome EC device registered\n"); 287 288 /* 289 * Unlock EC that may be waiting for AP to process MKBP events. 290 * If the AP takes to long to answer, the EC would stop sending events. 291 */ 292 if (ec_dev->mkbp_event_supported) 293 cros_ec_irq_thread(0, ec_dev); 294 295 return 0; 296 exit: 297 platform_device_unregister(ec_dev->ec); 298 platform_device_unregister(ec_dev->pd); 299 destroy_mutex: 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 */ 314 void cros_ec_unregister(struct cros_ec_device *ec_dev) 315 { 316 if (ec_dev->pd) 317 platform_device_unregister(ec_dev->pd); 318 platform_device_unregister(ec_dev->ec); 319 mutex_destroy(&ec_dev->lock); 320 lockdep_unregister_key(&ec_dev->lockdep_key); 321 } 322 EXPORT_SYMBOL(cros_ec_unregister); 323 324 #ifdef CONFIG_PM_SLEEP 325 /** 326 * cros_ec_suspend() - Handle a suspend operation for the ChromeOS EC device. 327 * @ec_dev: Device to suspend. 328 * 329 * This can be called by drivers to handle a suspend event. 330 * 331 * Return: 0 on success or negative error code. 332 */ 333 int cros_ec_suspend(struct cros_ec_device *ec_dev) 334 { 335 struct device *dev = ec_dev->dev; 336 int ret; 337 u8 sleep_event; 338 339 sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ? 340 HOST_SLEEP_EVENT_S3_SUSPEND : 341 HOST_SLEEP_EVENT_S0IX_SUSPEND; 342 343 ret = cros_ec_sleep_event(ec_dev, sleep_event); 344 if (ret < 0) 345 dev_dbg(ec_dev->dev, "Error %d sending suspend event to ec\n", 346 ret); 347 348 if (device_may_wakeup(dev)) 349 ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq); 350 else 351 ec_dev->wake_enabled = false; 352 353 disable_irq(ec_dev->irq); 354 ec_dev->suspended = true; 355 356 return 0; 357 } 358 EXPORT_SYMBOL(cros_ec_suspend); 359 360 static void cros_ec_report_events_during_suspend(struct cros_ec_device *ec_dev) 361 { 362 bool wake_event; 363 364 while (ec_dev->mkbp_event_supported && 365 cros_ec_get_next_event(ec_dev, &wake_event, NULL) > 0) { 366 blocking_notifier_call_chain(&ec_dev->event_notifier, 367 1, ec_dev); 368 369 if (wake_event && device_may_wakeup(ec_dev->dev)) 370 pm_wakeup_event(ec_dev->dev, 0); 371 } 372 } 373 374 /** 375 * cros_ec_resume() - Handle a resume operation for the ChromeOS EC device. 376 * @ec_dev: Device to resume. 377 * 378 * This can be called by drivers to handle a resume event. 379 * 380 * Return: 0 on success or negative error code. 381 */ 382 int cros_ec_resume(struct cros_ec_device *ec_dev) 383 { 384 int ret; 385 u8 sleep_event; 386 387 ec_dev->suspended = false; 388 enable_irq(ec_dev->irq); 389 390 sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ? 391 HOST_SLEEP_EVENT_S3_RESUME : 392 HOST_SLEEP_EVENT_S0IX_RESUME; 393 394 ret = cros_ec_sleep_event(ec_dev, sleep_event); 395 if (ret < 0) 396 dev_dbg(ec_dev->dev, "Error %d sending resume event to ec\n", 397 ret); 398 399 if (ec_dev->wake_enabled) 400 disable_irq_wake(ec_dev->irq); 401 402 /* 403 * Let the mfd devices know about events that occur during 404 * suspend. This way the clients know what to do with them. 405 */ 406 cros_ec_report_events_during_suspend(ec_dev); 407 408 409 return 0; 410 } 411 EXPORT_SYMBOL(cros_ec_resume); 412 413 #endif 414 415 MODULE_LICENSE("GPL"); 416 MODULE_DESCRIPTION("ChromeOS EC core driver"); 417