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_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 23 static 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 28 static 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 handler 35 * @irq: IRQ id 36 * @data: (ec_dev) Device with events to process. 37 * 38 * Return: Wakeup the bottom half 39 */ 40 static 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 EC 51 * @ec_dev: Device with events to process. 52 * 53 * Call this function in a loop when the kernel is notified that the EC has 54 * pending events. 55 * 56 * Return: true if more events are still pending and this function should be 57 * called again. 58 */ 59 static 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 if 69 * cros_ec_get_next_event() returned an error (default value for 70 * 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 handler 84 * @irq: IRQ id 85 * @data: (ec_dev) Device with events to process. 86 * 87 * Return: Interrupt handled. 88 */ 89 irqreturn_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 } 100 EXPORT_SYMBOL(cros_ec_irq_thread); 101 102 static 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 } 152 153 static 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 fill 176 * in all the fields up to the --private-- marker. 177 * 178 * Return: 0 on success or negative error code. 179 */ 180 int 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 pd 242 * - only one device added. 243 * - the EC is responsive at init time (it is not true for a 244 * 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 that 268 * 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_READY 278 * 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; 297 exit: 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 } 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 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 } 321 EXPORT_SYMBOL(cros_ec_unregister); 322 323 #ifdef CONFIG_PM_SLEEP 324 /** 325 * cros_ec_suspend() - Handle a suspend operation for the ChromeOS EC device. 326 * @ec_dev: Device to suspend. 327 * 328 * This can be called by drivers to handle a suspend event. 329 * 330 * Return: 0 on success or negative error code. 331 */ 332 int cros_ec_suspend(struct cros_ec_device *ec_dev) 333 { 334 struct device *dev = ec_dev->dev; 335 int ret; 336 u8 sleep_event; 337 338 sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ? 339 HOST_SLEEP_EVENT_S3_SUSPEND : 340 HOST_SLEEP_EVENT_S0IX_SUSPEND; 341 342 ret = cros_ec_sleep_event(ec_dev, sleep_event); 343 if (ret < 0) 344 dev_dbg(ec_dev->dev, "Error %d sending suspend event to ec\n", 345 ret); 346 347 if (device_may_wakeup(dev)) 348 ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq); 349 else 350 ec_dev->wake_enabled = false; 351 352 disable_irq(ec_dev->irq); 353 ec_dev->suspended = true; 354 355 return 0; 356 } 357 EXPORT_SYMBOL(cros_ec_suspend); 358 359 static void cros_ec_report_events_during_suspend(struct cros_ec_device *ec_dev) 360 { 361 bool wake_event; 362 363 while (ec_dev->mkbp_event_supported && 364 cros_ec_get_next_event(ec_dev, &wake_event, NULL) > 0) { 365 blocking_notifier_call_chain(&ec_dev->event_notifier, 366 1, ec_dev); 367 368 if (wake_event && device_may_wakeup(ec_dev->dev)) 369 pm_wakeup_event(ec_dev->dev, 0); 370 } 371 } 372 373 /** 374 * cros_ec_resume() - Handle a resume operation for the ChromeOS EC device. 375 * @ec_dev: Device to resume. 376 * 377 * This can be called by drivers to handle a resume event. 378 * 379 * Return: 0 on success or negative error code. 380 */ 381 int cros_ec_resume(struct cros_ec_device *ec_dev) 382 { 383 int ret; 384 u8 sleep_event; 385 386 ec_dev->suspended = false; 387 enable_irq(ec_dev->irq); 388 389 sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ? 390 HOST_SLEEP_EVENT_S3_RESUME : 391 HOST_SLEEP_EVENT_S0IX_RESUME; 392 393 ret = cros_ec_sleep_event(ec_dev, sleep_event); 394 if (ret < 0) 395 dev_dbg(ec_dev->dev, "Error %d sending resume event to ec\n", 396 ret); 397 398 if (ec_dev->wake_enabled) 399 disable_irq_wake(ec_dev->irq); 400 401 /* 402 * Let the mfd devices know about events that occur during 403 * suspend. This way the clients know what to do with them. 404 */ 405 cros_ec_report_events_during_suspend(ec_dev); 406 407 408 return 0; 409 } 410 EXPORT_SYMBOL(cros_ec_resume); 411 412 #endif 413 414 MODULE_LICENSE("GPL"); 415 MODULE_DESCRIPTION("ChromeOS EC core driver"); 416