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); 185 186 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; 292 exit: 293 platform_device_unregister(ec_dev->ec); 294 platform_device_unregister(ec_dev->pd); 295 return err; 296 } 297 EXPORT_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 */ 307 void 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 } 313 EXPORT_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 */ 324 int 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 } 349 EXPORT_SYMBOL(cros_ec_suspend); 350 351 static void cros_ec_report_events_during_suspend(struct cros_ec_device *ec_dev) 352 { 353 while (ec_dev->mkbp_event_supported && 354 cros_ec_get_next_event(ec_dev, NULL, NULL) > 0) 355 blocking_notifier_call_chain(&ec_dev->event_notifier, 356 1, ec_dev); 357 } 358 359 /** 360 * cros_ec_resume() - Handle a resume operation for the ChromeOS EC device. 361 * @ec_dev: Device to resume. 362 * 363 * This can be called by drivers to handle a resume event. 364 * 365 * Return: 0 on success or negative error code. 366 */ 367 int cros_ec_resume(struct cros_ec_device *ec_dev) 368 { 369 int ret; 370 u8 sleep_event; 371 372 ec_dev->suspended = false; 373 enable_irq(ec_dev->irq); 374 375 sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ? 376 HOST_SLEEP_EVENT_S3_RESUME : 377 HOST_SLEEP_EVENT_S0IX_RESUME; 378 379 ret = cros_ec_sleep_event(ec_dev, sleep_event); 380 if (ret < 0) 381 dev_dbg(ec_dev->dev, "Error %d sending resume event to ec\n", 382 ret); 383 384 if (ec_dev->wake_enabled) 385 disable_irq_wake(ec_dev->irq); 386 387 /* 388 * Let the mfd devices know about events that occur during 389 * suspend. This way the clients know what to do with them. 390 */ 391 cros_ec_report_events_during_suspend(ec_dev); 392 393 394 return 0; 395 } 396 EXPORT_SYMBOL(cros_ec_resume); 397 398 #endif 399 400 MODULE_LICENSE("GPL"); 401 MODULE_DESCRIPTION("ChromeOS EC core driver"); 402