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/of_platform.h> 13 #include <linux/interrupt.h> 14 #include <linux/slab.h> 15 #include <linux/module.h> 16 #include <linux/platform_data/cros_ec_commands.h> 17 #include <linux/platform_data/cros_ec_proto.h> 18 #include <linux/suspend.h> 19 20 #include "cros_ec.h" 21 22 #define CROS_EC_DEV_EC_INDEX 0 23 #define CROS_EC_DEV_PD_INDEX 1 24 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), 28 }; 29 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), 33 }; 34 35 /** 36 * cros_ec_irq_handler() - top half part of the interrupt handler 37 * @irq: IRQ id 38 * @data: (ec_dev) Device with events to process. 39 * 40 * Return: Wakeup the bottom half 41 */ 42 static irqreturn_t cros_ec_irq_handler(int irq, void *data) 43 { 44 struct cros_ec_device *ec_dev = data; 45 46 ec_dev->last_event_time = cros_ec_get_time_ns(); 47 48 return IRQ_WAKE_THREAD; 49 } 50 51 /** 52 * cros_ec_handle_event() - process and forward pending events on EC 53 * @ec_dev: Device with events to process. 54 * 55 * Call this function in a loop when the kernel is notified that the EC has 56 * pending events. 57 * 58 * Return: true if more events are still pending and this function should be 59 * called again. 60 */ 61 static bool cros_ec_handle_event(struct cros_ec_device *ec_dev) 62 { 63 bool wake_event; 64 bool ec_has_more_events; 65 int ret; 66 67 ret = cros_ec_get_next_event(ec_dev, &wake_event, &ec_has_more_events); 68 69 /* 70 * Signal only if wake host events or any interrupt if 71 * cros_ec_get_next_event() returned an error (default value for 72 * wake_event is true) 73 */ 74 if (wake_event && device_may_wakeup(ec_dev->dev)) 75 pm_wakeup_event(ec_dev->dev, 0); 76 77 if (ret > 0) 78 blocking_notifier_call_chain(&ec_dev->event_notifier, 79 0, ec_dev); 80 81 return ec_has_more_events; 82 } 83 84 /** 85 * cros_ec_irq_thread() - bottom half part of the interrupt handler 86 * @irq: IRQ id 87 * @data: (ec_dev) Device with events to process. 88 * 89 * Return: Interrupt handled. 90 */ 91 irqreturn_t cros_ec_irq_thread(int irq, void *data) 92 { 93 struct cros_ec_device *ec_dev = data; 94 bool ec_has_more_events; 95 96 do { 97 ec_has_more_events = cros_ec_handle_event(ec_dev); 98 } while (ec_has_more_events); 99 100 return IRQ_HANDLED; 101 } 102 EXPORT_SYMBOL(cros_ec_irq_thread); 103 104 static int cros_ec_sleep_event(struct cros_ec_device *ec_dev, u8 sleep_event) 105 { 106 int ret; 107 struct { 108 struct cros_ec_command msg; 109 union { 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; 113 } u; 114 } __packed buf; 115 116 memset(&buf, 0, sizeof(buf)); 117 118 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; 122 123 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); 127 128 buf.msg.version = 1; 129 130 } else { 131 buf.u.req0.sleep_event = sleep_event; 132 buf.msg.outsize = sizeof(buf.u.req0); 133 } 134 135 buf.msg.command = EC_CMD_HOST_SLEEP_EVENT; 136 137 ret = cros_ec_cmd_xfer_status(ec_dev, &buf.msg); 138 139 /* 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; 144 145 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); 150 } 151 152 return ret; 153 } 154 155 static int cros_ec_ready_event(struct notifier_block *nb, 156 unsigned long queued_during_suspend, 157 void *_notify) 158 { 159 struct cros_ec_device *ec_dev = container_of(nb, struct cros_ec_device, 160 notifier_ready); 161 u32 host_event = cros_ec_get_host_event(ec_dev); 162 163 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); 167 return NOTIFY_OK; 168 } 169 170 return NOTIFY_DONE; 171 } 172 173 /** 174 * cros_ec_register() - Register a new ChromeOS EC, using the provided info. 175 * @ec_dev: Device to register. 176 * 177 * Before calling this, allocate a pointer to a new device and then fill 178 * in all the fields up to the --private-- marker. 179 * 180 * Return: 0 on success or negative error code. 181 */ 182 int cros_ec_register(struct cros_ec_device *ec_dev) 183 { 184 struct device *dev = ec_dev->dev; 185 int err = 0; 186 187 BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->event_notifier); 188 189 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; 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", 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 platform_device_unregister(ec_dev->ec); 249 return PTR_ERR(ec_dev->pd); 250 } 251 } 252 253 if (IS_ENABLED(CONFIG_OF) && dev->of_node) { 254 err = devm_of_platform_populate(dev); 255 if (err) { 256 platform_device_unregister(ec_dev->pd); 257 platform_device_unregister(ec_dev->ec); 258 dev_err(dev, "Failed to register sub-devices\n"); 259 return err; 260 } 261 } 262 263 /* 264 * Clear sleep event - this will fail harmlessly on platforms that 265 * don't implement the sleep event host command. 266 */ 267 err = cros_ec_sleep_event(ec_dev, 0); 268 if (err < 0) 269 dev_dbg(ec_dev->dev, "Error %d clearing sleep event to ec", 270 err); 271 272 if (ec_dev->mkbp_event_supported) { 273 /* 274 * Register the notifier for EC_HOST_EVENT_INTERFACE_READY 275 * event. 276 */ 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); 280 if (err) 281 return err; 282 } 283 284 dev_info(dev, "Chrome EC device registered\n"); 285 286 /* 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. 289 */ 290 if (ec_dev->mkbp_event_supported) 291 cros_ec_irq_thread(0, ec_dev); 292 293 return 0; 294 } 295 EXPORT_SYMBOL(cros_ec_register); 296 297 /** 298 * cros_ec_unregister() - Remove a ChromeOS EC. 299 * @ec_dev: Device to unregister. 300 * 301 * Call this to deregister a ChromeOS EC, then clean up any private data. 302 * 303 * Return: 0 on success or negative error code. 304 */ 305 int cros_ec_unregister(struct cros_ec_device *ec_dev) 306 { 307 if (ec_dev->pd) 308 platform_device_unregister(ec_dev->pd); 309 platform_device_unregister(ec_dev->ec); 310 311 return 0; 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", 337 ret); 338 339 if (device_may_wakeup(dev)) 340 ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq); 341 342 disable_irq(ec_dev->irq); 343 ec_dev->was_wake_device = ec_dev->wake_enabled; 344 ec_dev->suspended = true; 345 346 return 0; 347 } 348 EXPORT_SYMBOL(cros_ec_suspend); 349 350 static void cros_ec_report_events_during_suspend(struct cros_ec_device *ec_dev) 351 { 352 while (ec_dev->mkbp_event_supported && 353 cros_ec_get_next_event(ec_dev, NULL, NULL) > 0) 354 blocking_notifier_call_chain(&ec_dev->event_notifier, 355 1, ec_dev); 356 } 357 358 /** 359 * cros_ec_resume() - Handle a resume operation for the ChromeOS EC device. 360 * @ec_dev: Device to resume. 361 * 362 * This can be called by drivers to handle a resume event. 363 * 364 * Return: 0 on success or negative error code. 365 */ 366 int cros_ec_resume(struct cros_ec_device *ec_dev) 367 { 368 int ret; 369 u8 sleep_event; 370 371 ec_dev->suspended = false; 372 enable_irq(ec_dev->irq); 373 374 sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ? 375 HOST_SLEEP_EVENT_S3_RESUME : 376 HOST_SLEEP_EVENT_S0IX_RESUME; 377 378 ret = cros_ec_sleep_event(ec_dev, sleep_event); 379 if (ret < 0) 380 dev_dbg(ec_dev->dev, "Error %d sending resume event to ec", 381 ret); 382 383 if (ec_dev->wake_enabled) { 384 disable_irq_wake(ec_dev->irq); 385 ec_dev->wake_enabled = 0; 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