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 static irqreturn_t ec_irq_handler(int irq, void *data) 36 { 37 struct cros_ec_device *ec_dev = data; 38 39 ec_dev->last_event_time = cros_ec_get_time_ns(); 40 41 return IRQ_WAKE_THREAD; 42 } 43 44 /** 45 * cros_ec_handle_event() - process and forward pending events on EC 46 * @ec_dev: Device with events to process. 47 * 48 * Call this function in a loop when the kernel is notified that the EC has 49 * pending events. 50 * 51 * Return: true if more events are still pending and this function should be 52 * called again. 53 */ 54 bool cros_ec_handle_event(struct cros_ec_device *ec_dev) 55 { 56 bool wake_event; 57 bool ec_has_more_events; 58 int ret; 59 60 ret = cros_ec_get_next_event(ec_dev, &wake_event, &ec_has_more_events); 61 62 /* 63 * Signal only if wake host events or any interrupt if 64 * cros_ec_get_next_event() returned an error (default value for 65 * wake_event is true) 66 */ 67 if (wake_event && device_may_wakeup(ec_dev->dev)) 68 pm_wakeup_event(ec_dev->dev, 0); 69 70 if (ret > 0) 71 blocking_notifier_call_chain(&ec_dev->event_notifier, 72 0, ec_dev); 73 74 return ec_has_more_events; 75 } 76 EXPORT_SYMBOL(cros_ec_handle_event); 77 78 static irqreturn_t ec_irq_thread(int irq, void *data) 79 { 80 struct cros_ec_device *ec_dev = data; 81 bool ec_has_more_events; 82 83 do { 84 ec_has_more_events = cros_ec_handle_event(ec_dev); 85 } while (ec_has_more_events); 86 87 return IRQ_HANDLED; 88 } 89 90 static int cros_ec_sleep_event(struct cros_ec_device *ec_dev, u8 sleep_event) 91 { 92 int ret; 93 struct { 94 struct cros_ec_command msg; 95 union { 96 struct ec_params_host_sleep_event req0; 97 struct ec_params_host_sleep_event_v1 req1; 98 struct ec_response_host_sleep_event_v1 resp1; 99 } u; 100 } __packed buf; 101 102 memset(&buf, 0, sizeof(buf)); 103 104 if (ec_dev->host_sleep_v1) { 105 buf.u.req1.sleep_event = sleep_event; 106 buf.u.req1.suspend_params.sleep_timeout_ms = 107 EC_HOST_SLEEP_TIMEOUT_DEFAULT; 108 109 buf.msg.outsize = sizeof(buf.u.req1); 110 if ((sleep_event == HOST_SLEEP_EVENT_S3_RESUME) || 111 (sleep_event == HOST_SLEEP_EVENT_S0IX_RESUME)) 112 buf.msg.insize = sizeof(buf.u.resp1); 113 114 buf.msg.version = 1; 115 116 } else { 117 buf.u.req0.sleep_event = sleep_event; 118 buf.msg.outsize = sizeof(buf.u.req0); 119 } 120 121 buf.msg.command = EC_CMD_HOST_SLEEP_EVENT; 122 123 ret = cros_ec_cmd_xfer_status(ec_dev, &buf.msg); 124 125 /* For now, report failure to transition to S0ix with a warning. */ 126 if (ret >= 0 && ec_dev->host_sleep_v1 && 127 (sleep_event == HOST_SLEEP_EVENT_S0IX_RESUME)) { 128 ec_dev->last_resume_result = 129 buf.u.resp1.resume_response.sleep_transitions; 130 131 WARN_ONCE(buf.u.resp1.resume_response.sleep_transitions & 132 EC_HOST_RESUME_SLEEP_TIMEOUT, 133 "EC detected sleep transition timeout. Total slp_s0 transitions: %d", 134 buf.u.resp1.resume_response.sleep_transitions & 135 EC_HOST_RESUME_SLEEP_TRANSITIONS_MASK); 136 } 137 138 return ret; 139 } 140 141 static int cros_ec_ready_event(struct notifier_block *nb, 142 unsigned long queued_during_suspend, 143 void *_notify) 144 { 145 struct cros_ec_device *ec_dev = container_of(nb, struct cros_ec_device, 146 notifier_ready); 147 u32 host_event = cros_ec_get_host_event(ec_dev); 148 149 if (host_event & EC_HOST_EVENT_MASK(EC_HOST_EVENT_INTERFACE_READY)) { 150 mutex_lock(&ec_dev->lock); 151 cros_ec_query_all(ec_dev); 152 mutex_unlock(&ec_dev->lock); 153 return NOTIFY_OK; 154 } 155 156 return NOTIFY_DONE; 157 } 158 159 /** 160 * cros_ec_register() - Register a new ChromeOS EC, using the provided info. 161 * @ec_dev: Device to register. 162 * 163 * Before calling this, allocate a pointer to a new device and then fill 164 * in all the fields up to the --private-- marker. 165 * 166 * Return: 0 on success or negative error code. 167 */ 168 int cros_ec_register(struct cros_ec_device *ec_dev) 169 { 170 struct device *dev = ec_dev->dev; 171 int err = 0; 172 173 BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->event_notifier); 174 175 ec_dev->max_request = sizeof(struct ec_params_hello); 176 ec_dev->max_response = sizeof(struct ec_response_get_protocol_info); 177 ec_dev->max_passthru = 0; 178 179 ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL); 180 if (!ec_dev->din) 181 return -ENOMEM; 182 183 ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL); 184 if (!ec_dev->dout) 185 return -ENOMEM; 186 187 mutex_init(&ec_dev->lock); 188 189 err = cros_ec_query_all(ec_dev); 190 if (err) { 191 dev_err(dev, "Cannot identify the EC: error %d\n", err); 192 return err; 193 } 194 195 if (ec_dev->irq > 0) { 196 err = devm_request_threaded_irq(dev, ec_dev->irq, 197 ec_irq_handler, 198 ec_irq_thread, 199 IRQF_TRIGGER_LOW | IRQF_ONESHOT, 200 "chromeos-ec", ec_dev); 201 if (err) { 202 dev_err(dev, "Failed to request IRQ %d: %d", 203 ec_dev->irq, err); 204 return err; 205 } 206 } 207 208 /* Register a platform device for the main EC instance */ 209 ec_dev->ec = platform_device_register_data(ec_dev->dev, "cros-ec-dev", 210 PLATFORM_DEVID_AUTO, &ec_p, 211 sizeof(struct cros_ec_platform)); 212 if (IS_ERR(ec_dev->ec)) { 213 dev_err(ec_dev->dev, 214 "Failed to create CrOS EC platform device\n"); 215 return PTR_ERR(ec_dev->ec); 216 } 217 218 if (ec_dev->max_passthru) { 219 /* 220 * Register a platform device for the PD behind the main EC. 221 * We make the following assumptions: 222 * - behind an EC, we have a pd 223 * - only one device added. 224 * - the EC is responsive at init time (it is not true for a 225 * sensor hub). 226 */ 227 ec_dev->pd = platform_device_register_data(ec_dev->dev, 228 "cros-ec-dev", 229 PLATFORM_DEVID_AUTO, &pd_p, 230 sizeof(struct cros_ec_platform)); 231 if (IS_ERR(ec_dev->pd)) { 232 dev_err(ec_dev->dev, 233 "Failed to create CrOS PD platform device\n"); 234 platform_device_unregister(ec_dev->ec); 235 return PTR_ERR(ec_dev->pd); 236 } 237 } 238 239 if (IS_ENABLED(CONFIG_OF) && dev->of_node) { 240 err = devm_of_platform_populate(dev); 241 if (err) { 242 platform_device_unregister(ec_dev->pd); 243 platform_device_unregister(ec_dev->ec); 244 dev_err(dev, "Failed to register sub-devices\n"); 245 return err; 246 } 247 } 248 249 /* 250 * Clear sleep event - this will fail harmlessly on platforms that 251 * don't implement the sleep event host command. 252 */ 253 err = cros_ec_sleep_event(ec_dev, 0); 254 if (err < 0) 255 dev_dbg(ec_dev->dev, "Error %d clearing sleep event to ec", 256 err); 257 258 if (ec_dev->mkbp_event_supported) { 259 /* 260 * Register the notifier for EC_HOST_EVENT_INTERFACE_READY 261 * event. 262 */ 263 ec_dev->notifier_ready.notifier_call = cros_ec_ready_event; 264 err = blocking_notifier_chain_register(&ec_dev->event_notifier, 265 &ec_dev->notifier_ready); 266 if (err) 267 return err; 268 } 269 270 dev_info(dev, "Chrome EC device registered\n"); 271 272 return 0; 273 } 274 EXPORT_SYMBOL(cros_ec_register); 275 276 /** 277 * cros_ec_unregister() - Remove a ChromeOS EC. 278 * @ec_dev: Device to unregister. 279 * 280 * Call this to deregister a ChromeOS EC, then clean up any private data. 281 * 282 * Return: 0 on success or negative error code. 283 */ 284 int cros_ec_unregister(struct cros_ec_device *ec_dev) 285 { 286 if (ec_dev->pd) 287 platform_device_unregister(ec_dev->pd); 288 platform_device_unregister(ec_dev->ec); 289 290 return 0; 291 } 292 EXPORT_SYMBOL(cros_ec_unregister); 293 294 #ifdef CONFIG_PM_SLEEP 295 /** 296 * cros_ec_suspend() - Handle a suspend operation for the ChromeOS EC device. 297 * @ec_dev: Device to suspend. 298 * 299 * This can be called by drivers to handle a suspend event. 300 * 301 * Return: 0 on success or negative error code. 302 */ 303 int cros_ec_suspend(struct cros_ec_device *ec_dev) 304 { 305 struct device *dev = ec_dev->dev; 306 int ret; 307 u8 sleep_event; 308 309 sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ? 310 HOST_SLEEP_EVENT_S3_SUSPEND : 311 HOST_SLEEP_EVENT_S0IX_SUSPEND; 312 313 ret = cros_ec_sleep_event(ec_dev, sleep_event); 314 if (ret < 0) 315 dev_dbg(ec_dev->dev, "Error %d sending suspend event to ec", 316 ret); 317 318 if (device_may_wakeup(dev)) 319 ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq); 320 321 disable_irq(ec_dev->irq); 322 ec_dev->was_wake_device = ec_dev->wake_enabled; 323 ec_dev->suspended = true; 324 325 return 0; 326 } 327 EXPORT_SYMBOL(cros_ec_suspend); 328 329 static void cros_ec_report_events_during_suspend(struct cros_ec_device *ec_dev) 330 { 331 while (ec_dev->mkbp_event_supported && 332 cros_ec_get_next_event(ec_dev, NULL, NULL) > 0) 333 blocking_notifier_call_chain(&ec_dev->event_notifier, 334 1, ec_dev); 335 } 336 337 /** 338 * cros_ec_resume() - Handle a resume operation for the ChromeOS EC device. 339 * @ec_dev: Device to resume. 340 * 341 * This can be called by drivers to handle a resume event. 342 * 343 * Return: 0 on success or negative error code. 344 */ 345 int cros_ec_resume(struct cros_ec_device *ec_dev) 346 { 347 int ret; 348 u8 sleep_event; 349 350 ec_dev->suspended = false; 351 enable_irq(ec_dev->irq); 352 353 sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ? 354 HOST_SLEEP_EVENT_S3_RESUME : 355 HOST_SLEEP_EVENT_S0IX_RESUME; 356 357 ret = cros_ec_sleep_event(ec_dev, sleep_event); 358 if (ret < 0) 359 dev_dbg(ec_dev->dev, "Error %d sending resume event to ec", 360 ret); 361 362 if (ec_dev->wake_enabled) { 363 disable_irq_wake(ec_dev->irq); 364 ec_dev->wake_enabled = 0; 365 } 366 /* 367 * Let the mfd devices know about events that occur during 368 * suspend. This way the clients know what to do with them. 369 */ 370 cros_ec_report_events_during_suspend(ec_dev); 371 372 373 return 0; 374 } 375 EXPORT_SYMBOL(cros_ec_resume); 376 377 #endif 378 379 MODULE_LICENSE("GPL"); 380 MODULE_DESCRIPTION("ChromeOS EC core driver"); 381