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(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 /** 142 * cros_ec_register() - Register a new ChromeOS EC, using the provided info. 143 * @ec_dev: Device to register. 144 * 145 * Before calling this, allocate a pointer to a new device and then fill 146 * in all the fields up to the --private-- marker. 147 * 148 * Return: 0 on success or negative error code. 149 */ 150 int cros_ec_register(struct cros_ec_device *ec_dev) 151 { 152 struct device *dev = ec_dev->dev; 153 int err = 0; 154 155 BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->event_notifier); 156 157 ec_dev->max_request = sizeof(struct ec_params_hello); 158 ec_dev->max_response = sizeof(struct ec_response_get_protocol_info); 159 ec_dev->max_passthru = 0; 160 161 ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL); 162 if (!ec_dev->din) 163 return -ENOMEM; 164 165 ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL); 166 if (!ec_dev->dout) 167 return -ENOMEM; 168 169 mutex_init(&ec_dev->lock); 170 171 err = cros_ec_query_all(ec_dev); 172 if (err) { 173 dev_err(dev, "Cannot identify the EC: error %d\n", err); 174 return err; 175 } 176 177 if (ec_dev->irq > 0) { 178 err = devm_request_threaded_irq(dev, ec_dev->irq, 179 ec_irq_handler, 180 ec_irq_thread, 181 IRQF_TRIGGER_LOW | IRQF_ONESHOT, 182 "chromeos-ec", ec_dev); 183 if (err) { 184 dev_err(dev, "Failed to request IRQ %d: %d", 185 ec_dev->irq, err); 186 return err; 187 } 188 } 189 190 /* Register a platform device for the main EC instance */ 191 ec_dev->ec = platform_device_register_data(ec_dev->dev, "cros-ec-dev", 192 PLATFORM_DEVID_AUTO, &ec_p, 193 sizeof(struct cros_ec_platform)); 194 if (IS_ERR(ec_dev->ec)) { 195 dev_err(ec_dev->dev, 196 "Failed to create CrOS EC platform device\n"); 197 return PTR_ERR(ec_dev->ec); 198 } 199 200 if (ec_dev->max_passthru) { 201 /* 202 * Register a platform device for the PD behind the main EC. 203 * We make the following assumptions: 204 * - behind an EC, we have a pd 205 * - only one device added. 206 * - the EC is responsive at init time (it is not true for a 207 * sensor hub). 208 */ 209 ec_dev->pd = platform_device_register_data(ec_dev->dev, 210 "cros-ec-dev", 211 PLATFORM_DEVID_AUTO, &pd_p, 212 sizeof(struct cros_ec_platform)); 213 if (IS_ERR(ec_dev->pd)) { 214 dev_err(ec_dev->dev, 215 "Failed to create CrOS PD platform device\n"); 216 platform_device_unregister(ec_dev->ec); 217 return PTR_ERR(ec_dev->pd); 218 } 219 } 220 221 if (IS_ENABLED(CONFIG_OF) && dev->of_node) { 222 err = devm_of_platform_populate(dev); 223 if (err) { 224 platform_device_unregister(ec_dev->pd); 225 platform_device_unregister(ec_dev->ec); 226 dev_err(dev, "Failed to register sub-devices\n"); 227 return err; 228 } 229 } 230 231 /* 232 * Clear sleep event - this will fail harmlessly on platforms that 233 * don't implement the sleep event host command. 234 */ 235 err = cros_ec_sleep_event(ec_dev, 0); 236 if (err < 0) 237 dev_dbg(ec_dev->dev, "Error %d clearing sleep event to ec", 238 err); 239 240 dev_info(dev, "Chrome EC device registered\n"); 241 242 return 0; 243 } 244 EXPORT_SYMBOL(cros_ec_register); 245 246 /** 247 * cros_ec_unregister() - Remove a ChromeOS EC. 248 * @ec_dev: Device to unregister. 249 * 250 * Call this to deregister a ChromeOS EC, then clean up any private data. 251 * 252 * Return: 0 on success or negative error code. 253 */ 254 int cros_ec_unregister(struct cros_ec_device *ec_dev) 255 { 256 if (ec_dev->pd) 257 platform_device_unregister(ec_dev->pd); 258 platform_device_unregister(ec_dev->ec); 259 260 return 0; 261 } 262 EXPORT_SYMBOL(cros_ec_unregister); 263 264 #ifdef CONFIG_PM_SLEEP 265 /** 266 * cros_ec_suspend() - Handle a suspend operation for the ChromeOS EC device. 267 * @ec_dev: Device to suspend. 268 * 269 * This can be called by drivers to handle a suspend event. 270 * 271 * Return: 0 on success or negative error code. 272 */ 273 int cros_ec_suspend(struct cros_ec_device *ec_dev) 274 { 275 struct device *dev = ec_dev->dev; 276 int ret; 277 u8 sleep_event; 278 279 sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ? 280 HOST_SLEEP_EVENT_S3_SUSPEND : 281 HOST_SLEEP_EVENT_S0IX_SUSPEND; 282 283 ret = cros_ec_sleep_event(ec_dev, sleep_event); 284 if (ret < 0) 285 dev_dbg(ec_dev->dev, "Error %d sending suspend event to ec", 286 ret); 287 288 if (device_may_wakeup(dev)) 289 ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq); 290 291 disable_irq(ec_dev->irq); 292 ec_dev->was_wake_device = ec_dev->wake_enabled; 293 ec_dev->suspended = true; 294 295 return 0; 296 } 297 EXPORT_SYMBOL(cros_ec_suspend); 298 299 static void cros_ec_report_events_during_suspend(struct cros_ec_device *ec_dev) 300 { 301 while (ec_dev->mkbp_event_supported && 302 cros_ec_get_next_event(ec_dev, NULL, NULL) > 0) 303 blocking_notifier_call_chain(&ec_dev->event_notifier, 304 1, ec_dev); 305 } 306 307 /** 308 * cros_ec_resume() - Handle a resume operation for the ChromeOS EC device. 309 * @ec_dev: Device to resume. 310 * 311 * This can be called by drivers to handle a resume event. 312 * 313 * Return: 0 on success or negative error code. 314 */ 315 int cros_ec_resume(struct cros_ec_device *ec_dev) 316 { 317 int ret; 318 u8 sleep_event; 319 320 ec_dev->suspended = false; 321 enable_irq(ec_dev->irq); 322 323 sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ? 324 HOST_SLEEP_EVENT_S3_RESUME : 325 HOST_SLEEP_EVENT_S0IX_RESUME; 326 327 ret = cros_ec_sleep_event(ec_dev, sleep_event); 328 if (ret < 0) 329 dev_dbg(ec_dev->dev, "Error %d sending resume event to ec", 330 ret); 331 332 if (ec_dev->wake_enabled) { 333 disable_irq_wake(ec_dev->irq); 334 ec_dev->wake_enabled = 0; 335 } 336 /* 337 * Let the mfd devices know about events that occur during 338 * suspend. This way the clients know what to do with them. 339 */ 340 cros_ec_report_events_during_suspend(ec_dev); 341 342 343 return 0; 344 } 345 EXPORT_SYMBOL(cros_ec_resume); 346 347 #endif 348 349 MODULE_LICENSE("GPL"); 350 MODULE_DESCRIPTION("ChromeOS EC core driver"); 351