root/drivers/platform/chrome/cros_ec.c

DEFINITIONS

1. ec_irq_thread
2. cros_ec_sleep_event
3. cros_ec_register
4. cros_ec_unregister
5. cros_ec_suspend
6. cros_ec_report_events_during_suspend
7. cros_ec_resume

   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 #include <asm/unaligned.h>
  20 
  21 #define CROS_EC_DEV_EC_INDEX 0
  22 #define CROS_EC_DEV_PD_INDEX 1
  23 
  24 static struct cros_ec_platform ec_p = {
  25         .ec_name = CROS_EC_DEV_NAME,
  26         .cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_EC_INDEX),
  27 };
  28 
  29 static struct cros_ec_platform pd_p = {
  30         .ec_name = CROS_EC_DEV_PD_NAME,
  31         .cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX),
  32 };
  33 
  34 static irqreturn_t ec_irq_thread(int irq, void *data)
  35 {
  36         struct cros_ec_device *ec_dev = data;
  37         bool wake_event = true;
  38         int ret;
  39 
  40         ret = cros_ec_get_next_event(ec_dev, &wake_event);
  41 
  42         /*
  43          * Signal only if wake host events or any interrupt if
  44          * cros_ec_get_next_event() returned an error (default value for
  45          * wake_event is true)
  46          */
  47         if (wake_event && device_may_wakeup(ec_dev->dev))
  48                 pm_wakeup_event(ec_dev->dev, 0);
  49 
  50         if (ret > 0)
  51                 blocking_notifier_call_chain(&ec_dev->event_notifier,
  52                                              0, ec_dev);
  53         return IRQ_HANDLED;
  54 }
  55 
  56 static int cros_ec_sleep_event(struct cros_ec_device *ec_dev, u8 sleep_event)
  57 {
  58         int ret;
  59         struct {
  60                 struct cros_ec_command msg;
  61                 union {
  62                         struct ec_params_host_sleep_event req0;
  63                         struct ec_params_host_sleep_event_v1 req1;
  64                         struct ec_response_host_sleep_event_v1 resp1;
  65                 } u;
  66         } __packed buf;
  67 
  68         memset(&buf, 0, sizeof(buf));
  69 
  70         if (ec_dev->host_sleep_v1) {
  71                 buf.u.req1.sleep_event = sleep_event;
  72                 buf.u.req1.suspend_params.sleep_timeout_ms =
  73                                 EC_HOST_SLEEP_TIMEOUT_DEFAULT;
  74 
  75                 buf.msg.outsize = sizeof(buf.u.req1);
  76                 if ((sleep_event == HOST_SLEEP_EVENT_S3_RESUME) ||
  77                     (sleep_event == HOST_SLEEP_EVENT_S0IX_RESUME))
  78                         buf.msg.insize = sizeof(buf.u.resp1);
  79 
  80                 buf.msg.version = 1;
  81 
  82         } else {
  83                 buf.u.req0.sleep_event = sleep_event;
  84                 buf.msg.outsize = sizeof(buf.u.req0);
  85         }
  86 
  87         buf.msg.command = EC_CMD_HOST_SLEEP_EVENT;
  88 
  89         ret = cros_ec_cmd_xfer(ec_dev, &buf.msg);
  90 
  91         /* For now, report failure to transition to S0ix with a warning. */
  92         if (ret >= 0 && ec_dev->host_sleep_v1 &&
  93             (sleep_event == HOST_SLEEP_EVENT_S0IX_RESUME)) {
  94                 ec_dev->last_resume_result =
  95                         buf.u.resp1.resume_response.sleep_transitions;
  96 
  97                 WARN_ONCE(buf.u.resp1.resume_response.sleep_transitions &
  98                           EC_HOST_RESUME_SLEEP_TIMEOUT,
  99                           "EC detected sleep transition timeout. Total slp_s0 transitions: %d",
 100                           buf.u.resp1.resume_response.sleep_transitions &
 101                           EC_HOST_RESUME_SLEEP_TRANSITIONS_MASK);
 102         }
 103 
 104         return ret;
 105 }
 106 
 107 int cros_ec_register(struct cros_ec_device *ec_dev)
 108 {
 109         struct device *dev = ec_dev->dev;
 110         int err = 0;
 111 
 112         BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->event_notifier);
 113 
 114         ec_dev->max_request = sizeof(struct ec_params_hello);
 115         ec_dev->max_response = sizeof(struct ec_response_get_protocol_info);
 116         ec_dev->max_passthru = 0;
 117 
 118         ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
 119         if (!ec_dev->din)
 120                 return -ENOMEM;
 121 
 122         ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
 123         if (!ec_dev->dout)
 124                 return -ENOMEM;
 125 
 126         mutex_init(&ec_dev->lock);
 127 
 128         err = cros_ec_query_all(ec_dev);
 129         if (err) {
 130                 dev_err(dev, "Cannot identify the EC: error %d\n", err);
 131                 return err;
 132         }
 133 
 134         if (ec_dev->irq) {
 135                 err = devm_request_threaded_irq(dev, ec_dev->irq, NULL,
 136                                 ec_irq_thread, IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 137                                 "chromeos-ec", ec_dev);
 138                 if (err) {
 139                         dev_err(dev, "Failed to request IRQ %d: %d",
 140                                 ec_dev->irq, err);
 141                         return err;
 142                 }
 143         }
 144 
 145         /* Register a platform device for the main EC instance */
 146         ec_dev->ec = platform_device_register_data(ec_dev->dev, "cros-ec-dev",
 147                                         PLATFORM_DEVID_AUTO, &ec_p,
 148                                         sizeof(struct cros_ec_platform));
 149         if (IS_ERR(ec_dev->ec)) {
 150                 dev_err(ec_dev->dev,
 151                         "Failed to create CrOS EC platform device\n");
 152                 return PTR_ERR(ec_dev->ec);
 153         }
 154 
 155         if (ec_dev->max_passthru) {
 156                 /*
 157                  * Register a platform device for the PD behind the main EC.
 158                  * We make the following assumptions:
 159                  * - behind an EC, we have a pd
 160                  * - only one device added.
 161                  * - the EC is responsive at init time (it is not true for a
 162                  *   sensor hub).
 163                  */
 164                 ec_dev->pd = platform_device_register_data(ec_dev->dev,
 165                                         "cros-ec-dev",
 166                                         PLATFORM_DEVID_AUTO, &pd_p,
 167                                         sizeof(struct cros_ec_platform));
 168                 if (IS_ERR(ec_dev->pd)) {
 169                         dev_err(ec_dev->dev,
 170                                 "Failed to create CrOS PD platform device\n");
 171                         platform_device_unregister(ec_dev->ec);
 172                         return PTR_ERR(ec_dev->pd);
 173                 }
 174         }
 175 
 176         if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
 177                 err = devm_of_platform_populate(dev);
 178                 if (err) {
 179                         platform_device_unregister(ec_dev->pd);
 180                         platform_device_unregister(ec_dev->ec);
 181                         dev_err(dev, "Failed to register sub-devices\n");
 182                         return err;
 183                 }
 184         }
 185 
 186         /*
 187          * Clear sleep event - this will fail harmlessly on platforms that
 188          * don't implement the sleep event host command.
 189          */
 190         err = cros_ec_sleep_event(ec_dev, 0);
 191         if (err < 0)
 192                 dev_dbg(ec_dev->dev, "Error %d clearing sleep event to ec",
 193                         err);
 194 
 195         dev_info(dev, "Chrome EC device registered\n");
 196 
 197         return 0;
 198 }
 199 EXPORT_SYMBOL(cros_ec_register);
 200 
 201 int cros_ec_unregister(struct cros_ec_device *ec_dev)
 202 {
 203         if (ec_dev->pd)
 204                 platform_device_unregister(ec_dev->pd);
 205         platform_device_unregister(ec_dev->ec);
 206 
 207         return 0;
 208 }
 209 EXPORT_SYMBOL(cros_ec_unregister);
 210 
 211 #ifdef CONFIG_PM_SLEEP
 212 int cros_ec_suspend(struct cros_ec_device *ec_dev)
 213 {
 214         struct device *dev = ec_dev->dev;
 215         int ret;
 216         u8 sleep_event;
 217 
 218         sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ?
 219                       HOST_SLEEP_EVENT_S3_SUSPEND :
 220                       HOST_SLEEP_EVENT_S0IX_SUSPEND;
 221 
 222         ret = cros_ec_sleep_event(ec_dev, sleep_event);
 223         if (ret < 0)
 224                 dev_dbg(ec_dev->dev, "Error %d sending suspend event to ec",
 225                         ret);
 226 
 227         if (device_may_wakeup(dev))
 228                 ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq);
 229 
 230         disable_irq(ec_dev->irq);
 231         ec_dev->was_wake_device = ec_dev->wake_enabled;
 232         ec_dev->suspended = true;
 233 
 234         return 0;
 235 }
 236 EXPORT_SYMBOL(cros_ec_suspend);
 237 
 238 static void cros_ec_report_events_during_suspend(struct cros_ec_device *ec_dev)
 239 {
 240         while (ec_dev->mkbp_event_supported &&
 241                cros_ec_get_next_event(ec_dev, NULL) > 0)
 242                 blocking_notifier_call_chain(&ec_dev->event_notifier,
 243                                              1, ec_dev);
 244 }
 245 
 246 int cros_ec_resume(struct cros_ec_device *ec_dev)
 247 {
 248         int ret;
 249         u8 sleep_event;
 250 
 251         ec_dev->suspended = false;
 252         enable_irq(ec_dev->irq);
 253 
 254         sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ?
 255                       HOST_SLEEP_EVENT_S3_RESUME :
 256                       HOST_SLEEP_EVENT_S0IX_RESUME;
 257 
 258         ret = cros_ec_sleep_event(ec_dev, sleep_event);
 259         if (ret < 0)
 260                 dev_dbg(ec_dev->dev, "Error %d sending resume event to ec",
 261                         ret);
 262 
 263         if (ec_dev->wake_enabled) {
 264                 disable_irq_wake(ec_dev->irq);
 265                 ec_dev->wake_enabled = 0;
 266         }
 267         /*
 268          * Let the mfd devices know about events that occur during
 269          * suspend. This way the clients know what to do with them.
 270          */
 271         cros_ec_report_events_during_suspend(ec_dev);
 272 
 273 
 274         return 0;
 275 }
 276 EXPORT_SYMBOL(cros_ec_resume);
 277 
 278 #endif
 279 
 280 MODULE_LICENSE("GPL");
 281 MODULE_DESCRIPTION("ChromeOS EC core driver");