drivers/platform/chrome/cros_ec_sensorhub.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Sensor HUB driver that discovers sensors behind a ChromeOS Embedded
   4  * Controller.
   5  *
   6  * Copyright 2019 Google LLC
   7  */
   8
   9 #include <linux/init.h>
  10 #include <linux/device.h>
  11 #include <linux/module.h>
  12 #include <linux/platform_data/cros_ec_commands.h>
  13 #include <linux/platform_data/cros_ec_proto.h>
  14 #include <linux/platform_data/cros_ec_sensorhub.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/slab.h>
  17 #include <linux/types.h>
  18
  19 #define DRV_NAME                "cros-ec-sensorhub"
  20
  21 static void cros_ec_sensorhub_free_sensor(void *arg)
  22 {
  23         struct platform_device *pdev = arg;
  24
  25         platform_device_unregister(pdev);
  26 }
  27
  28 static int cros_ec_sensorhub_allocate_sensor(struct device *parent,
  29                                              char *sensor_name,
  30                                              int sensor_num)
  31 {
  32         struct cros_ec_sensor_platform sensor_platforms = {
  33                 .sensor_num = sensor_num,
  34         };
  35         struct platform_device *pdev;
  36
  37         pdev = platform_device_register_data(parent, sensor_name,
  38                                              PLATFORM_DEVID_AUTO,
  39                                              &sensor_platforms,
  40                                              sizeof(sensor_platforms));
  41         if (IS_ERR(pdev))
  42                 return PTR_ERR(pdev);
  43
  44         return devm_add_action_or_reset(parent,
  45                                         cros_ec_sensorhub_free_sensor,
  46                                         pdev);
  47 }
  48
  49 static int cros_ec_sensorhub_register(struct device *dev,
  50                                       struct cros_ec_sensorhub *sensorhub)
  51 {
  52         int sensor_type[MOTIONSENSE_TYPE_MAX] = { 0 };
  53         struct cros_ec_command *msg = sensorhub->msg;
  54         struct cros_ec_dev *ec = sensorhub->ec;
  55         int ret, i;
  56         char *name;
  57
  58
  59         msg->version = 1;
  60         msg->insize = sizeof(struct ec_response_motion_sense);
  61         msg->outsize = sizeof(struct ec_params_motion_sense);
  62
  63         for (i = 0; i < sensorhub->sensor_num; i++) {
  64                 sensorhub->params->cmd = MOTIONSENSE_CMD_INFO;
  65                 sensorhub->params->info.sensor_num = i;
  66
  67                 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
  68                 if (ret < 0) {
  69                         dev_warn(dev, "no info for EC sensor %d : %d/%d\n",
  70                                  i, ret, msg->result);
  71                         continue;
  72                 }
  73
  74                 switch (sensorhub->resp->info.type) {
  75                 case MOTIONSENSE_TYPE_ACCEL:
  76                         name = "cros-ec-accel";
  77                         break;
  78                 case MOTIONSENSE_TYPE_BARO:
  79                         name = "cros-ec-baro";
  80                         break;
  81                 case MOTIONSENSE_TYPE_GYRO:
  82                         name = "cros-ec-gyro";
  83                         break;
  84                 case MOTIONSENSE_TYPE_MAG:
  85                         name = "cros-ec-mag";
  86                         break;
  87                 case MOTIONSENSE_TYPE_PROX:
  88                         name = "cros-ec-prox";
  89                         break;
  90                 case MOTIONSENSE_TYPE_LIGHT:
  91                         name = "cros-ec-light";
  92                         break;
  93                 case MOTIONSENSE_TYPE_ACTIVITY:
  94                         name = "cros-ec-activity";
  95                         break;
  96                 default:
  97                         dev_warn(dev, "unknown type %d\n",
  98                                  sensorhub->resp->info.type);
  99                         continue;
 100                 }
 101
 102                 ret = cros_ec_sensorhub_allocate_sensor(dev, name, i);
 103                 if (ret)
 104                         return ret;
 105
 106                 sensor_type[sensorhub->resp->info.type]++;
 107         }
 108
 109         if (sensor_type[MOTIONSENSE_TYPE_ACCEL] >= 2)
 110                 ec->has_kb_wake_angle = true;
 111
 112         if (cros_ec_check_features(ec,
 113                                    EC_FEATURE_REFINED_TABLET_MODE_HYSTERESIS)) {
 114                 ret = cros_ec_sensorhub_allocate_sensor(dev,
 115                                                         "cros-ec-lid-angle",
 116                                                         0);
 117                 if (ret)
 118                         return ret;
 119         }
 120
 121         return 0;
 122 }
 123
 124 static int cros_ec_sensorhub_probe(struct platform_device *pdev)
 125 {
 126         struct device *dev = &pdev->dev;
 127         struct cros_ec_dev *ec = dev_get_drvdata(dev->parent);
 128         struct cros_ec_sensorhub *data;
 129         struct cros_ec_command *msg;
 130         int ret, i, sensor_num;
 131
 132         msg = devm_kzalloc(dev, sizeof(struct cros_ec_command) +
 133                            max((u16)sizeof(struct ec_params_motion_sense),
 134                                ec->ec_dev->max_response), GFP_KERNEL);
 135         if (!msg)
 136                 return -ENOMEM;
 137
 138         msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
 139
 140         data = devm_kzalloc(dev, sizeof(struct cros_ec_sensorhub), GFP_KERNEL);
 141         if (!data)
 142                 return -ENOMEM;
 143
 144         mutex_init(&data->cmd_lock);
 145
 146         data->dev = dev;
 147         data->ec = ec;
 148         data->msg = msg;
 149         data->params = (struct ec_params_motion_sense *)msg->data;
 150         data->resp = (struct ec_response_motion_sense *)msg->data;
 151
 152         dev_set_drvdata(dev, data);
 153
 154         /* Check whether this EC is a sensor hub. */
 155         if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE)) {
 156                 sensor_num = cros_ec_get_sensor_count(ec);
 157                 if (sensor_num < 0) {
 158                         dev_err(dev,
 159                                 "Unable to retrieve sensor information (err:%d)\n",
 160                                 sensor_num);
 161                         return sensor_num;
 162                 }
 163                 if (sensor_num == 0) {
 164                         dev_err(dev, "Zero sensors reported.\n");
 165                         return -EINVAL;
 166                 }
 167                 data->sensor_num = sensor_num;
 168
 169                 /*
 170                  * Prepare the ring handler before enumering the
 171                  * sensors.
 172                  */
 173                 if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) {
 174                         ret = cros_ec_sensorhub_ring_allocate(data);
 175                         if (ret)
 176                                 return ret;
 177                 }
 178
 179                 /* Enumerate the sensors.*/
 180                 ret = cros_ec_sensorhub_register(dev, data);
 181                 if (ret)
 182                         return ret;
 183
 184                 /*
 185                  * When the EC does not have a FIFO, the sensors will query
 186                  * their data themselves via sysfs or a software trigger.
 187                  */
 188                 if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) {
 189                         ret = cros_ec_sensorhub_ring_add(data);
 190                         if (ret)
 191                                 return ret;
 192                         /*
 193                          * The msg and its data is not under the control of the
 194                          * ring handler.
 195                          */
 196                         return devm_add_action_or_reset(dev,
 197                                         cros_ec_sensorhub_ring_remove,
 198                                         data);
 199                 }
 200
 201         } else {
 202                 /*
 203                  * If the device has sensors but does not claim to
 204                  * be a sensor hub, we are in legacy mode.
 205                  */
 206                 data->sensor_num = 2;
 207                 for (i = 0; i < data->sensor_num; i++) {
 208                         ret = cros_ec_sensorhub_allocate_sensor(dev,
 209                                                 "cros-ec-accel-legacy", i);
 210                         if (ret)
 211                                 return ret;
 212                 }
 213         }
 214
 215
 216         return 0;
 217 }
 218
 219 #ifdef CONFIG_PM_SLEEP
 220 /*
 221  * When the EC is suspending, we must stop sending interrupt,
 222  * we may use the same interrupt line for waking up the device.
 223  * Tell the EC to stop sending non-interrupt event on the iio ring.
 224  */
 225 static int cros_ec_sensorhub_suspend(struct device *dev)
 226 {
 227         struct cros_ec_sensorhub *sensorhub = dev_get_drvdata(dev);
 228         struct cros_ec_dev *ec = sensorhub->ec;
 229
 230         if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO))
 231                 return cros_ec_sensorhub_ring_fifo_enable(sensorhub, false);
 232         return 0;
 233 }
 234
 235 static int cros_ec_sensorhub_resume(struct device *dev)
 236 {
 237         struct cros_ec_sensorhub *sensorhub = dev_get_drvdata(dev);
 238         struct cros_ec_dev *ec = sensorhub->ec;
 239
 240         if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO))
 241                 return cros_ec_sensorhub_ring_fifo_enable(sensorhub, true);
 242         return 0;
 243 }
 244 #endif
 245
 246 static SIMPLE_DEV_PM_OPS(cros_ec_sensorhub_pm_ops,
 247                 cros_ec_sensorhub_suspend,
 248                 cros_ec_sensorhub_resume);
 249
 250 static struct platform_driver cros_ec_sensorhub_driver = {
 251         .driver = {
 252                 .name = DRV_NAME,
 253                 .pm = &cros_ec_sensorhub_pm_ops,
 254         },
 255         .probe = cros_ec_sensorhub_probe,
 256 };
 257
 258 module_platform_driver(cros_ec_sensorhub_driver);
 259
 260 MODULE_ALIAS("platform:" DRV_NAME);
 261 MODULE_AUTHOR("Gwendal Grignou <[email protected]>");
 262 MODULE_DESCRIPTION("ChromeOS EC MEMS Sensor Hub Driver");
 263 MODULE_LICENSE("GPL");