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, sensor_num;
  56         char *name;
  57
  58         sensor_num = cros_ec_get_sensor_count(ec);
  59         if (sensor_num < 0) {
  60                 dev_err(dev,
  61                         "Unable to retrieve sensor information (err:%d)\n",
  62                         sensor_num);
  63                 return sensor_num;
  64         }
  65
  66         sensorhub->sensor_num = sensor_num;
  67         if (sensor_num == 0) {
  68                 dev_err(dev, "Zero sensors reported.\n");
  69                 return -EINVAL;
  70         }
  71
  72         msg->version = 1;
  73         msg->insize = sizeof(struct ec_response_motion_sense);
  74         msg->outsize = sizeof(struct ec_params_motion_sense);
  75
  76         for (i = 0; i < sensor_num; i++) {
  77                 sensorhub->params->cmd = MOTIONSENSE_CMD_INFO;
  78                 sensorhub->params->info.sensor_num = i;
  79
  80                 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
  81                 if (ret < 0) {
  82                         dev_warn(dev, "no info for EC sensor %d : %d/%d\n",
  83                                  i, ret, msg->result);
  84                         continue;
  85                 }
  86
  87                 switch (sensorhub->resp->info.type) {
  88                 case MOTIONSENSE_TYPE_ACCEL:
  89                         name = "cros-ec-accel";
  90                         break;
  91                 case MOTIONSENSE_TYPE_BARO:
  92                         name = "cros-ec-baro";
  93                         break;
  94                 case MOTIONSENSE_TYPE_GYRO:
  95                         name = "cros-ec-gyro";
  96                         break;
  97                 case MOTIONSENSE_TYPE_MAG:
  98                         name = "cros-ec-mag";
  99                         break;
 100                 case MOTIONSENSE_TYPE_PROX:
 101                         name = "cros-ec-prox";
 102                         break;
 103                 case MOTIONSENSE_TYPE_LIGHT:
 104                         name = "cros-ec-light";
 105                         break;
 106                 case MOTIONSENSE_TYPE_ACTIVITY:
 107                         name = "cros-ec-activity";
 108                         break;
 109                 default:
 110                         dev_warn(dev, "unknown type %d\n",
 111                                  sensorhub->resp->info.type);
 112                         continue;
 113                 }
 114
 115                 ret = cros_ec_sensorhub_allocate_sensor(dev, name, i);
 116                 if (ret)
 117                         return ret;
 118
 119                 sensor_type[sensorhub->resp->info.type]++;
 120         }
 121
 122         if (sensor_type[MOTIONSENSE_TYPE_ACCEL] >= 2)
 123                 ec->has_kb_wake_angle = true;
 124
 125         if (cros_ec_check_features(ec,
 126                                    EC_FEATURE_REFINED_TABLET_MODE_HYSTERESIS)) {
 127                 ret = cros_ec_sensorhub_allocate_sensor(dev,
 128                                                         "cros-ec-lid-angle",
 129                                                         0);
 130                 if (ret)
 131                         return ret;
 132         }
 133
 134         return 0;
 135 }
 136
 137 static int cros_ec_sensorhub_probe(struct platform_device *pdev)
 138 {
 139         struct device *dev = &pdev->dev;
 140         struct cros_ec_dev *ec = dev_get_drvdata(dev->parent);
 141         struct cros_ec_sensorhub *data;
 142         struct cros_ec_command *msg;
 143         int ret;
 144         int i;
 145
 146         msg = devm_kzalloc(dev, sizeof(struct cros_ec_command) +
 147                            max((u16)sizeof(struct ec_params_motion_sense),
 148                                ec->ec_dev->max_response), GFP_KERNEL);
 149         if (!msg)
 150                 return -ENOMEM;
 151
 152         msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
 153
 154         data = devm_kzalloc(dev, sizeof(struct cros_ec_sensorhub), GFP_KERNEL);
 155         if (!data)
 156                 return -ENOMEM;
 157
 158         mutex_init(&data->cmd_lock);
 159
 160         data->dev = dev;
 161         data->ec = ec;
 162         data->msg = msg;
 163         data->params = (struct ec_params_motion_sense *)msg->data;
 164         data->resp = (struct ec_response_motion_sense *)msg->data;
 165
 166         dev_set_drvdata(dev, data);
 167
 168         /* Check whether this EC is a sensor hub. */
 169         if (cros_ec_check_features(data->ec, EC_FEATURE_MOTION_SENSE)) {
 170                 ret = cros_ec_sensorhub_register(dev, data);
 171                 if (ret)
 172                         return ret;
 173         } else {
 174                 /*
 175                  * If the device has sensors but does not claim to
 176                  * be a sensor hub, we are in legacy mode.
 177                  */
 178                 data->sensor_num = 2;
 179                 for (i = 0; i < data->sensor_num; i++) {
 180                         ret = cros_ec_sensorhub_allocate_sensor(dev,
 181                                                 "cros-ec-accel-legacy", i);
 182                         if (ret)
 183                                 return ret;
 184                 }
 185         }
 186
 187         /*
 188          * If the EC does not have a FIFO, the sensors will query their data
 189          * themselves via sysfs or a software trigger.
 190          */
 191         if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) {
 192                 ret = cros_ec_sensorhub_ring_add(data);
 193                 if (ret)
 194                         return ret;
 195                 /*
 196                  * The msg and its data is not under the control of the ring
 197                  * handler.
 198                  */
 199                 return devm_add_action_or_reset(dev,
 200                                                 cros_ec_sensorhub_ring_remove,
 201                                                 data);
 202         }
 203
 204         return 0;
 205 }
 206
 207 #ifdef CONFIG_PM_SLEEP
 208 /*
 209  * When the EC is suspending, we must stop sending interrupt,
 210  * we may use the same interrupt line for waking up the device.
 211  * Tell the EC to stop sending non-interrupt event on the iio ring.
 212  */
 213 static int cros_ec_sensorhub_suspend(struct device *dev)
 214 {
 215         struct platform_device *pdev = to_platform_device(dev);
 216         struct cros_ec_sensorhub *sensorhub = platform_get_drvdata(pdev);
 217         struct cros_ec_dev *ec = sensorhub->ec;
 218
 219         if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO))
 220                 return cros_ec_sensorhub_ring_fifo_enable(sensorhub, false);
 221         return 0;
 222 }
 223
 224 static int cros_ec_sensorhub_resume(struct device *dev)
 225 {
 226         struct platform_device *pdev = to_platform_device(dev);
 227         struct cros_ec_sensorhub *sensorhub = platform_get_drvdata(pdev);
 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, true);
 232         return 0;
 233 }
 234 #endif
 235
 236 static SIMPLE_DEV_PM_OPS(cros_ec_sensorhub_pm_ops,
 237                 cros_ec_sensorhub_suspend,
 238                 cros_ec_sensorhub_resume);
 239
 240 static struct platform_driver cros_ec_sensorhub_driver = {
 241         .driver = {
 242                 .name = DRV_NAME,
 243                 .pm = &cros_ec_sensorhub_pm_ops,
 244         },
 245         .probe = cros_ec_sensorhub_probe,
 246 };
 247
 248 module_platform_driver(cros_ec_sensorhub_driver);
 249
 250 MODULE_ALIAS("platform:" DRV_NAME);
 251 MODULE_AUTHOR("Gwendal Grignou <gwendal@chromium.org>");
 252 MODULE_DESCRIPTION("ChromeOS EC MEMS Sensor Hub Driver");
 253 MODULE_LICENSE("GPL");