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/mod_devicetable.h>
  12 #include <linux/module.h>
  13 #include <linux/platform_data/cros_ec_commands.h>
  14 #include <linux/platform_data/cros_ec_proto.h>
  15 #include <linux/platform_data/cros_ec_sensorhub.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/slab.h>
  18 #include <linux/types.h>
  19
  20 #define DRV_NAME                "cros-ec-sensorhub"
  21
  22 static void cros_ec_sensorhub_free_sensor(void *arg)
  23 {
  24         struct platform_device *pdev = arg;
  25
  26         platform_device_unregister(pdev);
  27 }
  28
  29 static int cros_ec_sensorhub_allocate_sensor(struct device *parent,
  30                                              char *sensor_name,
  31                                              int sensor_num)
  32 {
  33         struct cros_ec_sensor_platform sensor_platforms = {
  34                 .sensor_num = sensor_num,
  35         };
  36         struct platform_device *pdev;
  37
  38         pdev = platform_device_register_data(parent, sensor_name,
  39                                              PLATFORM_DEVID_AUTO,
  40                                              &sensor_platforms,
  41                                              sizeof(sensor_platforms));
  42         if (IS_ERR(pdev))
  43                 return PTR_ERR(pdev);
  44
  45         return devm_add_action_or_reset(parent,
  46                                         cros_ec_sensorhub_free_sensor,
  47                                         pdev);
  48 }
  49
  50 static int cros_ec_sensorhub_register(struct device *dev,
  51                                       struct cros_ec_sensorhub *sensorhub)
  52 {
  53         int sensor_type[MOTIONSENSE_TYPE_MAX] = { 0 };
  54         struct cros_ec_command *msg = sensorhub->msg;
  55         struct cros_ec_dev *ec = sensorhub->ec;
  56         int ret, i;
  57         char *name;
  58
  59
  60         msg->version = 1;
  61         msg->insize = sizeof(struct ec_response_motion_sense);
  62         msg->outsize = sizeof(struct ec_params_motion_sense);
  63
  64         for (i = 0; i < sensorhub->sensor_num; i++) {
  65                 sensorhub->params->cmd = MOTIONSENSE_CMD_INFO;
  66                 sensorhub->params->info.sensor_num = i;
  67
  68                 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
  69                 if (ret < 0) {
  70                         dev_warn(dev, "no info for EC sensor %d : %d/%d\n",
  71                                  i, ret, msg->result);
  72                         continue;
  73                 }
  74
  75                 switch (sensorhub->resp->info.type) {
  76                 case MOTIONSENSE_TYPE_ACCEL:
  77                         name = "cros-ec-accel";
  78                         break;
  79                 case MOTIONSENSE_TYPE_BARO:
  80                         name = "cros-ec-baro";
  81                         break;
  82                 case MOTIONSENSE_TYPE_GYRO:
  83                         name = "cros-ec-gyro";
  84                         break;
  85                 case MOTIONSENSE_TYPE_MAG:
  86                         name = "cros-ec-mag";
  87                         break;
  88                 case MOTIONSENSE_TYPE_PROX:
  89                         name = "cros-ec-prox";
  90                         break;
  91                 case MOTIONSENSE_TYPE_LIGHT:
  92                         name = "cros-ec-light";
  93                         break;
  94                 case MOTIONSENSE_TYPE_ACTIVITY:
  95                         name = "cros-ec-activity";
  96                         break;
  97                 default:
  98                         dev_warn(dev, "unknown type %d\n",
  99                                  sensorhub->resp->info.type);
 100                         continue;
 101                 }
 102
 103                 ret = cros_ec_sensorhub_allocate_sensor(dev, name, i);
 104                 if (ret)
 105                         return ret;
 106
 107                 sensor_type[sensorhub->resp->info.type]++;
 108         }
 109
 110         if (sensor_type[MOTIONSENSE_TYPE_ACCEL] >= 2)
 111                 ec->has_kb_wake_angle = true;
 112
 113         if (cros_ec_check_features(ec,
 114                                    EC_FEATURE_REFINED_TABLET_MODE_HYSTERESIS)) {
 115                 ret = cros_ec_sensorhub_allocate_sensor(dev,
 116                                                         "cros-ec-lid-angle",
 117                                                         0);
 118                 if (ret)
 119                         return ret;
 120         }
 121
 122         return 0;
 123 }
 124
 125 static int cros_ec_sensorhub_probe(struct platform_device *pdev)
 126 {
 127         struct device *dev = &pdev->dev;
 128         struct cros_ec_dev *ec = dev_get_drvdata(dev->parent);
 129         struct cros_ec_sensorhub *data;
 130         struct cros_ec_command *msg;
 131         int ret, i, sensor_num;
 132
 133         msg = devm_kzalloc(dev, sizeof(struct cros_ec_command) +
 134                            max((u16)sizeof(struct ec_params_motion_sense),
 135                                ec->ec_dev->max_response), GFP_KERNEL);
 136         if (!msg)
 137                 return -ENOMEM;
 138
 139         msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
 140
 141         data = devm_kzalloc(dev, sizeof(struct cros_ec_sensorhub), GFP_KERNEL);
 142         if (!data)
 143                 return -ENOMEM;
 144
 145         mutex_init(&data->cmd_lock);
 146
 147         data->dev = dev;
 148         data->ec = ec;
 149         data->msg = msg;
 150         data->params = (struct ec_params_motion_sense *)msg->data;
 151         data->resp = (struct ec_response_motion_sense *)msg->data;
 152
 153         dev_set_drvdata(dev, data);
 154
 155         /* Check whether this EC is a sensor hub. */
 156         if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE)) {
 157                 sensor_num = cros_ec_get_sensor_count(ec);
 158                 if (sensor_num < 0) {
 159                         dev_err(dev,
 160                                 "Unable to retrieve sensor information (err:%d)\n",
 161                                 sensor_num);
 162                         return sensor_num;
 163                 }
 164                 if (sensor_num == 0) {
 165                         dev_err(dev, "Zero sensors reported.\n");
 166                         return -EINVAL;
 167                 }
 168                 data->sensor_num = sensor_num;
 169
 170                 /*
 171                  * Prepare the ring handler before enumering the
 172                  * sensors.
 173                  */
 174                 if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) {
 175                         ret = cros_ec_sensorhub_ring_allocate(data);
 176                         if (ret)
 177                                 return ret;
 178                 }
 179
 180                 /* Enumerate the sensors.*/
 181                 ret = cros_ec_sensorhub_register(dev, data);
 182                 if (ret)
 183                         return ret;
 184
 185                 /*
 186                  * When the EC does not have a FIFO, the sensors will query
 187                  * their data themselves via sysfs or a software trigger.
 188                  */
 189                 if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) {
 190                         ret = cros_ec_sensorhub_ring_add(data);
 191                         if (ret)
 192                                 return ret;
 193                         /*
 194                          * The msg and its data is not under the control of the
 195                          * ring handler.
 196                          */
 197                         return devm_add_action_or_reset(dev,
 198                                         cros_ec_sensorhub_ring_remove,
 199                                         data);
 200                 }
 201
 202         } else {
 203                 /*
 204                  * If the device has sensors but does not claim to
 205                  * be a sensor hub, we are in legacy mode.
 206                  */
 207                 data->sensor_num = 2;
 208                 for (i = 0; i < data->sensor_num; i++) {
 209                         ret = cros_ec_sensorhub_allocate_sensor(dev,
 210                                                 "cros-ec-accel-legacy", i);
 211                         if (ret)
 212                                 return ret;
 213                 }
 214         }
 215
 216
 217         return 0;
 218 }
 219
 220 #ifdef CONFIG_PM_SLEEP
 221 /*
 222  * When the EC is suspending, we must stop sending interrupt,
 223  * we may use the same interrupt line for waking up the device.
 224  * Tell the EC to stop sending non-interrupt event on the iio ring.
 225  */
 226 static int cros_ec_sensorhub_suspend(struct device *dev)
 227 {
 228         struct cros_ec_sensorhub *sensorhub = dev_get_drvdata(dev);
 229         struct cros_ec_dev *ec = sensorhub->ec;
 230
 231         if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO))
 232                 return cros_ec_sensorhub_ring_fifo_enable(sensorhub, false);
 233         return 0;
 234 }
 235
 236 static int cros_ec_sensorhub_resume(struct device *dev)
 237 {
 238         struct cros_ec_sensorhub *sensorhub = dev_get_drvdata(dev);
 239         struct cros_ec_dev *ec = sensorhub->ec;
 240
 241         if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO))
 242                 return cros_ec_sensorhub_ring_fifo_enable(sensorhub, true);
 243         return 0;
 244 }
 245 #endif
 246
 247 static SIMPLE_DEV_PM_OPS(cros_ec_sensorhub_pm_ops,
 248                 cros_ec_sensorhub_suspend,
 249                 cros_ec_sensorhub_resume);
 250
 251 static const struct platform_device_id cros_ec_sensorhub_id[] = {
 252         { DRV_NAME, 0 },
 253         {}
 254 };
 255 MODULE_DEVICE_TABLE(platform, cros_ec_sensorhub_id);
 256
 257 static struct platform_driver cros_ec_sensorhub_driver = {
 258         .driver = {
 259                 .name = DRV_NAME,
 260                 .pm = &cros_ec_sensorhub_pm_ops,
 261         },
 262         .probe = cros_ec_sensorhub_probe,
 263         .id_table = cros_ec_sensorhub_id,
 264 };
 265
 266 module_platform_driver(cros_ec_sensorhub_driver);
 267
 268 MODULE_AUTHOR("Gwendal Grignou <[email protected]>");
 269 MODULE_DESCRIPTION("ChromeOS EC MEMS Sensor Hub Driver");
 270 MODULE_LICENSE("GPL");