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/delay.h> 12 #include <linux/mod_devicetable.h> 13 #include <linux/module.h> 14 #include <linux/platform_data/cros_ec_commands.h> 15 #include <linux/platform_data/cros_ec_proto.h> 16 #include <linux/platform_data/cros_ec_sensorhub.h> 17 #include <linux/platform_device.h> 18 #include <linux/slab.h> 19 #include <linux/types.h> 20 21 #define DRV_NAME "cros-ec-sensorhub" 22 #define CROS_EC_CMD_INFO_RETRIES 50 23 24 static void cros_ec_sensorhub_free_sensor(void *arg) 25 { 26 struct platform_device *pdev = arg; 27 28 platform_device_unregister(pdev); 29 } 30 31 static int cros_ec_sensorhub_allocate_sensor(struct device *parent, 32 char *sensor_name, 33 int sensor_num) 34 { 35 struct cros_ec_sensor_platform sensor_platforms = { 36 .sensor_num = sensor_num, 37 }; 38 struct platform_device *pdev; 39 40 pdev = platform_device_register_data(parent, sensor_name, 41 PLATFORM_DEVID_AUTO, 42 &sensor_platforms, 43 sizeof(sensor_platforms)); 44 if (IS_ERR(pdev)) 45 return PTR_ERR(pdev); 46 47 return devm_add_action_or_reset(parent, 48 cros_ec_sensorhub_free_sensor, 49 pdev); 50 } 51 52 static int cros_ec_sensorhub_register(struct device *dev, 53 struct cros_ec_sensorhub *sensorhub) 54 { 55 int sensor_type[MOTIONSENSE_TYPE_MAX] = { 0 }; 56 struct cros_ec_command *msg = sensorhub->msg; 57 struct cros_ec_dev *ec = sensorhub->ec; 58 int ret, i, retries; 59 char *name; 60 61 62 msg->version = 1; 63 msg->insize = sizeof(struct ec_response_motion_sense); 64 msg->outsize = sizeof(struct ec_params_motion_sense); 65 66 for (i = 0; i < sensorhub->sensor_num; i++) { 67 sensorhub->params->cmd = MOTIONSENSE_CMD_INFO; 68 sensorhub->params->info.sensor_num = i; 69 70 retries = CROS_EC_CMD_INFO_RETRIES; 71 do { 72 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg); 73 if (ret == -EBUSY) { 74 /* The EC is still busy initializing sensors. */ 75 usleep_range(5000, 6000); 76 retries--; 77 } 78 } while (ret == -EBUSY && retries); 79 80 if (ret < 0) { 81 dev_err(dev, "no info for EC sensor %d : %d/%d\n", 82 i, ret, msg->result); 83 continue; 84 } 85 if (retries < CROS_EC_CMD_INFO_RETRIES) { 86 dev_warn(dev, "%d retries needed to bring up sensor %d\n", 87 CROS_EC_CMD_INFO_RETRIES - retries, i); 88 } 89 90 switch (sensorhub->resp->info.type) { 91 case MOTIONSENSE_TYPE_ACCEL: 92 name = "cros-ec-accel"; 93 break; 94 case MOTIONSENSE_TYPE_BARO: 95 name = "cros-ec-baro"; 96 break; 97 case MOTIONSENSE_TYPE_GYRO: 98 name = "cros-ec-gyro"; 99 break; 100 case MOTIONSENSE_TYPE_MAG: 101 name = "cros-ec-mag"; 102 break; 103 case MOTIONSENSE_TYPE_PROX: 104 name = "cros-ec-prox"; 105 break; 106 case MOTIONSENSE_TYPE_LIGHT: 107 name = "cros-ec-light"; 108 break; 109 case MOTIONSENSE_TYPE_ACTIVITY: 110 name = "cros-ec-activity"; 111 break; 112 default: 113 dev_warn(dev, "unknown type %d\n", 114 sensorhub->resp->info.type); 115 continue; 116 } 117 118 ret = cros_ec_sensorhub_allocate_sensor(dev, name, i); 119 if (ret) 120 return ret; 121 122 sensor_type[sensorhub->resp->info.type]++; 123 } 124 125 if (sensor_type[MOTIONSENSE_TYPE_ACCEL] >= 2) 126 ec->has_kb_wake_angle = true; 127 128 if (cros_ec_check_features(ec, 129 EC_FEATURE_REFINED_TABLET_MODE_HYSTERESIS)) { 130 ret = cros_ec_sensorhub_allocate_sensor(dev, 131 "cros-ec-lid-angle", 132 0); 133 if (ret) 134 return ret; 135 } 136 137 return 0; 138 } 139 140 static int cros_ec_sensorhub_probe(struct platform_device *pdev) 141 { 142 struct device *dev = &pdev->dev; 143 struct cros_ec_dev *ec = dev_get_drvdata(dev->parent); 144 struct cros_ec_sensorhub *data; 145 struct cros_ec_command *msg; 146 int ret, i, sensor_num; 147 148 msg = devm_kzalloc(dev, sizeof(struct cros_ec_command) + 149 max((u16)sizeof(struct ec_params_motion_sense), 150 ec->ec_dev->max_response), GFP_KERNEL); 151 if (!msg) 152 return -ENOMEM; 153 154 msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset; 155 156 data = devm_kzalloc(dev, sizeof(struct cros_ec_sensorhub), GFP_KERNEL); 157 if (!data) 158 return -ENOMEM; 159 160 mutex_init(&data->cmd_lock); 161 162 data->dev = dev; 163 data->ec = ec; 164 data->msg = msg; 165 data->params = (struct ec_params_motion_sense *)msg->data; 166 data->resp = (struct ec_response_motion_sense *)msg->data; 167 168 dev_set_drvdata(dev, data); 169 170 /* Check whether this EC is a sensor hub. */ 171 if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE)) { 172 sensor_num = cros_ec_get_sensor_count(ec); 173 if (sensor_num < 0) { 174 dev_err(dev, 175 "Unable to retrieve sensor information (err:%d)\n", 176 sensor_num); 177 return sensor_num; 178 } 179 if (sensor_num == 0) { 180 dev_err(dev, "Zero sensors reported.\n"); 181 return -EINVAL; 182 } 183 data->sensor_num = sensor_num; 184 185 /* 186 * Prepare the ring handler before enumering the 187 * sensors. 188 */ 189 if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) { 190 ret = cros_ec_sensorhub_ring_allocate(data); 191 if (ret) 192 return ret; 193 } 194 195 /* Enumerate the sensors.*/ 196 ret = cros_ec_sensorhub_register(dev, data); 197 if (ret) 198 return ret; 199 200 /* 201 * When the EC does not have a FIFO, the sensors will query 202 * their data themselves via sysfs or a software trigger. 203 */ 204 if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) { 205 ret = cros_ec_sensorhub_ring_add(data); 206 if (ret) 207 return ret; 208 /* 209 * The msg and its data is not under the control of the 210 * ring handler. 211 */ 212 return devm_add_action_or_reset(dev, 213 cros_ec_sensorhub_ring_remove, 214 data); 215 } 216 217 } else { 218 /* 219 * If the device has sensors but does not claim to 220 * be a sensor hub, we are in legacy mode. 221 */ 222 data->sensor_num = 2; 223 for (i = 0; i < data->sensor_num; i++) { 224 ret = cros_ec_sensorhub_allocate_sensor(dev, 225 "cros-ec-accel-legacy", i); 226 if (ret) 227 return ret; 228 } 229 } 230 231 232 return 0; 233 } 234 235 #ifdef CONFIG_PM_SLEEP 236 /* 237 * When the EC is suspending, we must stop sending interrupt, 238 * we may use the same interrupt line for waking up the device. 239 * Tell the EC to stop sending non-interrupt event on the iio ring. 240 */ 241 static int cros_ec_sensorhub_suspend(struct device *dev) 242 { 243 struct cros_ec_sensorhub *sensorhub = dev_get_drvdata(dev); 244 struct cros_ec_dev *ec = sensorhub->ec; 245 246 if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) 247 return cros_ec_sensorhub_ring_fifo_enable(sensorhub, false); 248 return 0; 249 } 250 251 static int cros_ec_sensorhub_resume(struct device *dev) 252 { 253 struct cros_ec_sensorhub *sensorhub = dev_get_drvdata(dev); 254 struct cros_ec_dev *ec = sensorhub->ec; 255 256 if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) 257 return cros_ec_sensorhub_ring_fifo_enable(sensorhub, true); 258 return 0; 259 } 260 #endif 261 262 static SIMPLE_DEV_PM_OPS(cros_ec_sensorhub_pm_ops, 263 cros_ec_sensorhub_suspend, 264 cros_ec_sensorhub_resume); 265 266 static const struct platform_device_id cros_ec_sensorhub_id[] = { 267 { DRV_NAME, 0 }, 268 {} 269 }; 270 MODULE_DEVICE_TABLE(platform, cros_ec_sensorhub_id); 271 272 static struct platform_driver cros_ec_sensorhub_driver = { 273 .driver = { 274 .name = DRV_NAME, 275 .pm = &cros_ec_sensorhub_pm_ops, 276 }, 277 .probe = cros_ec_sensorhub_probe, 278 .id_table = cros_ec_sensorhub_id, 279 }; 280 281 module_platform_driver(cros_ec_sensorhub_driver); 282 283 MODULE_AUTHOR("Gwendal Grignou <gwendal@chromium.org>"); 284 MODULE_DESCRIPTION("ChromeOS EC MEMS Sensor Hub Driver"); 285 MODULE_LICENSE("GPL"); 286