1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * cros_ec_sensors - Driver for Chrome OS Embedded Controller sensors. 4 * 5 * Copyright (C) 2016 Google, Inc 6 * 7 * This driver uses the cros-ec interface to communicate with the Chrome OS 8 * EC about sensors data. Data access is presented through iio sysfs. 9 */ 10 11 #include <linux/device.h> 12 #include <linux/iio/buffer.h> 13 #include <linux/iio/common/cros_ec_sensors_core.h> 14 #include <linux/iio/iio.h> 15 #include <linux/iio/kfifo_buf.h> 16 #include <linux/iio/trigger_consumer.h> 17 #include <linux/iio/triggered_buffer.h> 18 #include <linux/kernel.h> 19 #include <linux/module.h> 20 #include <linux/platform_data/cros_ec_commands.h> 21 #include <linux/platform_data/cros_ec_proto.h> 22 #include <linux/platform_device.h> 23 #include <linux/slab.h> 24 25 #define CROS_EC_SENSORS_MAX_CHANNELS 4 26 27 /* State data for ec_sensors iio driver. */ 28 struct cros_ec_sensors_state { 29 /* Shared by all sensors */ 30 struct cros_ec_sensors_core_state core; 31 32 struct iio_chan_spec channels[CROS_EC_SENSORS_MAX_CHANNELS]; 33 }; 34 35 static int cros_ec_sensors_read(struct iio_dev *indio_dev, 36 struct iio_chan_spec const *chan, 37 int *val, int *val2, long mask) 38 { 39 struct cros_ec_sensors_state *st = iio_priv(indio_dev); 40 s16 data = 0; 41 s64 val64; 42 int i; 43 int ret; 44 int idx = chan->scan_index; 45 46 mutex_lock(&st->core.cmd_lock); 47 48 switch (mask) { 49 case IIO_CHAN_INFO_RAW: 50 ret = st->core.read_ec_sensors_data(indio_dev, 1 << idx, &data); 51 if (ret < 0) 52 break; 53 ret = IIO_VAL_INT; 54 *val = data; 55 break; 56 case IIO_CHAN_INFO_CALIBBIAS: 57 st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_OFFSET; 58 st->core.param.sensor_offset.flags = 0; 59 60 ret = cros_ec_motion_send_host_cmd(&st->core, 0); 61 if (ret < 0) 62 break; 63 64 /* Save values */ 65 for (i = CROS_EC_SENSOR_X; i < CROS_EC_SENSOR_MAX_AXIS; i++) 66 st->core.calib[i].offset = 67 st->core.resp->sensor_offset.offset[i]; 68 ret = IIO_VAL_INT; 69 *val = st->core.calib[idx].offset; 70 break; 71 case IIO_CHAN_INFO_CALIBSCALE: 72 st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_SCALE; 73 st->core.param.sensor_offset.flags = 0; 74 75 ret = cros_ec_motion_send_host_cmd(&st->core, 0); 76 if (ret == -EPROTO || ret == -EOPNOTSUPP) { 77 /* Reading calibscale is not supported on older EC. */ 78 *val = 1; 79 *val2 = 0; 80 ret = IIO_VAL_INT_PLUS_MICRO; 81 break; 82 } else if (ret) { 83 break; 84 } 85 86 /* Save values */ 87 for (i = CROS_EC_SENSOR_X; i < CROS_EC_SENSOR_MAX_AXIS; i++) 88 st->core.calib[i].scale = 89 st->core.resp->sensor_scale.scale[i]; 90 91 *val = st->core.calib[idx].scale >> 15; 92 *val2 = ((st->core.calib[idx].scale & 0x7FFF) * 1000000LL) / 93 MOTION_SENSE_DEFAULT_SCALE; 94 ret = IIO_VAL_INT_PLUS_MICRO; 95 break; 96 case IIO_CHAN_INFO_SCALE: 97 st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE; 98 st->core.param.sensor_range.data = EC_MOTION_SENSE_NO_VALUE; 99 100 ret = cros_ec_motion_send_host_cmd(&st->core, 0); 101 if (ret < 0) 102 break; 103 104 val64 = st->core.resp->sensor_range.ret; 105 switch (st->core.type) { 106 case MOTIONSENSE_TYPE_ACCEL: 107 /* 108 * EC returns data in g, iio exepects m/s^2. 109 * Do not use IIO_G_TO_M_S_2 to avoid precision loss. 110 */ 111 *val = div_s64(val64 * 980665, 10); 112 *val2 = 10000 << (CROS_EC_SENSOR_BITS - 1); 113 ret = IIO_VAL_FRACTIONAL; 114 break; 115 case MOTIONSENSE_TYPE_GYRO: 116 /* 117 * EC returns data in dps, iio expects rad/s. 118 * Do not use IIO_DEGREE_TO_RAD to avoid precision 119 * loss. Round to the nearest integer. 120 */ 121 *val = 0; 122 *val2 = div_s64(val64 * 3141592653ULL, 123 180 << (CROS_EC_SENSOR_BITS - 1)); 124 ret = IIO_VAL_INT_PLUS_NANO; 125 break; 126 case MOTIONSENSE_TYPE_MAG: 127 /* 128 * EC returns data in 16LSB / uT, 129 * iio expects Gauss 130 */ 131 *val = val64; 132 *val2 = 100 << (CROS_EC_SENSOR_BITS - 1); 133 ret = IIO_VAL_FRACTIONAL; 134 break; 135 default: 136 ret = -EINVAL; 137 } 138 break; 139 default: 140 ret = cros_ec_sensors_core_read(&st->core, chan, val, val2, 141 mask); 142 break; 143 } 144 mutex_unlock(&st->core.cmd_lock); 145 146 return ret; 147 } 148 149 static int cros_ec_sensors_write(struct iio_dev *indio_dev, 150 struct iio_chan_spec const *chan, 151 int val, int val2, long mask) 152 { 153 struct cros_ec_sensors_state *st = iio_priv(indio_dev); 154 int i; 155 int ret; 156 int idx = chan->scan_index; 157 158 mutex_lock(&st->core.cmd_lock); 159 160 switch (mask) { 161 case IIO_CHAN_INFO_CALIBBIAS: 162 st->core.calib[idx].offset = val; 163 164 /* Send to EC for each axis, even if not complete */ 165 st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_OFFSET; 166 st->core.param.sensor_offset.flags = 167 MOTION_SENSE_SET_OFFSET; 168 for (i = CROS_EC_SENSOR_X; i < CROS_EC_SENSOR_MAX_AXIS; i++) 169 st->core.param.sensor_offset.offset[i] = 170 st->core.calib[i].offset; 171 st->core.param.sensor_offset.temp = 172 EC_MOTION_SENSE_INVALID_CALIB_TEMP; 173 174 ret = cros_ec_motion_send_host_cmd(&st->core, 0); 175 break; 176 case IIO_CHAN_INFO_CALIBSCALE: 177 st->core.calib[idx].scale = val; 178 /* Send to EC for each axis, even if not complete */ 179 180 st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_SCALE; 181 st->core.param.sensor_offset.flags = 182 MOTION_SENSE_SET_OFFSET; 183 for (i = CROS_EC_SENSOR_X; i < CROS_EC_SENSOR_MAX_AXIS; i++) 184 st->core.param.sensor_scale.scale[i] = 185 st->core.calib[i].scale; 186 st->core.param.sensor_scale.temp = 187 EC_MOTION_SENSE_INVALID_CALIB_TEMP; 188 189 ret = cros_ec_motion_send_host_cmd(&st->core, 0); 190 break; 191 case IIO_CHAN_INFO_SCALE: 192 if (st->core.type == MOTIONSENSE_TYPE_MAG) { 193 ret = -EINVAL; 194 break; 195 } 196 st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE; 197 st->core.param.sensor_range.data = val; 198 199 /* Always roundup, so caller gets at least what it asks for. */ 200 st->core.param.sensor_range.roundup = 1; 201 202 ret = cros_ec_motion_send_host_cmd(&st->core, 0); 203 if (ret == 0) { 204 st->core.range_updated = true; 205 st->core.curr_range = val; 206 } 207 break; 208 default: 209 ret = cros_ec_sensors_core_write( 210 &st->core, chan, val, val2, mask); 211 break; 212 } 213 214 mutex_unlock(&st->core.cmd_lock); 215 216 return ret; 217 } 218 219 static const struct iio_info ec_sensors_info = { 220 .read_raw = &cros_ec_sensors_read, 221 .write_raw = &cros_ec_sensors_write, 222 .read_avail = &cros_ec_sensors_core_read_avail, 223 }; 224 225 static int cros_ec_sensors_probe(struct platform_device *pdev) 226 { 227 struct device *dev = &pdev->dev; 228 struct iio_dev *indio_dev; 229 struct cros_ec_sensors_state *state; 230 struct iio_chan_spec *channel; 231 int ret, i; 232 233 indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*state)); 234 if (!indio_dev) 235 return -ENOMEM; 236 237 ret = cros_ec_sensors_core_init(pdev, indio_dev, true, 238 cros_ec_sensors_capture, 239 cros_ec_sensors_push_data); 240 if (ret) 241 return ret; 242 243 indio_dev->info = &ec_sensors_info; 244 state = iio_priv(indio_dev); 245 for (channel = state->channels, i = CROS_EC_SENSOR_X; 246 i < CROS_EC_SENSOR_MAX_AXIS; i++, channel++) { 247 /* Common part */ 248 channel->info_mask_separate = 249 BIT(IIO_CHAN_INFO_RAW) | 250 BIT(IIO_CHAN_INFO_CALIBBIAS) | 251 BIT(IIO_CHAN_INFO_CALIBSCALE); 252 channel->info_mask_shared_by_all = 253 BIT(IIO_CHAN_INFO_SCALE) | 254 BIT(IIO_CHAN_INFO_SAMP_FREQ); 255 channel->info_mask_shared_by_all_available = 256 BIT(IIO_CHAN_INFO_SAMP_FREQ); 257 channel->scan_type.realbits = CROS_EC_SENSOR_BITS; 258 channel->scan_type.storagebits = CROS_EC_SENSOR_BITS; 259 channel->scan_index = i; 260 channel->ext_info = cros_ec_sensors_ext_info; 261 channel->modified = 1; 262 channel->channel2 = IIO_MOD_X + i; 263 channel->scan_type.sign = 's'; 264 265 /* Sensor specific */ 266 switch (state->core.type) { 267 case MOTIONSENSE_TYPE_ACCEL: 268 channel->type = IIO_ACCEL; 269 break; 270 case MOTIONSENSE_TYPE_GYRO: 271 channel->type = IIO_ANGL_VEL; 272 break; 273 case MOTIONSENSE_TYPE_MAG: 274 channel->type = IIO_MAGN; 275 break; 276 default: 277 dev_err(&pdev->dev, "Unknown motion sensor\n"); 278 return -EINVAL; 279 } 280 } 281 282 /* Timestamp */ 283 channel->type = IIO_TIMESTAMP; 284 channel->channel = -1; 285 channel->scan_index = CROS_EC_SENSOR_MAX_AXIS; 286 channel->scan_type.sign = 's'; 287 channel->scan_type.realbits = 64; 288 channel->scan_type.storagebits = 64; 289 290 indio_dev->channels = state->channels; 291 indio_dev->num_channels = CROS_EC_SENSORS_MAX_CHANNELS; 292 293 /* There is only enough room for accel and gyro in the io space */ 294 if ((state->core.ec->cmd_readmem != NULL) && 295 (state->core.type != MOTIONSENSE_TYPE_MAG)) 296 state->core.read_ec_sensors_data = cros_ec_sensors_read_lpc; 297 else 298 state->core.read_ec_sensors_data = cros_ec_sensors_read_cmd; 299 300 return devm_iio_device_register(dev, indio_dev); 301 } 302 303 static const struct platform_device_id cros_ec_sensors_ids[] = { 304 { 305 .name = "cros-ec-accel", 306 }, 307 { 308 .name = "cros-ec-gyro", 309 }, 310 { 311 .name = "cros-ec-mag", 312 }, 313 { /* sentinel */ } 314 }; 315 MODULE_DEVICE_TABLE(platform, cros_ec_sensors_ids); 316 317 static struct platform_driver cros_ec_sensors_platform_driver = { 318 .driver = { 319 .name = "cros-ec-sensors", 320 .pm = &cros_ec_sensors_pm_ops, 321 }, 322 .probe = cros_ec_sensors_probe, 323 .id_table = cros_ec_sensors_ids, 324 }; 325 module_platform_driver(cros_ec_sensors_platform_driver); 326 327 MODULE_DESCRIPTION("ChromeOS EC 3-axis sensors driver"); 328 MODULE_LICENSE("GPL v2"); 329