drivers/iio/light/cros_ec_light_prox.c

   1 /*
   2  * cros_ec_light_prox - Driver for light and prox sensors behing CrosEC.
   3  *
   4  * Copyright (C) 2017 Google, Inc
   5  *
   6  * This software is licensed under the terms of the GNU General Public
   7  * License version 2, as published by the Free Software Foundation, and
   8  * may be copied, distributed, and modified under those terms.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 #include <linux/delay.h>
  17 #include <linux/device.h>
  18 #include <linux/iio/buffer.h>
  19 #include <linux/iio/iio.h>
  20 #include <linux/iio/kfifo_buf.h>
  21 #include <linux/iio/trigger.h>
  22 #include <linux/iio/triggered_buffer.h>
  23 #include <linux/iio/trigger_consumer.h>
  24 #include <linux/kernel.h>
  25 #include <linux/mfd/cros_ec.h>
  26 #include <linux/mfd/cros_ec_commands.h>
  27 #include <linux/module.h>
  28 #include <linux/platform_device.h>
  29 #include <linux/slab.h>
  30 #include <linux/sysfs.h>
  31
  32 #include "../common/cros_ec_sensors/cros_ec_sensors_core.h"
  33
  34 /*
  35  * We only represent one entry for light or proximity. EC is merging different
  36  * light sensors to return the what the eye would see. For proximity, we
  37  * currently support only one light source.
  38  */
  39 #define CROS_EC_LIGHT_PROX_MAX_CHANNELS (1 + 1)
  40
  41 /* State data for ec_sensors iio driver. */
  42 struct cros_ec_light_prox_state {
  43         /* Shared by all sensors */
  44         struct cros_ec_sensors_core_state core;
  45
  46         struct iio_chan_spec channels[CROS_EC_LIGHT_PROX_MAX_CHANNELS];
  47 };
  48
  49 static int cros_ec_light_prox_read(struct iio_dev *indio_dev,
  50                                    struct iio_chan_spec const *chan,
  51                                    int *val, int *val2, long mask)
  52 {
  53         struct cros_ec_light_prox_state *st = iio_priv(indio_dev);
  54         u16 data = 0;
  55         s64 val64;
  56         int ret = IIO_VAL_INT;
  57         int idx = chan->scan_index;
  58
  59         mutex_lock(&st->core.cmd_lock);
  60
  61         switch (mask) {
  62         case IIO_CHAN_INFO_RAW:
  63                 if (chan->type == IIO_PROXIMITY) {
  64                         if (cros_ec_sensors_read_cmd(indio_dev, 1 << idx,
  65                                                      (s16 *)&data) < 0) {
  66                                 ret = -EIO;
  67                                 break;
  68                         }
  69                         *val = data;
  70                 } else {
  71                         ret = -EINVAL;
  72                 }
  73                 break;
  74         case IIO_CHAN_INFO_PROCESSED:
  75                 if (chan->type == IIO_LIGHT) {
  76                         if (cros_ec_sensors_read_cmd(indio_dev, 1 << idx,
  77                                                      (s16 *)&data) < 0) {
  78                                 ret = -EIO;
  79                                 break;
  80                         }
  81                         /*
  82                          * The data coming from the light sensor is
  83                          * pre-processed and represents the ambient light
  84                          * illuminance reading expressed in lux.
  85                          */
  86                         *val = data;
  87                         ret = IIO_VAL_INT;
  88                 } else {
  89                         ret = -EINVAL;
  90                 }
  91                 break;
  92         case IIO_CHAN_INFO_CALIBBIAS:
  93                 st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_OFFSET;
  94                 st->core.param.sensor_offset.flags = 0;
  95
  96                 if (cros_ec_motion_send_host_cmd(&st->core, 0)) {
  97                         ret = -EIO;
  98                         break;
  99                 }
 100
 101                 /* Save values */
 102                 st->core.calib[0] = st->core.resp->sensor_offset.offset[0];
 103
 104                 *val = st->core.calib[idx];
 105                 break;
 106         case IIO_CHAN_INFO_CALIBSCALE:
 107                 /*
 108                  * RANGE is used for calibration
 109                  * scale is a number x.y, where x is coded on 16 bits,
 110                  * y coded on 16 bits, between 0 and 9999.
 111                  */
 112                 st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE;
 113                 st->core.param.sensor_range.data = EC_MOTION_SENSE_NO_VALUE;
 114
 115                 if (cros_ec_motion_send_host_cmd(&st->core, 0)) {
 116                         ret = -EIO;
 117                         break;
 118                 }
 119
 120                 val64 = st->core.resp->sensor_range.ret;
 121                 *val = val64 >> 16;
 122                 *val2 = (val64 & 0xffff) * 100;
 123                 ret = IIO_VAL_INT_PLUS_MICRO;
 124                 break;
 125         default:
 126                 ret = cros_ec_sensors_core_read(&st->core, chan, val, val2,
 127                                                 mask);
 128                 break;
 129         }
 130
 131         mutex_unlock(&st->core.cmd_lock);
 132
 133         return ret;
 134 }
 135
 136 static int cros_ec_light_prox_write(struct iio_dev *indio_dev,
 137                                struct iio_chan_spec const *chan,
 138                                int val, int val2, long mask)
 139 {
 140         struct cros_ec_light_prox_state *st = iio_priv(indio_dev);
 141         int ret = 0;
 142         int idx = chan->scan_index;
 143
 144         mutex_lock(&st->core.cmd_lock);
 145
 146         switch (mask) {
 147         case IIO_CHAN_INFO_CALIBBIAS:
 148                 st->core.calib[idx] = val;
 149                 /* Send to EC for each axis, even if not complete */
 150                 st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_OFFSET;
 151                 st->core.param.sensor_offset.flags = MOTION_SENSE_SET_OFFSET;
 152                 st->core.param.sensor_offset.offset[0] = st->core.calib[0];
 153                 st->core.param.sensor_offset.temp =
 154                                         EC_MOTION_SENSE_INVALID_CALIB_TEMP;
 155                 if (cros_ec_motion_send_host_cmd(&st->core, 0))
 156                         ret = -EIO;
 157                 break;
 158         case IIO_CHAN_INFO_CALIBSCALE:
 159                 st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE;
 160                 st->core.param.sensor_range.data = (val << 16) | (val2 / 100);
 161                 if (cros_ec_motion_send_host_cmd(&st->core, 0))
 162                         ret = -EIO;
 163                 break;
 164         default:
 165                 ret = cros_ec_sensors_core_write(&st->core, chan, val, val2,
 166                                                  mask);
 167                 break;
 168         }
 169
 170         mutex_unlock(&st->core.cmd_lock);
 171
 172         return ret;
 173 }
 174
 175 static const struct iio_info cros_ec_light_prox_info = {
 176         .read_raw = &cros_ec_light_prox_read,
 177         .write_raw = &cros_ec_light_prox_write,
 178 };
 179
 180 static int cros_ec_light_prox_probe(struct platform_device *pdev)
 181 {
 182         struct device *dev = &pdev->dev;
 183         struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
 184         struct iio_dev *indio_dev;
 185         struct cros_ec_light_prox_state *state;
 186         struct iio_chan_spec *channel;
 187         int ret;
 188
 189         if (!ec_dev || !ec_dev->ec_dev) {
 190                 dev_warn(dev, "No CROS EC device found.\n");
 191                 return -EINVAL;
 192         }
 193
 194         indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
 195         if (!indio_dev)
 196                 return -ENOMEM;
 197
 198         ret = cros_ec_sensors_core_init(pdev, indio_dev, true);
 199         if (ret)
 200                 return ret;
 201
 202         indio_dev->info = &cros_ec_light_prox_info;
 203         state = iio_priv(indio_dev);
 204         state->core.type = state->core.resp->info.type;
 205         state->core.loc = state->core.resp->info.location;
 206         channel = state->channels;
 207
 208         /* Common part */
 209         channel->info_mask_shared_by_all =
 210                 BIT(IIO_CHAN_INFO_SAMP_FREQ) |
 211                 BIT(IIO_CHAN_INFO_FREQUENCY);
 212         channel->scan_type.realbits = CROS_EC_SENSOR_BITS;
 213         channel->scan_type.storagebits = CROS_EC_SENSOR_BITS;
 214         channel->scan_type.shift = 0;
 215         channel->scan_index = 0;
 216         channel->ext_info = cros_ec_sensors_ext_info;
 217         channel->scan_type.sign = 'u';
 218
 219         state->core.calib[0] = 0;
 220
 221         /* Sensor specific */
 222         switch (state->core.type) {
 223         case MOTIONSENSE_TYPE_LIGHT:
 224                 channel->type = IIO_LIGHT;
 225                 channel->info_mask_separate =
 226                         BIT(IIO_CHAN_INFO_PROCESSED) |
 227                         BIT(IIO_CHAN_INFO_CALIBBIAS) |
 228                         BIT(IIO_CHAN_INFO_CALIBSCALE);
 229                 break;
 230         case MOTIONSENSE_TYPE_PROX:
 231                 channel->type = IIO_PROXIMITY;
 232                 channel->info_mask_separate =
 233                         BIT(IIO_CHAN_INFO_RAW) |
 234                         BIT(IIO_CHAN_INFO_CALIBBIAS) |
 235                         BIT(IIO_CHAN_INFO_CALIBSCALE);
 236                 break;
 237         default:
 238                 dev_warn(dev, "Unknown motion sensor\n");
 239                 return -EINVAL;
 240         }
 241
 242         /* Timestamp */
 243         channel++;
 244         channel->type = IIO_TIMESTAMP;
 245         channel->channel = -1;
 246         channel->scan_index = 1;
 247         channel->scan_type.sign = 's';
 248         channel->scan_type.realbits = 64;
 249         channel->scan_type.storagebits = 64;
 250
 251         indio_dev->channels = state->channels;
 252
 253         indio_dev->num_channels = CROS_EC_LIGHT_PROX_MAX_CHANNELS;
 254
 255         state->core.read_ec_sensors_data = cros_ec_sensors_read_cmd;
 256
 257         ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
 258                                               cros_ec_sensors_capture, NULL);
 259         if (ret)
 260                 return ret;
 261
 262         return devm_iio_device_register(dev, indio_dev);
 263 }
 264
 265 static const struct platform_device_id cros_ec_light_prox_ids[] = {
 266         {
 267                 .name = "cros-ec-prox",
 268         },
 269         {
 270                 .name = "cros-ec-light",
 271         },
 272         { /* sentinel */ }
 273 };
 274 MODULE_DEVICE_TABLE(platform, cros_ec_light_prox_ids);
 275
 276 static struct platform_driver cros_ec_light_prox_platform_driver = {
 277         .driver = {
 278                 .name   = "cros-ec-light-prox",
 279         },
 280         .probe          = cros_ec_light_prox_probe,
 281         .id_table       = cros_ec_light_prox_ids,
 282 };
 283 module_platform_driver(cros_ec_light_prox_platform_driver);
 284
 285 MODULE_DESCRIPTION("ChromeOS EC light/proximity sensors driver");
 286 MODULE_LICENSE("GPL v2");