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