drivers/input/touchscreen/tsc2007_iio.c

   1 /*
   2  * Copyright (c) 2016 Golden Delicious Comp. GmbH&Co. KG
   3  *      Nikolaus Schaller <hns@goldelico.com>
   4  *
   5  *  This program is free software; you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License version 2 as
   7  *  published by the Free Software Foundation.
   8  */
   9
  10 #include <linux/i2c.h>
  11 #include <linux/iio/iio.h>
  12 #include "tsc2007.h"
  13
  14 struct tsc2007_iio {
  15         struct tsc2007 *ts;
  16 };
  17
  18 #define TSC2007_CHAN_IIO(_chan, _name, _type, _chan_info) \
  19 { \
  20         .datasheet_name = _name, \
  21         .type = _type, \
  22         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |  \
  23                         BIT(_chan_info), \
  24         .indexed = 1, \
  25         .channel = _chan, \
  26 }
  27
  28 static const struct iio_chan_spec tsc2007_iio_channel[] = {
  29         TSC2007_CHAN_IIO(0, "x", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
  30         TSC2007_CHAN_IIO(1, "y", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
  31         TSC2007_CHAN_IIO(2, "z1", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
  32         TSC2007_CHAN_IIO(3, "z2", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
  33         TSC2007_CHAN_IIO(4, "adc", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
  34         TSC2007_CHAN_IIO(5, "rt", IIO_VOLTAGE, IIO_CHAN_INFO_RAW), /* Ohms? */
  35         TSC2007_CHAN_IIO(6, "pen", IIO_PRESSURE, IIO_CHAN_INFO_RAW),
  36         TSC2007_CHAN_IIO(7, "temp0", IIO_TEMP, IIO_CHAN_INFO_RAW),
  37         TSC2007_CHAN_IIO(8, "temp1", IIO_TEMP, IIO_CHAN_INFO_RAW),
  38 };
  39
  40 static int tsc2007_read_raw(struct iio_dev *indio_dev,
  41                             struct iio_chan_spec const *chan,
  42                             int *val, int *val2, long mask)
  43 {
  44         struct tsc2007_iio *iio = iio_priv(indio_dev);
  45         struct tsc2007 *tsc = iio->ts;
  46         int adc_chan = chan->channel;
  47         int ret = 0;
  48
  49         if (adc_chan >= ARRAY_SIZE(tsc2007_iio_channel))
  50                 return -EINVAL;
  51
  52         if (mask != IIO_CHAN_INFO_RAW)
  53                 return -EINVAL;
  54
  55         mutex_lock(&tsc->mlock);
  56
  57         switch (chan->channel) {
  58         case 0:
  59                 *val = tsc2007_xfer(tsc, READ_X);
  60                 break;
  61         case 1:
  62                 *val = tsc2007_xfer(tsc, READ_Y);
  63                 break;
  64         case 2:
  65                 *val = tsc2007_xfer(tsc, READ_Z1);
  66                 break;
  67         case 3:
  68                 *val = tsc2007_xfer(tsc, READ_Z2);
  69                 break;
  70         case 4:
  71                 *val = tsc2007_xfer(tsc, (ADC_ON_12BIT | TSC2007_MEASURE_AUX));
  72                 break;
  73         case 5: {
  74                 struct ts_event tc;
  75
  76                 tc.x = tsc2007_xfer(tsc, READ_X);
  77                 tc.z1 = tsc2007_xfer(tsc, READ_Z1);
  78                 tc.z2 = tsc2007_xfer(tsc, READ_Z2);
  79                 *val = tsc2007_calculate_resistance(tsc, &tc);
  80                 break;
  81         }
  82         case 6:
  83                 *val = tsc2007_is_pen_down(tsc);
  84                 break;
  85         case 7:
  86                 *val = tsc2007_xfer(tsc,
  87                                     (ADC_ON_12BIT | TSC2007_MEASURE_TEMP0));
  88                 break;
  89         case 8:
  90                 *val = tsc2007_xfer(tsc,
  91                                     (ADC_ON_12BIT | TSC2007_MEASURE_TEMP1));
  92                 break;
  93         }
  94
  95         /* Prepare for next touch reading - power down ADC, enable PENIRQ */
  96         tsc2007_xfer(tsc, PWRDOWN);
  97
  98         mutex_unlock(&tsc->mlock);
  99
 100         ret = IIO_VAL_INT;
 101
 102         return ret;
 103 }
 104
 105 static const struct iio_info tsc2007_iio_info = {
 106         .read_raw = tsc2007_read_raw,
 107         .driver_module = THIS_MODULE,
 108 };
 109
 110 int tsc2007_iio_configure(struct tsc2007 *ts)
 111 {
 112         struct iio_dev *indio_dev;
 113         struct tsc2007_iio *iio;
 114         int error;
 115
 116         indio_dev = devm_iio_device_alloc(&ts->client->dev, sizeof(*iio));
 117         if (!indio_dev) {
 118                 dev_err(&ts->client->dev, "iio_device_alloc failed\n");
 119                 return -ENOMEM;
 120         }
 121
 122         iio = iio_priv(indio_dev);
 123         iio->ts = ts;
 124
 125         indio_dev->name = "tsc2007";
 126         indio_dev->dev.parent = &ts->client->dev;
 127         indio_dev->info = &tsc2007_iio_info;
 128         indio_dev->modes = INDIO_DIRECT_MODE;
 129         indio_dev->channels = tsc2007_iio_channel;
 130         indio_dev->num_channels = ARRAY_SIZE(tsc2007_iio_channel);
 131
 132         error = devm_iio_device_register(&ts->client->dev, indio_dev);
 133         if (error) {
 134                 dev_err(&ts->client->dev,
 135                         "iio_device_register() failed: %d\n", error);
 136                 return error;
 137         }
 138
 139         return 0;
 140 }