drivers/iio/gyro/itg3200_buffer.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * itg3200_buffer.c -- support InvenSense ITG3200
   4  *                     Digital 3-Axis Gyroscope driver
   5  *
   6  * Copyright (c) 2011 Christian Strobel <christian.strobel@iis.fraunhofer.de>
   7  * Copyright (c) 2011 Manuel Stahl <manuel.stahl@iis.fraunhofer.de>
   8  * Copyright (c) 2012 Thorsten Nowak <thorsten.nowak@iis.fraunhofer.de>
   9  */
  10
  11 #include <linux/slab.h>
  12 #include <linux/i2c.h>
  13 #include <linux/interrupt.h>
  14
  15 #include <linux/iio/iio.h>
  16 #include <linux/iio/buffer.h>
  17 #include <linux/iio/trigger.h>
  18 #include <linux/iio/trigger_consumer.h>
  19 #include <linux/iio/triggered_buffer.h>
  20 #include <linux/iio/gyro/itg3200.h>
  21
  22
  23 static int itg3200_read_all_channels(struct i2c_client *i2c, __be16 *buf)
  24 {
  25         u8 tx = 0x80 | ITG3200_REG_TEMP_OUT_H;
  26         struct i2c_msg msg[2] = {
  27                 {
  28                         .addr = i2c->addr,
  29                         .flags = i2c->flags,
  30                         .len = 1,
  31                         .buf = &tx,
  32                 },
  33                 {
  34                         .addr = i2c->addr,
  35                         .flags = i2c->flags | I2C_M_RD,
  36                         .len = ITG3200_SCAN_ELEMENTS * sizeof(s16),
  37                         .buf = (char *)&buf,
  38                 },
  39         };
  40
  41         return i2c_transfer(i2c->adapter, msg, 2);
  42 }
  43
  44 static irqreturn_t itg3200_trigger_handler(int irq, void *p)
  45 {
  46         struct iio_poll_func *pf = p;
  47         struct iio_dev *indio_dev = pf->indio_dev;
  48         struct itg3200 *st = iio_priv(indio_dev);
  49         __be16 buf[ITG3200_SCAN_ELEMENTS + sizeof(s64)/sizeof(u16)];
  50
  51         int ret = itg3200_read_all_channels(st->i2c, buf);
  52         if (ret < 0)
  53                 goto error_ret;
  54
  55         iio_push_to_buffers_with_timestamp(indio_dev, buf, pf->timestamp);
  56
  57         iio_trigger_notify_done(indio_dev->trig);
  58
  59 error_ret:
  60         return IRQ_HANDLED;
  61 }
  62
  63 int itg3200_buffer_configure(struct iio_dev *indio_dev)
  64 {
  65         return iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
  66                 itg3200_trigger_handler, NULL);
  67 }
  68
  69 void itg3200_buffer_unconfigure(struct iio_dev *indio_dev)
  70 {
  71         iio_triggered_buffer_cleanup(indio_dev);
  72 }
  73
  74
  75 static int itg3200_data_rdy_trigger_set_state(struct iio_trigger *trig,
  76                 bool state)
  77 {
  78         struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
  79         int ret;
  80         u8 msc;
  81
  82         ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_IRQ_CONFIG, &msc);
  83         if (ret)
  84                 goto error_ret;
  85
  86         if (state)
  87                 msc |= ITG3200_IRQ_DATA_RDY_ENABLE;
  88         else
  89                 msc &= ~ITG3200_IRQ_DATA_RDY_ENABLE;
  90
  91         ret = itg3200_write_reg_8(indio_dev, ITG3200_REG_IRQ_CONFIG, msc);
  92         if (ret)
  93                 goto error_ret;
  94
  95 error_ret:
  96         return ret;
  97
  98 }
  99
 100 static const struct iio_trigger_ops itg3200_trigger_ops = {
 101         .set_trigger_state = &itg3200_data_rdy_trigger_set_state,
 102 };
 103
 104 int itg3200_probe_trigger(struct iio_dev *indio_dev)
 105 {
 106         int ret;
 107         struct itg3200 *st = iio_priv(indio_dev);
 108
 109         st->trig = iio_trigger_alloc("%s-dev%d", indio_dev->name,
 110                                      indio_dev->id);
 111         if (!st->trig)
 112                 return -ENOMEM;
 113
 114         ret = request_irq(st->i2c->irq,
 115                           &iio_trigger_generic_data_rdy_poll,
 116                           IRQF_TRIGGER_RISING,
 117                           "itg3200_data_rdy",
 118                           st->trig);
 119         if (ret)
 120                 goto error_free_trig;
 121
 122
 123         st->trig->dev.parent = &st->i2c->dev;
 124         st->trig->ops = &itg3200_trigger_ops;
 125         iio_trigger_set_drvdata(st->trig, indio_dev);
 126         ret = iio_trigger_register(st->trig);
 127         if (ret)
 128                 goto error_free_irq;
 129
 130         /* select default trigger */
 131         indio_dev->trig = iio_trigger_get(st->trig);
 132
 133         return 0;
 134
 135 error_free_irq:
 136         free_irq(st->i2c->irq, st->trig);
 137 error_free_trig:
 138         iio_trigger_free(st->trig);
 139         return ret;
 140 }
 141
 142 void itg3200_remove_trigger(struct iio_dev *indio_dev)
 143 {
 144         struct itg3200 *st = iio_priv(indio_dev);
 145
 146         iio_trigger_unregister(st->trig);
 147         free_irq(st->i2c->irq, st->trig);
 148         iio_trigger_free(st->trig);
 149 }