LXR linux/drivers/iio/gyro/itg3200

   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
  23static 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
  44static 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        /*
  50         * Ensure correct alignment and padding including for the
  51         * timestamp that may be inserted.
  52         */
  53        struct {
  54                __be16 buf[ITG3200_SCAN_ELEMENTS];
  55                s64 ts __aligned(8);
  56        } scan;
  57
  58        int ret = itg3200_read_all_channels(st->i2c, scan.buf);
  59        if (ret < 0)
  60                goto error_ret;
  61
  62        iio_push_to_buffers_with_timestamp(indio_dev, &scan, pf->timestamp);
  63
  64        iio_trigger_notify_done(indio_dev->trig);
  65
  66error_ret:
  67        return IRQ_HANDLED;
  68}
  69
  70int itg3200_buffer_configure(struct iio_dev *indio_dev)
  71{
  72        return iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
  73                itg3200_trigger_handler, NULL);
  74}
  75
  76void itg3200_buffer_unconfigure(struct iio_dev *indio_dev)
  77{
  78        iio_triggered_buffer_cleanup(indio_dev);
  79}
  80
  81
  82static int itg3200_data_rdy_trigger_set_state(struct iio_trigger *trig,
  83                bool state)
  84{
  85        struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
  86        int ret;
  87        u8 msc;
  88
  89        ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_IRQ_CONFIG, &msc);
  90        if (ret)
  91                goto error_ret;
  92
  93        if (state)
  94                msc |= ITG3200_IRQ_DATA_RDY_ENABLE;
  95        else
  96                msc &= ~ITG3200_IRQ_DATA_RDY_ENABLE;
  97
  98        ret = itg3200_write_reg_8(indio_dev, ITG3200_REG_IRQ_CONFIG, msc);
  99        if (ret)
 100                goto error_ret;
 101
 102error_ret:
 103        return ret;
 104
 105}
 106
 107static const struct iio_trigger_ops itg3200_trigger_ops = {
 108        .set_trigger_state = &itg3200_data_rdy_trigger_set_state,
 109};
 110
 111int itg3200_probe_trigger(struct iio_dev *indio_dev)
 112{
 113        int ret;
 114        struct itg3200 *st = iio_priv(indio_dev);
 115
 116        st->trig = iio_trigger_alloc(&st->i2c->dev, "%s-dev%d", indio_dev->name,
 117                                     iio_device_id(indio_dev));
 118        if (!st->trig)
 119                return -ENOMEM;
 120
 121        ret = request_irq(st->i2c->irq,
 122                          &iio_trigger_generic_data_rdy_poll,
 123                          IRQF_TRIGGER_RISING,
 124                          "itg3200_data_rdy",
 125                          st->trig);
 126        if (ret)
 127                goto error_free_trig;
 128
 129
 130        st->trig->ops = &itg3200_trigger_ops;
 131        iio_trigger_set_drvdata(st->trig, indio_dev);
 132        ret = iio_trigger_register(st->trig);
 133        if (ret)
 134                goto error_free_irq;
 135
 136        /* select default trigger */
 137        indio_dev->trig = iio_trigger_get(st->trig);
 138
 139        return 0;
 140
 141error_free_irq:
 142        free_irq(st->i2c->irq, st->trig);
 143error_free_trig:
 144        iio_trigger_free(st->trig);
 145        return ret;
 146}
 147
 148void itg3200_remove_trigger(struct iio_dev *indio_dev)
 149{
 150        struct itg3200 *st = iio_priv(indio_dev);
 151
 152        iio_trigger_unregister(st->trig);
 153        free_irq(st->i2c->irq, st->trig);
 154        iio_trigger_free(st->trig);
 155}
 156