LXR linux/drivers/iio/imu/adis

   1/*
   2 * Common library for ADIS16XXX devices
   3 *
   4 * Copyright 2012 Analog Devices Inc.
   5 *   Author: Lars-Peter Clausen <lars@metafoo.de>
   6 *
   7 * Licensed under the GPL-2 or later.
   8 */
   9
  10#include <linux/export.h>
  11#include <linux/interrupt.h>
  12#include <linux/mutex.h>
  13#include <linux/kernel.h>
  14#include <linux/spi/spi.h>
  15#include <linux/slab.h>
  16
  17#include <linux/iio/iio.h>
  18#include <linux/iio/buffer.h>
  19#include <linux/iio/trigger_consumer.h>
  20#include <linux/iio/triggered_buffer.h>
  21#include <linux/iio/imu/adis.h>
  22
  23int adis_update_scan_mode(struct iio_dev *indio_dev,
  24        const unsigned long *scan_mask)
  25{
  26        struct adis *adis = iio_device_get_drvdata(indio_dev);
  27        const struct iio_chan_spec *chan;
  28        unsigned int scan_count;
  29        unsigned int i, j;
  30        __be16 *tx, *rx;
  31
  32        kfree(adis->xfer);
  33        kfree(adis->buffer);
  34
  35        scan_count = indio_dev->scan_bytes / 2;
  36
  37        adis->xfer = kcalloc(scan_count + 1, sizeof(*adis->xfer), GFP_KERNEL);
  38        if (!adis->xfer)
  39                return -ENOMEM;
  40
  41        adis->buffer = kzalloc(indio_dev->scan_bytes * 2, GFP_KERNEL);
  42        if (!adis->buffer)
  43                return -ENOMEM;
  44
  45        rx = adis->buffer;
  46        tx = rx + scan_count;
  47
  48        spi_message_init(&adis->msg);
  49
  50        for (j = 0; j <= scan_count; j++) {
  51                adis->xfer[j].bits_per_word = 8;
  52                if (j != scan_count)
  53                        adis->xfer[j].cs_change = 1;
  54                adis->xfer[j].len = 2;
  55                adis->xfer[j].delay_usecs = adis->data->read_delay;
  56                if (j < scan_count)
  57                        adis->xfer[j].tx_buf = &tx[j];
  58                if (j >= 1)
  59                        adis->xfer[j].rx_buf = &rx[j - 1];
  60                spi_message_add_tail(&adis->xfer[j], &adis->msg);
  61        }
  62
  63        chan = indio_dev->channels;
  64        for (i = 0; i < indio_dev->num_channels; i++, chan++) {
  65                if (!test_bit(chan->scan_index, scan_mask))
  66                        continue;
  67                if (chan->scan_type.storagebits == 32)
  68                        *tx++ = cpu_to_be16((chan->address + 2) << 8);
  69                *tx++ = cpu_to_be16(chan->address << 8);
  70        }
  71
  72        return 0;
  73}
  74EXPORT_SYMBOL_GPL(adis_update_scan_mode);
  75
  76static irqreturn_t adis_trigger_handler(int irq, void *p)
  77{
  78        struct iio_poll_func *pf = p;
  79        struct iio_dev *indio_dev = pf->indio_dev;
  80        struct adis *adis = iio_device_get_drvdata(indio_dev);
  81        int ret;
  82
  83        if (!adis->buffer)
  84                return -ENOMEM;
  85
  86        if (adis->data->has_paging) {
  87                mutex_lock(&adis->txrx_lock);
  88                if (adis->current_page != 0) {
  89                        adis->tx[0] = ADIS_WRITE_REG(ADIS_REG_PAGE_ID);
  90                        adis->tx[1] = 0;
  91                        spi_write(adis->spi, adis->tx, 2);
  92                }
  93        }
  94
  95        ret = spi_sync(adis->spi, &adis->msg);
  96        if (ret)
  97                dev_err(&adis->spi->dev, "Failed to read data: %d", ret);
  98
  99
 100        if (adis->data->has_paging) {
 101                adis->current_page = 0;
 102                mutex_unlock(&adis->txrx_lock);
 103        }
 104
 105        iio_push_to_buffers_with_timestamp(indio_dev, adis->buffer,
 106                pf->timestamp);
 107
 108        iio_trigger_notify_done(indio_dev->trig);
 109
 110        return IRQ_HANDLED;
 111}
 112
 113/**
 114 * adis_setup_buffer_and_trigger() - Sets up buffer and trigger for the adis device
 115 * @adis: The adis device.
 116 * @indio_dev: The IIO device.
 117 * @trigger_handler: Optional trigger handler, may be NULL.
 118 *
 119 * Returns 0 on success, a negative error code otherwise.
 120 *
 121 * This function sets up the buffer and trigger for a adis devices.  If
 122 * 'trigger_handler' is NULL the default trigger handler will be used. The
 123 * default trigger handler will simply read the registers assigned to the
 124 * currently active channels.
 125 *
 126 * adis_cleanup_buffer_and_trigger() should be called to free the resources
 127 * allocated by this function.
 128 */
 129int adis_setup_buffer_and_trigger(struct adis *adis, struct iio_dev *indio_dev,
 130        irqreturn_t (*trigger_handler)(int, void *))
 131{
 132        int ret;
 133
 134        if (!trigger_handler)
 135                trigger_handler = adis_trigger_handler;
 136
 137        ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
 138                trigger_handler, NULL);
 139        if (ret)
 140                return ret;
 141
 142        if (adis->spi->irq) {
 143                ret = adis_probe_trigger(adis, indio_dev);
 144                if (ret)
 145                        goto error_buffer_cleanup;
 146        }
 147        return 0;
 148
 149error_buffer_cleanup:
 150        iio_triggered_buffer_cleanup(indio_dev);
 151        return ret;
 152}
 153EXPORT_SYMBOL_GPL(adis_setup_buffer_and_trigger);
 154
 155/**
 156 * adis_cleanup_buffer_and_trigger() - Free buffer and trigger resources
 157 * @adis: The adis device.
 158 * @indio_dev: The IIO device.
 159 *
 160 * Frees resources allocated by adis_setup_buffer_and_trigger()
 161 */
 162void adis_cleanup_buffer_and_trigger(struct adis *adis,
 163        struct iio_dev *indio_dev)
 164{
 165        if (adis->spi->irq)
 166                adis_remove_trigger(adis);
 167        kfree(adis->buffer);
 168        kfree(adis->xfer);
 169        iio_triggered_buffer_cleanup(indio_dev);
 170}
 171EXPORT_SYMBOL_GPL(adis_cleanup_buffer_and_trigger);
 172