linux/drivers/iio/imu/adis16400_buffer.c
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   1#include <linux/interrupt.h>
   2#include <linux/mutex.h>
   3#include <linux/kernel.h>
   4#include <linux/spi/spi.h>
   5#include <linux/slab.h>
   6#include <linux/bitops.h>
   7#include <linux/export.h>
   8
   9#include <linux/iio/iio.h>
  10#include <linux/iio/buffer.h>
  11#include <linux/iio/triggered_buffer.h>
  12#include <linux/iio/trigger_consumer.h>
  13
  14#include "adis16400.h"
  15
  16int adis16400_update_scan_mode(struct iio_dev *indio_dev,
  17        const unsigned long *scan_mask)
  18{
  19        struct adis16400_state *st = iio_priv(indio_dev);
  20        struct adis *adis = &st->adis;
  21        unsigned int burst_length;
  22        u8 *tx;
  23
  24        if (st->variant->flags & ADIS16400_NO_BURST)
  25                return adis_update_scan_mode(indio_dev, scan_mask);
  26
  27        kfree(adis->xfer);
  28        kfree(adis->buffer);
  29
  30        /* All but the timestamp channel */
  31        burst_length = (indio_dev->num_channels - 1) * sizeof(u16);
  32        if (st->variant->flags & ADIS16400_BURST_DIAG_STAT)
  33                burst_length += sizeof(u16);
  34
  35        adis->xfer = kcalloc(2, sizeof(*adis->xfer), GFP_KERNEL);
  36        if (!adis->xfer)
  37                return -ENOMEM;
  38
  39        adis->buffer = kzalloc(burst_length + sizeof(u16), GFP_KERNEL);
  40        if (!adis->buffer)
  41                return -ENOMEM;
  42
  43        tx = adis->buffer + burst_length;
  44        tx[0] = ADIS_READ_REG(ADIS16400_GLOB_CMD);
  45        tx[1] = 0;
  46
  47        adis->xfer[0].tx_buf = tx;
  48        adis->xfer[0].bits_per_word = 8;
  49        adis->xfer[0].len = 2;
  50        adis->xfer[1].rx_buf = adis->buffer;
  51        adis->xfer[1].bits_per_word = 8;
  52        adis->xfer[1].len = burst_length;
  53
  54        spi_message_init(&adis->msg);
  55        spi_message_add_tail(&adis->xfer[0], &adis->msg);
  56        spi_message_add_tail(&adis->xfer[1], &adis->msg);
  57
  58        return 0;
  59}
  60
  61irqreturn_t adis16400_trigger_handler(int irq, void *p)
  62{
  63        struct iio_poll_func *pf = p;
  64        struct iio_dev *indio_dev = pf->indio_dev;
  65        struct adis16400_state *st = iio_priv(indio_dev);
  66        struct adis *adis = &st->adis;
  67        u32 old_speed_hz = st->adis.spi->max_speed_hz;
  68        void *buffer;
  69        int ret;
  70
  71        if (!adis->buffer)
  72                return -ENOMEM;
  73
  74        if (!(st->variant->flags & ADIS16400_NO_BURST) &&
  75                st->adis.spi->max_speed_hz > ADIS16400_SPI_BURST) {
  76                st->adis.spi->max_speed_hz = ADIS16400_SPI_BURST;
  77                spi_setup(st->adis.spi);
  78        }
  79
  80        ret = spi_sync(adis->spi, &adis->msg);
  81        if (ret)
  82                dev_err(&adis->spi->dev, "Failed to read data: %d\n", ret);
  83
  84        if (!(st->variant->flags & ADIS16400_NO_BURST)) {
  85                st->adis.spi->max_speed_hz = old_speed_hz;
  86                spi_setup(st->adis.spi);
  87        }
  88
  89        if (st->variant->flags & ADIS16400_BURST_DIAG_STAT)
  90                buffer = adis->buffer + sizeof(u16);
  91        else
  92                buffer = adis->buffer;
  93
  94        iio_push_to_buffers_with_timestamp(indio_dev, buffer,
  95                pf->timestamp);
  96
  97        iio_trigger_notify_done(indio_dev->trig);
  98
  99        return IRQ_HANDLED;
 100}
 101