drivers/iio/imu/adis16400_buffer.c

   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
  16 int 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         uint16_t *tx;
  22
  23         if (st->variant->flags & ADIS16400_NO_BURST)
  24                 return adis_update_scan_mode(indio_dev, scan_mask);
  25
  26         kfree(adis->xfer);
  27         kfree(adis->buffer);
  28
  29         adis->xfer = kcalloc(2, sizeof(*adis->xfer), GFP_KERNEL);
  30         if (!adis->xfer)
  31                 return -ENOMEM;
  32
  33         adis->buffer = kzalloc(indio_dev->scan_bytes + sizeof(u16),
  34                 GFP_KERNEL);
  35         if (!adis->buffer)
  36                 return -ENOMEM;
  37
  38         tx = adis->buffer + indio_dev->scan_bytes;
  39
  40         tx[0] = ADIS_READ_REG(ADIS16400_GLOB_CMD);
  41         tx[1] = 0;
  42
  43         adis->xfer[0].tx_buf = tx;
  44         adis->xfer[0].bits_per_word = 8;
  45         adis->xfer[0].len = 2;
  46         adis->xfer[1].tx_buf = tx;
  47         adis->xfer[1].bits_per_word = 8;
  48         adis->xfer[1].len = indio_dev->scan_bytes;
  49
  50         spi_message_init(&adis->msg);
  51         spi_message_add_tail(&adis->xfer[0], &adis->msg);
  52         spi_message_add_tail(&adis->xfer[1], &adis->msg);
  53
  54         return 0;
  55 }
  56
  57 irqreturn_t adis16400_trigger_handler(int irq, void *p)
  58 {
  59         struct iio_poll_func *pf = p;
  60         struct iio_dev *indio_dev = pf->indio_dev;
  61         struct adis16400_state *st = iio_priv(indio_dev);
  62         struct adis *adis = &st->adis;
  63         u32 old_speed_hz = st->adis.spi->max_speed_hz;
  64         int ret;
  65
  66         if (!adis->buffer)
  67                 return -ENOMEM;
  68
  69         if (!(st->variant->flags & ADIS16400_NO_BURST) &&
  70                 st->adis.spi->max_speed_hz > ADIS16400_SPI_BURST) {
  71                 st->adis.spi->max_speed_hz = ADIS16400_SPI_BURST;
  72                 spi_setup(st->adis.spi);
  73         }
  74
  75         ret = spi_sync(adis->spi, &adis->msg);
  76         if (ret)
  77                 dev_err(&adis->spi->dev, "Failed to read data: %d\n", ret);
  78
  79         if (!(st->variant->flags & ADIS16400_NO_BURST)) {
  80                 st->adis.spi->max_speed_hz = old_speed_hz;
  81                 spi_setup(st->adis.spi);
  82         }
  83
  84         iio_push_to_buffers_with_timestamp(indio_dev, adis->buffer,
  85                 pf->timestamp);
  86
  87         iio_trigger_notify_done(indio_dev->trig);
  88
  89         return IRQ_HANDLED;
  90 }