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         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
  61 irqreturn_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 }