drivers/iio/imu/adis16400_buffer.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/interrupt.h>
   3 #include <linux/mutex.h>
   4 #include <linux/kernel.h>
   5 #include <linux/spi/spi.h>
   6 #include <linux/slab.h>
   7 #include <linux/bitops.h>
   8 #include <linux/export.h>
   9
  10 #include <linux/iio/iio.h>
  11 #include <linux/iio/buffer.h>
  12 #include <linux/iio/triggered_buffer.h>
  13 #include <linux/iio/trigger_consumer.h>
  14
  15 #include "adis16400.h"
  16
  17 int adis16400_update_scan_mode(struct iio_dev *indio_dev,
  18         const unsigned long *scan_mask)
  19 {
  20         struct adis16400_state *st = iio_priv(indio_dev);
  21         struct adis *adis = &st->adis;
  22         unsigned int burst_length;
  23         u8 *tx;
  24
  25         if (st->variant->flags & ADIS16400_NO_BURST)
  26                 return adis_update_scan_mode(indio_dev, scan_mask);
  27
  28         kfree(adis->xfer);
  29         kfree(adis->buffer);
  30
  31         /* All but the timestamp channel */
  32         burst_length = (indio_dev->num_channels - 1) * sizeof(u16);
  33         if (st->variant->flags & ADIS16400_BURST_DIAG_STAT)
  34                 burst_length += sizeof(u16);
  35
  36         adis->xfer = kcalloc(2, sizeof(*adis->xfer), GFP_KERNEL);
  37         if (!adis->xfer)
  38                 return -ENOMEM;
  39
  40         adis->buffer = kzalloc(burst_length + sizeof(u16), GFP_KERNEL);
  41         if (!adis->buffer)
  42                 return -ENOMEM;
  43
  44         tx = adis->buffer + burst_length;
  45         tx[0] = ADIS_READ_REG(ADIS16400_GLOB_CMD);
  46         tx[1] = 0;
  47
  48         adis->xfer[0].tx_buf = tx;
  49         adis->xfer[0].bits_per_word = 8;
  50         adis->xfer[0].len = 2;
  51         adis->xfer[1].rx_buf = adis->buffer;
  52         adis->xfer[1].bits_per_word = 8;
  53         adis->xfer[1].len = burst_length;
  54
  55         spi_message_init(&adis->msg);
  56         spi_message_add_tail(&adis->xfer[0], &adis->msg);
  57         spi_message_add_tail(&adis->xfer[1], &adis->msg);
  58
  59         return 0;
  60 }
  61
  62 irqreturn_t adis16400_trigger_handler(int irq, void *p)
  63 {
  64         struct iio_poll_func *pf = p;
  65         struct iio_dev *indio_dev = pf->indio_dev;
  66         struct adis16400_state *st = iio_priv(indio_dev);
  67         struct adis *adis = &st->adis;
  68         u32 old_speed_hz = st->adis.spi->max_speed_hz;
  69         void *buffer;
  70         int ret;
  71
  72         if (!adis->buffer)
  73                 return -ENOMEM;
  74
  75         if (!(st->variant->flags & ADIS16400_NO_BURST) &&
  76                 st->adis.spi->max_speed_hz > ADIS16400_SPI_BURST) {
  77                 st->adis.spi->max_speed_hz = ADIS16400_SPI_BURST;
  78                 spi_setup(st->adis.spi);
  79         }
  80
  81         ret = spi_sync(adis->spi, &adis->msg);
  82         if (ret)
  83                 dev_err(&adis->spi->dev, "Failed to read data: %d\n", ret);
  84
  85         if (!(st->variant->flags & ADIS16400_NO_BURST)) {
  86                 st->adis.spi->max_speed_hz = old_speed_hz;
  87                 spi_setup(st->adis.spi);
  88         }
  89
  90         if (st->variant->flags & ADIS16400_BURST_DIAG_STAT)
  91                 buffer = adis->buffer + sizeof(u16);
  92         else
  93                 buffer = adis->buffer;
  94
  95         iio_push_to_buffers_with_timestamp(indio_dev, buffer,
  96                 pf->timestamp);
  97
  98         iio_trigger_notify_done(indio_dev->trig);
  99
 100         return IRQ_HANDLED;
 101 }