drivers/staging/iio/gyro/adis16260_ring.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
   7 #include "../iio.h"
   8 #include "../ring_sw.h"
   9 #include "../trigger_consumer.h"
  10 #include "adis16260.h"
  11
  12 /**
  13  * adis16260_read_ring_data() read data registers which will be placed into ring
  14  * @dev: device associated with child of actual device (iio_dev or iio_trig)
  15  * @rx: somewhere to pass back the value read
  16  **/
  17 static int adis16260_read_ring_data(struct device *dev, u8 *rx)
  18 {
  19         struct spi_message msg;
  20         struct iio_dev *indio_dev = dev_get_drvdata(dev);
  21         struct adis16260_state *st = iio_priv(indio_dev);
  22         struct spi_transfer xfers[ADIS16260_OUTPUTS + 1];
  23         int ret;
  24         int i;
  25
  26         mutex_lock(&st->buf_lock);
  27
  28         spi_message_init(&msg);
  29
  30         memset(xfers, 0, sizeof(xfers));
  31         for (i = 0; i <= ADIS16260_OUTPUTS; i++) {
  32                 xfers[i].bits_per_word = 8;
  33                 xfers[i].cs_change = 1;
  34                 xfers[i].len = 2;
  35                 xfers[i].delay_usecs = 30;
  36                 xfers[i].tx_buf = st->tx + 2 * i;
  37                 if (i < 2) /* SUPPLY_OUT:0x02 GYRO_OUT:0x04 */
  38                         st->tx[2 * i]
  39                                 = ADIS16260_READ_REG(ADIS16260_SUPPLY_OUT
  40                                                 + 2 * i);
  41                 else /* 0x06 to 0x09 is reserved */
  42                         st->tx[2 * i]
  43                                 = ADIS16260_READ_REG(ADIS16260_SUPPLY_OUT
  44                                                 + 2 * i + 4);
  45                 st->tx[2 * i + 1] = 0;
  46                 if (i >= 1)
  47                         xfers[i].rx_buf = rx + 2 * (i - 1);
  48                 spi_message_add_tail(&xfers[i], &msg);
  49         }
  50
  51         ret = spi_sync(st->us, &msg);
  52         if (ret)
  53                 dev_err(&st->us->dev, "problem when burst reading");
  54
  55         mutex_unlock(&st->buf_lock);
  56
  57         return ret;
  58 }
  59
  60 static irqreturn_t adis16260_trigger_handler(int irq, void *p)
  61 {
  62         struct iio_poll_func *pf = p;
  63         struct iio_dev *indio_dev = pf->indio_dev;
  64         struct adis16260_state *st = iio_priv(indio_dev);
  65         struct iio_ring_buffer *ring = indio_dev->ring;
  66         int i = 0;
  67         s16 *data;
  68         size_t datasize = ring->access->get_bytes_per_datum(ring);
  69
  70         data = kmalloc(datasize , GFP_KERNEL);
  71         if (data == NULL) {
  72                 dev_err(&st->us->dev, "memory alloc failed in ring bh");
  73                 return -ENOMEM;
  74         }
  75
  76         if (ring->scan_count &&
  77             adis16260_read_ring_data(&indio_dev->dev, st->rx) >= 0)
  78                 for (; i < ring->scan_count; i++)
  79                         data[i] = be16_to_cpup((__be16 *)&(st->rx[i*2]));
  80
  81         /* Guaranteed to be aligned with 8 byte boundary */
  82         if (ring->scan_timestamp)
  83                 *((s64 *)(data + ((i + 3)/4)*4)) = pf->timestamp;
  84
  85         ring->access->store_to(ring, (u8 *)data, pf->timestamp);
  86
  87         iio_trigger_notify_done(indio_dev->trig);
  88         kfree(data);
  89
  90         return IRQ_HANDLED;
  91 }
  92
  93 void adis16260_unconfigure_ring(struct iio_dev *indio_dev)
  94 {
  95         iio_dealloc_pollfunc(indio_dev->pollfunc);
  96         iio_sw_rb_free(indio_dev->ring);
  97 }
  98
  99 static const struct iio_ring_setup_ops adis16260_ring_setup_ops = {
 100         .preenable = &iio_sw_ring_preenable,
 101         .postenable = &iio_triggered_ring_postenable,
 102         .predisable = &iio_triggered_ring_predisable,
 103 };
 104
 105 int adis16260_configure_ring(struct iio_dev *indio_dev)
 106 {
 107         int ret = 0;
 108         struct iio_ring_buffer *ring;
 109
 110         ring = iio_sw_rb_allocate(indio_dev);
 111         if (!ring) {
 112                 ret = -ENOMEM;
 113                 return ret;
 114         }
 115         indio_dev->ring = ring;
 116         /* Effectively select the ring buffer implementation */
 117         ring->access = &ring_sw_access_funcs;
 118         ring->bpe = 2;
 119         ring->scan_timestamp = true;
 120         ring->setup_ops = &adis16260_ring_setup_ops;
 121         ring->owner = THIS_MODULE;
 122
 123         indio_dev->pollfunc = iio_alloc_pollfunc(&iio_pollfunc_store_time,
 124                                                  &adis16260_trigger_handler,
 125                                                  IRQF_ONESHOT,
 126                                                  indio_dev,
 127                                                  "adis16260_consumer%d",
 128                                                  indio_dev->id);
 129         if (indio_dev->pollfunc == NULL) {
 130                 ret = -ENOMEM;
 131                 goto error_iio_sw_rb_free;
 132         }
 133
 134         indio_dev->modes |= INDIO_RING_TRIGGERED;
 135         return 0;
 136
 137 error_iio_sw_rb_free:
 138         iio_sw_rb_free(indio_dev->ring);
 139         return ret;
 140 }