drivers/staging/iio/accel/adis16240_ring.c

   1 #include <linux/export.h>
   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
   8 #include <linux/iio/iio.h>
   9 #include "../ring_sw.h"
  10 #include <linux/iio/trigger_consumer.h>
  11 #include "adis16240.h"
  12
  13 /**
  14  * adis16240_read_ring_data() read data registers which will be placed into ring
  15  * @indio_dev: the IIO device
  16  * @rx: somewhere to pass back the value read
  17  **/
  18 static int adis16240_read_ring_data(struct iio_dev *indio_dev, u8 *rx)
  19 {
  20         struct spi_message msg;
  21         struct adis16240_state *st = iio_priv(indio_dev);
  22         struct spi_transfer xfers[ADIS16240_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 <= ADIS16240_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                 st->tx[2 * i]
  38                         = ADIS16240_READ_REG(ADIS16240_SUPPLY_OUT + 2 * i);
  39                 st->tx[2 * i + 1] = 0;
  40                 if (i >= 1)
  41                         xfers[i].rx_buf = rx + 2 * (i - 1);
  42                 spi_message_add_tail(&xfers[i], &msg);
  43         }
  44
  45         ret = spi_sync(st->us, &msg);
  46         if (ret)
  47                 dev_err(&st->us->dev, "problem when burst reading");
  48
  49         mutex_unlock(&st->buf_lock);
  50
  51         return ret;
  52 }
  53
  54 static irqreturn_t adis16240_trigger_handler(int irq, void *p)
  55 {
  56         struct iio_poll_func *pf = p;
  57         struct iio_dev *indio_dev = pf->indio_dev;
  58         struct adis16240_state *st = iio_priv(indio_dev);
  59         struct iio_buffer *ring = indio_dev->buffer;
  60
  61         int i = 0;
  62         s16 *data;
  63
  64         data = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
  65         if (data == NULL) {
  66                 dev_err(&st->us->dev, "memory alloc failed in ring bh");
  67                 goto done;
  68         }
  69
  70         if (!bitmap_empty(indio_dev->active_scan_mask, indio_dev->masklength) &&
  71             adis16240_read_ring_data(indio_dev, st->rx) >= 0)
  72                 for (; i < bitmap_weight(indio_dev->active_scan_mask,
  73                                          indio_dev->masklength); i++)
  74                         data[i] = be16_to_cpup((__be16 *)&(st->rx[i*2]));
  75
  76         /* Guaranteed to be aligned with 8 byte boundary */
  77         if (indio_dev->scan_timestamp)
  78                 *((s64 *)(data + ((i + 3)/4)*4)) = pf->timestamp;
  79
  80         ring->access->store_to(ring, (u8 *)data, pf->timestamp);
  81
  82         kfree(data);
  83 done:
  84         iio_trigger_notify_done(indio_dev->trig);
  85
  86         return IRQ_HANDLED;
  87 }
  88
  89 void adis16240_unconfigure_ring(struct iio_dev *indio_dev)
  90 {
  91         iio_dealloc_pollfunc(indio_dev->pollfunc);
  92         iio_sw_rb_free(indio_dev->buffer);
  93 }
  94
  95 static const struct iio_buffer_setup_ops adis16240_ring_setup_ops = {
  96         .preenable = &iio_sw_buffer_preenable,
  97         .postenable = &iio_triggered_buffer_postenable,
  98         .predisable = &iio_triggered_buffer_predisable,
  99 };
 100
 101 int adis16240_configure_ring(struct iio_dev *indio_dev)
 102 {
 103         int ret = 0;
 104         struct iio_buffer *ring;
 105
 106         ring = iio_sw_rb_allocate(indio_dev);
 107         if (!ring) {
 108                 ret = -ENOMEM;
 109                 return ret;
 110         }
 111         indio_dev->buffer = ring;
 112         ring->scan_timestamp = true;
 113         indio_dev->setup_ops = &adis16240_ring_setup_ops;
 114
 115         indio_dev->pollfunc = iio_alloc_pollfunc(&iio_pollfunc_store_time,
 116                                                  &adis16240_trigger_handler,
 117                                                  IRQF_ONESHOT,
 118                                                  indio_dev,
 119                                                  "%s_consumer%d",
 120                                                  indio_dev->name,
 121                                                  indio_dev->id);
 122         if (indio_dev->pollfunc == NULL) {
 123                 ret = -ENOMEM;
 124                 goto error_iio_sw_rb_free;
 125         }
 126
 127         indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
 128         return 0;
 129
 130 error_iio_sw_rb_free:
 131         iio_sw_rb_free(indio_dev->buffer);
 132         return ret;
 133 }