drivers/staging/iio/gyro/adis16260_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 "../iio.h"
   9 #include "../ring_sw.h"
  10 #include "../trigger_consumer.h"
  11 #include "adis16260.h"
  12
  13 /**
  14  * adis16260_read_ring_data() read data registers which will be placed into ring
  15  * @dev: device associated with child of actual device (iio_dev or iio_trig)
  16  * @rx: somewhere to pass back the value read
  17  **/
  18 static int adis16260_read_ring_data(struct device *dev, u8 *rx)
  19 {
  20         struct spi_message msg;
  21         struct iio_dev *indio_dev = dev_get_drvdata(dev);
  22         struct adis16260_state *st = iio_priv(indio_dev);
  23         struct spi_transfer xfers[ADIS16260_OUTPUTS + 1];
  24         int ret;
  25         int i;
  26
  27         mutex_lock(&st->buf_lock);
  28
  29         spi_message_init(&msg);
  30
  31         memset(xfers, 0, sizeof(xfers));
  32         for (i = 0; i <= ADIS16260_OUTPUTS; i++) {
  33                 xfers[i].bits_per_word = 8;
  34                 xfers[i].cs_change = 1;
  35                 xfers[i].len = 2;
  36                 xfers[i].delay_usecs = 30;
  37                 xfers[i].tx_buf = st->tx + 2 * i;
  38                 if (i < 2) /* SUPPLY_OUT:0x02 GYRO_OUT:0x04 */
  39                         st->tx[2 * i]
  40                                 = ADIS16260_READ_REG(ADIS16260_SUPPLY_OUT
  41                                                 + 2 * i);
  42                 else /* 0x06 to 0x09 is reserved */
  43                         st->tx[2 * i]
  44                                 = ADIS16260_READ_REG(ADIS16260_SUPPLY_OUT
  45                                                 + 2 * i + 4);
  46                 st->tx[2 * i + 1] = 0;
  47                 if (i >= 1)
  48                         xfers[i].rx_buf = rx + 2 * (i - 1);
  49                 spi_message_add_tail(&xfers[i], &msg);
  50         }
  51
  52         ret = spi_sync(st->us, &msg);
  53         if (ret)
  54                 dev_err(&st->us->dev, "problem when burst reading");
  55
  56         mutex_unlock(&st->buf_lock);
  57
  58         return ret;
  59 }
  60
  61 static irqreturn_t adis16260_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 adis16260_state *st = iio_priv(indio_dev);
  66         struct iio_buffer *ring = indio_dev->buffer;
  67         int i = 0;
  68         s16 *data;
  69         size_t datasize = ring->access->get_bytes_per_datum(ring);
  70
  71         data = kmalloc(datasize , GFP_KERNEL);
  72         if (data == NULL) {
  73                 dev_err(&st->us->dev, "memory alloc failed in ring bh");
  74                 return -ENOMEM;
  75         }
  76
  77         if (ring->scan_count &&
  78             adis16260_read_ring_data(&indio_dev->dev, st->rx) >= 0)
  79                 for (; i < ring->scan_count; i++)
  80                         data[i] = be16_to_cpup((__be16 *)&(st->rx[i*2]));
  81
  82         /* Guaranteed to be aligned with 8 byte boundary */
  83         if (ring->scan_timestamp)
  84                 *((s64 *)(data + ((i + 3)/4)*4)) = pf->timestamp;
  85
  86         ring->access->store_to(ring, (u8 *)data, pf->timestamp);
  87
  88         iio_trigger_notify_done(indio_dev->trig);
  89         kfree(data);
  90
  91         return IRQ_HANDLED;
  92 }
  93
  94 void adis16260_unconfigure_ring(struct iio_dev *indio_dev)
  95 {
  96         iio_dealloc_pollfunc(indio_dev->pollfunc);
  97         iio_sw_rb_free(indio_dev->buffer);
  98 }
  99
 100 static const struct iio_buffer_setup_ops adis16260_ring_setup_ops = {
 101         .preenable = &iio_sw_buffer_preenable,
 102         .postenable = &iio_triggered_buffer_postenable,
 103         .predisable = &iio_triggered_buffer_predisable,
 104 };
 105
 106 int adis16260_configure_ring(struct iio_dev *indio_dev)
 107 {
 108         int ret = 0;
 109         struct iio_buffer *ring;
 110
 111         ring = iio_sw_rb_allocate(indio_dev);
 112         if (!ring) {
 113                 ret = -ENOMEM;
 114                 return ret;
 115         }
 116         indio_dev->buffer = ring;
 117         /* Effectively select the ring buffer implementation */
 118         ring->access = &ring_sw_access_funcs;
 119         ring->bpe = 2;
 120         ring->scan_timestamp = true;
 121         ring->setup_ops = &adis16260_ring_setup_ops;
 122         ring->owner = THIS_MODULE;
 123
 124         indio_dev->pollfunc = iio_alloc_pollfunc(&iio_pollfunc_store_time,
 125                                                  &adis16260_trigger_handler,
 126                                                  IRQF_ONESHOT,
 127                                                  indio_dev,
 128                                                  "adis16260_consumer%d",
 129                                                  indio_dev->id);
 130         if (indio_dev->pollfunc == NULL) {
 131                 ret = -ENOMEM;
 132                 goto error_iio_sw_rb_free;
 133         }
 134
 135         indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
 136         return 0;
 137
 138 error_iio_sw_rb_free:
 139         iio_sw_rb_free(indio_dev->buffer);
 140         return ret;
 141 }