drivers/staging/iio/accel/adis16203_ring.c

   1 #include <linux/interrupt.h>
   2 #include <linux/irq.h>
   3 #include <linux/gpio.h>
   4 #include <linux/workqueue.h>
   5 #include <linux/mutex.h>
   6 #include <linux/device.h>
   7 #include <linux/kernel.h>
   8 #include <linux/spi/spi.h>
   9 #include <linux/slab.h>
  10 #include <linux/sysfs.h>
  11 #include <linux/list.h>
  12
  13 #include "../iio.h"
  14 #include "../sysfs.h"
  15 #include "../ring_sw.h"
  16 #include "accel.h"
  17 #include "../trigger.h"
  18 #include "adis16203.h"
  19
  20 /**
  21  * adis16203_read_ring_data() read data registers which will be placed into ring
  22  * @dev: device associated with child of actual device (iio_dev or iio_trig)
  23  * @rx: somewhere to pass back the value read
  24  **/
  25 static int adis16203_read_ring_data(struct device *dev, u8 *rx)
  26 {
  27         struct spi_message msg;
  28         struct iio_dev *indio_dev = dev_get_drvdata(dev);
  29         struct adis16203_state *st = iio_dev_get_devdata(indio_dev);
  30         struct spi_transfer xfers[ADIS16203_OUTPUTS + 1];
  31         int ret;
  32         int i;
  33
  34         mutex_lock(&st->buf_lock);
  35
  36         spi_message_init(&msg);
  37
  38         memset(xfers, 0, sizeof(xfers));
  39         for (i = 0; i <= ADIS16203_OUTPUTS; i++) {
  40                 xfers[i].bits_per_word = 8;
  41                 xfers[i].cs_change = 1;
  42                 xfers[i].len = 2;
  43                 xfers[i].delay_usecs = 20;
  44                 xfers[i].tx_buf = st->tx + 2 * i;
  45                 if (i < 1) /* SUPPLY_OUT: 0x02, AUX_ADC: 0x08 */
  46                         st->tx[2 * i] = ADIS16203_READ_REG(ADIS16203_SUPPLY_OUT + 2 * i);
  47                 else
  48                         st->tx[2 * i] = ADIS16203_READ_REG(ADIS16203_SUPPLY_OUT + 2 * i + 6);
  49                 st->tx[2 * i + 1] = 0;
  50                 if (i >= 1)
  51                         xfers[i].rx_buf = rx + 2 * (i - 1);
  52                 spi_message_add_tail(&xfers[i], &msg);
  53         }
  54
  55         ret = spi_sync(st->us, &msg);
  56         if (ret)
  57                 dev_err(&st->us->dev, "problem when burst reading");
  58
  59         mutex_unlock(&st->buf_lock);
  60
  61         return ret;
  62 }
  63
  64 /* Whilst this makes a lot of calls to iio_sw_ring functions - it is to device
  65  * specific to be rolled into the core.
  66  */
  67 static irqreturn_t adis16203_trigger_handler(int irq, void *p)
  68 {
  69         struct iio_poll_func *pf = p;
  70         struct iio_dev *indio_dev = pf->private_data;
  71         struct adis16203_state *st = iio_dev_get_devdata(indio_dev);
  72         struct iio_ring_buffer *ring = indio_dev->ring;
  73
  74         int i = 0;
  75         s16 *data;
  76         size_t datasize = ring->access->get_bytes_per_datum(ring);
  77
  78         data = kmalloc(datasize, GFP_KERNEL);
  79         if (data == NULL) {
  80                 dev_err(&st->us->dev, "memory alloc failed in ring bh");
  81                 return -ENOMEM;
  82         }
  83
  84         if (ring->scan_count)
  85                 if (adis16203_read_ring_data(&st->indio_dev->dev, st->rx) >= 0)
  86                         for (; i < ring->scan_count; i++)
  87                                 data[i] = be16_to_cpup(
  88                                         (__be16 *)&(st->rx[i*2]));
  89
  90         /* Guaranteed to be aligned with 8 byte boundary */
  91         if (ring->scan_timestamp)
  92                 *((s64 *)(data + ((i + 3)/4)*4)) = pf->timestamp;
  93
  94         ring->access->store_to(ring,
  95                               (u8 *)data,
  96                               pf->timestamp);
  97
  98         iio_trigger_notify_done(st->indio_dev->trig);
  99         kfree(data);
 100
 101         return IRQ_HANDLED;
 102 }
 103
 104 void adis16203_unconfigure_ring(struct iio_dev *indio_dev)
 105 {
 106         iio_dealloc_pollfunc(indio_dev->pollfunc);
 107         iio_sw_rb_free(indio_dev->ring);
 108 }
 109
 110 static const struct iio_ring_setup_ops adis16203_ring_setup_ops = {
 111         .preenable = &iio_sw_ring_preenable,
 112         .postenable = &iio_triggered_ring_postenable,
 113         .predisable = &iio_triggered_ring_predisable,
 114 };
 115
 116 int adis16203_configure_ring(struct iio_dev *indio_dev)
 117 {
 118         int ret = 0;
 119         struct iio_ring_buffer *ring;
 120
 121         ring = iio_sw_rb_allocate(indio_dev);
 122         if (!ring) {
 123                 ret = -ENOMEM;
 124                 return ret;
 125         }
 126         indio_dev->ring = ring;
 127         /* Effectively select the ring buffer implementation */
 128         ring->bpe = 2;
 129         ring->scan_timestamp = true;
 130         ring->access = &ring_sw_access_funcs;
 131         ring->setup_ops = &adis16203_ring_setup_ops;
 132         ring->owner = THIS_MODULE;
 133
 134         /* Set default scan mode */
 135         iio_scan_mask_set(ring, ADIS16203_SCAN_SUPPLY);
 136         iio_scan_mask_set(ring, ADIS16203_SCAN_TEMP);
 137         iio_scan_mask_set(ring, ADIS16203_SCAN_AUX_ADC);
 138         iio_scan_mask_set(ring, ADIS16203_SCAN_INCLI_X);
 139         iio_scan_mask_set(ring, ADIS16203_SCAN_INCLI_Y);
 140
 141         indio_dev->pollfunc = iio_alloc_pollfunc(&iio_pollfunc_store_time,
 142                                                  &adis16203_trigger_handler,
 143                                                  IRQF_ONESHOT,
 144                                                  indio_dev,
 145                                                  "adis16203_consumer%d",
 146                                                  indio_dev->id);
 147         if (indio_dev->pollfunc == NULL) {
 148                 ret = -ENOMEM;
 149                 goto error_iio_sw_rb_free;
 150         }
 151
 152         indio_dev->modes |= INDIO_RING_TRIGGERED;
 153         return 0;
 154
 155 error_iio_sw_rb_free:
 156         iio_sw_rb_free(indio_dev->ring);
 157         return ret;
 158 }