drivers/staging/iio/gyro/adis16260_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/accel.h"
  17 #include "../trigger.h"
  18 #include "adis16260.h"
  19
  20 /**
  21  * adis16260_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 adis16260_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 adis16260_state *st = iio_priv(indio_dev);
  30         struct spi_transfer xfers[ADIS16260_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 <= ADIS16260_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 = 30;
  44                 xfers[i].tx_buf = st->tx + 2 * i;
  45                 if (i < 2) /* SUPPLY_OUT:0x02 GYRO_OUT:0x04 */
  46                         st->tx[2 * i]
  47                                 = ADIS16260_READ_REG(ADIS16260_SUPPLY_OUT
  48                                                 + 2 * i);
  49                 else /* 0x06 to 0x09 is reserved */
  50                         st->tx[2 * i]
  51                                 = ADIS16260_READ_REG(ADIS16260_SUPPLY_OUT
  52                                                 + 2 * i + 4);
  53                 st->tx[2 * i + 1] = 0;
  54                 if (i >= 1)
  55                         xfers[i].rx_buf = rx + 2 * (i - 1);
  56                 spi_message_add_tail(&xfers[i], &msg);
  57         }
  58
  59         ret = spi_sync(st->us, &msg);
  60         if (ret)
  61                 dev_err(&st->us->dev, "problem when burst reading");
  62
  63         mutex_unlock(&st->buf_lock);
  64
  65         return ret;
  66 }
  67
  68 static irqreturn_t adis16260_trigger_handler(int irq, void *p)
  69 {
  70         struct iio_poll_func *pf = p;
  71         struct iio_dev *indio_dev = pf->private_data;
  72         struct adis16260_state *st = iio_priv(indio_dev);
  73         struct iio_ring_buffer *ring = indio_dev->ring;
  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             adis16260_read_ring_data(&indio_dev->dev, st->rx) >= 0)
  86                 for (; i < ring->scan_count; i++)
  87                         data[i] = be16_to_cpup((__be16 *)&(st->rx[i*2]));
  88
  89         /* Guaranteed to be aligned with 8 byte boundary */
  90         if (ring->scan_timestamp)
  91                 *((s64 *)(data + ((i + 3)/4)*4)) = pf->timestamp;
  92
  93         ring->access->store_to(ring, (u8 *)data, pf->timestamp);
  94
  95         iio_trigger_notify_done(indio_dev->trig);
  96         kfree(data);
  97
  98         return IRQ_HANDLED;
  99 }
 100
 101 void adis16260_unconfigure_ring(struct iio_dev *indio_dev)
 102 {
 103         iio_dealloc_pollfunc(indio_dev->pollfunc);
 104         iio_sw_rb_free(indio_dev->ring);
 105 }
 106
 107 static const struct iio_ring_setup_ops adis16260_ring_setup_ops = {
 108         .preenable = &iio_sw_ring_preenable,
 109         .postenable = &iio_triggered_ring_postenable,
 110         .predisable = &iio_triggered_ring_predisable,
 111 };
 112
 113 int adis16260_configure_ring(struct iio_dev *indio_dev)
 114 {
 115         int ret = 0;
 116         struct iio_ring_buffer *ring;
 117
 118         ring = iio_sw_rb_allocate(indio_dev);
 119         if (!ring) {
 120                 ret = -ENOMEM;
 121                 return ret;
 122         }
 123         indio_dev->ring = ring;
 124         /* Effectively select the ring buffer implementation */
 125         ring->access = &ring_sw_access_funcs;
 126         ring->bpe = 2;
 127         ring->scan_timestamp = true;
 128         ring->setup_ops = &adis16260_ring_setup_ops;
 129         ring->owner = THIS_MODULE;
 130
 131         /* Set default scan mode */
 132         iio_scan_mask_set(ring, ADIS16260_SCAN_SUPPLY);
 133         iio_scan_mask_set(ring, ADIS16260_SCAN_GYRO);
 134         iio_scan_mask_set(ring, ADIS16260_SCAN_AUX_ADC);
 135         iio_scan_mask_set(ring, ADIS16260_SCAN_TEMP);
 136         iio_scan_mask_set(ring, ADIS16260_SCAN_ANGL);
 137
 138         indio_dev->pollfunc = iio_alloc_pollfunc(&iio_pollfunc_store_time,
 139                                                  &adis16260_trigger_handler,
 140                                                  IRQF_ONESHOT,
 141                                                  indio_dev,
 142                                                  "adis16260_consumer%d",
 143                                                  indio_dev->id);
 144         if (indio_dev->pollfunc == NULL) {
 145                 ret = -ENOMEM;
 146                 goto error_iio_sw_rb_free;
 147         }
 148
 149         indio_dev->modes |= INDIO_RING_TRIGGERED;
 150         return 0;
 151
 152 error_iio_sw_rb_free:
 153         iio_sw_rb_free(indio_dev->ring);
 154         return ret;
 155 }