drivers/staging/iio/imu/adis16400_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 #include <linux/bitops.h>
   7 #include <linux/export.h>
   8
   9 #include <linux/iio/iio.h>
  10 #include "../ring_sw.h"
  11 #include <linux/iio/trigger_consumer.h>
  12 #include "adis16400.h"
  13
  14 /**
  15  * adis16400_spi_read_burst() - read all data registers
  16  * @dev: device associated with child of actual device (iio_dev or iio_trig)
  17  * @rx: somewhere to pass back the value read (min size is 24 bytes)
  18  **/
  19 static int adis16400_spi_read_burst(struct device *dev, u8 *rx)
  20 {
  21         struct spi_message msg;
  22         struct iio_dev *indio_dev = dev_get_drvdata(dev);
  23         struct adis16400_state *st = iio_priv(indio_dev);
  24         u32 old_speed_hz = st->us->max_speed_hz;
  25         int ret;
  26
  27         struct spi_transfer xfers[] = {
  28                 {
  29                         .tx_buf = st->tx,
  30                         .bits_per_word = 8,
  31                         .len = 2,
  32                 }, {
  33                         .rx_buf = rx,
  34                         .bits_per_word = 8,
  35                         .len = 24,
  36                 },
  37         };
  38
  39         mutex_lock(&st->buf_lock);
  40         st->tx[0] = ADIS16400_READ_REG(ADIS16400_GLOB_CMD);
  41         st->tx[1] = 0;
  42
  43         spi_message_init(&msg);
  44         spi_message_add_tail(&xfers[0], &msg);
  45         spi_message_add_tail(&xfers[1], &msg);
  46
  47         st->us->max_speed_hz = min(ADIS16400_SPI_BURST, old_speed_hz);
  48         spi_setup(st->us);
  49
  50         ret = spi_sync(st->us, &msg);
  51         if (ret)
  52                 dev_err(&st->us->dev, "problem when burst reading");
  53
  54         st->us->max_speed_hz = old_speed_hz;
  55         spi_setup(st->us);
  56         mutex_unlock(&st->buf_lock);
  57         return ret;
  58 }
  59
  60 static const u16 read_all_tx_array[] = {
  61         cpu_to_be16(ADIS16400_READ_REG(ADIS16400_SUPPLY_OUT)),
  62         cpu_to_be16(ADIS16400_READ_REG(ADIS16400_XGYRO_OUT)),
  63         cpu_to_be16(ADIS16400_READ_REG(ADIS16400_YGYRO_OUT)),
  64         cpu_to_be16(ADIS16400_READ_REG(ADIS16400_ZGYRO_OUT)),
  65         cpu_to_be16(ADIS16400_READ_REG(ADIS16400_XACCL_OUT)),
  66         cpu_to_be16(ADIS16400_READ_REG(ADIS16400_YACCL_OUT)),
  67         cpu_to_be16(ADIS16400_READ_REG(ADIS16400_ZACCL_OUT)),
  68         cpu_to_be16(ADIS16400_READ_REG(ADIS16350_XTEMP_OUT)),
  69         cpu_to_be16(ADIS16400_READ_REG(ADIS16350_YTEMP_OUT)),
  70         cpu_to_be16(ADIS16400_READ_REG(ADIS16350_ZTEMP_OUT)),
  71         cpu_to_be16(ADIS16400_READ_REG(ADIS16400_AUX_ADC)),
  72 };
  73
  74 static int adis16350_spi_read_all(struct device *dev, u8 *rx)
  75 {
  76         struct iio_dev *indio_dev = dev_get_drvdata(dev);
  77         struct adis16400_state *st = iio_priv(indio_dev);
  78
  79         struct spi_message msg;
  80         int i, j = 0, ret;
  81         struct spi_transfer *xfers;
  82         int scan_count = bitmap_weight(indio_dev->active_scan_mask,
  83                                        indio_dev->masklength);
  84
  85         xfers = kzalloc(sizeof(*xfers)*(scan_count + 1),
  86                         GFP_KERNEL);
  87         if (xfers == NULL)
  88                 return -ENOMEM;
  89
  90         for (i = 0; i < ARRAY_SIZE(read_all_tx_array); i++)
  91                 if (test_bit(i, indio_dev->active_scan_mask)) {
  92                         xfers[j].tx_buf = &read_all_tx_array[i];
  93                         xfers[j].bits_per_word = 16;
  94                         xfers[j].len = 2;
  95                         xfers[j + 1].rx_buf = rx + j*2;
  96                         j++;
  97                 }
  98         xfers[j].bits_per_word = 16;
  99         xfers[j].len = 2;
 100
 101         spi_message_init(&msg);
 102         for (j = 0; j < scan_count + 1; j++)
 103                 spi_message_add_tail(&xfers[j], &msg);
 104
 105         ret = spi_sync(st->us, &msg);
 106         kfree(xfers);
 107
 108         return ret;
 109 }
 110
 111 /* Whilst this makes a lot of calls to iio_sw_ring functions - it is to device
 112  * specific to be rolled into the core.
 113  */
 114 static irqreturn_t adis16400_trigger_handler(int irq, void *p)
 115 {
 116         struct iio_poll_func *pf = p;
 117         struct iio_dev *indio_dev = pf->indio_dev;
 118         struct adis16400_state *st = iio_priv(indio_dev);
 119         struct iio_buffer *ring = indio_dev->buffer;
 120         int i = 0, j, ret = 0;
 121         s16 *data;
 122
 123         /* Asumption that long is enough for maximum channels */
 124         unsigned long mask = *indio_dev->active_scan_mask;
 125         int scan_count = bitmap_weight(indio_dev->active_scan_mask,
 126                                        indio_dev->masklength);
 127         data = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
 128         if (data == NULL) {
 129                 dev_err(&st->us->dev, "memory alloc failed in ring bh");
 130                 return -ENOMEM;
 131         }
 132
 133         if (scan_count) {
 134                 if (st->variant->flags & ADIS16400_NO_BURST) {
 135                         ret = adis16350_spi_read_all(&indio_dev->dev, st->rx);
 136                         if (ret < 0)
 137                                 goto err;
 138                         for (; i < scan_count; i++)
 139                                 data[i] = *(s16 *)(st->rx + i*2);
 140                 } else {
 141                         ret = adis16400_spi_read_burst(&indio_dev->dev, st->rx);
 142                         if (ret < 0)
 143                                 goto err;
 144                         for (; i < scan_count; i++) {
 145                                 j = __ffs(mask);
 146                                 mask &= ~(1 << j);
 147                                 data[i] = be16_to_cpup(
 148                                         (__be16 *)&(st->rx[j*2]));
 149                         }
 150                 }
 151         }
 152         /* Guaranteed to be aligned with 8 byte boundary */
 153         if (ring->scan_timestamp)
 154                 *((s64 *)(data + ((i + 3)/4)*4)) = pf->timestamp;
 155         ring->access->store_to(indio_dev->buffer, (u8 *) data, pf->timestamp);
 156
 157         iio_trigger_notify_done(indio_dev->trig);
 158
 159         kfree(data);
 160         return IRQ_HANDLED;
 161
 162 err:
 163         kfree(data);
 164         return ret;
 165 }
 166
 167 void adis16400_unconfigure_ring(struct iio_dev *indio_dev)
 168 {
 169         iio_dealloc_pollfunc(indio_dev->pollfunc);
 170         iio_sw_rb_free(indio_dev->buffer);
 171 }
 172
 173 static const struct iio_buffer_setup_ops adis16400_ring_setup_ops = {
 174         .preenable = &iio_sw_buffer_preenable,
 175         .postenable = &iio_triggered_buffer_postenable,
 176         .predisable = &iio_triggered_buffer_predisable,
 177 };
 178
 179 int adis16400_configure_ring(struct iio_dev *indio_dev)
 180 {
 181         int ret = 0;
 182         struct iio_buffer *ring;
 183
 184         ring = iio_sw_rb_allocate(indio_dev);
 185         if (!ring) {
 186                 ret = -ENOMEM;
 187                 return ret;
 188         }
 189         indio_dev->buffer = ring;
 190         ring->scan_timestamp = true;
 191         indio_dev->setup_ops = &adis16400_ring_setup_ops;
 192
 193         indio_dev->pollfunc = iio_alloc_pollfunc(&iio_pollfunc_store_time,
 194                                                  &adis16400_trigger_handler,
 195                                                  IRQF_ONESHOT,
 196                                                  indio_dev,
 197                                                  "%s_consumer%d",
 198                                                  indio_dev->name,
 199                                                  indio_dev->id);
 200         if (indio_dev->pollfunc == NULL) {
 201                 ret = -ENOMEM;
 202                 goto error_iio_sw_rb_free;
 203         }
 204
 205         indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
 206         return 0;
 207 error_iio_sw_rb_free:
 208         iio_sw_rb_free(indio_dev->buffer);
 209         return ret;
 210 }