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