drivers/staging/iio/imu/adis16400_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 #include <linux/bitops.h>
  13
  14 #include "../iio.h"
  15 #include "../sysfs.h"
  16 #include "../ring_sw.h"
  17 #include "../accel/accel.h"
  18 #include "../trigger.h"
  19 #include "adis16400.h"
  20
  21 /**
  22  * adis16400_spi_read_burst() - read all data registers
  23  * @dev: device associated with child of actual device (iio_dev or iio_trig)
  24  * @rx: somewhere to pass back the value read (min size is 24 bytes)
  25  **/
  26 static int adis16400_spi_read_burst(struct device *dev, u8 *rx)
  27 {
  28         struct spi_message msg;
  29         struct iio_dev *indio_dev = dev_get_drvdata(dev);
  30         struct adis16400_state *st = iio_priv(indio_dev);
  31         u32 old_speed_hz = st->us->max_speed_hz;
  32         int ret;
  33
  34         struct spi_transfer xfers[] = {
  35                 {
  36                         .tx_buf = st->tx,
  37                         .bits_per_word = 8,
  38                         .len = 2,
  39                 }, {
  40                         .rx_buf = rx,
  41                         .bits_per_word = 8,
  42                         .len = 24,
  43                 },
  44         };
  45
  46         mutex_lock(&st->buf_lock);
  47         st->tx[0] = ADIS16400_READ_REG(ADIS16400_GLOB_CMD);
  48         st->tx[1] = 0;
  49
  50         spi_message_init(&msg);
  51         spi_message_add_tail(&xfers[0], &msg);
  52         spi_message_add_tail(&xfers[1], &msg);
  53
  54         st->us->max_speed_hz = min(ADIS16400_SPI_BURST, old_speed_hz);
  55         spi_setup(st->us);
  56
  57         ret = spi_sync(st->us, &msg);
  58         if (ret)
  59                 dev_err(&st->us->dev, "problem when burst reading");
  60
  61         st->us->max_speed_hz = old_speed_hz;
  62         spi_setup(st->us);
  63         mutex_unlock(&st->buf_lock);
  64         return ret;
  65 }
  66
  67 static const u16 read_all_tx_array[] = {
  68         cpu_to_be16(ADIS16400_READ_REG(ADIS16400_SUPPLY_OUT)),
  69         cpu_to_be16(ADIS16400_READ_REG(ADIS16400_XGYRO_OUT)),
  70         cpu_to_be16(ADIS16400_READ_REG(ADIS16400_YGYRO_OUT)),
  71         cpu_to_be16(ADIS16400_READ_REG(ADIS16400_ZGYRO_OUT)),
  72         cpu_to_be16(ADIS16400_READ_REG(ADIS16400_XACCL_OUT)),
  73         cpu_to_be16(ADIS16400_READ_REG(ADIS16400_YACCL_OUT)),
  74         cpu_to_be16(ADIS16400_READ_REG(ADIS16400_ZACCL_OUT)),
  75         cpu_to_be16(ADIS16400_READ_REG(ADIS16350_XTEMP_OUT)),
  76         cpu_to_be16(ADIS16400_READ_REG(ADIS16350_YTEMP_OUT)),
  77         cpu_to_be16(ADIS16400_READ_REG(ADIS16350_ZTEMP_OUT)),
  78         cpu_to_be16(ADIS16400_READ_REG(ADIS16400_AUX_ADC)),
  79 };
  80
  81 static int adis16350_spi_read_all(struct device *dev, u8 *rx)
  82 {
  83         struct iio_dev *indio_dev = dev_get_drvdata(dev);
  84         struct adis16400_state *st = iio_priv(indio_dev);
  85
  86         struct spi_message msg;
  87         int i, j = 0, ret;
  88         struct spi_transfer *xfers;
  89
  90         xfers = kzalloc(sizeof(*xfers)*indio_dev->ring->scan_count + 1,
  91                         GFP_KERNEL);
  92         if (xfers == NULL)
  93                 return -ENOMEM;
  94
  95         for (i = 0; i < ARRAY_SIZE(read_all_tx_array); i++)
  96                 if (indio_dev->ring->scan_mask & (1 << i)) {
  97                         xfers[j].tx_buf = &read_all_tx_array[i];
  98                         xfers[j].bits_per_word = 16;
  99                         xfers[j].len = 2;
 100                         xfers[j + 1].rx_buf = rx + j*2;
 101                         j++;
 102                 }
 103         xfers[j].bits_per_word = 16;
 104         xfers[j].len = 2;
 105
 106         spi_message_init(&msg);
 107         for (j = 0; j < indio_dev->ring->scan_count + 1; j++)
 108                 spi_message_add_tail(&xfers[j], &msg);
 109
 110         ret = spi_sync(st->us, &msg);
 111         kfree(xfers);
 112
 113         return ret;
 114 }
 115
 116 /* Whilst this makes a lot of calls to iio_sw_ring functions - it is to device
 117  * specific to be rolled into the core.
 118  */
 119 static irqreturn_t adis16400_trigger_handler(int irq, void *p)
 120 {
 121         struct iio_poll_func *pf = p;
 122         struct iio_dev *indio_dev = pf->private_data;
 123         struct adis16400_state *st = iio_priv(indio_dev);
 124         struct iio_ring_buffer *ring = indio_dev->ring;
 125         int i = 0, j, ret = 0;
 126         s16 *data;
 127         size_t datasize = ring->access->get_bytes_per_datum(ring);
 128         unsigned long mask = ring->scan_mask;
 129
 130         data = kmalloc(datasize , GFP_KERNEL);
 131         if (data == NULL) {
 132                 dev_err(&st->us->dev, "memory alloc failed in ring bh");
 133                 return -ENOMEM;
 134         }
 135
 136         if (ring->scan_count) {
 137                 if (st->variant->flags & ADIS16400_NO_BURST) {
 138                         ret = adis16350_spi_read_all(&indio_dev->dev, st->rx);
 139                         if (ret < 0)
 140                                 goto err;
 141                         for (; i < ring->scan_count; i++)
 142                                 data[i] = *(s16 *)(st->rx + i*2);
 143                 } else {
 144                         ret = adis16400_spi_read_burst(&indio_dev->dev, st->rx);
 145                         if (ret < 0)
 146                                 goto err;
 147                         for (; i < indio_dev->ring->scan_count; i++) {
 148                                 j = __ffs(mask);
 149                                 mask &= ~(1 << j);
 150                                 data[i] = be16_to_cpup(
 151                                         (__be16 *)&(st->rx[j*2]));
 152                         }
 153                 }
 154         }
 155         /* Guaranteed to be aligned with 8 byte boundary */
 156         if (ring->scan_timestamp)
 157                 *((s64 *)(data + ((i + 3)/4)*4)) = pf->timestamp;
 158         ring->access->store_to(indio_dev->ring, (u8 *) data, pf->timestamp);
 159
 160         iio_trigger_notify_done(indio_dev->trig);
 161
 162         kfree(data);
 163         return IRQ_HANDLED;
 164
 165 err:
 166         kfree(data);
 167         return ret;
 168 }
 169
 170 void adis16400_unconfigure_ring(struct iio_dev *indio_dev)
 171 {
 172         iio_dealloc_pollfunc(indio_dev->pollfunc);
 173         iio_sw_rb_free(indio_dev->ring);
 174 }
 175
 176 static const struct iio_ring_setup_ops adis16400_ring_setup_ops = {
 177         .preenable = &iio_sw_ring_preenable,
 178         .postenable = &iio_triggered_ring_postenable,
 179         .predisable = &iio_triggered_ring_predisable,
 180 };
 181
 182 int adis16400_configure_ring(struct iio_dev *indio_dev)
 183 {
 184         int ret = 0;
 185         struct adis16400_state *st = iio_priv(indio_dev);
 186         struct iio_ring_buffer *ring;
 187
 188         ring = iio_sw_rb_allocate(indio_dev);
 189         if (!ring) {
 190                 ret = -ENOMEM;
 191                 return ret;
 192         }
 193         indio_dev->ring = ring;
 194         /* Effectively select the ring buffer implementation */
 195         ring->access = &ring_sw_access_funcs;
 196         ring->bpe = 2;
 197         ring->scan_timestamp = true;
 198         ring->setup_ops = &adis16400_ring_setup_ops;
 199         ring->owner = THIS_MODULE;
 200         /* Set default scan mode */
 201         ring->scan_mask = st->variant->default_scan_mask;
 202         ring->scan_count = hweight_long(st->variant->default_scan_mask);
 203
 204         indio_dev->pollfunc = iio_alloc_pollfunc(&iio_pollfunc_store_time,
 205                                                  &adis16400_trigger_handler,
 206                                                  IRQF_ONESHOT,
 207                                                  indio_dev,
 208                                                  "%s_consumer%d",
 209                                                  indio_dev->name,
 210                                                  indio_dev->id);
 211         if (indio_dev->pollfunc == NULL) {
 212                 ret = -ENOMEM;
 213                 goto error_iio_sw_rb_free;
 214         }
 215
 216         indio_dev->modes |= INDIO_RING_TRIGGERED;
 217         return 0;
 218 error_iio_sw_rb_free:
 219         iio_sw_rb_free(indio_dev->ring);
 220         return ret;
 221 }