drivers/staging/iio/imu/adis16300_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/sysfs.h>
  10 #include <linux/list.h>
  11
  12 #include "../iio.h"
  13 #include "../sysfs.h"
  14 #include "../ring_sw.h"
  15 #include "../accel/accel.h"
  16 #include "../trigger.h"
  17 #include "adis16300.h"
  18
  19 /**
  20  * combine_8_to_16() utility function to munge to u8s into u16
  21  **/
  22 static inline u16 combine_8_to_16(u8 lower, u8 upper)
  23 {
  24         u16 _lower = lower;
  25         u16 _upper = upper;
  26         return _lower | (_upper << 8);
  27 }
  28
  29 static IIO_SCAN_EL_C(supply, ADIS16300_SCAN_SUPPLY, IIO_SIGNED(14),
  30                      ADIS16300_SUPPLY_OUT, NULL);
  31
  32 static IIO_SCAN_EL_C(gyro_x, ADIS16300_SCAN_GYRO_X, IIO_SIGNED(14),
  33                      ADIS16300_XGYRO_OUT, NULL);
  34
  35 static IIO_SCAN_EL_C(accel_x, ADIS16300_SCAN_ACC_X, IIO_SIGNED(14),
  36                      ADIS16300_XACCL_OUT, NULL);
  37 static IIO_SCAN_EL_C(accel_y, ADIS16300_SCAN_ACC_Y, IIO_SIGNED(14),
  38                      ADIS16300_YACCL_OUT, NULL);
  39 static IIO_SCAN_EL_C(accel_z, ADIS16300_SCAN_ACC_Z, IIO_SIGNED(14),
  40                      ADIS16300_ZACCL_OUT, NULL);
  41
  42 static IIO_SCAN_EL_C(temp, ADIS16300_SCAN_TEMP, IIO_SIGNED(12),
  43                      ADIS16300_TEMP_OUT, NULL);
  44 static IIO_SCAN_EL_C(adc_0, ADIS16300_SCAN_ADC_0, IIO_SIGNED(12),
  45                      ADIS16300_AUX_ADC, NULL);
  46
  47 static IIO_SCAN_EL_C(incli_x, ADIS16300_SCAN_INCLI_X, IIO_SIGNED(12),
  48                      ADIS16300_XINCLI_OUT, NULL);
  49 static IIO_SCAN_EL_C(incli_y, ADIS16300_SCAN_INCLI_Y, IIO_SIGNED(12),
  50                      ADIS16300_YINCLI_OUT, NULL);
  51
  52 static IIO_SCAN_EL_TIMESTAMP(9);
  53
  54 static struct attribute *adis16300_scan_el_attrs[] = {
  55         &iio_scan_el_supply.dev_attr.attr,
  56         &iio_scan_el_gyro_x.dev_attr.attr,
  57         &iio_scan_el_temp.dev_attr.attr,
  58         &iio_scan_el_accel_x.dev_attr.attr,
  59         &iio_scan_el_accel_y.dev_attr.attr,
  60         &iio_scan_el_accel_z.dev_attr.attr,
  61         &iio_scan_el_incli_x.dev_attr.attr,
  62         &iio_scan_el_incli_y.dev_attr.attr,
  63         &iio_scan_el_adc_0.dev_attr.attr,
  64         &iio_scan_el_timestamp.dev_attr.attr,
  65         NULL,
  66 };
  67
  68 static struct attribute_group adis16300_scan_el_group = {
  69         .attrs = adis16300_scan_el_attrs,
  70         .name = "scan_elements",
  71 };
  72
  73 /**
  74  * adis16300_poll_func_th() top half interrupt handler called by trigger
  75  * @private_data:       iio_dev
  76  **/
  77 static void adis16300_poll_func_th(struct iio_dev *indio_dev)
  78 {
  79         struct adis16300_state *st = iio_dev_get_devdata(indio_dev);
  80         st->last_timestamp = indio_dev->trig->timestamp;
  81         schedule_work(&st->work_trigger_to_ring);
  82         /* Indicate that this interrupt is being handled */
  83
  84         /* Technically this is trigger related, but without this
  85          * handler running there is currently no way for the interrupt
  86          * to clear.
  87          */
  88 }
  89
  90 /* Whilst this makes a lot of calls to iio_sw_ring functions - it is to device
  91  * specific to be rolled into the core.
  92  */
  93 static void adis16300_trigger_bh_to_ring(struct work_struct *work_s)
  94 {
  95         struct adis16300_state *st
  96                 = container_of(work_s, struct adis16300_state,
  97                                work_trigger_to_ring);
  98
  99         int i = 0;
 100         s16 *data;
 101         size_t datasize = st->indio_dev
 102                 ->ring->access.get_bpd(st->indio_dev->ring);
 103
 104         data = kmalloc(datasize , GFP_KERNEL);
 105         if (data == NULL) {
 106                 dev_err(&st->us->dev, "memory alloc failed in ring bh");
 107                 return;
 108         }
 109
 110         if (st->indio_dev->scan_count)
 111                 if (adis16300_spi_read_burst(&st->indio_dev->dev, st->rx) >= 0)
 112                         for (; i < st->indio_dev->scan_count; i++) {
 113                                 data[i] = combine_8_to_16(st->rx[i*2+1],
 114                                                           st->rx[i*2]);
 115                         }
 116
 117         /* Guaranteed to be aligned with 8 byte boundary */
 118         if (st->indio_dev->scan_timestamp)
 119                 *((s64 *)(data + ((i + 3)/4)*4)) = st->last_timestamp;
 120
 121         st->indio_dev->ring->access.store_to(st->indio_dev->ring,
 122                                             (u8 *)data,
 123                                             st->last_timestamp);
 124
 125         iio_trigger_notify_done(st->indio_dev->trig);
 126         kfree(data);
 127
 128         return;
 129 }
 130 /* in these circumstances is it better to go with unaligned packing and
 131  * deal with the cost?*/
 132 static int adis16300_data_rdy_ring_preenable(struct iio_dev *indio_dev)
 133 {
 134         size_t size;
 135         dev_dbg(&indio_dev->dev, "%s\n", __func__);
 136         /* Check if there are any scan elements enabled, if not fail*/
 137         if (!(indio_dev->scan_count || indio_dev->scan_timestamp))
 138                 return -EINVAL;
 139
 140         if (indio_dev->ring->access.set_bpd) {
 141                 if (indio_dev->scan_timestamp)
 142                         if (indio_dev->scan_count) /* Timestamp and data */
 143                                 size = 4*sizeof(s64);
 144                         else /* Timestamp only  */
 145                                 size = sizeof(s64);
 146                 else /* Data only */
 147                         size = indio_dev->scan_count*sizeof(s16);
 148                 indio_dev->ring->access.set_bpd(indio_dev->ring, size);
 149         }
 150
 151         return 0;
 152 }
 153
 154 static int adis16300_data_rdy_ring_postenable(struct iio_dev *indio_dev)
 155 {
 156         return indio_dev->trig
 157                 ? iio_trigger_attach_poll_func(indio_dev->trig,
 158                                                indio_dev->pollfunc)
 159                 : 0;
 160 }
 161
 162 static int adis16300_data_rdy_ring_predisable(struct iio_dev *indio_dev)
 163 {
 164         return indio_dev->trig
 165                 ? iio_trigger_dettach_poll_func(indio_dev->trig,
 166                                                 indio_dev->pollfunc)
 167                 : 0;
 168 }
 169
 170 void adis16300_unconfigure_ring(struct iio_dev *indio_dev)
 171 {
 172         kfree(indio_dev->pollfunc);
 173         iio_sw_rb_free(indio_dev->ring);
 174 }
 175
 176 int adis16300_configure_ring(struct iio_dev *indio_dev)
 177 {
 178         int ret = 0;
 179         struct adis16300_state *st = indio_dev->dev_data;
 180         struct iio_ring_buffer *ring;
 181         INIT_WORK(&st->work_trigger_to_ring, adis16300_trigger_bh_to_ring);
 182         /* Set default scan mode */
 183
 184         iio_scan_mask_set(indio_dev, iio_scan_el_supply.number);
 185         iio_scan_mask_set(indio_dev, iio_scan_el_gyro_x.number);
 186         iio_scan_mask_set(indio_dev, iio_scan_el_accel_x.number);
 187         iio_scan_mask_set(indio_dev, iio_scan_el_accel_y.number);
 188         iio_scan_mask_set(indio_dev, iio_scan_el_accel_z.number);
 189         iio_scan_mask_set(indio_dev, iio_scan_el_temp.number);
 190         iio_scan_mask_set(indio_dev, iio_scan_el_adc_0.number);
 191         iio_scan_mask_set(indio_dev, iio_scan_el_incli_x.number);
 192         iio_scan_mask_set(indio_dev, iio_scan_el_incli_y.number);
 193         indio_dev->scan_timestamp = true;
 194
 195         indio_dev->scan_el_attrs = &adis16300_scan_el_group;
 196
 197         ring = iio_sw_rb_allocate(indio_dev);
 198         if (!ring) {
 199                 ret = -ENOMEM;
 200                 return ret;
 201         }
 202         indio_dev->ring = ring;
 203         /* Effectively select the ring buffer implementation */
 204         iio_ring_sw_register_funcs(&ring->access);
 205         ring->preenable = &adis16300_data_rdy_ring_preenable;
 206         ring->postenable = &adis16300_data_rdy_ring_postenable;
 207         ring->predisable = &adis16300_data_rdy_ring_predisable;
 208         ring->owner = THIS_MODULE;
 209
 210         indio_dev->pollfunc = kzalloc(sizeof(*indio_dev->pollfunc), GFP_KERNEL);
 211         if (indio_dev->pollfunc == NULL) {
 212                 ret = -ENOMEM;
 213                 goto error_iio_sw_rb_free;;
 214         }
 215         indio_dev->pollfunc->poll_func_main = &adis16300_poll_func_th;
 216         indio_dev->pollfunc->private_data = indio_dev;
 217         indio_dev->modes |= INDIO_RING_TRIGGERED;
 218         return 0;
 219
 220 error_iio_sw_rb_free:
 221         iio_sw_rb_free(indio_dev->ring);
 222         return ret;
 223 }
 224
 225 int adis16300_initialize_ring(struct iio_ring_buffer *ring)
 226 {
 227         return iio_ring_buffer_register(ring, 0);
 228 }
 229
 230 void adis16300_uninitialize_ring(struct iio_ring_buffer *ring)
 231 {
 232         iio_ring_buffer_unregister(ring);
 233 }