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/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 "adis16400.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, ADIS16400_SCAN_SUPPLY, IIO_SIGNED(14),
  30                      ADIS16400_SUPPLY_OUT, NULL);
  31
  32 static IIO_SCAN_EL_C(gyro_x, ADIS16400_SCAN_GYRO_X, IIO_SIGNED(14),
  33                      ADIS16400_XGYRO_OUT, NULL);
  34 static IIO_SCAN_EL_C(gyro_y, ADIS16400_SCAN_GYRO_Y, IIO_SIGNED(14),
  35                      ADIS16400_YGYRO_OUT, NULL);
  36 static IIO_SCAN_EL_C(gyro_z, ADIS16400_SCAN_GYRO_Z, IIO_SIGNED(14),
  37                      ADIS16400_ZGYRO_OUT, NULL);
  38
  39 static IIO_SCAN_EL_C(accel_x, ADIS16400_SCAN_ACC_X, IIO_SIGNED(14),
  40                      ADIS16400_XACCL_OUT, NULL);
  41 static IIO_SCAN_EL_C(accel_y, ADIS16400_SCAN_ACC_Y, IIO_SIGNED(14),
  42                      ADIS16400_YACCL_OUT, NULL);
  43 static IIO_SCAN_EL_C(accel_z, ADIS16400_SCAN_ACC_Z, IIO_SIGNED(14),
  44                      ADIS16400_ZACCL_OUT, NULL);
  45
  46 static IIO_SCAN_EL_C(magn_x, ADIS16400_SCAN_MAGN_X, IIO_SIGNED(14),
  47                      ADIS16400_XMAGN_OUT, NULL);
  48 static IIO_SCAN_EL_C(magn_y, ADIS16400_SCAN_MAGN_Y, IIO_SIGNED(14),
  49                      ADIS16400_YMAGN_OUT, NULL);
  50 static IIO_SCAN_EL_C(magn_z, ADIS16400_SCAN_MAGN_Z, IIO_SIGNED(14),
  51                      ADIS16400_ZMAGN_OUT, NULL);
  52
  53 static IIO_SCAN_EL_C(temp, ADIS16400_SCAN_TEMP, IIO_SIGNED(12),
  54                      ADIS16400_TEMP_OUT, NULL);
  55 static IIO_SCAN_EL_C(adc_0, ADIS16400_SCAN_ADC_0, IIO_SIGNED(12),
  56                      ADIS16400_AUX_ADC, NULL);
  57
  58 static IIO_SCAN_EL_TIMESTAMP(12);
  59
  60 static struct attribute *adis16400_scan_el_attrs[] = {
  61         &iio_scan_el_supply.dev_attr.attr,
  62         &iio_scan_el_gyro_x.dev_attr.attr,
  63         &iio_scan_el_gyro_y.dev_attr.attr,
  64         &iio_scan_el_gyro_z.dev_attr.attr,
  65         &iio_scan_el_accel_x.dev_attr.attr,
  66         &iio_scan_el_accel_y.dev_attr.attr,
  67         &iio_scan_el_accel_z.dev_attr.attr,
  68         &iio_scan_el_magn_x.dev_attr.attr,
  69         &iio_scan_el_magn_y.dev_attr.attr,
  70         &iio_scan_el_magn_z.dev_attr.attr,
  71         &iio_scan_el_temp.dev_attr.attr,
  72         &iio_scan_el_adc_0.dev_attr.attr,
  73         &iio_scan_el_timestamp.dev_attr.attr,
  74         NULL,
  75 };
  76
  77 static struct attribute_group adis16400_scan_el_group = {
  78         .attrs = adis16400_scan_el_attrs,
  79         .name = "scan_elements",
  80 };
  81
  82 /**
  83  * adis16400_poll_func_th() top half interrupt handler called by trigger
  84  * @private_data:       iio_dev
  85  **/
  86 static void adis16400_poll_func_th(struct iio_dev *indio_dev)
  87 {
  88         struct adis16400_state *st = iio_dev_get_devdata(indio_dev);
  89         st->last_timestamp = indio_dev->trig->timestamp;
  90         schedule_work(&st->work_trigger_to_ring);
  91         /* Indicate that this interrupt is being handled */
  92
  93         /* Technically this is trigger related, but without this
  94          * handler running there is currently no way for the interrupt
  95          * to clear.
  96          */
  97 }
  98
  99 /* Whilst this makes a lot of calls to iio_sw_ring functions - it is to device
 100  * specific to be rolled into the core.
 101  */
 102 static void adis16400_trigger_bh_to_ring(struct work_struct *work_s)
 103 {
 104         struct adis16400_state *st
 105                 = container_of(work_s, struct adis16400_state,
 106                                work_trigger_to_ring);
 107
 108         int i = 0;
 109         s16 *data;
 110         size_t datasize = st->indio_dev
 111                 ->ring->access.get_bpd(st->indio_dev->ring);
 112
 113         data = kmalloc(datasize , GFP_KERNEL);
 114         if (data == NULL) {
 115                 dev_err(&st->us->dev, "memory alloc failed in ring bh");
 116                 return;
 117         }
 118
 119         if (st->indio_dev->scan_count)
 120                 if (adis16400_spi_read_burst(&st->indio_dev->dev, st->rx) >= 0)
 121                         for (; i < st->indio_dev->scan_count; i++) {
 122                                 data[i] = combine_8_to_16(st->rx[i*2+1],
 123                                                           st->rx[i*2]);
 124                         }
 125
 126         /* Guaranteed to be aligned with 8 byte boundary */
 127         if (st->indio_dev->scan_timestamp)
 128                 *((s64 *)(data + ((i + 3)/4)*4)) = st->last_timestamp;
 129
 130         st->indio_dev->ring->access.store_to(st->indio_dev->ring,
 131                                             (u8 *)data,
 132                                             st->last_timestamp);
 133
 134         iio_trigger_notify_done(st->indio_dev->trig);
 135         kfree(data);
 136
 137         return;
 138 }
 139 /* in these circumstances is it better to go with unaligned packing and
 140  * deal with the cost?*/
 141 static int adis16400_data_rdy_ring_preenable(struct iio_dev *indio_dev)
 142 {
 143         size_t size;
 144         dev_dbg(&indio_dev->dev, "%s\n", __func__);
 145         /* Check if there are any scan elements enabled, if not fail*/
 146         if (!(indio_dev->scan_count || indio_dev->scan_timestamp))
 147                 return -EINVAL;
 148
 149         if (indio_dev->ring->access.set_bpd) {
 150                 if (indio_dev->scan_timestamp)
 151                         if (indio_dev->scan_count) /* Timestamp and data */
 152                                 size = 6*sizeof(s64);
 153                         else /* Timestamp only  */
 154                                 size = sizeof(s64);
 155                 else /* Data only */
 156                         size = indio_dev->scan_count*sizeof(s16);
 157                 indio_dev->ring->access.set_bpd(indio_dev->ring, size);
 158         }
 159
 160         return 0;
 161 }
 162
 163 static int adis16400_data_rdy_ring_postenable(struct iio_dev *indio_dev)
 164 {
 165         return indio_dev->trig
 166                 ? iio_trigger_attach_poll_func(indio_dev->trig,
 167                                                indio_dev->pollfunc)
 168                 : 0;
 169 }
 170
 171 static int adis16400_data_rdy_ring_predisable(struct iio_dev *indio_dev)
 172 {
 173         return indio_dev->trig
 174                 ? iio_trigger_dettach_poll_func(indio_dev->trig,
 175                                                 indio_dev->pollfunc)
 176                 : 0;
 177 }
 178
 179 void adis16400_unconfigure_ring(struct iio_dev *indio_dev)
 180 {
 181         kfree(indio_dev->pollfunc);
 182         iio_sw_rb_free(indio_dev->ring);
 183 }
 184
 185 int adis16400_configure_ring(struct iio_dev *indio_dev)
 186 {
 187         int ret = 0;
 188         struct adis16400_state *st = indio_dev->dev_data;
 189         struct iio_ring_buffer *ring;
 190         INIT_WORK(&st->work_trigger_to_ring, adis16400_trigger_bh_to_ring);
 191         /* Set default scan mode */
 192
 193         iio_scan_mask_set(indio_dev, iio_scan_el_supply.number);
 194         iio_scan_mask_set(indio_dev, iio_scan_el_gyro_x.number);
 195         iio_scan_mask_set(indio_dev, iio_scan_el_gyro_y.number);
 196         iio_scan_mask_set(indio_dev, iio_scan_el_gyro_z.number);
 197         iio_scan_mask_set(indio_dev, iio_scan_el_accel_x.number);
 198         iio_scan_mask_set(indio_dev, iio_scan_el_accel_y.number);
 199         iio_scan_mask_set(indio_dev, iio_scan_el_accel_z.number);
 200         iio_scan_mask_set(indio_dev, iio_scan_el_magn_x.number);
 201         iio_scan_mask_set(indio_dev, iio_scan_el_magn_y.number);
 202         iio_scan_mask_set(indio_dev, iio_scan_el_magn_z.number);
 203         iio_scan_mask_set(indio_dev, iio_scan_el_temp.number);
 204         iio_scan_mask_set(indio_dev, iio_scan_el_adc_0.number);
 205         indio_dev->scan_timestamp = true;
 206
 207         indio_dev->scan_el_attrs = &adis16400_scan_el_group;
 208
 209         ring = iio_sw_rb_allocate(indio_dev);
 210         if (!ring) {
 211                 ret = -ENOMEM;
 212                 return ret;
 213         }
 214         indio_dev->ring = ring;
 215         /* Effectively select the ring buffer implementation */
 216         iio_ring_sw_register_funcs(&ring->access);
 217         ring->preenable = &adis16400_data_rdy_ring_preenable;
 218         ring->postenable = &adis16400_data_rdy_ring_postenable;
 219         ring->predisable = &adis16400_data_rdy_ring_predisable;
 220         ring->owner = THIS_MODULE;
 221
 222         indio_dev->pollfunc = kzalloc(sizeof(*indio_dev->pollfunc), GFP_KERNEL);
 223         if (indio_dev->pollfunc == NULL) {
 224                 ret = -ENOMEM;
 225                 goto error_iio_sw_rb_free;;
 226         }
 227         indio_dev->pollfunc->poll_func_main = &adis16400_poll_func_th;
 228         indio_dev->pollfunc->private_data = indio_dev;
 229         indio_dev->modes |= INDIO_RING_TRIGGERED;
 230         return 0;
 231
 232 error_iio_sw_rb_free:
 233         iio_sw_rb_free(indio_dev->ring);
 234         return ret;
 235 }
 236
 237 int adis16400_initialize_ring(struct iio_ring_buffer *ring)
 238 {
 239         return iio_ring_buffer_register(ring, 0);
 240 }
 241
 242 void adis16400_uninitialize_ring(struct iio_ring_buffer *ring)
 243 {
 244         iio_ring_buffer_unregister(ring);
 245 }