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/slab.h>
  10 #include <linux/sysfs.h>
  11 #include <linux/list.h>
  12
  13 #include "../iio.h"
  14 #include "../sysfs.h"
  15 #include "../ring_sw.h"
  16 #include "../accel/accel.h"
  17 #include "../trigger.h"
  18 #include "adis16300.h"
  19
  20 /**
  21  * combine_8_to_16() utility function to munge to u8s into u16
  22  **/
  23 static inline u16 combine_8_to_16(u8 lower, u8 upper)
  24 {
  25         u16 _lower = lower;
  26         u16 _upper = upper;
  27         return _lower | (_upper << 8);
  28 }
  29
  30 static IIO_SCAN_EL_C(supply, ADIS16300_SCAN_SUPPLY, IIO_SIGNED(14),
  31                      ADIS16300_SUPPLY_OUT, NULL);
  32
  33 static IIO_SCAN_EL_C(gyro_x, ADIS16300_SCAN_GYRO_X, IIO_SIGNED(14),
  34                      ADIS16300_XGYRO_OUT, NULL);
  35
  36 static IIO_SCAN_EL_C(accel_x, ADIS16300_SCAN_ACC_X, IIO_SIGNED(14),
  37                      ADIS16300_XACCL_OUT, NULL);
  38 static IIO_SCAN_EL_C(accel_y, ADIS16300_SCAN_ACC_Y, IIO_SIGNED(14),
  39                      ADIS16300_YACCL_OUT, NULL);
  40 static IIO_SCAN_EL_C(accel_z, ADIS16300_SCAN_ACC_Z, IIO_SIGNED(14),
  41                      ADIS16300_ZACCL_OUT, NULL);
  42
  43 static IIO_SCAN_EL_C(temp, ADIS16300_SCAN_TEMP, IIO_SIGNED(12),
  44                      ADIS16300_TEMP_OUT, NULL);
  45 static IIO_SCAN_EL_C(adc_0, ADIS16300_SCAN_ADC_0, IIO_SIGNED(12),
  46                      ADIS16300_AUX_ADC, NULL);
  47
  48 static IIO_SCAN_EL_C(incli_x, ADIS16300_SCAN_INCLI_X, IIO_SIGNED(12),
  49                      ADIS16300_XINCLI_OUT, NULL);
  50 static IIO_SCAN_EL_C(incli_y, ADIS16300_SCAN_INCLI_Y, IIO_SIGNED(12),
  51                      ADIS16300_YINCLI_OUT, NULL);
  52
  53 static IIO_SCAN_EL_TIMESTAMP(9);
  54
  55 static struct attribute *adis16300_scan_el_attrs[] = {
  56         &iio_scan_el_supply.dev_attr.attr,
  57         &iio_scan_el_gyro_x.dev_attr.attr,
  58         &iio_scan_el_temp.dev_attr.attr,
  59         &iio_scan_el_accel_x.dev_attr.attr,
  60         &iio_scan_el_accel_y.dev_attr.attr,
  61         &iio_scan_el_accel_z.dev_attr.attr,
  62         &iio_scan_el_incli_x.dev_attr.attr,
  63         &iio_scan_el_incli_y.dev_attr.attr,
  64         &iio_scan_el_adc_0.dev_attr.attr,
  65         &iio_scan_el_timestamp.dev_attr.attr,
  66         NULL,
  67 };
  68
  69 static struct attribute_group adis16300_scan_el_group = {
  70         .attrs = adis16300_scan_el_attrs,
  71         .name = "scan_elements",
  72 };
  73
  74 /**
  75  * adis16300_poll_func_th() top half interrupt handler called by trigger
  76  * @private_data:       iio_dev
  77  **/
  78 static void adis16300_poll_func_th(struct iio_dev *indio_dev)
  79 {
  80         struct adis16300_state *st = iio_dev_get_devdata(indio_dev);
  81         st->last_timestamp = indio_dev->trig->timestamp;
  82         schedule_work(&st->work_trigger_to_ring);
  83         /* Indicate that this interrupt is being handled */
  84
  85         /* Technically this is trigger related, but without this
  86          * handler running there is currently no way for the interrupt
  87          * to clear.
  88          */
  89 }
  90
  91 /* Whilst this makes a lot of calls to iio_sw_ring functions - it is to device
  92  * specific to be rolled into the core.
  93  */
  94 static void adis16300_trigger_bh_to_ring(struct work_struct *work_s)
  95 {
  96         struct adis16300_state *st
  97                 = container_of(work_s, struct adis16300_state,
  98                                work_trigger_to_ring);
  99
 100         int i = 0;
 101         s16 *data;
 102         size_t datasize = st->indio_dev
 103                 ->ring->access.get_bpd(st->indio_dev->ring);
 104
 105         data = kmalloc(datasize , GFP_KERNEL);
 106         if (data == NULL) {
 107                 dev_err(&st->us->dev, "memory alloc failed in ring bh");
 108                 return;
 109         }
 110
 111         if (st->indio_dev->scan_count)
 112                 if (adis16300_spi_read_burst(&st->indio_dev->dev, st->rx) >= 0)
 113                         for (; i < st->indio_dev->scan_count; i++) {
 114                                 data[i] = combine_8_to_16(st->rx[i*2+1],
 115                                                           st->rx[i*2]);
 116                         }
 117
 118         /* Guaranteed to be aligned with 8 byte boundary */
 119         if (st->indio_dev->scan_timestamp)
 120                 *((s64 *)(data + ((i + 3)/4)*4)) = st->last_timestamp;
 121
 122         st->indio_dev->ring->access.store_to(st->indio_dev->ring,
 123                                             (u8 *)data,
 124                                             st->last_timestamp);
 125
 126         iio_trigger_notify_done(st->indio_dev->trig);
 127         kfree(data);
 128
 129         return;
 130 }
 131 /* in these circumstances is it better to go with unaligned packing and
 132  * deal with the cost?*/
 133 static int adis16300_data_rdy_ring_preenable(struct iio_dev *indio_dev)
 134 {
 135         size_t size;
 136         dev_dbg(&indio_dev->dev, "%s\n", __func__);
 137         /* Check if there are any scan elements enabled, if not fail*/
 138         if (!(indio_dev->scan_count || indio_dev->scan_timestamp))
 139                 return -EINVAL;
 140
 141         if (indio_dev->ring->access.set_bpd) {
 142                 if (indio_dev->scan_timestamp)
 143                         if (indio_dev->scan_count) /* Timestamp and data */
 144                                 size = 4*sizeof(s64);
 145                         else /* Timestamp only  */
 146                                 size = sizeof(s64);
 147                 else /* Data only */
 148                         size = indio_dev->scan_count*sizeof(s16);
 149                 indio_dev->ring->access.set_bpd(indio_dev->ring, size);
 150         }
 151
 152         return 0;
 153 }
 154
 155 static int adis16300_data_rdy_ring_postenable(struct iio_dev *indio_dev)
 156 {
 157         return indio_dev->trig
 158                 ? iio_trigger_attach_poll_func(indio_dev->trig,
 159                                                indio_dev->pollfunc)
 160                 : 0;
 161 }
 162
 163 static int adis16300_data_rdy_ring_predisable(struct iio_dev *indio_dev)
 164 {
 165         return indio_dev->trig
 166                 ? iio_trigger_dettach_poll_func(indio_dev->trig,
 167                                                 indio_dev->pollfunc)
 168                 : 0;
 169 }
 170
 171 void adis16300_unconfigure_ring(struct iio_dev *indio_dev)
 172 {
 173         kfree(indio_dev->pollfunc);
 174         iio_sw_rb_free(indio_dev->ring);
 175 }
 176
 177 int adis16300_configure_ring(struct iio_dev *indio_dev)
 178 {
 179         int ret = 0;
 180         struct adis16300_state *st = indio_dev->dev_data;
 181         struct iio_ring_buffer *ring;
 182         INIT_WORK(&st->work_trigger_to_ring, adis16300_trigger_bh_to_ring);
 183         /* Set default scan mode */
 184
 185         iio_scan_mask_set(indio_dev, iio_scan_el_supply.number);
 186         iio_scan_mask_set(indio_dev, iio_scan_el_gyro_x.number);
 187         iio_scan_mask_set(indio_dev, iio_scan_el_accel_x.number);
 188         iio_scan_mask_set(indio_dev, iio_scan_el_accel_y.number);
 189         iio_scan_mask_set(indio_dev, iio_scan_el_accel_z.number);
 190         iio_scan_mask_set(indio_dev, iio_scan_el_temp.number);
 191         iio_scan_mask_set(indio_dev, iio_scan_el_adc_0.number);
 192         iio_scan_mask_set(indio_dev, iio_scan_el_incli_x.number);
 193         iio_scan_mask_set(indio_dev, iio_scan_el_incli_y.number);
 194         indio_dev->scan_timestamp = true;
 195
 196         indio_dev->scan_el_attrs = &adis16300_scan_el_group;
 197
 198         ring = iio_sw_rb_allocate(indio_dev);
 199         if (!ring) {
 200                 ret = -ENOMEM;
 201                 return ret;
 202         }
 203         indio_dev->ring = ring;
 204         /* Effectively select the ring buffer implementation */
 205         iio_ring_sw_register_funcs(&ring->access);
 206         ring->preenable = &adis16300_data_rdy_ring_preenable;
 207         ring->postenable = &adis16300_data_rdy_ring_postenable;
 208         ring->predisable = &adis16300_data_rdy_ring_predisable;
 209         ring->owner = THIS_MODULE;
 210
 211         indio_dev->pollfunc = kzalloc(sizeof(*indio_dev->pollfunc), GFP_KERNEL);
 212         if (indio_dev->pollfunc == NULL) {
 213                 ret = -ENOMEM;
 214                 goto error_iio_sw_rb_free;;
 215         }
 216         indio_dev->pollfunc->poll_func_main = &adis16300_poll_func_th;
 217         indio_dev->pollfunc->private_data = indio_dev;
 218         indio_dev->modes |= INDIO_RING_TRIGGERED;
 219         return 0;
 220
 221 error_iio_sw_rb_free:
 222         iio_sw_rb_free(indio_dev->ring);
 223         return ret;
 224 }
 225
 226 int adis16300_initialize_ring(struct iio_ring_buffer *ring)
 227 {
 228         return iio_ring_buffer_register(ring, 0);
 229 }
 230
 231 void adis16300_uninitialize_ring(struct iio_ring_buffer *ring)
 232 {
 233         iio_ring_buffer_unregister(ring);
 234 }