drivers/staging/iio/imu/adis16350_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 "adis16350.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, ADIS16350_SCAN_SUPPLY, IIO_UNSIGNED(12),
  30                 ADIS16350_SUPPLY_OUT, NULL);
  31
  32 static IIO_SCAN_EL_C(gyro_x, ADIS16350_SCAN_GYRO_X, IIO_SIGNED(14),
  33                 ADIS16350_XGYRO_OUT, NULL);
  34 static IIO_SCAN_EL_C(gyro_y, ADIS16350_SCAN_GYRO_Y, IIO_SIGNED(14),
  35                 ADIS16350_YGYRO_OUT, NULL);
  36 static IIO_SCAN_EL_C(gyro_z, ADIS16350_SCAN_GYRO_Z, IIO_SIGNED(14),
  37                 ADIS16350_ZGYRO_OUT, NULL);
  38
  39 static IIO_SCAN_EL_C(accel_x, ADIS16350_SCAN_ACC_X, IIO_SIGNED(14),
  40                 ADIS16350_XACCL_OUT, NULL);
  41 static IIO_SCAN_EL_C(accel_y, ADIS16350_SCAN_ACC_Y, IIO_SIGNED(14),
  42                 ADIS16350_YACCL_OUT, NULL);
  43 static IIO_SCAN_EL_C(accel_z, ADIS16350_SCAN_ACC_Z, IIO_SIGNED(14),
  44                 ADIS16350_ZACCL_OUT, NULL);
  45
  46 static IIO_SCAN_EL_C(temp_x, ADIS16350_SCAN_TEMP_X, IIO_SIGNED(12),
  47                 ADIS16350_XTEMP_OUT, NULL);
  48 static IIO_SCAN_EL_C(temp_y, ADIS16350_SCAN_TEMP_Y, IIO_SIGNED(12),
  49                 ADIS16350_YTEMP_OUT, NULL);
  50 static IIO_SCAN_EL_C(temp_z, ADIS16350_SCAN_TEMP_Z, IIO_SIGNED(12),
  51                 ADIS16350_ZTEMP_OUT, NULL);
  52
  53 static IIO_SCAN_EL_C(adc_0, ADIS16350_SCAN_ADC_0, IIO_UNSIGNED(12),
  54                 ADIS16350_AUX_ADC, NULL);
  55
  56 static IIO_SCAN_EL_TIMESTAMP(11);
  57
  58 static struct attribute *adis16350_scan_el_attrs[] = {
  59         &iio_scan_el_supply.dev_attr.attr,
  60         &iio_scan_el_gyro_x.dev_attr.attr,
  61         &iio_scan_el_gyro_y.dev_attr.attr,
  62         &iio_scan_el_gyro_z.dev_attr.attr,
  63         &iio_scan_el_accel_x.dev_attr.attr,
  64         &iio_scan_el_accel_y.dev_attr.attr,
  65         &iio_scan_el_accel_z.dev_attr.attr,
  66         &iio_scan_el_temp_x.dev_attr.attr,
  67         &iio_scan_el_temp_y.dev_attr.attr,
  68         &iio_scan_el_temp_z.dev_attr.attr,
  69         &iio_scan_el_adc_0.dev_attr.attr,
  70         &iio_scan_el_timestamp.dev_attr.attr,
  71         NULL,
  72 };
  73
  74 static struct attribute_group adis16350_scan_el_group = {
  75         .attrs = adis16350_scan_el_attrs,
  76         .name = "scan_elements",
  77 };
  78
  79 /**
  80  * adis16350_poll_func_th() top half interrupt handler called by trigger
  81  * @private_data:       iio_dev
  82  **/
  83 static void adis16350_poll_func_th(struct iio_dev *indio_dev)
  84 {
  85         struct adis16350_state *st = iio_dev_get_devdata(indio_dev);
  86         st->last_timestamp = indio_dev->trig->timestamp;
  87         schedule_work(&st->work_trigger_to_ring);
  88 }
  89
  90 /**
  91  * adis16350_spi_read_burst() - read all data registers
  92  * @dev: device associated with child of actual device (iio_dev or iio_trig)
  93  * @rx: somewhere to pass back the value read (min size is 24 bytes)
  94  **/
  95 static int adis16350_spi_read_burst(struct device *dev, u8 *rx)
  96 {
  97         struct spi_message msg;
  98         struct iio_dev *indio_dev = dev_get_drvdata(dev);
  99         struct adis16350_state *st = iio_dev_get_devdata(indio_dev);
 100         u32 old_speed_hz = st->us->max_speed_hz;
 101         int ret;
 102
 103         struct spi_transfer xfers[] = {
 104                 {
 105                         .tx_buf = st->tx,
 106                         .bits_per_word = 8,
 107                         .len = 2,
 108                         .cs_change = 0,
 109                 }, {
 110                         .rx_buf = rx,
 111                         .bits_per_word = 8,
 112                         .len = 22,
 113                         .cs_change = 0,
 114                 },
 115         };
 116
 117         mutex_lock(&st->buf_lock);
 118         st->tx[0] = ADIS16350_READ_REG(ADIS16350_GLOB_CMD);
 119         st->tx[1] = 0;
 120
 121         spi_message_init(&msg);
 122         spi_message_add_tail(&xfers[0], &msg);
 123         spi_message_add_tail(&xfers[1], &msg);
 124
 125         st->us->max_speed_hz = ADIS16350_SPI_BURST;
 126         spi_setup(st->us);
 127
 128         ret = spi_sync(st->us, &msg);
 129         if (ret)
 130                 dev_err(&st->us->dev, "problem when burst reading");
 131
 132         st->us->max_speed_hz = old_speed_hz;
 133         spi_setup(st->us);
 134         mutex_unlock(&st->buf_lock);
 135         return ret;
 136 }
 137
 138 /* Whilst this makes a lot of calls to iio_sw_ring functions - it is to device
 139  * specific to be rolled into the core.
 140  */
 141 static void adis16350_trigger_bh_to_ring(struct work_struct *work_s)
 142 {
 143         struct adis16350_state *st
 144                 = container_of(work_s, struct adis16350_state,
 145                                work_trigger_to_ring);
 146
 147         int i = 0;
 148         s16 *data;
 149         size_t datasize = st->indio_dev
 150                 ->ring->access.get_bpd(st->indio_dev->ring);
 151
 152         data = kmalloc(datasize , GFP_KERNEL);
 153         if (data == NULL) {
 154                 dev_err(&st->us->dev, "memory alloc failed in ring bh");
 155                 return;
 156         }
 157
 158         if (st->indio_dev->scan_count)
 159                 if (adis16350_spi_read_burst(&st->indio_dev->dev, st->rx) >= 0)
 160                         for (; i < st->indio_dev->scan_count; i++) {
 161                                 data[i] = combine_8_to_16(st->rx[i*2+1],
 162                                                           st->rx[i*2]);
 163                         }
 164
 165         /* Guaranteed to be aligned with 8 byte boundary */
 166         if (st->indio_dev->scan_timestamp)
 167                 *((s64 *)(data + ((i + 3)/4)*4)) = st->last_timestamp;
 168
 169         st->indio_dev->ring->access.store_to(st->indio_dev->ring,
 170                                             (u8 *)data,
 171                                             st->last_timestamp);
 172
 173         iio_trigger_notify_done(st->indio_dev->trig);
 174         kfree(data);
 175
 176         return;
 177 }
 178
 179 static int adis16350_data_rdy_ring_preenable(struct iio_dev *indio_dev)
 180 {
 181         size_t size;
 182         dev_dbg(&indio_dev->dev, "%s\n", __func__);
 183         /* Check if there are any scan elements enabled, if not fail*/
 184         if (!(indio_dev->scan_count || indio_dev->scan_timestamp))
 185                 return -EINVAL;
 186
 187         if (indio_dev->ring->access.set_bpd) {
 188                 if (indio_dev->scan_timestamp)
 189                         if (indio_dev->scan_count)
 190                                 /* Timestamp (aligned sizeof(s64) and data */
 191                                 size = (((indio_dev->scan_count * sizeof(s16))
 192                                                 + sizeof(s64) - 1)
 193                                         & ~(sizeof(s64) - 1))
 194                                         + sizeof(s64);
 195                         else /* Timestamp only  */
 196                                 size = sizeof(s64);
 197                 else /* Data only */
 198                         size = indio_dev->scan_count*sizeof(s16);
 199                 indio_dev->ring->access.set_bpd(indio_dev->ring, size);
 200         }
 201
 202         return 0;
 203 }
 204
 205 static int adis16350_data_rdy_ring_postenable(struct iio_dev *indio_dev)
 206 {
 207         return indio_dev->trig
 208                 ? iio_trigger_attach_poll_func(indio_dev->trig,
 209                                                indio_dev->pollfunc)
 210                 : 0;
 211 }
 212
 213 static int adis16350_data_rdy_ring_predisable(struct iio_dev *indio_dev)
 214 {
 215         return indio_dev->trig
 216                 ? iio_trigger_dettach_poll_func(indio_dev->trig,
 217                                                 indio_dev->pollfunc)
 218                 : 0;
 219 }
 220
 221 void adis16350_unconfigure_ring(struct iio_dev *indio_dev)
 222 {
 223         kfree(indio_dev->pollfunc);
 224         iio_sw_rb_free(indio_dev->ring);
 225 }
 226
 227 int adis16350_configure_ring(struct iio_dev *indio_dev)
 228 {
 229         int ret = 0;
 230         struct adis16350_state *st = indio_dev->dev_data;
 231         struct iio_ring_buffer *ring;
 232         INIT_WORK(&st->work_trigger_to_ring, adis16350_trigger_bh_to_ring);
 233         /* Set default scan mode */
 234
 235         iio_scan_mask_set(indio_dev, iio_scan_el_supply.number);
 236         iio_scan_mask_set(indio_dev, iio_scan_el_gyro_x.number);
 237         iio_scan_mask_set(indio_dev, iio_scan_el_gyro_y.number);
 238         iio_scan_mask_set(indio_dev, iio_scan_el_gyro_z.number);
 239         iio_scan_mask_set(indio_dev, iio_scan_el_accel_x.number);
 240         iio_scan_mask_set(indio_dev, iio_scan_el_accel_y.number);
 241         iio_scan_mask_set(indio_dev, iio_scan_el_accel_z.number);
 242         iio_scan_mask_set(indio_dev, iio_scan_el_temp_x.number);
 243         iio_scan_mask_set(indio_dev, iio_scan_el_temp_y.number);
 244         iio_scan_mask_set(indio_dev, iio_scan_el_temp_z.number);
 245         iio_scan_mask_set(indio_dev, iio_scan_el_adc_0.number);
 246         indio_dev->scan_timestamp = true;
 247
 248         indio_dev->scan_el_attrs = &adis16350_scan_el_group;
 249
 250         ring = iio_sw_rb_allocate(indio_dev);
 251         if (!ring) {
 252                 ret = -ENOMEM;
 253                 return ret;
 254         }
 255         indio_dev->ring = ring;
 256         /* Effectively select the ring buffer implementation */
 257         iio_ring_sw_register_funcs(&ring->access);
 258         ring->preenable = &adis16350_data_rdy_ring_preenable;
 259         ring->postenable = &adis16350_data_rdy_ring_postenable;
 260         ring->predisable = &adis16350_data_rdy_ring_predisable;
 261         ring->owner = THIS_MODULE;
 262
 263         indio_dev->pollfunc = kzalloc(sizeof(*indio_dev->pollfunc), GFP_KERNEL);
 264         if (indio_dev->pollfunc == NULL) {
 265                 ret = -ENOMEM;
 266                 goto error_iio_sw_rb_free;;
 267         }
 268         indio_dev->pollfunc->poll_func_main = &adis16350_poll_func_th;
 269         indio_dev->pollfunc->private_data = indio_dev;
 270         indio_dev->modes |= INDIO_RING_TRIGGERED;
 271         return 0;
 272
 273 error_iio_sw_rb_free:
 274         iio_sw_rb_free(indio_dev->ring);
 275         return ret;
 276 }
 277
 278 int adis16350_initialize_ring(struct iio_ring_buffer *ring)
 279 {
 280         return iio_ring_buffer_register(ring, 0);
 281 }
 282
 283 void adis16350_uninitialize_ring(struct iio_ring_buffer *ring)
 284 {
 285         iio_ring_buffer_unregister(ring);
 286 }