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/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 "adis16350.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, ADIS16350_SCAN_SUPPLY, IIO_UNSIGNED(12),
  31                 ADIS16350_SUPPLY_OUT, NULL);
  32
  33 static IIO_SCAN_EL_C(gyro_x, ADIS16350_SCAN_GYRO_X, IIO_SIGNED(14),
  34                 ADIS16350_XGYRO_OUT, NULL);
  35 static IIO_SCAN_EL_C(gyro_y, ADIS16350_SCAN_GYRO_Y, IIO_SIGNED(14),
  36                 ADIS16350_YGYRO_OUT, NULL);
  37 static IIO_SCAN_EL_C(gyro_z, ADIS16350_SCAN_GYRO_Z, IIO_SIGNED(14),
  38                 ADIS16350_ZGYRO_OUT, NULL);
  39
  40 static IIO_SCAN_EL_C(accel_x, ADIS16350_SCAN_ACC_X, IIO_SIGNED(14),
  41                 ADIS16350_XACCL_OUT, NULL);
  42 static IIO_SCAN_EL_C(accel_y, ADIS16350_SCAN_ACC_Y, IIO_SIGNED(14),
  43                 ADIS16350_YACCL_OUT, NULL);
  44 static IIO_SCAN_EL_C(accel_z, ADIS16350_SCAN_ACC_Z, IIO_SIGNED(14),
  45                 ADIS16350_ZACCL_OUT, NULL);
  46
  47 static IIO_SCAN_EL_C(temp_x, ADIS16350_SCAN_TEMP_X, IIO_SIGNED(12),
  48                 ADIS16350_XTEMP_OUT, NULL);
  49 static IIO_SCAN_EL_C(temp_y, ADIS16350_SCAN_TEMP_Y, IIO_SIGNED(12),
  50                 ADIS16350_YTEMP_OUT, NULL);
  51 static IIO_SCAN_EL_C(temp_z, ADIS16350_SCAN_TEMP_Z, IIO_SIGNED(12),
  52                 ADIS16350_ZTEMP_OUT, NULL);
  53
  54 static IIO_SCAN_EL_C(adc_0, ADIS16350_SCAN_ADC_0, IIO_UNSIGNED(12),
  55                 ADIS16350_AUX_ADC, NULL);
  56
  57 static IIO_SCAN_EL_TIMESTAMP(11);
  58
  59 static struct attribute *adis16350_scan_el_attrs[] = {
  60         &iio_scan_el_supply.dev_attr.attr,
  61         &iio_scan_el_gyro_x.dev_attr.attr,
  62         &iio_scan_el_gyro_y.dev_attr.attr,
  63         &iio_scan_el_gyro_z.dev_attr.attr,
  64         &iio_scan_el_accel_x.dev_attr.attr,
  65         &iio_scan_el_accel_y.dev_attr.attr,
  66         &iio_scan_el_accel_z.dev_attr.attr,
  67         &iio_scan_el_temp_x.dev_attr.attr,
  68         &iio_scan_el_temp_y.dev_attr.attr,
  69         &iio_scan_el_temp_z.dev_attr.attr,
  70         &iio_scan_el_adc_0.dev_attr.attr,
  71         &iio_scan_el_timestamp.dev_attr.attr,
  72         NULL,
  73 };
  74
  75 static struct attribute_group adis16350_scan_el_group = {
  76         .attrs = adis16350_scan_el_attrs,
  77         .name = "scan_elements",
  78 };
  79
  80 /**
  81  * adis16350_poll_func_th() top half interrupt handler called by trigger
  82  * @private_data:       iio_dev
  83  **/
  84 static void adis16350_poll_func_th(struct iio_dev *indio_dev)
  85 {
  86         struct adis16350_state *st = iio_dev_get_devdata(indio_dev);
  87         st->last_timestamp = indio_dev->trig->timestamp;
  88         schedule_work(&st->work_trigger_to_ring);
  89 }
  90
  91 /**
  92  * adis16350_spi_read_burst() - read all data registers
  93  * @dev: device associated with child of actual device (iio_dev or iio_trig)
  94  * @rx: somewhere to pass back the value read (min size is 24 bytes)
  95  **/
  96 static int adis16350_spi_read_burst(struct device *dev, u8 *rx)
  97 {
  98         struct spi_message msg;
  99         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 100         struct adis16350_state *st = iio_dev_get_devdata(indio_dev);
 101         u32 old_speed_hz = st->us->max_speed_hz;
 102         int ret;
 103
 104         struct spi_transfer xfers[] = {
 105                 {
 106                         .tx_buf = st->tx,
 107                         .bits_per_word = 8,
 108                         .len = 2,
 109                         .cs_change = 0,
 110                 }, {
 111                         .rx_buf = rx,
 112                         .bits_per_word = 8,
 113                         .len = 22,
 114                         .cs_change = 0,
 115                 },
 116         };
 117
 118         mutex_lock(&st->buf_lock);
 119         st->tx[0] = ADIS16350_READ_REG(ADIS16350_GLOB_CMD);
 120         st->tx[1] = 0;
 121
 122         spi_message_init(&msg);
 123         spi_message_add_tail(&xfers[0], &msg);
 124         spi_message_add_tail(&xfers[1], &msg);
 125
 126         st->us->max_speed_hz = ADIS16350_SPI_BURST;
 127         spi_setup(st->us);
 128
 129         ret = spi_sync(st->us, &msg);
 130         if (ret)
 131                 dev_err(&st->us->dev, "problem when burst reading");
 132
 133         st->us->max_speed_hz = old_speed_hz;
 134         spi_setup(st->us);
 135         mutex_unlock(&st->buf_lock);
 136         return ret;
 137 }
 138
 139 /* Whilst this makes a lot of calls to iio_sw_ring functions - it is to device
 140  * specific to be rolled into the core.
 141  */
 142 static void adis16350_trigger_bh_to_ring(struct work_struct *work_s)
 143 {
 144         struct adis16350_state *st
 145                 = container_of(work_s, struct adis16350_state,
 146                                work_trigger_to_ring);
 147
 148         int i = 0;
 149         s16 *data;
 150         size_t datasize = st->indio_dev
 151                 ->ring->access.get_bpd(st->indio_dev->ring);
 152
 153         data = kmalloc(datasize , GFP_KERNEL);
 154         if (data == NULL) {
 155                 dev_err(&st->us->dev, "memory alloc failed in ring bh");
 156                 return;
 157         }
 158
 159         if (st->indio_dev->scan_count)
 160                 if (adis16350_spi_read_burst(&st->indio_dev->dev, st->rx) >= 0)
 161                         for (; i < st->indio_dev->scan_count; i++) {
 162                                 data[i] = combine_8_to_16(st->rx[i*2+1],
 163                                                           st->rx[i*2]);
 164                         }
 165
 166         /* Guaranteed to be aligned with 8 byte boundary */
 167         if (st->indio_dev->scan_timestamp)
 168                 *((s64 *)(data + ((i + 3)/4)*4)) = st->last_timestamp;
 169
 170         st->indio_dev->ring->access.store_to(st->indio_dev->ring,
 171                                             (u8 *)data,
 172                                             st->last_timestamp);
 173
 174         iio_trigger_notify_done(st->indio_dev->trig);
 175         kfree(data);
 176
 177         return;
 178 }
 179
 180 static int adis16350_data_rdy_ring_preenable(struct iio_dev *indio_dev)
 181 {
 182         size_t size;
 183         dev_dbg(&indio_dev->dev, "%s\n", __func__);
 184         /* Check if there are any scan elements enabled, if not fail*/
 185         if (!(indio_dev->scan_count || indio_dev->scan_timestamp))
 186                 return -EINVAL;
 187
 188         if (indio_dev->ring->access.set_bpd) {
 189                 if (indio_dev->scan_timestamp)
 190                         if (indio_dev->scan_count)
 191                                 /* Timestamp (aligned sizeof(s64) and data */
 192                                 size = (((indio_dev->scan_count * sizeof(s16))
 193                                                 + sizeof(s64) - 1)
 194                                         & ~(sizeof(s64) - 1))
 195                                         + sizeof(s64);
 196                         else /* Timestamp only  */
 197                                 size = sizeof(s64);
 198                 else /* Data only */
 199                         size = indio_dev->scan_count*sizeof(s16);
 200                 indio_dev->ring->access.set_bpd(indio_dev->ring, size);
 201         }
 202
 203         return 0;
 204 }
 205
 206 static int adis16350_data_rdy_ring_postenable(struct iio_dev *indio_dev)
 207 {
 208         return indio_dev->trig
 209                 ? iio_trigger_attach_poll_func(indio_dev->trig,
 210                                                indio_dev->pollfunc)
 211                 : 0;
 212 }
 213
 214 static int adis16350_data_rdy_ring_predisable(struct iio_dev *indio_dev)
 215 {
 216         return indio_dev->trig
 217                 ? iio_trigger_dettach_poll_func(indio_dev->trig,
 218                                                 indio_dev->pollfunc)
 219                 : 0;
 220 }
 221
 222 void adis16350_unconfigure_ring(struct iio_dev *indio_dev)
 223 {
 224         kfree(indio_dev->pollfunc);
 225         iio_sw_rb_free(indio_dev->ring);
 226 }
 227
 228 int adis16350_configure_ring(struct iio_dev *indio_dev)
 229 {
 230         int ret = 0;
 231         struct adis16350_state *st = indio_dev->dev_data;
 232         struct iio_ring_buffer *ring;
 233         INIT_WORK(&st->work_trigger_to_ring, adis16350_trigger_bh_to_ring);
 234         /* Set default scan mode */
 235
 236         iio_scan_mask_set(indio_dev, iio_scan_el_supply.number);
 237         iio_scan_mask_set(indio_dev, iio_scan_el_gyro_x.number);
 238         iio_scan_mask_set(indio_dev, iio_scan_el_gyro_y.number);
 239         iio_scan_mask_set(indio_dev, iio_scan_el_gyro_z.number);
 240         iio_scan_mask_set(indio_dev, iio_scan_el_accel_x.number);
 241         iio_scan_mask_set(indio_dev, iio_scan_el_accel_y.number);
 242         iio_scan_mask_set(indio_dev, iio_scan_el_accel_z.number);
 243         iio_scan_mask_set(indio_dev, iio_scan_el_temp_x.number);
 244         iio_scan_mask_set(indio_dev, iio_scan_el_temp_y.number);
 245         iio_scan_mask_set(indio_dev, iio_scan_el_temp_z.number);
 246         iio_scan_mask_set(indio_dev, iio_scan_el_adc_0.number);
 247         indio_dev->scan_timestamp = true;
 248
 249         indio_dev->scan_el_attrs = &adis16350_scan_el_group;
 250
 251         ring = iio_sw_rb_allocate(indio_dev);
 252         if (!ring) {
 253                 ret = -ENOMEM;
 254                 return ret;
 255         }
 256         indio_dev->ring = ring;
 257         /* Effectively select the ring buffer implementation */
 258         iio_ring_sw_register_funcs(&ring->access);
 259         ring->preenable = &adis16350_data_rdy_ring_preenable;
 260         ring->postenable = &adis16350_data_rdy_ring_postenable;
 261         ring->predisable = &adis16350_data_rdy_ring_predisable;
 262         ring->owner = THIS_MODULE;
 263
 264         indio_dev->pollfunc = kzalloc(sizeof(*indio_dev->pollfunc), GFP_KERNEL);
 265         if (indio_dev->pollfunc == NULL) {
 266                 ret = -ENOMEM;
 267                 goto error_iio_sw_rb_free;;
 268         }
 269         indio_dev->pollfunc->poll_func_main = &adis16350_poll_func_th;
 270         indio_dev->pollfunc->private_data = indio_dev;
 271         indio_dev->modes |= INDIO_RING_TRIGGERED;
 272         return 0;
 273
 274 error_iio_sw_rb_free:
 275         iio_sw_rb_free(indio_dev->ring);
 276         return ret;
 277 }
 278
 279 int adis16350_initialize_ring(struct iio_ring_buffer *ring)
 280 {
 281         return iio_ring_buffer_register(ring, 0);
 282 }
 283
 284 void adis16350_uninitialize_ring(struct iio_ring_buffer *ring)
 285 {
 286         iio_ring_buffer_unregister(ring);
 287 }