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_UNSIGNED(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_UNSIGNED(12),
  44                      ADIS16300_TEMP_OUT, NULL);
  45 static IIO_SCAN_EL_C(adc_0, ADIS16300_SCAN_ADC_0, IIO_UNSIGNED(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 /**
  92  * adis16300_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 adis16300_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 adis16300_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 = 18,
 114                         .cs_change = 0,
 115                 },
 116         };
 117
 118         mutex_lock(&st->buf_lock);
 119         st->tx[0] = ADIS16300_READ_REG(ADIS16300_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 = ADIS16300_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 adis16300_trigger_bh_to_ring(struct work_struct *work_s)
 143 {
 144         struct adis16300_state *st
 145                 = container_of(work_s, struct adis16300_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 (adis16300_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 /* in these circumstances is it better to go with unaligned packing and
 180  * deal with the cost?*/
 181 static int adis16300_data_rdy_ring_preenable(struct iio_dev *indio_dev)
 182 {
 183         size_t size;
 184         dev_dbg(&indio_dev->dev, "%s\n", __func__);
 185         /* Check if there are any scan elements enabled, if not fail*/
 186         if (!(indio_dev->scan_count || indio_dev->scan_timestamp))
 187                 return -EINVAL;
 188
 189         if (indio_dev->ring->access.set_bpd) {
 190                 if (indio_dev->scan_timestamp)
 191                         if (indio_dev->scan_count) /* Timestamp and data */
 192                                 size = 4*sizeof(s64);
 193                         else /* Timestamp only  */
 194                                 size = sizeof(s64);
 195                 else /* Data only */
 196                         size = indio_dev->scan_count*sizeof(s16);
 197                 indio_dev->ring->access.set_bpd(indio_dev->ring, size);
 198         }
 199
 200         return 0;
 201 }
 202
 203 static int adis16300_data_rdy_ring_postenable(struct iio_dev *indio_dev)
 204 {
 205         return indio_dev->trig
 206                 ? iio_trigger_attach_poll_func(indio_dev->trig,
 207                                                indio_dev->pollfunc)
 208                 : 0;
 209 }
 210
 211 static int adis16300_data_rdy_ring_predisable(struct iio_dev *indio_dev)
 212 {
 213         return indio_dev->trig
 214                 ? iio_trigger_dettach_poll_func(indio_dev->trig,
 215                                                 indio_dev->pollfunc)
 216                 : 0;
 217 }
 218
 219 void adis16300_unconfigure_ring(struct iio_dev *indio_dev)
 220 {
 221         kfree(indio_dev->pollfunc);
 222         iio_sw_rb_free(indio_dev->ring);
 223 }
 224
 225 int adis16300_configure_ring(struct iio_dev *indio_dev)
 226 {
 227         int ret = 0;
 228         struct adis16300_state *st = indio_dev->dev_data;
 229         struct iio_ring_buffer *ring;
 230         INIT_WORK(&st->work_trigger_to_ring, adis16300_trigger_bh_to_ring);
 231         /* Set default scan mode */
 232
 233         iio_scan_mask_set(indio_dev, iio_scan_el_supply.number);
 234         iio_scan_mask_set(indio_dev, iio_scan_el_gyro_x.number);
 235         iio_scan_mask_set(indio_dev, iio_scan_el_accel_x.number);
 236         iio_scan_mask_set(indio_dev, iio_scan_el_accel_y.number);
 237         iio_scan_mask_set(indio_dev, iio_scan_el_accel_z.number);
 238         iio_scan_mask_set(indio_dev, iio_scan_el_temp.number);
 239         iio_scan_mask_set(indio_dev, iio_scan_el_adc_0.number);
 240         iio_scan_mask_set(indio_dev, iio_scan_el_incli_x.number);
 241         iio_scan_mask_set(indio_dev, iio_scan_el_incli_y.number);
 242         indio_dev->scan_timestamp = true;
 243
 244         indio_dev->scan_el_attrs = &adis16300_scan_el_group;
 245
 246         ring = iio_sw_rb_allocate(indio_dev);
 247         if (!ring) {
 248                 ret = -ENOMEM;
 249                 return ret;
 250         }
 251         indio_dev->ring = ring;
 252         /* Effectively select the ring buffer implementation */
 253         iio_ring_sw_register_funcs(&ring->access);
 254         ring->preenable = &adis16300_data_rdy_ring_preenable;
 255         ring->postenable = &adis16300_data_rdy_ring_postenable;
 256         ring->predisable = &adis16300_data_rdy_ring_predisable;
 257         ring->owner = THIS_MODULE;
 258
 259         indio_dev->pollfunc = kzalloc(sizeof(*indio_dev->pollfunc), GFP_KERNEL);
 260         if (indio_dev->pollfunc == NULL) {
 261                 ret = -ENOMEM;
 262                 goto error_iio_sw_rb_free;;
 263         }
 264         indio_dev->pollfunc->poll_func_main = &adis16300_poll_func_th;
 265         indio_dev->pollfunc->private_data = indio_dev;
 266         indio_dev->modes |= INDIO_RING_TRIGGERED;
 267         return 0;
 268
 269 error_iio_sw_rb_free:
 270         iio_sw_rb_free(indio_dev->ring);
 271         return ret;
 272 }
 273
 274 int adis16300_initialize_ring(struct iio_ring_buffer *ring)
 275 {
 276         return iio_ring_buffer_register(ring, 0);
 277 }
 278
 279 void adis16300_uninitialize_ring(struct iio_ring_buffer *ring)
 280 {
 281         iio_ring_buffer_unregister(ring);
 282 }