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/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 "adis16400.h"
  19
  20 static IIO_SCAN_EL_C(supply, ADIS16400_SCAN_SUPPLY, IIO_SIGNED(14),
  21                      ADIS16400_SUPPLY_OUT, NULL);
  22
  23 static IIO_SCAN_EL_C(gyro_x, ADIS16400_SCAN_GYRO_X, IIO_SIGNED(14),
  24                      ADIS16400_XGYRO_OUT, NULL);
  25 static IIO_SCAN_EL_C(gyro_y, ADIS16400_SCAN_GYRO_Y, IIO_SIGNED(14),
  26                      ADIS16400_YGYRO_OUT, NULL);
  27 static IIO_SCAN_EL_C(gyro_z, ADIS16400_SCAN_GYRO_Z, IIO_SIGNED(14),
  28                      ADIS16400_ZGYRO_OUT, NULL);
  29
  30 static IIO_SCAN_EL_C(accel_x, ADIS16400_SCAN_ACC_X, IIO_SIGNED(14),
  31                      ADIS16400_XACCL_OUT, NULL);
  32 static IIO_SCAN_EL_C(accel_y, ADIS16400_SCAN_ACC_Y, IIO_SIGNED(14),
  33                      ADIS16400_YACCL_OUT, NULL);
  34 static IIO_SCAN_EL_C(accel_z, ADIS16400_SCAN_ACC_Z, IIO_SIGNED(14),
  35                      ADIS16400_ZACCL_OUT, NULL);
  36
  37 static IIO_SCAN_EL_C(magn_x, ADIS16400_SCAN_MAGN_X, IIO_SIGNED(14),
  38                      ADIS16400_XMAGN_OUT, NULL);
  39 static IIO_SCAN_EL_C(magn_y, ADIS16400_SCAN_MAGN_Y, IIO_SIGNED(14),
  40                      ADIS16400_YMAGN_OUT, NULL);
  41 static IIO_SCAN_EL_C(magn_z, ADIS16400_SCAN_MAGN_Z, IIO_SIGNED(14),
  42                      ADIS16400_ZMAGN_OUT, NULL);
  43
  44 static IIO_SCAN_EL_C(temp, ADIS16400_SCAN_TEMP, IIO_SIGNED(12),
  45                      ADIS16400_TEMP_OUT, NULL);
  46 static IIO_SCAN_EL_C(adc_0, ADIS16400_SCAN_ADC_0, IIO_SIGNED(12),
  47                      ADIS16400_AUX_ADC, NULL);
  48
  49 static IIO_SCAN_EL_TIMESTAMP(12);
  50
  51 static struct attribute *adis16400_scan_el_attrs[] = {
  52         &iio_scan_el_supply.dev_attr.attr,
  53         &iio_scan_el_gyro_x.dev_attr.attr,
  54         &iio_scan_el_gyro_y.dev_attr.attr,
  55         &iio_scan_el_gyro_z.dev_attr.attr,
  56         &iio_scan_el_accel_x.dev_attr.attr,
  57         &iio_scan_el_accel_y.dev_attr.attr,
  58         &iio_scan_el_accel_z.dev_attr.attr,
  59         &iio_scan_el_magn_x.dev_attr.attr,
  60         &iio_scan_el_magn_y.dev_attr.attr,
  61         &iio_scan_el_magn_z.dev_attr.attr,
  62         &iio_scan_el_temp.dev_attr.attr,
  63         &iio_scan_el_adc_0.dev_attr.attr,
  64         &iio_scan_el_timestamp.dev_attr.attr,
  65         NULL,
  66 };
  67
  68 static struct attribute_group adis16400_scan_el_group = {
  69         .attrs = adis16400_scan_el_attrs,
  70         .name = "scan_elements",
  71 };
  72
  73 /**
  74  * adis16400_poll_func_th() top half interrupt handler called by trigger
  75  * @private_data:       iio_dev
  76  **/
  77 static void adis16400_poll_func_th(struct iio_dev *indio_dev, s64 time)
  78 {
  79         struct adis16400_state *st = iio_dev_get_devdata(indio_dev);
  80         st->last_timestamp = time;
  81         schedule_work(&st->work_trigger_to_ring);
  82         /* Indicate that this interrupt is being handled */
  83
  84         /* Technically this is trigger related, but without this
  85          * handler running there is currently no way for the interrupt
  86          * to clear.
  87          */
  88 }
  89
  90 /**
  91  * adis16400_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 adis16400_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 adis16400_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 = 24,
 113                         .cs_change = 1,
 114                 },
 115         };
 116
 117         mutex_lock(&st->buf_lock);
 118         st->tx[0] = ADIS16400_READ_REG(ADIS16400_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 = min(ADIS16400_SPI_BURST, old_speed_hz);
 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 adis16400_trigger_bh_to_ring(struct work_struct *work_s)
 142 {
 143         struct adis16400_state *st
 144                 = container_of(work_s, struct adis16400_state,
 145                                work_trigger_to_ring);
 146         struct iio_ring_buffer *ring = st->indio_dev->ring;
 147
 148         int i = 0;
 149         s16 *data;
 150         size_t datasize = ring->access.get_bytes_per_datum(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 (ring->scan_count)
 159                 if (adis16400_spi_read_burst(&st->indio_dev->dev, st->rx) >= 0)
 160                         for (; i < ring->scan_count; i++)
 161                                 data[i] = be16_to_cpup(
 162                                         (__be16 *)&(st->rx[i*2]));
 163
 164         /* Guaranteed to be aligned with 8 byte boundary */
 165         if (ring->scan_timestamp)
 166                 *((s64 *)(data + ((i + 3)/4)*4)) = st->last_timestamp;
 167
 168         ring->access.store_to(ring,
 169                         (u8 *) data,
 170                         st->last_timestamp);
 171
 172         iio_trigger_notify_done(st->indio_dev->trig);
 173         kfree(data);
 174
 175         return;
 176 }
 177
 178 void adis16400_unconfigure_ring(struct iio_dev *indio_dev)
 179 {
 180         kfree(indio_dev->pollfunc);
 181         iio_sw_rb_free(indio_dev->ring);
 182 }
 183
 184 int adis16400_configure_ring(struct iio_dev *indio_dev)
 185 {
 186         int ret = 0;
 187         struct adis16400_state *st = indio_dev->dev_data;
 188         struct iio_ring_buffer *ring;
 189         INIT_WORK(&st->work_trigger_to_ring, adis16400_trigger_bh_to_ring);
 190
 191         ring = iio_sw_rb_allocate(indio_dev);
 192         if (!ring) {
 193                 ret = -ENOMEM;
 194                 return ret;
 195         }
 196         indio_dev->ring = ring;
 197         /* Effectively select the ring buffer implementation */
 198         iio_ring_sw_register_funcs(&ring->access);
 199         ring->bpe = 2;
 200         ring->scan_el_attrs = &adis16400_scan_el_group;
 201         ring->scan_timestamp = true;
 202         ring->preenable = &iio_sw_ring_preenable;
 203         ring->postenable = &iio_triggered_ring_postenable;
 204         ring->predisable = &iio_triggered_ring_predisable;
 205         ring->owner = THIS_MODULE;
 206
 207         /* Set default scan mode */
 208         iio_scan_mask_set(ring, iio_scan_el_supply.number);
 209         iio_scan_mask_set(ring, iio_scan_el_gyro_x.number);
 210         iio_scan_mask_set(ring, iio_scan_el_gyro_y.number);
 211         iio_scan_mask_set(ring, iio_scan_el_gyro_z.number);
 212         iio_scan_mask_set(ring, iio_scan_el_accel_x.number);
 213         iio_scan_mask_set(ring, iio_scan_el_accel_y.number);
 214         iio_scan_mask_set(ring, iio_scan_el_accel_z.number);
 215         iio_scan_mask_set(ring, iio_scan_el_magn_x.number);
 216         iio_scan_mask_set(ring, iio_scan_el_magn_y.number);
 217         iio_scan_mask_set(ring, iio_scan_el_magn_z.number);
 218         iio_scan_mask_set(ring, iio_scan_el_temp.number);
 219         iio_scan_mask_set(ring, iio_scan_el_adc_0.number);
 220
 221         ret = iio_alloc_pollfunc(indio_dev, NULL, &adis16400_poll_func_th);
 222         if (ret)
 223                 goto error_iio_sw_rb_free;
 224
 225         indio_dev->modes |= INDIO_RING_TRIGGERED;
 226         return 0;
 227
 228 error_iio_sw_rb_free:
 229         iio_sw_rb_free(indio_dev->ring);
 230         return ret;
 231 }