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 static IIO_SCAN_EL_C(supply, ADIS16300_SCAN_SUPPLY, IIO_UNSIGNED(14),
  21                      ADIS16300_SUPPLY_OUT, NULL);
  22
  23 static IIO_SCAN_EL_C(gyro_x, ADIS16300_SCAN_GYRO_X, IIO_SIGNED(14),
  24                      ADIS16300_XGYRO_OUT, NULL);
  25
  26 static IIO_SCAN_EL_C(accel_x, ADIS16300_SCAN_ACC_X, IIO_SIGNED(14),
  27                      ADIS16300_XACCL_OUT, NULL);
  28 static IIO_SCAN_EL_C(accel_y, ADIS16300_SCAN_ACC_Y, IIO_SIGNED(14),
  29                      ADIS16300_YACCL_OUT, NULL);
  30 static IIO_SCAN_EL_C(accel_z, ADIS16300_SCAN_ACC_Z, IIO_SIGNED(14),
  31                      ADIS16300_ZACCL_OUT, NULL);
  32
  33 static IIO_SCAN_EL_C(temp, ADIS16300_SCAN_TEMP, IIO_UNSIGNED(12),
  34                      ADIS16300_TEMP_OUT, NULL);
  35 static IIO_SCAN_EL_C(adc_0, ADIS16300_SCAN_ADC_0, IIO_UNSIGNED(12),
  36                      ADIS16300_AUX_ADC, NULL);
  37
  38 static IIO_SCAN_EL_C(incli_x, ADIS16300_SCAN_INCLI_X, IIO_SIGNED(12),
  39                      ADIS16300_XINCLI_OUT, NULL);
  40 static IIO_SCAN_EL_C(incli_y, ADIS16300_SCAN_INCLI_Y, IIO_SIGNED(12),
  41                      ADIS16300_YINCLI_OUT, NULL);
  42
  43 static IIO_SCAN_EL_TIMESTAMP(9);
  44
  45 static struct attribute *adis16300_scan_el_attrs[] = {
  46         &iio_scan_el_supply.dev_attr.attr,
  47         &iio_scan_el_gyro_x.dev_attr.attr,
  48         &iio_scan_el_temp.dev_attr.attr,
  49         &iio_scan_el_accel_x.dev_attr.attr,
  50         &iio_scan_el_accel_y.dev_attr.attr,
  51         &iio_scan_el_accel_z.dev_attr.attr,
  52         &iio_scan_el_incli_x.dev_attr.attr,
  53         &iio_scan_el_incli_y.dev_attr.attr,
  54         &iio_scan_el_adc_0.dev_attr.attr,
  55         &iio_scan_el_timestamp.dev_attr.attr,
  56         NULL,
  57 };
  58
  59 static struct attribute_group adis16300_scan_el_group = {
  60         .attrs = adis16300_scan_el_attrs,
  61         .name = "scan_elements",
  62 };
  63
  64 /**
  65  * adis16300_poll_func_th() top half interrupt handler called by trigger
  66  * @private_data:       iio_dev
  67  **/
  68 static void adis16300_poll_func_th(struct iio_dev *indio_dev, s64 time)
  69 {
  70         struct adis16300_state *st = iio_dev_get_devdata(indio_dev);
  71         st->last_timestamp = time;
  72         schedule_work(&st->work_trigger_to_ring);
  73         /* Indicate that this interrupt is being handled */
  74
  75         /* Technically this is trigger related, but without this
  76          * handler running there is currently no way for the interrupt
  77          * to clear.
  78          */
  79 }
  80
  81 /**
  82  * adis16300_spi_read_burst() - read all data registers
  83  * @dev: device associated with child of actual device (iio_dev or iio_trig)
  84  * @rx: somewhere to pass back the value read (min size is 24 bytes)
  85  **/
  86 static int adis16300_spi_read_burst(struct device *dev, u8 *rx)
  87 {
  88         struct spi_message msg;
  89         struct iio_dev *indio_dev = dev_get_drvdata(dev);
  90         struct adis16300_state *st = iio_dev_get_devdata(indio_dev);
  91         u32 old_speed_hz = st->us->max_speed_hz;
  92         int ret;
  93
  94         struct spi_transfer xfers[] = {
  95                 {
  96                         .tx_buf = st->tx,
  97                         .bits_per_word = 8,
  98                         .len = 2,
  99                         .cs_change = 0,
 100                 }, {
 101                         .rx_buf = rx,
 102                         .bits_per_word = 8,
 103                         .len = 18,
 104                         .cs_change = 0,
 105                 },
 106         };
 107
 108         mutex_lock(&st->buf_lock);
 109         st->tx[0] = ADIS16300_READ_REG(ADIS16300_GLOB_CMD);
 110         st->tx[1] = 0;
 111
 112         spi_message_init(&msg);
 113         spi_message_add_tail(&xfers[0], &msg);
 114         spi_message_add_tail(&xfers[1], &msg);
 115
 116         st->us->max_speed_hz = ADIS16300_SPI_BURST;
 117         spi_setup(st->us);
 118
 119         ret = spi_sync(st->us, &msg);
 120         if (ret)
 121                 dev_err(&st->us->dev, "problem when burst reading");
 122
 123         st->us->max_speed_hz = old_speed_hz;
 124         spi_setup(st->us);
 125         mutex_unlock(&st->buf_lock);
 126         return ret;
 127 }
 128
 129 /* Whilst this makes a lot of calls to iio_sw_ring functions - it is to device
 130  * specific to be rolled into the core.
 131  */
 132 static void adis16300_trigger_bh_to_ring(struct work_struct *work_s)
 133 {
 134         struct adis16300_state *st
 135                 = container_of(work_s, struct adis16300_state,
 136                                work_trigger_to_ring);
 137
 138         int i = 0;
 139         s16 *data;
 140         size_t datasize = st->indio_dev
 141                 ->ring->access.get_bpd(st->indio_dev->ring);
 142
 143         data = kmalloc(datasize , GFP_KERNEL);
 144         if (data == NULL) {
 145                 dev_err(&st->us->dev, "memory alloc failed in ring bh");
 146                 return;
 147         }
 148
 149         if (st->indio_dev->scan_count)
 150                 if (adis16300_spi_read_burst(&st->indio_dev->dev, st->rx) >= 0)
 151                         for (; i < st->indio_dev->scan_count; i++)
 152                                 data[i] = be16_to_cpup(
 153                                         (__be16 *)&(st->rx[i*2]));
 154
 155         /* Guaranteed to be aligned with 8 byte boundary */
 156         if (st->indio_dev->scan_timestamp)
 157                 *((s64 *)(data + ((i + 3)/4)*4)) = st->last_timestamp;
 158
 159         st->indio_dev->ring->access.store_to(st->indio_dev->ring,
 160                                             (u8 *)data,
 161                                             st->last_timestamp);
 162
 163         iio_trigger_notify_done(st->indio_dev->trig);
 164         kfree(data);
 165
 166         return;
 167 }
 168
 169 void adis16300_unconfigure_ring(struct iio_dev *indio_dev)
 170 {
 171         kfree(indio_dev->pollfunc);
 172         iio_sw_rb_free(indio_dev->ring);
 173 }
 174
 175 int adis16300_configure_ring(struct iio_dev *indio_dev)
 176 {
 177         int ret = 0;
 178         struct adis16300_state *st = indio_dev->dev_data;
 179         struct iio_ring_buffer *ring;
 180         INIT_WORK(&st->work_trigger_to_ring, adis16300_trigger_bh_to_ring);
 181         /* Set default scan mode */
 182
 183         iio_scan_mask_set(indio_dev, iio_scan_el_supply.number);
 184         iio_scan_mask_set(indio_dev, iio_scan_el_gyro_x.number);
 185         iio_scan_mask_set(indio_dev, iio_scan_el_accel_x.number);
 186         iio_scan_mask_set(indio_dev, iio_scan_el_accel_y.number);
 187         iio_scan_mask_set(indio_dev, iio_scan_el_accel_z.number);
 188         iio_scan_mask_set(indio_dev, iio_scan_el_temp.number);
 189         iio_scan_mask_set(indio_dev, iio_scan_el_adc_0.number);
 190         iio_scan_mask_set(indio_dev, iio_scan_el_incli_x.number);
 191         iio_scan_mask_set(indio_dev, iio_scan_el_incli_y.number);
 192         indio_dev->scan_timestamp = true;
 193
 194         indio_dev->scan_el_attrs = &adis16300_scan_el_group;
 195
 196         ring = iio_sw_rb_allocate(indio_dev);
 197         if (!ring) {
 198                 ret = -ENOMEM;
 199                 return ret;
 200         }
 201         indio_dev->ring = ring;
 202         /* Effectively select the ring buffer implementation */
 203         iio_ring_sw_register_funcs(&ring->access);
 204         ring->bpe = 2;
 205         ring->preenable = &iio_sw_ring_preenable;
 206         ring->postenable = &iio_triggered_ring_postenable;
 207         ring->predisable = &iio_triggered_ring_predisable;
 208         ring->owner = THIS_MODULE;
 209
 210         ret = iio_alloc_pollfunc(indio_dev, NULL, &adis16300_poll_func_th);
 211         if (ret)
 212                 goto error_iio_sw_rb_free;
 213
 214         indio_dev->modes |= INDIO_RING_TRIGGERED;
 215         return 0;
 216
 217 error_iio_sw_rb_free:
 218         iio_sw_rb_free(indio_dev->ring);
 219         return ret;
 220 }
 221