LXR linux/drivers/staging/iio/accel/lis3l02dq

   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#include <linux/slab.h>
  12
  13#include "../iio.h"
  14#include "../sysfs.h"
  15#include "../ring_sw.h"
  16#include "accel.h"
  17#include "../trigger.h"
  18#include "lis3l02dq.h"
  19
  20/**
  21 * combine_8_to_16() utility function to munge to u8s into u16
  22 **/
  23static 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/**
  31 * lis3l02dq_scan_el_set_state() set whether a scan contains a given channel
  32 * @scan_el:    associtate iio scan element attribute
  33 * @indio_dev:  the device structure
  34 * @bool:       desired state
  35 *
  36 * mlock already held when this is called.
  37 **/
  38static int lis3l02dq_scan_el_set_state(struct iio_scan_el *scan_el,
  39                                       struct iio_dev *indio_dev,
  40                                       bool state)
  41{
  42        u8 t, mask;
  43        int ret;
  44
  45        ret = lis3l02dq_spi_read_reg_8(&indio_dev->dev,
  46                                       LIS3L02DQ_REG_CTRL_1_ADDR,
  47                                       &t);
  48        if (ret)
  49                goto error_ret;
  50        switch (scan_el->label) {
  51        case LIS3L02DQ_REG_OUT_X_L_ADDR:
  52                mask = LIS3L02DQ_REG_CTRL_1_AXES_X_ENABLE;
  53                break;
  54        case LIS3L02DQ_REG_OUT_Y_L_ADDR:
  55                mask = LIS3L02DQ_REG_CTRL_1_AXES_Y_ENABLE;
  56                break;
  57        case LIS3L02DQ_REG_OUT_Z_L_ADDR:
  58                mask = LIS3L02DQ_REG_CTRL_1_AXES_Z_ENABLE;
  59                break;
  60        default:
  61                ret = -EINVAL;
  62                goto error_ret;
  63        }
  64
  65        if (!(mask & t) == state) {
  66                if (state)
  67                        t |= mask;
  68                else
  69                        t &= ~mask;
  70                ret = lis3l02dq_spi_write_reg_8(&indio_dev->dev,
  71                                                LIS3L02DQ_REG_CTRL_1_ADDR,
  72                                                &t);
  73        }
  74error_ret:
  75        return ret;
  76
  77}
  78static IIO_SCAN_EL_C(accel_x, 0,
  79                     LIS3L02DQ_REG_OUT_X_L_ADDR,
  80                     &lis3l02dq_scan_el_set_state);
  81static IIO_SCAN_EL_C(accel_y, 1,
  82                     LIS3L02DQ_REG_OUT_Y_L_ADDR,
  83                     &lis3l02dq_scan_el_set_state);
  84static IIO_SCAN_EL_C(accel_z, 2,
  85                     LIS3L02DQ_REG_OUT_Z_L_ADDR,
  86                     &lis3l02dq_scan_el_set_state);
  87static IIO_CONST_ATTR_SCAN_EL_TYPE(accel, s, 12, 16);
  88static IIO_SCAN_EL_TIMESTAMP(3);
  89static IIO_CONST_ATTR_SCAN_EL_TYPE(timestamp, s, 64, 64);
  90
  91static struct attribute *lis3l02dq_scan_el_attrs[] = {
  92        &iio_scan_el_accel_x.dev_attr.attr,
  93        &iio_const_attr_accel_x_index.dev_attr.attr,
  94        &iio_scan_el_accel_y.dev_attr.attr,
  95        &iio_const_attr_accel_y_index.dev_attr.attr,
  96        &iio_scan_el_accel_z.dev_attr.attr,
  97        &iio_const_attr_accel_z_index.dev_attr.attr,
  98        &iio_const_attr_accel_type.dev_attr.attr,
  99        &iio_scan_el_timestamp.dev_attr.attr,
 100        &iio_const_attr_timestamp_index.dev_attr.attr,
 101        &iio_const_attr_timestamp_type.dev_attr.attr,
 102        NULL,
 103};
 104
 105static struct attribute_group lis3l02dq_scan_el_group = {
 106        .attrs = lis3l02dq_scan_el_attrs,
 107        .name = "scan_elements",
 108};
 109
 110/**
 111 * lis3l02dq_poll_func_th() top half interrupt handler called by trigger
 112 * @private_data:       iio_dev
 113 **/
 114static void lis3l02dq_poll_func_th(struct iio_dev *indio_dev, s64 time)
 115{
 116        struct iio_sw_ring_helper_state *h
 117                = iio_dev_get_devdata(indio_dev);
 118        struct lis3l02dq_state *st = lis3l02dq_h_to_s(h);
 119        /* in this case we need to slightly extend the helper function */
 120        iio_sw_poll_func_th(indio_dev, time);
 121
 122        /* Indicate that this interrupt is being handled */
 123        /* Technically this is trigger related, but without this
 124         * handler running there is currently now way for the interrupt
 125         * to clear.
 126         */
 127        st->inter = 1;
 128}
 129
 130/**
 131 * lis3l02dq_data_rdy_trig_poll() the event handler for the data rdy trig
 132 **/
 133static int lis3l02dq_data_rdy_trig_poll(struct iio_dev *indio_dev,
 134                                       int index,
 135                                       s64 timestamp,
 136                                       int no_test)
 137{
 138        struct iio_sw_ring_helper_state *h
 139                = iio_dev_get_devdata(indio_dev);
 140        struct lis3l02dq_state *st = lis3l02dq_h_to_s(h);
 141
 142        iio_trigger_poll(st->trig, timestamp);
 143
 144        return IRQ_HANDLED;
 145}
 146
 147/* This is an event as it is a response to a physical interrupt */
 148IIO_EVENT_SH(data_rdy_trig, &lis3l02dq_data_rdy_trig_poll);
 149
 150/**
 151 * lis3l02dq_read_accel_from_ring() individual acceleration read from ring
 152 **/
 153ssize_t lis3l02dq_read_accel_from_ring(struct device *dev,
 154                                       struct device_attribute *attr,
 155                                       char *buf)
 156{
 157        struct iio_scan_el *el = NULL;
 158        int ret, len = 0, i = 0;
 159        struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 160        struct iio_dev *dev_info = dev_get_drvdata(dev);
 161        struct iio_ring_buffer *ring = dev_info->ring;
 162        struct attribute_group *scan_el_attrs = ring->scan_el_attrs;
 163        s16 *data;
 164
 165        while (scan_el_attrs->attrs[i]) {
 166                el = to_iio_scan_el((struct device_attribute *)
 167                                    (scan_el_attrs->attrs[i]));
 168                /* label is in fact the address */
 169                if (el->label == this_attr->address)
 170                        break;
 171                i++;
 172        }
 173        if (!scan_el_attrs->attrs[i]) {
 174                ret = -EINVAL;
 175                goto error_ret;
 176        }
 177        /* If this element is in the scan mask */
 178        ret = iio_scan_mask_query(ring, el->number);
 179        if (ret < 0)
 180                goto error_ret;
 181        if (ret) {
 182                data = kmalloc(ring->access.get_bytes_per_datum(ring),
 183                               GFP_KERNEL);
 184                if (data == NULL)
 185                        return -ENOMEM;
 186                ret = ring->access.read_last(ring,
 187                                        (u8 *)data);
 188                if (ret)
 189                        goto error_free_data;
 190        } else {
 191                ret = -EINVAL;
 192                goto error_ret;
 193        }
 194        len = iio_scan_mask_count_to_right(ring, el->number);
 195        if (len < 0) {
 196                ret = len;
 197                goto error_free_data;
 198        }
 199        len = sprintf(buf, "ring %d\n", data[len]);
 200error_free_data:
 201        kfree(data);
 202error_ret:
 203        return ret ? ret : len;
 204
 205}
 206
 207static const u8 read_all_tx_array[] = {
 208        LIS3L02DQ_READ_REG(LIS3L02DQ_REG_OUT_X_L_ADDR), 0,
 209        LIS3L02DQ_READ_REG(LIS3L02DQ_REG_OUT_X_H_ADDR), 0,
 210        LIS3L02DQ_READ_REG(LIS3L02DQ_REG_OUT_Y_L_ADDR), 0,
 211        LIS3L02DQ_READ_REG(LIS3L02DQ_REG_OUT_Y_H_ADDR), 0,
 212        LIS3L02DQ_READ_REG(LIS3L02DQ_REG_OUT_Z_L_ADDR), 0,
 213        LIS3L02DQ_READ_REG(LIS3L02DQ_REG_OUT_Z_H_ADDR), 0,
 214};
 215
 216/**
 217 * lis3l02dq_read_all() Reads all channels currently selected
 218 * @st:         device specific state
 219 * @rx_array:   (dma capable) recieve array, must be at least
 220 *              4*number of channels
 221 **/
 222static int lis3l02dq_read_all(struct lis3l02dq_state *st, u8 *rx_array)
 223{
 224        struct iio_ring_buffer *ring = st->help.indio_dev->ring;
 225        struct spi_transfer *xfers;
 226        struct spi_message msg;
 227        int ret, i, j = 0;
 228
 229        xfers = kzalloc((ring->scan_count) * 2
 230                        * sizeof(*xfers), GFP_KERNEL);
 231        if (!xfers)
 232                return -ENOMEM;
 233
 234        mutex_lock(&st->buf_lock);
 235
 236        for (i = 0; i < ARRAY_SIZE(read_all_tx_array)/4; i++) {
 237                if (ring->scan_mask & (1 << i)) {
 238                        /* lower byte */
 239                        xfers[j].tx_buf = st->tx + 2*j;
 240                        st->tx[2*j] = read_all_tx_array[i*4];
 241                        st->tx[2*j + 1] = 0;
 242                        if (rx_array)
 243                                xfers[j].rx_buf = rx_array + j*2;
 244                        xfers[j].bits_per_word = 8;
 245                        xfers[j].len = 2;
 246                        xfers[j].cs_change = 1;
 247                        j++;
 248
 249                        /* upper byte */
 250                        xfers[j].tx_buf = st->tx + 2*j;
 251                        st->tx[2*j] = read_all_tx_array[i*4 + 2];
 252                        st->tx[2*j + 1] = 0;
 253                        if (rx_array)
 254                                xfers[j].rx_buf = rx_array + j*2;
 255                        xfers[j].bits_per_word = 8;
 256                        xfers[j].len = 2;
 257                        xfers[j].cs_change = 1;
 258                        j++;
 259                }
 260        }
 261        /* After these are transmitted, the rx_buff should have
 262         * values in alternate bytes
 263         */
 264        spi_message_init(&msg);
 265        for (j = 0; j < ring->scan_count * 2; j++)
 266                spi_message_add_tail(&xfers[j], &msg);
 267
 268        ret = spi_sync(st->us, &msg);
 269        mutex_unlock(&st->buf_lock);
 270        kfree(xfers);
 271
 272        return ret;
 273}
 274
 275static void lis3l02dq_trigger_bh_to_ring(struct work_struct *work_s)
 276{
 277        struct iio_sw_ring_helper_state *h
 278                = container_of(work_s, struct iio_sw_ring_helper_state,
 279                        work_trigger_to_ring);
 280        struct lis3l02dq_state *st = lis3l02dq_h_to_s(h);
 281
 282        st->inter = 0;
 283        iio_sw_trigger_bh_to_ring(work_s);
 284}
 285
 286static int lis3l02dq_get_ring_element(struct iio_sw_ring_helper_state *h,
 287                                u8 *buf)
 288{
 289        int ret, i;
 290        u8 *rx_array ;
 291        s16 *data = (s16 *)buf;
 292
 293        rx_array = kzalloc(4 * (h->indio_dev->ring->scan_count), GFP_KERNEL);
 294        if (rx_array == NULL)
 295                return -ENOMEM;
 296        ret = lis3l02dq_read_all(lis3l02dq_h_to_s(h), rx_array);
 297        if (ret < 0)
 298                return ret;
 299        for (i = 0; i < h->indio_dev->ring->scan_count; i++)
 300                data[i] = combine_8_to_16(rx_array[i*4+1],
 301                                        rx_array[i*4+3]);
 302        kfree(rx_array);
 303
 304        return i*sizeof(data[0]);
 305}
 306
 307/* Caller responsible for locking as necessary. */
 308static int
 309__lis3l02dq_write_data_ready_config(struct device *dev,
 310                                    struct iio_event_handler_list *list,
 311                                    bool state)
 312{
 313        int ret;
 314        u8 valold;
 315        bool currentlyset;
 316        struct iio_dev *indio_dev = dev_get_drvdata(dev);
 317
 318/* Get the current event mask register */
 319        ret = lis3l02dq_spi_read_reg_8(dev,
 320                                       LIS3L02DQ_REG_CTRL_2_ADDR,
 321                                       &valold);
 322        if (ret)
 323                goto error_ret;
 324/* Find out if data ready is already on */
 325        currentlyset
 326                = valold & LIS3L02DQ_REG_CTRL_2_ENABLE_DATA_READY_GENERATION;
 327
 328/* Disable requested */
 329        if (!state && currentlyset) {
 330
 331                valold &= ~LIS3L02DQ_REG_CTRL_2_ENABLE_DATA_READY_GENERATION;
 332                /* The double write is to overcome a hardware bug?*/
 333                ret = lis3l02dq_spi_write_reg_8(dev,
 334                                                LIS3L02DQ_REG_CTRL_2_ADDR,
 335                                                &valold);
 336                if (ret)
 337                        goto error_ret;
 338                ret = lis3l02dq_spi_write_reg_8(dev,
 339                                                LIS3L02DQ_REG_CTRL_2_ADDR,
 340                                                &valold);
 341                if (ret)
 342                        goto error_ret;
 343
 344                iio_remove_event_from_list(list,
 345                                           &indio_dev->interrupts[0]
 346                                           ->ev_list);
 347
 348/* Enable requested */
 349        } else if (state && !currentlyset) {
 350                /* if not set, enable requested */
 351                valold |= LIS3L02DQ_REG_CTRL_2_ENABLE_DATA_READY_GENERATION;
 352                iio_add_event_to_list(list, &indio_dev->interrupts[0]->ev_list);
 353                ret = lis3l02dq_spi_write_reg_8(dev,
 354                                                LIS3L02DQ_REG_CTRL_2_ADDR,
 355                                                &valold);
 356                if (ret)
 357                        goto error_ret;
 358        }
 359
 360        return 0;
 361error_ret:
 362        return ret;
 363}
 364
 365/**
 366 * lis3l02dq_data_rdy_trigger_set_state() set datardy interrupt state
 367 *
 368 * If disabling the interrupt also does a final read to ensure it is clear.
 369 * This is only important in some cases where the scan enable elements are
 370 * switched before the ring is reenabled.
 371 **/
 372static int lis3l02dq_data_rdy_trigger_set_state(struct iio_trigger *trig,
 373                                                bool state)
 374{
 375        struct lis3l02dq_state *st = trig->private_data;
 376        int ret = 0;
 377        u8 t;
 378        __lis3l02dq_write_data_ready_config(&st->help.indio_dev->dev,
 379                                            &iio_event_data_rdy_trig,
 380                                            state);
 381        if (state == false) {
 382                /* possible quirk with handler currently worked around
 383                   by ensuring the work queue is empty */
 384                flush_scheduled_work();
 385                /* Clear any outstanding ready events */
 386                ret = lis3l02dq_read_all(st, NULL);
 387        }
 388        lis3l02dq_spi_read_reg_8(&st->help.indio_dev->dev,
 389                                 LIS3L02DQ_REG_WAKE_UP_SRC_ADDR,
 390                                 &t);
 391        return ret;
 392}
 393
 394static IIO_TRIGGER_NAME_ATTR;
 395
 396static struct attribute *lis3l02dq_trigger_attrs[] = {
 397        &dev_attr_name.attr,
 398        NULL,
 399};
 400
 401static const struct attribute_group lis3l02dq_trigger_attr_group = {
 402        .attrs = lis3l02dq_trigger_attrs,
 403};
 404
 405/**
 406 * lis3l02dq_trig_try_reen() try renabling irq for data rdy trigger
 407 * @trig:       the datardy trigger
 408 *
 409 * As the trigger may occur on any data element being updated it is
 410 * really rather likely to occur during the read from the previous
 411 * trigger event.  The only way to discover if this has occured on
 412 * boards not supporting level interrupts is to take a look at the line.
 413 * If it is indicating another interrupt and we don't seem to have a
 414 * handler looking at it, then we need to notify the core that we need
 415 * to tell the triggering core to try reading all these again.
 416 **/
 417static int lis3l02dq_trig_try_reen(struct iio_trigger *trig)
 418{
 419        struct lis3l02dq_state *st = trig->private_data;
 420        enable_irq(st->us->irq);
 421        /* If gpio still high (or high again) */
 422        if (gpio_get_value(irq_to_gpio(st->us->irq)))
 423                if (st->inter == 0) {
 424                        /* already interrupt handler dealing with it */
 425                        disable_irq_nosync(st->us->irq);
 426                        if (st->inter == 1) {
 427                                /* interrupt handler snuck in between test
 428                                 * and disable */
 429                                enable_irq(st->us->irq);
 430                                return 0;
 431                        }
 432                        return -EAGAIN;
 433                }
 434        /* irq reenabled so success! */
 435        return 0;
 436}
 437
 438int lis3l02dq_probe_trigger(struct iio_dev *indio_dev)
 439{
 440        int ret;
 441        struct lis3l02dq_state *state = indio_dev->dev_data;
 442
 443        state->trig = iio_allocate_trigger();
 444        if (!state->trig)
 445                return -ENOMEM;
 446
 447        state->trig->name = kasprintf(GFP_KERNEL,
 448                                      "lis3l02dq-dev%d",
 449                                      indio_dev->id);
 450        if (!state->trig->name) {
 451                ret = -ENOMEM;
 452                goto error_free_trig;
 453        }
 454
 455        state->trig->dev.parent = &state->us->dev;
 456        state->trig->owner = THIS_MODULE;
 457        state->trig->private_data = state;
 458        state->trig->set_trigger_state = &lis3l02dq_data_rdy_trigger_set_state;
 459        state->trig->try_reenable = &lis3l02dq_trig_try_reen;
 460        state->trig->control_attrs = &lis3l02dq_trigger_attr_group;
 461        ret = iio_trigger_register(state->trig);
 462        if (ret)
 463                goto error_free_trig_name;
 464
 465        return 0;
 466
 467error_free_trig_name:
 468        kfree(state->trig->name);
 469error_free_trig:
 470        iio_free_trigger(state->trig);
 471
 472        return ret;
 473}
 474
 475void lis3l02dq_remove_trigger(struct iio_dev *indio_dev)
 476{
 477        struct lis3l02dq_state *state = indio_dev->dev_data;
 478
 479        iio_trigger_unregister(state->trig);
 480        kfree(state->trig->name);
 481        iio_free_trigger(state->trig);
 482}
 483
 484void lis3l02dq_unconfigure_ring(struct iio_dev *indio_dev)
 485{
 486        kfree(indio_dev->pollfunc);
 487        iio_sw_rb_free(indio_dev->ring);
 488}
 489
 490int lis3l02dq_configure_ring(struct iio_dev *indio_dev)
 491{
 492        int ret;
 493        struct iio_sw_ring_helper_state *h = iio_dev_get_devdata(indio_dev);
 494        struct iio_ring_buffer *ring;
 495        INIT_WORK(&h->work_trigger_to_ring, lis3l02dq_trigger_bh_to_ring);
 496        h->get_ring_element = &lis3l02dq_get_ring_element;
 497
 498        ring = iio_sw_rb_allocate(indio_dev);
 499        if (!ring)
 500                return -ENOMEM;
 501
 502        indio_dev->ring = ring;
 503        /* Effectively select the ring buffer implementation */
 504        iio_ring_sw_register_funcs(&ring->access);
 505        ring->bpe = 2;
 506        ring->scan_el_attrs = &lis3l02dq_scan_el_group;
 507        ring->scan_timestamp = true;
 508        ring->preenable = &iio_sw_ring_preenable;
 509        ring->postenable = &iio_triggered_ring_postenable;
 510        ring->predisable = &iio_triggered_ring_predisable;
 511        ring->owner = THIS_MODULE;
 512
 513        /* Set default scan mode */
 514        iio_scan_mask_set(ring, iio_scan_el_accel_x.number);
 515        iio_scan_mask_set(ring, iio_scan_el_accel_y.number);
 516        iio_scan_mask_set(ring, iio_scan_el_accel_z.number);
 517
 518        ret = iio_alloc_pollfunc(indio_dev, NULL, &lis3l02dq_poll_func_th);
 519        if (ret)
 520                goto error_iio_sw_rb_free;
 521        indio_dev->modes |= INDIO_RING_TRIGGERED;
 522        return 0;
 523
 524error_iio_sw_rb_free:
 525        iio_sw_rb_free(indio_dev->ring);
 526        return ret;
 527}
 528