--- /dev/null
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/gpio.h>
+#include <linux/workqueue.h>
+#include <linux/mutex.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/spi/spi.h>
+#include <linux/sysfs.h>
+#include <linux/list.h>
+
+#include "../iio.h"
+#include "../sysfs.h"
+#include "../ring_sw.h"
+#include "accel.h"
+#include "../trigger.h"
+#include "lis3l02dq.h"
+
+/**
+ * combine_8_to_16() utility function to munge to u8s into u16
+ **/
+static inline u16 combine_8_to_16(u8 lower, u8 upper)
+{
+ u16 _lower = lower;
+ u16 _upper = upper;
+ return _lower | (_upper << 8);
+}
+
+/**
+ * lis3l02dq_scan_el_set_state() set whether a scan contains a given channel
+ * @scan_el: associtate iio scan element attribute
+ * @indio_dev: the device structure
+ * @bool: desired state
+ *
+ * mlock already held when this is called.
+ **/
+static int lis3l02dq_scan_el_set_state(struct iio_scan_el *scan_el,
+ struct iio_dev *indio_dev,
+ bool state)
+{
+ u8 t, mask;
+ int ret;
+
+ ret = lis3l02dq_spi_read_reg_8(&indio_dev->dev,
+ LIS3L02DQ_REG_CTRL_1_ADDR,
+ &t);
+ if (ret)
+ goto error_ret;
+ switch (scan_el->label) {
+ case LIS3L02DQ_REG_OUT_X_L_ADDR:
+ mask = LIS3L02DQ_REG_CTRL_1_AXES_X_ENABLE;
+ break;
+ case LIS3L02DQ_REG_OUT_Y_L_ADDR:
+ mask = LIS3L02DQ_REG_CTRL_1_AXES_Y_ENABLE;
+ break;
+ case LIS3L02DQ_REG_OUT_Z_L_ADDR:
+ mask = LIS3L02DQ_REG_CTRL_1_AXES_Z_ENABLE;
+ break;
+ default:
+ ret = -EINVAL;
+ goto error_ret;
+ }
+
+ if (!(mask & t) == state) {
+ if (state)
+ t |= mask;
+ else
+ t &= ~mask;
+ ret = lis3l02dq_spi_write_reg_8(&indio_dev->dev,
+ LIS3L02DQ_REG_CTRL_1_ADDR,
+ &t);
+ }
+error_ret:
+ return ret;
+
+}
+static IIO_SCAN_EL_C(accel_x, LIS3L02DQ_SCAN_ACC_X, IIO_SIGNED(16),
+ LIS3L02DQ_REG_OUT_X_L_ADDR,
+ &lis3l02dq_scan_el_set_state);
+static IIO_SCAN_EL_C(accel_y, LIS3L02DQ_SCAN_ACC_Y, IIO_SIGNED(16),
+ LIS3L02DQ_REG_OUT_Y_L_ADDR,
+ &lis3l02dq_scan_el_set_state);
+static IIO_SCAN_EL_C(accel_z, LIS3L02DQ_SCAN_ACC_Z, IIO_SIGNED(16),
+ LIS3L02DQ_REG_OUT_Z_L_ADDR,
+ &lis3l02dq_scan_el_set_state);
+static IIO_SCAN_EL_TIMESTAMP;
+
+static struct attribute *lis3l02dq_scan_el_attrs[] = {
+ &iio_scan_el_accel_x.dev_attr.attr,
+ &iio_scan_el_accel_y.dev_attr.attr,
+ &iio_scan_el_accel_z.dev_attr.attr,
+ &iio_scan_el_timestamp.dev_attr.attr,
+ NULL,
+};
+
+static struct attribute_group lis3l02dq_scan_el_group = {
+ .attrs = lis3l02dq_scan_el_attrs,
+ .name = "scan_elements",
+};
+
+/**
+ * lis3l02dq_poll_func_th() top half interrupt handler called by trigger
+ * @private_data: iio_dev
+ **/
+static void lis3l02dq_poll_func_th(struct iio_dev *indio_dev)
+{
+ struct lis3l02dq_state *st = iio_dev_get_devdata(indio_dev);
+ st->last_timestamp = indio_dev->trig->timestamp;
+ schedule_work(&st->work_trigger_to_ring);
+ /* Indicate that this interrupt is being handled */
+
+ /* Technically this is trigger related, but without this
+ * handler running there is currently now way for the interrupt
+ * to clear.
+ */
+ st->inter = 1;
+}
+
+/**
+ * lis3l02dq_data_rdy_trig_poll() the event handler for the data rdy trig
+ **/
+static int lis3l02dq_data_rdy_trig_poll(struct iio_dev *dev_info,
+ int index,
+ s64 timestamp,
+ int no_test)
+{
+ struct lis3l02dq_state *st = iio_dev_get_devdata(dev_info);
+ struct iio_trigger *trig = st->trig;
+
+ trig->timestamp = timestamp;
+ iio_trigger_poll(trig);
+
+ return IRQ_HANDLED;
+}
+
+/* This is an event as it is a response to a physical interrupt */
+IIO_EVENT_SH(data_rdy_trig, &lis3l02dq_data_rdy_trig_poll);
+
+/**
+ * lis3l02dq_read_accel_from_ring() individual acceleration read from ring
+ **/
+ssize_t lis3l02dq_read_accel_from_ring(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_scan_el *el = NULL;
+ int ret, len = 0, i = 0;
+ struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+ struct iio_dev *dev_info = dev_get_drvdata(dev);
+ s16 *data;
+
+ while (dev_info->scan_el_attrs->attrs[i]) {
+ el = to_iio_scan_el((struct device_attribute *)
+ (dev_info->scan_el_attrs->attrs[i]));
+ /* label is in fact the address */
+ if (el->label == this_attr->address)
+ break;
+ i++;
+ }
+ if (!dev_info->scan_el_attrs->attrs[i]) {
+ ret = -EINVAL;
+ goto error_ret;
+ }
+ /* If this element is in the scan mask */
+ ret = iio_scan_mask_query(dev_info, el->number);
+ if (ret < 0)
+ goto error_ret;
+ if (ret) {
+ data = kmalloc(dev_info->ring->access.get_bpd(dev_info->ring),
+ GFP_KERNEL);
+ if (data == NULL)
+ return -ENOMEM;
+ ret = dev_info->ring->access.read_last(dev_info->ring,
+ (u8 *)data);
+ if (ret)
+ goto error_free_data;
+ } else {
+ ret = -EINVAL;
+ goto error_ret;
+ }
+ len = iio_scan_mask_count_to_right(dev_info, el->number);
+ if (len < 0) {
+ ret = len;
+ goto error_free_data;
+ }
+ len = sprintf(buf, "ring %d\n", data[len]);
+error_free_data:
+ kfree(data);
+error_ret:
+ return ret ? ret : len;
+
+}
+
+static const u8 read_all_tx_array[] =
+{
+ LIS3L02DQ_READ_REG(LIS3L02DQ_REG_OUT_X_L_ADDR), 0,
+ LIS3L02DQ_READ_REG(LIS3L02DQ_REG_OUT_X_H_ADDR), 0,
+ LIS3L02DQ_READ_REG(LIS3L02DQ_REG_OUT_Y_L_ADDR), 0,
+ LIS3L02DQ_READ_REG(LIS3L02DQ_REG_OUT_Y_H_ADDR), 0,
+ LIS3L02DQ_READ_REG(LIS3L02DQ_REG_OUT_Z_L_ADDR), 0,
+ LIS3L02DQ_READ_REG(LIS3L02DQ_REG_OUT_Z_H_ADDR), 0,
+};
+
+/**
+ * lis3l02dq_read_all() Reads all channels currently selected
+ * @st: device specific state
+ * @rx_array: (dma capable) recieve array, must be at least
+ * 4*number of channels
+ **/
+int lis3l02dq_read_all(struct lis3l02dq_state *st, u8 *rx_array)
+{
+ struct spi_transfer *xfers;
+ struct spi_message msg;
+ int ret, i, j = 0;
+
+ xfers = kzalloc((st->indio_dev->scan_count) * 2
+ * sizeof(*xfers), GFP_KERNEL);
+ if (!xfers)
+ return -ENOMEM;
+
+ mutex_lock(&st->buf_lock);
+
+ for (i = 0; i < ARRAY_SIZE(read_all_tx_array)/4; i++) {
+ if (st->indio_dev->scan_mask & (1 << i)) {
+ /* lower byte */
+ xfers[j].tx_buf = st->tx + 2*j;
+ st->tx[2*j] = read_all_tx_array[i*4];
+ st->tx[2*j + 1] = 0;
+ if (rx_array)
+ xfers[j].rx_buf = rx_array + j*2;
+ xfers[j].bits_per_word = 8;
+ xfers[j].len = 2;
+ xfers[j].cs_change = 1;
+ j++;
+
+ /* upper byte */
+ xfers[j].tx_buf = st->tx + 2*j;
+ st->tx[2*j] = read_all_tx_array[i*4 + 2];
+ st->tx[2*j + 1] = 0;
+ if (rx_array)
+ xfers[j].rx_buf = rx_array + j*2;
+ xfers[j].bits_per_word = 8;
+ xfers[j].len = 2;
+ xfers[j].cs_change = 1;
+ j++;
+ }
+ }
+ /* After these are transmitted, the rx_buff should have
+ * values in alternate bytes
+ */
+ spi_message_init(&msg);
+ for (j = 0; j < st->indio_dev->scan_count * 2; j++)
+ spi_message_add_tail(&xfers[j], &msg);
+
+ ret = spi_sync(st->us, &msg);
+ mutex_unlock(&st->buf_lock);
+ kfree(xfers);
+
+ return ret;
+}
+
+
+/* Whilst this makes a lot of calls to iio_sw_ring functions - it is to device
+ * specific to be rolled into the core.
+ */
+static void lis3l02dq_trigger_bh_to_ring(struct work_struct *work_s)
+{
+ struct lis3l02dq_state *st
+ = container_of(work_s, struct lis3l02dq_state,
+ work_trigger_to_ring);
+
+ u8 *rx_array;
+ int i = 0;
+ u16 *data;
+ size_t datasize = st->indio_dev
+ ->ring->access.get_bpd(st->indio_dev->ring);
+
+ data = kmalloc(datasize , GFP_KERNEL);
+ if (data == NULL) {
+ dev_err(&st->us->dev, "memory alloc failed in ring bh");
+ return;
+ }
+ /* Due to interleaved nature of transmission this buffer must be
+ * twice the number of bytes, or 4 times the number of channels
+ */
+ rx_array = kmalloc(4 * (st->indio_dev->scan_count), GFP_KERNEL);
+ if (rx_array == NULL) {
+ dev_err(&st->us->dev, "memory alloc failed in ring bh");
+ return;
+ }
+
+ /* whilst trigger specific, if this read does nto occur the data
+ ready interrupt will not be cleared. Need to add a mechanism
+ to provide a dummy read function if this is not triggering on
+ the data ready function but something else is.
+ */
+ st->inter = 0;
+
+ if (st->indio_dev->scan_count)
+ if (lis3l02dq_read_all(st, rx_array) >= 0)
+ for (; i < st->indio_dev->scan_count; i++)
+ data[i] = combine_8_to_16(rx_array[i*4+1],
+ rx_array[i*4+3]);
+ /* Guaranteed to be aligned with 8 byte boundary */
+ if (st->indio_dev->scan_timestamp)
+ *((s64 *)(data + ((i + 3)/4)*4)) = st->last_timestamp;
+
+ st->indio_dev->ring->access.store_to(st->indio_dev->ring,
+ (u8 *)data,
+ st->last_timestamp);
+
+ iio_trigger_notify_done(st->indio_dev->trig);
+ kfree(rx_array);
+ kfree(data);
+
+ return;
+}
+/* in these circumstances is it better to go with unaligned packing and
+ * deal with the cost?*/
+static int lis3l02dq_data_rdy_ring_preenable(struct iio_dev *indio_dev)
+{
+ size_t size;
+ /* Check if there are any scan elements enabled, if not fail*/
+ if (!(indio_dev->scan_count || indio_dev->scan_timestamp))
+ return -EINVAL;
+
+ if (indio_dev->ring->access.set_bpd) {
+ if (indio_dev->scan_timestamp)
+ if (indio_dev->scan_count) /* Timestamp and data */
+ size = 2*sizeof(s64);
+ else /* Timestamp only */
+ size = sizeof(s64);
+ else /* Data only */
+ size = indio_dev->scan_count*sizeof(s16);
+ indio_dev->ring->access.set_bpd(indio_dev->ring, size);
+ }
+
+ return 0;
+}
+
+static int lis3l02dq_data_rdy_ring_postenable(struct iio_dev *indio_dev)
+{
+ return indio_dev->trig
+ ? iio_trigger_attach_poll_func(indio_dev->trig,
+ indio_dev->pollfunc)
+ : 0;
+}
+
+static int lis3l02dq_data_rdy_ring_predisable(struct iio_dev *indio_dev)
+{
+ return indio_dev->trig
+ ? iio_trigger_dettach_poll_func(indio_dev->trig,
+ indio_dev->pollfunc)
+ : 0;
+}
+
+
+/* Caller responsible for locking as necessary. */
+static int __lis3l02dq_write_data_ready_config(struct device *dev,
+ struct
+ iio_event_handler_list *list,
+ bool state)
+{
+ int ret;
+ u8 valold;
+ bool currentlyset;
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+
+/* Get the current event mask register */
+ ret = lis3l02dq_spi_read_reg_8(dev,
+ LIS3L02DQ_REG_CTRL_2_ADDR,
+ &valold);
+ if (ret)
+ goto error_ret;
+/* Find out if data ready is already on */
+ currentlyset
+ = valold & LIS3L02DQ_REG_CTRL_2_ENABLE_DATA_READY_GENERATION;
+
+/* Disable requested */
+ if (!state && currentlyset) {
+
+ valold &= ~LIS3L02DQ_REG_CTRL_2_ENABLE_DATA_READY_GENERATION;
+ /* The double write is to overcome a hardware bug?*/
+ ret = lis3l02dq_spi_write_reg_8(dev,
+ LIS3L02DQ_REG_CTRL_2_ADDR,
+ &valold);
+ if (ret)
+ goto error_ret;
+ ret = lis3l02dq_spi_write_reg_8(dev,
+ LIS3L02DQ_REG_CTRL_2_ADDR,
+ &valold);
+ if (ret)
+ goto error_ret;
+
+ iio_remove_event_from_list(list,
+ &indio_dev->interrupts[0]
+ ->ev_list);
+
+/* Enable requested */
+ } else if (state && !currentlyset) {
+ /* if not set, enable requested */
+ valold |= LIS3L02DQ_REG_CTRL_2_ENABLE_DATA_READY_GENERATION;
+ iio_add_event_to_list(list, &indio_dev->interrupts[0]->ev_list);
+ ret = lis3l02dq_spi_write_reg_8(dev,
+ LIS3L02DQ_REG_CTRL_2_ADDR,
+ &valold);
+ if (ret)
+ goto error_ret;
+ }
+
+ return 0;
+error_ret:
+ return ret;
+}
+
+/**
+ * lis3l02dq_data_rdy_trigger_set_state() set datardy interrupt state
+ *
+ * If disabling the interrupt also does a final read to ensure it is clear.
+ * This is only important in some cases where the scan enable elements are
+ * switched before the ring is reenabled.
+ **/
+static int lis3l02dq_data_rdy_trigger_set_state(struct iio_trigger *trig,
+ bool state)
+{
+ struct lis3l02dq_state *st = trig->private_data;
+ int ret = 0;
+ u8 t;
+ __lis3l02dq_write_data_ready_config(&st->indio_dev->dev,
+ &iio_event_data_rdy_trig,
+ state);
+ if (state == false) {
+ /* possible quirk with handler currently worked around
+ by ensuring the work queue is empty */
+ flush_scheduled_work();
+ /* Clear any outstanding ready events */
+ ret = lis3l02dq_read_all(st, NULL);
+ }
+ lis3l02dq_spi_read_reg_8(&st->indio_dev->dev,
+ LIS3L02DQ_REG_WAKE_UP_SRC_ADDR,
+ &t);
+ return ret;
+}
+DEVICE_ATTR(name, S_IRUGO, iio_trigger_read_name, NULL);
+
+static struct attribute *lis3l02dq_trigger_attrs[] = {
+ &dev_attr_name.attr,
+ NULL,
+};
+
+static const struct attribute_group lis3l02dq_trigger_attr_group = {
+ .attrs = lis3l02dq_trigger_attrs,
+};
+
+/**
+ * lis3l02dq_trig_try_reen() try renabling irq for data rdy trigger
+ * @trig: the datardy trigger
+ *
+ * As the trigger may occur on any data element being updated it is
+ * really rather likely to occur during the read from the previous
+ * trigger event. The only way to discover if this has occured on
+ * boards not supporting level interrupts is to take a look at the line.
+ * If it is indicating another interrupt and we don't seem to have a
+ * handler looking at it, then we need to notify the core that we need
+ * to tell the triggering core to try reading all these again.
+ **/
+static int lis3l02dq_trig_try_reen(struct iio_trigger *trig)
+{
+ struct lis3l02dq_state *st = trig->private_data;
+ enable_irq(st->us->irq);
+ /* If gpio still high (or high again) */
+ if (gpio_get_value(irq_to_gpio(st->us->irq)))
+ if (st->inter == 0) {
+ /* already interrupt handler dealing with it */
+ disable_irq_nosync(st->us->irq);
+ if (st->inter == 1) {
+ /* interrupt handler snuck in between test
+ * and disable */
+ enable_irq(st->us->irq);
+ return 0;
+ }
+ return -EAGAIN;
+ }
+ /* irq reenabled so success! */
+ return 0;
+}
+
+int lis3l02dq_probe_trigger(struct iio_dev *indio_dev)
+{
+ int ret;
+ struct lis3l02dq_state *state = indio_dev->dev_data;
+
+ state->trig = iio_allocate_trigger();
+ state->trig->name = kmalloc(IIO_TRIGGER_NAME_LENGTH, GFP_KERNEL);
+ if (!state->trig->name) {
+ ret = -ENOMEM;
+ goto error_free_trig;
+ }
+ snprintf((char *)state->trig->name,
+ IIO_TRIGGER_NAME_LENGTH,
+ "lis3l02dq-dev%d", indio_dev->id);
+ state->trig->dev.parent = &state->us->dev;
+ state->trig->owner = THIS_MODULE;
+ state->trig->private_data = state;
+ state->trig->set_trigger_state = &lis3l02dq_data_rdy_trigger_set_state;
+ state->trig->try_reenable = &lis3l02dq_trig_try_reen;
+ state->trig->control_attrs = &lis3l02dq_trigger_attr_group;
+ ret = iio_trigger_register(state->trig);
+ if (ret)
+ goto error_free_trig_name;
+
+ return 0;
+
+error_free_trig_name:
+ kfree(state->trig->name);
+error_free_trig:
+ iio_free_trigger(state->trig);
+
+ return ret;
+}
+
+void lis3l02dq_remove_trigger(struct iio_dev *indio_dev)
+{
+ struct lis3l02dq_state *state = indio_dev->dev_data;
+
+ iio_trigger_unregister(state->trig);
+ kfree(state->trig->name);
+ iio_free_trigger(state->trig);
+}
+
+void lis3l02dq_unconfigure_ring(struct iio_dev *indio_dev)
+{
+ kfree(indio_dev->pollfunc);
+ iio_sw_rb_free(indio_dev->ring);
+}
+
+int lis3l02dq_configure_ring(struct iio_dev *indio_dev)
+{
+ int ret = 0;
+ struct lis3l02dq_state *st = indio_dev->dev_data;
+ struct iio_ring_buffer *ring;
+ INIT_WORK(&st->work_trigger_to_ring, lis3l02dq_trigger_bh_to_ring);
+ /* Set default scan mode */
+
+ iio_scan_mask_set(indio_dev, iio_scan_el_accel_x.number);
+ iio_scan_mask_set(indio_dev, iio_scan_el_accel_y.number);
+ iio_scan_mask_set(indio_dev, iio_scan_el_accel_z.number);
+ indio_dev->scan_timestamp = true;
+
+ indio_dev->scan_el_attrs = &lis3l02dq_scan_el_group;
+
+ ring = iio_sw_rb_allocate(indio_dev);
+ if (!ring) {
+ ret = -ENOMEM;
+ return ret;
+ }
+ indio_dev->ring = ring;
+ /* Effectively select the ring buffer implementation */
+ iio_ring_sw_register_funcs(&ring->access);
+ ring->preenable = &lis3l02dq_data_rdy_ring_preenable;
+ ring->postenable = &lis3l02dq_data_rdy_ring_postenable;
+ ring->predisable = &lis3l02dq_data_rdy_ring_predisable;
+ ring->owner = THIS_MODULE;
+
+ indio_dev->pollfunc = kzalloc(sizeof(*indio_dev->pollfunc), GFP_KERNEL);
+ if (indio_dev->pollfunc == NULL) {
+ ret = -ENOMEM;
+ goto error_iio_sw_rb_free;;
+ }
+ indio_dev->pollfunc->poll_func_main = &lis3l02dq_poll_func_th;
+ indio_dev->pollfunc->private_data = indio_dev;
+ indio_dev->modes |= INDIO_RING_TRIGGERED;
+ return 0;
+
+error_iio_sw_rb_free:
+ iio_sw_rb_free(indio_dev->ring);
+ return ret;
+}
+
+int lis3l02dq_initialize_ring(struct iio_ring_buffer *ring)
+{
+ return iio_ring_buffer_register(ring);
+}
+
+void lis3l02dq_uninitialize_ring(struct iio_ring_buffer *ring)
+{
+ iio_ring_buffer_unregister(ring);
+}
+
+
+int lis3l02dq_set_ring_length(struct iio_dev *indio_dev, int length)
+{
+ /* Set sensible defaults for the ring buffer */
+ if (indio_dev->ring->access.set_length)
+ return indio_dev->ring->access.set_length(indio_dev->ring, 500);
+ return 0;
+}
+
+