@@ -344,6 +344,56 @@ static int adxl345_get_fifo_entries(struct adxl34x_state *st, int *fifo_entries)
return 0;
}
+/**
+ * Read fifo_entries number of elements into *st
+ *
+ * It is recommended that a multiple-byte read of all registers be
+ * performed to prevent a change in data between reads of sequential
+ * registers.
+ * That is to read out the data registers X0, X1, Y0, Y1, Z0, Z1 at once.
+ *
+ * @st: The instance of the state object of this sensor.
+ * @fifo_entries: The number of lines in the FIFO referred to as fifo_entry,
+ * a fifo_entry has 3 elements for X, Y and Z direction of 2 bytes each.
+ */
+static int adxl345_read_fifo_elements(struct adxl34x_state *st, int fifo_entries)
+{
+ size_t count, ndirs = 3;
+ int i, ret;
+
+ count = 2 * ndirs; /* 2 byte per direction */
+ for (i = 0; i < fifo_entries; i++) {
+ ret = regmap_noinc_read(st->regmap, ADXL345_REG_XYZ_BASE,
+ st->fifo_buf + (i * count / 2), count);
+ if (ret) {
+ pr_warn("%s(): regmap_noinc_read() failed\n", __func__);
+ return -EFAULT;
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * Empty the fifo. This is needed also in case of overflow or error handling.
+ * Read out all remaining elements and reset the fifo_entries counter.
+ *
+ * @st: The instance to the state object of the sensor.
+ */
+void adxl345_empty_fifo(struct adxl34x_state *st)
+{
+ int regval;
+ int fifo_entries;
+
+ /* In case the HW is not "clean" just read out remaining elements */
+ adxl345_get_fifo_entries(st, &fifo_entries);
+ if (fifo_entries > 0)
+ adxl345_read_fifo_elements(st, fifo_entries);
+
+ /* Reset the INT_SOURCE register by reading the register */
+ regmap_read(st->regmap, ADXL345_REG_INT_SOURCE, ®val);
+}
+
static const struct iio_buffer_setup_ops adxl345_buffer_ops = {
};
@@ -390,30 +440,34 @@ static irqreturn_t adxl345_trigger_handler(int irq, void *p)
ret = adxl345_get_status(st, &int_stat);
if (ret < 0)
- goto done;
+ goto err;
/* Ignore already read event by reissued too fast */
if (int_stat == 0x0)
- goto done;
+ goto err;
/* evaluation */
if (int_stat & ADXL345_INT_OVERRUN) {
pr_debug("%s(): OVERRUN event detected\n", __func__);
- goto done;
+ goto err;
}
if (int_stat & (ADXL345_INT_DATA_READY | ADXL345_INT_WATERMARK)) {
pr_debug("%s(): WATERMARK or DATA_READY event detected\n", __func__);
if (adxl345_get_fifo_entries(st, &fifo_entries) < 0)
- goto done;
- }
- goto done;
-done:
+ goto err;
- if (indio_dev)
iio_trigger_notify_done(indio_dev->trig);
+ }
+ goto done;
+err:
+ iio_trigger_notify_done(indio_dev->trig);
+ adxl345_empty_fifo(st);
+ return IRQ_NONE;
+
+done:
return IRQ_HANDLED;
}
Add a function to empty the FIFO and reset the INT_SOURCE register. Reading out is used to reset the fifo again. For cleanup also a read on the INT_SOURCE register is needed to allow the adxl345 to issue interrupts again. Without clearing the fields no further interrupts will happen. Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com> --- drivers/iio/accel/adxl345_core.c | 70 ++++++++++++++++++++++++++++---- 1 file changed, 62 insertions(+), 8 deletions(-)