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[18/22] iio: accel: adxl345: start measure at buffer en/disable

Message ID 20241114231002.98595-19-l.rubusch@gmail.com (mailing list archive)
State New
Headers show
Series iio: accel: adxl345: add FIFO operating with IRQ triggered watermark events | expand

Commit Message

Lothar Rubusch Nov. 14, 2024, 11:09 p.m. UTC
Add and initialize the buffer options to use the FIFO and watermark
feature of the adxl345 sensor. In this way measure enable will happen
in at enabling the buffer.

Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
---
 drivers/iio/accel/adxl345_core.c | 105 +++++++++++++++++++++++++++++--
 1 file changed, 101 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/drivers/iio/accel/adxl345_core.c b/drivers/iio/accel/adxl345_core.c
index f686037df3..a5b2efa69e 100644
--- a/drivers/iio/accel/adxl345_core.c
+++ b/drivers/iio/accel/adxl345_core.c
@@ -181,6 +181,28 @@  static const struct iio_chan_spec adxl34x_channels[] = {
 	ADXL34x_CHANNEL(2, chan_z, Z),
 };
 
+static int adxl345_set_interrupts(struct adxl34x_state *st)
+{
+	int ret;
+	unsigned int int_enable = st->int_map;
+	unsigned int int_map;
+
+	/* Any bits set to 0 in the INT map register send their respective
+	 * interrupts to the INT1 pin, whereas bits set to 1 send their respective
+	 * interrupts to the INT2 pin. The intio shall convert this accordingly.
+	 */
+	int_map = 0xFF & (st->intio ? st->int_map : ~st->int_map);
+	pr_debug("%s(): Setting INT_MAP 0x%02X\n", __func__, int_map);
+
+	ret = regmap_write(st->regmap, ADXL345_REG_INT_MAP, int_map);
+	if (ret)
+		return ret;
+
+	pr_debug("%s(): Setting INT_ENABLE 0x%02X\n", __func__, int_enable);
+	ret = regmap_write(st->regmap, ADXL345_REG_INT_ENABLE, int_enable);
+	return ret;
+}
+
 static int adxl345_read_raw(struct iio_dev *indio_dev,
 			    struct iio_chan_spec const *chan,
 			    int *val, int *val2, long mask)
@@ -328,6 +350,41 @@  static const struct attribute_group adxl345_attrs_group = {
 	.attrs = adxl345_attrs,
 };
 
+static int adxl345_set_fifo(struct adxl34x_state *st)
+{
+	struct adxl34x_platform_data *data = &st->data;
+	u8 fifo_ctl;
+	int ret;
+
+	/* FIFO should be configured while in standby mode */
+	adxl345_set_measure_en(st, false);
+
+	/* The watermark bit is set when the number of samples in FIFO
+	 * equals the value stored in the samples bits (register
+	 * FIFO_CTL). The watermark bit is cleared automatically when
+	 * FIFO is read, and the content returns to a value below the
+	 * value stored in the samples bits.
+	 */
+	fifo_ctl = 0x00 |
+		ADXL345_FIFO_CTL_SAMLPES(data->watermark) |
+		ADXL345_FIFO_CTL_TRIGGER(st->intio) |
+		ADXL345_FIFO_CTL_MODE(data->fifo_mode);
+
+	pr_debug("%s(): fifo_ctl 0x%02X\n", __func__, fifo_ctl);
+
+	/* The watermark bit is set when the number of samples in FIFO
+	 * equals the value stored in the samples bits (register
+	 * FIFO_CTL). The watermark bit is cleared automatically when
+	 * FIFO is read, and the content returns to a value below the
+	 * value stored in the samples bits.
+	 */
+	ret = regmap_write(st->regmap, ADXL345_REG_FIFO_CTL, fifo_ctl);
+	if (ret < 0)
+		return ret;
+
+	return adxl345_set_measure_en(st, true);
+}
+
 /**
  * Read number of FIFO entries into *fifo_entries
  */
@@ -399,7 +456,50 @@  void adxl345_empty_fifo(struct adxl34x_state *st)
 	regmap_read(st->regmap, ADXL345_REG_INT_SOURCE, &regval);
 }
 
+static int adxl345_buffer_postenable(struct iio_dev *indio_dev)
+{
+	struct adxl34x_state *st = iio_priv(indio_dev);
+	struct adxl34x_platform_data *data = &st->data;
+	int ret;
+
+	ret = adxl345_set_interrupts(st);
+	if (ret)
+		return -EINVAL;
+
+	/* Default to FIFO mode: STREAM, since it covers the general usage
+	 * and does not bypass the FIFO
+	 */
+	data->fifo_mode = ADXL_FIFO_STREAM;
+	adxl345_set_fifo(st);
+
+	return 0;
+}
+
+static int adxl345_buffer_predisable(struct iio_dev *indio_dev)
+{
+	struct adxl34x_state *st = iio_priv(indio_dev);
+	struct adxl34x_platform_data *data = &st->data;
+	int ret;
+
+	/* Turn off interrupts */
+	st->int_map = 0x00;
+
+	ret = adxl345_set_interrupts(st);
+	if (ret) {
+		pr_warn("%s(): Failed to disable INTs\n", __func__);
+		return -EINVAL;
+	}
+
+	/* Set FIFO mode: BYPASS, according to the situation */
+	data->fifo_mode = ADXL_FIFO_BYPASS;
+	adxl345_set_fifo(st);
+
+	return 0;
+}
+
 static const struct iio_buffer_setup_ops adxl345_buffer_ops = {
+	.postenable = adxl345_buffer_postenable,
+	.predisable = adxl345_buffer_predisable,
 };
 
 static int adxl345_get_status(struct adxl34x_state *st, u8 *int_stat)
@@ -609,7 +709,7 @@  int adxl345_core_probe(struct device *dev, struct regmap *regmap,
 
 	indio_dev->name = st->info->name;
 	indio_dev->info = &adxl345_info;
-	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
 	indio_dev->channels = adxl34x_channels;
 	indio_dev->num_channels = ARRAY_SIZE(adxl34x_channels);
 
@@ -669,9 +769,6 @@  int adxl345_core_probe(struct device *dev, struct regmap *regmap,
 		ret = regmap_write(st->regmap, ADXL345_REG_FIFO_CTL, fifo_ctl);
 		if (ret < 0)
 			return ret;
-
-		/* Enable measurement mode */
-		adxl345_set_measure_en(st, true);
 	}
 	dev_dbg(dev, "Driver operational\n");
 	return devm_iio_device_register(dev, indio_dev);