[PATCH v4 00/10] iio: accel: adxl345: add FIFO operating with IRQ triggered watermark events

[PATCH v4 00/10] iio: accel: adxl345: add FIFO operating with IRQ triggered watermark events

[Lothar Rubusch]

The adxl345 sensor offers several features. Most of them are based on
using the hardware FIFO and reacting on events coming in on an interrupt
line. Add access to configure and read out the FIFO, handling of interrupts
and configuration and application of the watermark feature on that FIFO.

Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
---
Although I tried to implement most of the requested changes, now the code
is simplified and clearer, I still encounter some issues.

1) Unsure if my way reading out the FIFO elements with a regmap_noinc_read()
   is supposed to be like that. TBH, isn't there a better way, say, to
   configure the channel correctly and this is handled by the iio API
   internally? As I understood from v2 there might be a way using
   available data, also in iio_info I see now as buffer attributes an
   available data field. Where can I find information how to use it or
   did I get this wrong?

2) Overrun handling: I'm trying to reset the FIFO and registers. Unsure,
   if this is the correct dealing here.

3) I can see the IRQs coming in, and with a `watch -n 0.1 iio_info` I can
   see the correct fields changing. I tried the follwoing down below,
   but the iio_readdev shows me the following result. I don't quite
   understand if I still have an issue here, or if this is a calibration
   thing?

# iio_info 
Library version: 0.23 (git tag: v0.23)
Compiled with backends: local xml ip usb
IIO context created with local backend.
Backend version: 0.23 (git tag: v0.23)
Backend description string: Linux dut1138 6.6.21-lothar02 #3 SMP PREEMPT Wed Nov  6 21:21:14 UTC 2024 aarch64
IIO context has 2 attributes:
	local,kernel: 6.6.21-lothar02
	uri: local:
IIO context has 1 devices:
	iio:device0: adxl345 (buffer capable)
		3 channels found:
			accel_x:  (input, index: 0, format: le:s13/16>>0)
			4 channel-specific attributes found:
				attr  0: calibbias value: 0
				attr  1: raw value: -14                          <--- CHANGES
				attr  2: sampling_frequency value: 100.000000000
				attr  3: scale value: 0.038300
			accel_y:  (input, index: 1, format: le:s13/16>>0)
			4 channel-specific attributes found:
				attr  0: calibbias value: 0
				attr  1: raw value: 6                            <--- CHANGES
				attr  2: sampling_frequency value: 100.000000000
				attr  3: scale value: 0.038300
			accel_z:  (input, index: 2, format: le:s13/16>>0)
			4 channel-specific attributes found:
				attr  0: calibbias value: 0
				attr  1: raw value: 247                          <--- CHANGES
				attr  2: sampling_frequency value: 100.000000000
				attr  3: scale value: 0.038300
		2 device-specific attributes found:
				attr  0: sampling_frequency_available value: 0.09765625 0.1953125 0.390625 0.78125 1.5625 3.125 6.25 12.5 25 50 100 200 400 800 1600 3200
				attr  1: waiting_for_supplier value: 0
		3 buffer-specific attributes found:
				attr  0: data_available value: 13
				attr  1: direction value: in
				attr  2: watermark value: 15
		No trigger on this device

  Above I marked what keeps changing with "CHANGES", that's what I expect. Then with readdev
  I obtain the following result.

# iio_attr -c adxl345
dev 'adxl345', channel 'accel_x' (input, index: 0, format: le:s13/16>>0), found 4 channel-specific attributes
dev 'adxl345', channel 'accel_y' (input, index: 1, format: le:s13/16>>0), found 4 channel-specific attributes
dev 'adxl345', channel 'accel_z' (input, index: 2, format: le:s13/16>>0), found 4 channel-specific attributes
# echo 1 > ./scan_elements/in_accel_x_en
# echo 1 > ./scan_elements/in_accel_y_en
# echo 1 > ./scan_elements/in_accel_z_en
# echo 32 > ./buffer0/length
# echo 15 > ./buffer0/watermark
# echo 1 > ./buffer0/enable
# iio_readdev -b 16 -s 21 adxl345 > samples.dat
# hexdump -d ./samples.dat 
0000000   65523   00006   00248   65523   00005   00235   65522   00006
0000010   00248   65522   00006   00248   65521   00005   00247   65522
0000020   00007   00249   65523   00005   00249   65521   00006   00248
0000030   65522   00006   00248   65522   00006   00250   65522   00006
0000040   00249   65522   00005   00248   65523   00005   00248   65521
0000050   00007   00248   65521   00006   00250   65522   00005   00248
0000060   65521   00006   00248   65522   00007   00247   65522   00006
0000070   00248   65522   00006   00248   65521   00004   00250        
000007e

  Am I doing this actually correctly?

---
v3 -> v4: fix kernel-doc warning; fix dt-binding indention
v2 -> v3: Implementation reworked and simplified
          - INT lines are defined by binding
          - kfifo is prepared by devm_iio_kfifo_buffer_setup()
          - event handler is registered w/ devm_request_threaded_irq()
v1 -> v2: Fix comments according to Documentation/doc-guide/kernel-doc.rst
          and missing static declaration of function.
---
Lothar Rubusch (10):
  iio: accel: adxl345: fix comment on probe
  iio: accel: adxl345: rename variable data to st
  iio: accel: adxl345: measure right-justified
  iio: accel: adxl345: add function to switch measuring
  iio: accel: adxl345: extend list of defines
  dt-bindings: iio: accel: add interrupt-names
  iio: accel: adxl345: initialize IRQ number
  iio: accel: adxl345: initialize FIFO delay value for SPI
  iio: accel: adxl345: prepare channel for scan_index
  iio: accel: adxl345: add kfifo with watermark

 .../bindings/iio/accel/adi,adxl345.yaml       |  11 +
 drivers/iio/accel/adxl345.h                   |  90 +++-
 drivers/iio/accel/adxl345_core.c              | 427 ++++++++++++++++--
 drivers/iio/accel/adxl345_i2c.c               |   2 +-
 drivers/iio/accel/adxl345_spi.c               |   7 +-
 5 files changed, 482 insertions(+), 55 deletions(-)

-- 
2.39.2

[PATCH v4 01/10] iio: accel: adxl345: fix comment on probe

[Lothar Rubusch]

Fix comment on the probe function. Add covered sensors and fix typo.

Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
---
 drivers/iio/accel/adxl345_core.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/iio/accel/adxl345_core.c b/drivers/iio/accel/adxl345_core.c
index 006ce66c0aa..eb3ce4434a5 100644
--- a/drivers/iio/accel/adxl345_core.c
+++ b/drivers/iio/accel/adxl345_core.c
@@ -169,8 +169,7 @@ static void adxl345_powerdown(void *regmap)
 }
 
 /**
- * adxl345_core_probe() - probe and setup for the adxl345 accelerometer,
- *                        also covers the adlx375 accelerometer
+ * adxl345_core_probe() - Probe and setup for the accelerometer.
  * @dev:	Driver model representation of the device
  * @regmap:	Regmap instance for the device
  * @setup:	Setup routine to be executed right before the standard device
-- 
2.39.2

[PATCH v4 02/10] iio: accel: adxl345: rename variable data to st

[Lothar Rubusch]

Rename the locally used variable data to st. The st refers to "state",
representing the internal state of the driver object. Further it
prepares the usage of an internal data pointer needed for the
implementation of the sensor features.

Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
---
 drivers/iio/accel/adxl345_core.c | 44 ++++++++++++++++----------------
 1 file changed, 22 insertions(+), 22 deletions(-)

diff --git a/drivers/iio/accel/adxl345_core.c b/drivers/iio/accel/adxl345_core.c
index eb3ce4434a5..88df9547bd6 100644
--- a/drivers/iio/accel/adxl345_core.c
+++ b/drivers/iio/accel/adxl345_core.c
@@ -17,7 +17,7 @@
 
 #include "adxl345.h"
 
-struct adxl345_data {
+struct adxl345_state {
 	const struct adxl345_chip_info *info;
 	struct regmap *regmap;
 };
@@ -43,7 +43,7 @@ static int adxl345_read_raw(struct iio_dev *indio_dev,
 			    struct iio_chan_spec const *chan,
 			    int *val, int *val2, long mask)
 {
-	struct adxl345_data *data = iio_priv(indio_dev);
+	struct adxl345_state *st = iio_priv(indio_dev);
 	__le16 accel;
 	long long samp_freq_nhz;
 	unsigned int regval;
@@ -56,7 +56,7 @@ static int adxl345_read_raw(struct iio_dev *indio_dev,
 		 * ADXL345_REG_DATA(X0/Y0/Z0) contain the least significant byte
 		 * and ADXL345_REG_DATA(X0/Y0/Z0) + 1 the most significant byte
 		 */
-		ret = regmap_bulk_read(data->regmap,
+		ret = regmap_bulk_read(st->regmap,
 				       ADXL345_REG_DATA_AXIS(chan->address),
 				       &accel, sizeof(accel));
 		if (ret < 0)
@@ -66,10 +66,10 @@ static int adxl345_read_raw(struct iio_dev *indio_dev,
 		return IIO_VAL_INT;
 	case IIO_CHAN_INFO_SCALE:
 		*val = 0;
-		*val2 = data->info->uscale;
+		*val2 = st->info->uscale;
 		return IIO_VAL_INT_PLUS_MICRO;
 	case IIO_CHAN_INFO_CALIBBIAS:
-		ret = regmap_read(data->regmap,
+		ret = regmap_read(st->regmap,
 				  ADXL345_REG_OFS_AXIS(chan->address), &regval);
 		if (ret < 0)
 			return ret;
@@ -81,7 +81,7 @@ static int adxl345_read_raw(struct iio_dev *indio_dev,
 
 		return IIO_VAL_INT;
 	case IIO_CHAN_INFO_SAMP_FREQ:
-		ret = regmap_read(data->regmap, ADXL345_REG_BW_RATE, &regval);
+		ret = regmap_read(st->regmap, ADXL345_REG_BW_RATE, &regval);
 		if (ret < 0)
 			return ret;
 
@@ -99,7 +99,7 @@ static int adxl345_write_raw(struct iio_dev *indio_dev,
 			     struct iio_chan_spec const *chan,
 			     int val, int val2, long mask)
 {
-	struct adxl345_data *data = iio_priv(indio_dev);
+	struct adxl345_state *st = iio_priv(indio_dev);
 	s64 n;
 
 	switch (mask) {
@@ -108,14 +108,14 @@ static int adxl345_write_raw(struct iio_dev *indio_dev,
 		 * 8-bit resolution at +/- 2g, that is 4x accel data scale
 		 * factor
 		 */
-		return regmap_write(data->regmap,
+		return regmap_write(st->regmap,
 				    ADXL345_REG_OFS_AXIS(chan->address),
 				    val / 4);
 	case IIO_CHAN_INFO_SAMP_FREQ:
 		n = div_s64(val * NANOHZ_PER_HZ + val2,
 			    ADXL345_BASE_RATE_NANO_HZ);
 
-		return regmap_update_bits(data->regmap, ADXL345_REG_BW_RATE,
+		return regmap_update_bits(st->regmap, ADXL345_REG_BW_RATE,
 					  ADXL345_BW_RATE,
 					  clamp_val(ilog2(n), 0,
 						    ADXL345_BW_RATE));
@@ -180,7 +180,7 @@ static void adxl345_powerdown(void *regmap)
 int adxl345_core_probe(struct device *dev, struct regmap *regmap,
 		       int (*setup)(struct device*, struct regmap*))
 {
-	struct adxl345_data *data;
+	struct adxl345_state *st;
 	struct iio_dev *indio_dev;
 	u32 regval;
 	unsigned int data_format_mask = (ADXL345_DATA_FORMAT_RANGE |
@@ -189,17 +189,17 @@ int adxl345_core_probe(struct device *dev, struct regmap *regmap,
 					 ADXL345_DATA_FORMAT_SELF_TEST);
 	int ret;
 
-	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
 	if (!indio_dev)
 		return -ENOMEM;
 
-	data = iio_priv(indio_dev);
-	data->regmap = regmap;
-	data->info = device_get_match_data(dev);
-	if (!data->info)
+	st = iio_priv(indio_dev);
+	st->regmap = regmap;
+	st->info = device_get_match_data(dev);
+	if (!st->info)
 		return -ENODEV;
 
-	indio_dev->name = data->info->name;
+	indio_dev->name = st->info->name;
 	indio_dev->info = &adxl345_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->channels = adxl345_channels;
@@ -207,12 +207,12 @@ int adxl345_core_probe(struct device *dev, struct regmap *regmap,
 
 	if (setup) {
 		/* Perform optional initial bus specific configuration */
-		ret = setup(dev, data->regmap);
+		ret = setup(dev, st->regmap);
 		if (ret)
 			return ret;
 
 		/* Enable full-resolution mode */
-		ret = regmap_update_bits(data->regmap, ADXL345_REG_DATA_FORMAT,
+		ret = regmap_update_bits(st->regmap, ADXL345_REG_DATA_FORMAT,
 					 data_format_mask,
 					 ADXL345_DATA_FORMAT_FULL_RES);
 		if (ret)
@@ -221,14 +221,14 @@ int adxl345_core_probe(struct device *dev, struct regmap *regmap,
 
 	} else {
 		/* Enable full-resolution mode (init all data_format bits) */
-		ret = regmap_write(data->regmap, ADXL345_REG_DATA_FORMAT,
+		ret = regmap_write(st->regmap, ADXL345_REG_DATA_FORMAT,
 				   ADXL345_DATA_FORMAT_FULL_RES);
 		if (ret)
 			return dev_err_probe(dev, ret,
 					     "Failed to set data range\n");
 	}
 
-	ret = regmap_read(data->regmap, ADXL345_REG_DEVID, &regval);
+	ret = regmap_read(st->regmap, ADXL345_REG_DEVID, &regval);
 	if (ret < 0)
 		return dev_err_probe(dev, ret, "Error reading device ID\n");
 
@@ -237,11 +237,11 @@ int adxl345_core_probe(struct device *dev, struct regmap *regmap,
 				     regval, ADXL345_DEVID);
 
 	/* Enable measurement mode */
-	ret = adxl345_powerup(data->regmap);
+	ret = adxl345_powerup(st->regmap);
 	if (ret < 0)
 		return dev_err_probe(dev, ret, "Failed to enable measurement mode\n");
 
-	ret = devm_add_action_or_reset(dev, adxl345_powerdown, data->regmap);
+	ret = devm_add_action_or_reset(dev, adxl345_powerdown, st->regmap);
 	if (ret < 0)
 		return ret;
 
-- 
2.39.2

[PATCH v4 03/10] iio: accel: adxl345: measure right-justified

[Lothar Rubusch]

Make measurements right-justified, since it is the default for the
driver and sensor. By not setting the ADXL345_DATA_FORMAT_JUSTIFY bit,
the data becomes right-judstified. This was the original setting, there
is no reason to change it to left-justified, where right-justified
simplifies working on the registers.

Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
---
 drivers/iio/accel/adxl345_core.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/iio/accel/adxl345_core.c b/drivers/iio/accel/adxl345_core.c
index 88df9547bd6..98ff37271f1 100644
--- a/drivers/iio/accel/adxl345_core.c
+++ b/drivers/iio/accel/adxl345_core.c
@@ -184,7 +184,6 @@ int adxl345_core_probe(struct device *dev, struct regmap *regmap,
 	struct iio_dev *indio_dev;
 	u32 regval;
 	unsigned int data_format_mask = (ADXL345_DATA_FORMAT_RANGE |
-					 ADXL345_DATA_FORMAT_JUSTIFY |
 					 ADXL345_DATA_FORMAT_FULL_RES |
 					 ADXL345_DATA_FORMAT_SELF_TEST);
 	int ret;
-- 
2.39.2

[PATCH v4 04/10] iio: accel: adxl345: add function to switch measuring

[Lothar Rubusch]

Replace the powerup / powerdown functions by a generic function to put
the sensor in STANDBY, or MEASURE mode. This is needed for several
features of the accelerometer. It allows to change e.g. FIFO settings.

Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
---
 drivers/iio/accel/adxl345_core.c | 44 ++++++++++++++++++++++----------
 1 file changed, 31 insertions(+), 13 deletions(-)

diff --git a/drivers/iio/accel/adxl345_core.c b/drivers/iio/accel/adxl345_core.c
index 98ff37271f1..1d020b0d79c 100644
--- a/drivers/iio/accel/adxl345_core.c
+++ b/drivers/iio/accel/adxl345_core.c
@@ -138,6 +138,34 @@ static int adxl345_write_raw_get_fmt(struct iio_dev *indio_dev,
 	}
 }
 
+/**
+ * adxl345_set_measure_en() - Enable and disable measuring.
+ *
+ * @st: The device data.
+ * @en: Enable measurements, else standby mode.
+ *
+ * For lowest power operation, standby mode can be used. In standby mode,
+ * current consumption is supposed to be reduced to 0.1uA (typical). In this
+ * mode no measurements are made. Placing the device into standby mode
+ * preserves the contents of FIFO.
+ *
+ * Return: Returns 0 if successful, or a negative error value.
+ */
+static int adxl345_set_measure_en(struct adxl345_state *st, bool en)
+{
+	unsigned int val = 0;
+
+	val = (en) ? ADXL345_POWER_CTL_MEASURE : ADXL345_POWER_CTL_STANDBY;
+	return regmap_write(st->regmap, ADXL345_REG_POWER_CTL, val);
+}
+
+static void adxl345_powerdown(void *ptr)
+{
+	struct adxl345_state *st = ptr;
+
+	adxl345_set_measure_en(st, false);
+}
+
 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(
 "0.09765625 0.1953125 0.390625 0.78125 1.5625 3.125 6.25 12.5 25 50 100 200 400 800 1600 3200"
 );
@@ -158,16 +186,6 @@ static const struct iio_info adxl345_info = {
 	.write_raw_get_fmt	= adxl345_write_raw_get_fmt,
 };
 
-static int adxl345_powerup(void *regmap)
-{
-	return regmap_write(regmap, ADXL345_REG_POWER_CTL, ADXL345_POWER_CTL_MEASURE);
-}
-
-static void adxl345_powerdown(void *regmap)
-{
-	regmap_write(regmap, ADXL345_REG_POWER_CTL, ADXL345_POWER_CTL_STANDBY);
-}
-
 /**
  * adxl345_core_probe() - Probe and setup for the accelerometer.
  * @dev:	Driver model representation of the device
@@ -236,13 +254,13 @@ int adxl345_core_probe(struct device *dev, struct regmap *regmap,
 				     regval, ADXL345_DEVID);
 
 	/* Enable measurement mode */
-	ret = adxl345_powerup(st->regmap);
+	ret = adxl345_set_measure_en(st, true);
 	if (ret < 0)
 		return dev_err_probe(dev, ret, "Failed to enable measurement mode\n");
 
-	ret = devm_add_action_or_reset(dev, adxl345_powerdown, st->regmap);
+	ret = devm_add_action_or_reset(dev, adxl345_powerdown, st);
 	if (ret < 0)
-		return ret;
+		return dev_err_probe(dev, ret, "Failed to add action or reset\n");
 
 	return devm_iio_device_register(dev, indio_dev);
 }
-- 
2.39.2

[PATCH v4 05/10] iio: accel: adxl345: extend list of defines

[Lothar Rubusch]

Extend the list of constants. Keep them the header file for readability.
The constants allow the implementation of events like FIFO-watermark,
single tap, double tap, freefall, etc.

Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
---
 drivers/iio/accel/adxl345.h | 89 ++++++++++++++++++++++++++++++++-----
 1 file changed, 77 insertions(+), 12 deletions(-)

diff --git a/drivers/iio/accel/adxl345.h b/drivers/iio/accel/adxl345.h
index 3d5c8719db3..ed81d5cf445 100644
--- a/drivers/iio/accel/adxl345.h
+++ b/drivers/iio/accel/adxl345.h
@@ -9,37 +9,102 @@
 #define _ADXL345_H_
 
 #define ADXL345_REG_DEVID		0x00
+#define ADXL345_REG_THRESH_TAP	0x1D
 #define ADXL345_REG_OFSX		0x1E
 #define ADXL345_REG_OFSY		0x1F
 #define ADXL345_REG_OFSZ		0x20
-#define ADXL345_REG_OFS_AXIS(index)	(ADXL345_REG_OFSX + (index))
+/* Tap duration */
+#define ADXL345_REG_DUR		0x21
+/* Tap latency */
+#define ADXL345_REG_LATENT		0x22
+/* Tap window */
+#define ADXL345_REG_WINDOW		0x23
+/* Activity threshold */
+#define ADXL345_REG_THRESH_ACT		0x24
+/* Inactivity threshold */
+#define ADXL345_REG_THRESH_INACT	0x25
+/* Inactivity time */
+#define ADXL345_REG_TIME_INACT	0x26
+/* Axis enable control for activity and inactivity detection */
+#define ADXL345_REG_ACT_INACT_CTRL	0x27
+/* Free-fall threshold */
+#define ADXL345_REG_THRESH_FF		0x28
+/* Free-fall time */
+#define ADXL345_REG_TIME_FF		0x29
+/* Axis control for single tap or double tap */
+#define ADXL345_REG_TAP_AXIS		0x2A
+/* Source of single tap or double tap */
+#define ADXL345_REG_ACT_TAP_STATUS	0x2B
+/* Data rate and power mode control */
 #define ADXL345_REG_BW_RATE		0x2C
 #define ADXL345_REG_POWER_CTL		0x2D
+#define ADXL345_REG_INT_ENABLE		0x2E
+#define ADXL345_REG_INT_MAP		0x2F
+#define ADXL345_REG_INT_SOURCE		0x30
 #define ADXL345_REG_DATA_FORMAT		0x31
-#define ADXL345_REG_DATAX0		0x32
-#define ADXL345_REG_DATAY0		0x34
-#define ADXL345_REG_DATAZ0		0x36
-#define ADXL345_REG_DATA_AXIS(index)	\
-	(ADXL345_REG_DATAX0 + (index) * sizeof(__le16))
+#define ADXL345_REG_XYZ_BASE		0x32
+#define ADXL345_REG_DATA_AXIS(index)				\
+	(ADXL345_REG_XYZ_BASE + (index) * sizeof(__le16))
+
+#define ADXL345_REG_FIFO_CTL		0x38
+#define ADXL345_REG_FIFO_STATUS		0x39
+
+#define ADXL345_DEVID			0xE5
+
+#define ADXL345_FIFO_CTL_SAMLPES(x)	(0x1f & (x))
+#define ADXL345_FIFO_CTL_TRIGGER(x)	(0x20 & ((x) << 5)) /* 0: INT1, 1: INT2 */
+#define ADXL345_FIFO_CTL_MODE(x)	(0xc0 & ((x) << 6))
 
+#define ADXL345_INT_DATA_READY		BIT(7)
+#define ADXL345_INT_SINGLE_TAP		BIT(6)
+#define ADXL345_INT_DOUBLE_TAP		BIT(5)
+#define ADXL345_INT_ACTIVITY		BIT(4)
+#define ADXL345_INT_INACTIVITY		BIT(3)
+#define ADXL345_INT_FREE_FALL		BIT(2)
+#define ADXL345_INT_WATERMARK		BIT(1)
+#define ADXL345_INT_OVERRUN		BIT(0)
+
+#define ADXL345_S_TAP_MSK	ADXL345_INT_SINGLE_TAP
+#define ADXL345_D_TAP_MSK	ADXL345_INT_DOUBLE_TAP
+
+#define ADXL345_INT1			0
+#define ADXL345_INT2			1
+
+/*
+ * BW_RATE bits - Bandwidth and output data rate. The default value is
+ * 0x0A, which translates to a 100 Hz output data rate
+ */
 #define ADXL345_BW_RATE			GENMASK(3, 0)
+#define ADXL345_BW_LOW_POWER	BIT(4)
 #define ADXL345_BASE_RATE_NANO_HZ	97656250LL
 
-#define ADXL345_POWER_CTL_MEASURE	BIT(3)
 #define ADXL345_POWER_CTL_STANDBY	0x00
+#define ADXL345_POWER_CTL_WAKEUP	GENMASK(1, 0)
+#define ADXL345_POWER_CTL_SLEEP	BIT(2)
+#define ADXL345_POWER_CTL_MEASURE	BIT(3)
+#define ADXL345_POWER_CTL_AUTO_SLEEP	BIT(4)
+#define ADXL345_POWER_CTL_LINK	BIT(5)
 
 #define ADXL345_DATA_FORMAT_RANGE	GENMASK(1, 0)	/* Set the g range */
-#define ADXL345_DATA_FORMAT_JUSTIFY	BIT(2)	/* Left-justified (MSB) mode */
+#define ADXL345_DATA_FORMAT_IS_LEFT_JUSTIFIED	BIT(2)
 #define ADXL345_DATA_FORMAT_FULL_RES	BIT(3)	/* Up to 13-bits resolution */
-#define ADXL345_DATA_FORMAT_SPI_3WIRE	BIT(6)	/* 3-wire SPI mode */
-#define ADXL345_DATA_FORMAT_SELF_TEST	BIT(7)	/* Enable a self test */
-
+#define ADXL345_DATA_FORMAT_SPI_3WIRE	BIT(6)
+#define ADXL345_DATA_FORMAT_SELF_TEST	BIT(7)
 #define ADXL345_DATA_FORMAT_2G		0
 #define ADXL345_DATA_FORMAT_4G		1
 #define ADXL345_DATA_FORMAT_8G		2
 #define ADXL345_DATA_FORMAT_16G		3
 
-#define ADXL345_DEVID			0xE5
+#define ADXL345_REG_OFS_AXIS(index)	(ADXL345_REG_OFSX + (index))
+
+/*
+ * FIFO stores a maximum of 32 entries, which equates to a maximum of 33 entries
+ * available at any given time because an additional entry is available at the
+ * output filter of the device.
+ *
+ * (see datasheet FIFO_STATUS description on "Entries Bits")
+ */
+#define ADXL345_FIFO_SIZE  33
 
 /*
  * In full-resolution mode, scale factor is maintained at ~4 mg/LSB
-- 
2.39.2

[PATCH v4 06/10] dt-bindings: iio: accel: add interrupt-names

[Lothar Rubusch]

Add interrupt-names INT1 and INT2 for the two interrupt lines of the
sensor. Only one line will be connected for incoming events. The driver
needs to be configured accordingly. If no interrupt line is set up, the
sensor will still measure, but no events are possible.

Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
---
 .../devicetree/bindings/iio/accel/adi,adxl345.yaml    | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/Documentation/devicetree/bindings/iio/accel/adi,adxl345.yaml b/Documentation/devicetree/bindings/iio/accel/adi,adxl345.yaml
index 280ed479ef5..a4c2cefe1a4 100644
--- a/Documentation/devicetree/bindings/iio/accel/adi,adxl345.yaml
+++ b/Documentation/devicetree/bindings/iio/accel/adi,adxl345.yaml
@@ -37,6 +37,15 @@ properties:
   interrupts:
     maxItems: 1
 
+  interrupt-names:
+    description: Use either INT1 or INT2 for events, or ignore events.
+    minItems: 1
+    maxItems: 2
+    items:
+      enum:
+        - INT1
+        - INT2
+
 required:
   - compatible
   - reg
@@ -61,6 +70,7 @@ examples:
             reg = <0x2a>;
             interrupt-parent = <&gpio0>;
             interrupts = <0 IRQ_TYPE_LEVEL_HIGH>;
+            interrupt-names = "INT1";
         };
     };
   - |
@@ -79,5 +89,6 @@ examples:
             spi-cpha;
             interrupt-parent = <&gpio0>;
             interrupts = <0 IRQ_TYPE_LEVEL_HIGH>;
+            interrupt-names = "INT2";
         };
     };
-- 
2.39.2

[PATCH v4 07/10] iio: accel: adxl345: initialize IRQ number

[Lothar Rubusch]

Add the possibility to claim an interrupt and init the state structure
with interrupt number and interrupt line to use. The adxl345 can use
two different interrupt lines, mainly to signal FIFO watermark events,
single or double tap, activity, etc. Hence, having the interrupt line
available is crucial to implement such features.

Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
---
 drivers/iio/accel/adxl345_core.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/iio/accel/adxl345_core.c b/drivers/iio/accel/adxl345_core.c
index 1d020b0d79c..e0a8b32239f 100644
--- a/drivers/iio/accel/adxl345_core.c
+++ b/drivers/iio/accel/adxl345_core.c
@@ -11,6 +11,7 @@
 #include <linux/property.h>
 #include <linux/regmap.h>
 #include <linux/units.h>
+#include <linux/interrupt.h>
 
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
@@ -18,8 +19,10 @@
 #include "adxl345.h"
 
 struct adxl345_state {
+	int irq;
 	const struct adxl345_chip_info *info;
 	struct regmap *regmap;
+	u8 intio;
 };
 
 #define ADXL345_CHANNEL(index, axis) {					\
@@ -212,6 +215,17 @@ int adxl345_core_probe(struct device *dev, struct regmap *regmap,
 
 	st = iio_priv(indio_dev);
 	st->regmap = regmap;
+
+	st->intio = -1;
+	st->irq = fwnode_irq_get_byname(dev_fwnode(dev), "INT1");
+	if (st->irq > 0)
+		st->intio = ADXL345_INT1;
+	else {
+		st->irq = fwnode_irq_get_byname(dev_fwnode(dev), "INT2");
+		if (st->irq > 0)
+			st->intio = ADXL345_INT2;
+	}
+
 	st->info = device_get_match_data(dev);
 	if (!st->info)
 		return -ENODEV;
-- 
2.39.2

[PATCH v4 08/10] iio: accel: adxl345: initialize FIFO delay value for SPI

[Lothar Rubusch]

Add the possibility to delay FIFO access when SPI is used. According to
the datasheet this is needed for the adxl345. When initialization
happens over SPI the need for delay is to be signalized, and the delay
will be used.

Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
---
 drivers/iio/accel/adxl345.h      |  1 +
 drivers/iio/accel/adxl345_core.c | 12 ++++++++++++
 drivers/iio/accel/adxl345_i2c.c  |  2 +-
 drivers/iio/accel/adxl345_spi.c  |  7 +++++--
 4 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/accel/adxl345.h b/drivers/iio/accel/adxl345.h
index ed81d5cf445..c07709350d3 100644
--- a/drivers/iio/accel/adxl345.h
+++ b/drivers/iio/accel/adxl345.h
@@ -127,6 +127,7 @@ struct adxl345_chip_info {
 };
 
 int adxl345_core_probe(struct device *dev, struct regmap *regmap,
+		       bool fifo_delay_default,
 		       int (*setup)(struct device*, struct regmap*));
 
 #endif /* _ADXL345_H_ */
diff --git a/drivers/iio/accel/adxl345_core.c b/drivers/iio/accel/adxl345_core.c
index e0a8b32239f..0696e908bdf 100644
--- a/drivers/iio/accel/adxl345_core.c
+++ b/drivers/iio/accel/adxl345_core.c
@@ -22,6 +22,7 @@ struct adxl345_state {
 	int irq;
 	const struct adxl345_chip_info *info;
 	struct regmap *regmap;
+	bool fifo_delay; /* delay: delay is needed for SPI */
 	u8 intio;
 };
 
@@ -193,12 +194,21 @@ static const struct iio_info adxl345_info = {
  * adxl345_core_probe() - Probe and setup for the accelerometer.
  * @dev:	Driver model representation of the device
  * @regmap:	Regmap instance for the device
+ * @fifo_delay_default: Using FIFO with SPI needs delay
  * @setup:	Setup routine to be executed right before the standard device
  *		setup
  *
+ * For SPI operation greater than 1.6 MHz, it is necessary to deassert the CS
+ * pin to ensure a total delay of 5 us; otherwise, the delay is not sufficient.
+ * The total delay necessary for 5 MHz operation is at most 3.4 us. This is not
+ * a concern when using I2C mode because the communication rate is low enough
+ * to ensure a sufficient delay between FIFO reads.
+ * Ref: "Retrieving Data from FIFO", p. 21 of 36, Data Sheet ADXL345 Rev. G
+ *
  * Return: 0 on success, negative errno on error
  */
 int adxl345_core_probe(struct device *dev, struct regmap *regmap,
+		       bool fifo_delay_default,
 		       int (*setup)(struct device*, struct regmap*))
 {
 	struct adxl345_state *st;
@@ -230,6 +240,8 @@ int adxl345_core_probe(struct device *dev, struct regmap *regmap,
 	if (!st->info)
 		return -ENODEV;
 
+	st->fifo_delay = fifo_delay_default;
+
 	indio_dev->name = st->info->name;
 	indio_dev->info = &adxl345_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
diff --git a/drivers/iio/accel/adxl345_i2c.c b/drivers/iio/accel/adxl345_i2c.c
index 4065b8f7c8a..28d997c5860 100644
--- a/drivers/iio/accel/adxl345_i2c.c
+++ b/drivers/iio/accel/adxl345_i2c.c
@@ -27,7 +27,7 @@ static int adxl345_i2c_probe(struct i2c_client *client)
 	if (IS_ERR(regmap))
 		return dev_err_probe(&client->dev, PTR_ERR(regmap), "Error initializing regmap\n");
 
-	return adxl345_core_probe(&client->dev, regmap, NULL);
+	return adxl345_core_probe(&client->dev, regmap, false, NULL);
 }
 
 static const struct adxl345_chip_info adxl345_i2c_info = {
diff --git a/drivers/iio/accel/adxl345_spi.c b/drivers/iio/accel/adxl345_spi.c
index 61fd9a6f5fc..9829d5d3d43 100644
--- a/drivers/iio/accel/adxl345_spi.c
+++ b/drivers/iio/accel/adxl345_spi.c
@@ -12,6 +12,7 @@
 #include "adxl345.h"
 
 #define ADXL345_MAX_SPI_FREQ_HZ		5000000
+#define ADXL345_MAX_FREQ_NO_FIFO_DELAY	1500000
 
 static const struct regmap_config adxl345_spi_regmap_config = {
 	.reg_bits = 8,
@@ -28,6 +29,7 @@ static int adxl345_spi_setup(struct device *dev, struct regmap *regmap)
 static int adxl345_spi_probe(struct spi_device *spi)
 {
 	struct regmap *regmap;
+	bool needs_delay;
 
 	/* Bail out if max_speed_hz exceeds 5 MHz */
 	if (spi->max_speed_hz > ADXL345_MAX_SPI_FREQ_HZ)
@@ -38,10 +40,11 @@ static int adxl345_spi_probe(struct spi_device *spi)
 	if (IS_ERR(regmap))
 		return dev_err_probe(&spi->dev, PTR_ERR(regmap), "Error initializing regmap\n");
 
+	needs_delay = (spi->max_speed_hz > ADXL345_MAX_FREQ_NO_FIFO_DELAY);
 	if (spi->mode & SPI_3WIRE)
-		return adxl345_core_probe(&spi->dev, regmap, adxl345_spi_setup);
+		return adxl345_core_probe(&spi->dev, regmap, needs_delay, adxl345_spi_setup);
 	else
-		return adxl345_core_probe(&spi->dev, regmap, NULL);
+		return adxl345_core_probe(&spi->dev, regmap, needs_delay, NULL);
 }
 
 static const struct adxl345_chip_info adxl345_spi_info = {
-- 
2.39.2

[PATCH v4 09/10] iio: accel: adxl345: prepare channel for scan_index

[Lothar Rubusch]

Add separate fields for register and index to the channel definition.
The scan_index is set up with the kfifo in the follow up patches.

Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
---
 drivers/iio/accel/adxl345_core.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/iio/accel/adxl345_core.c b/drivers/iio/accel/adxl345_core.c
index 0696e908bdf..3067a70c54e 100644
--- a/drivers/iio/accel/adxl345_core.c
+++ b/drivers/iio/accel/adxl345_core.c
@@ -26,21 +26,26 @@ struct adxl345_state {
 	u8 intio;
 };
 
-#define ADXL345_CHANNEL(index, axis) {					\
+#define ADXL345_CHANNEL(index, reg, axis) {					\
 	.type = IIO_ACCEL,						\
 	.modified = 1,							\
 	.channel2 = IIO_MOD_##axis,					\
-	.address = index,						\
+	.address = (reg),						\
 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |			\
 		BIT(IIO_CHAN_INFO_CALIBBIAS),				\
 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |		\
 		BIT(IIO_CHAN_INFO_SAMP_FREQ),				\
+	.scan_index = (index),				\
 }
 
+enum adxl345_chans {
+	chan_x, chan_y, chan_z,
+};
+
 static const struct iio_chan_spec adxl345_channels[] = {
-	ADXL345_CHANNEL(0, X),
-	ADXL345_CHANNEL(1, Y),
-	ADXL345_CHANNEL(2, Z),
+	ADXL345_CHANNEL(0, chan_x, X),
+	ADXL345_CHANNEL(1, chan_y, Y),
+	ADXL345_CHANNEL(2, chan_z, Z),
 };
 
 static int adxl345_read_raw(struct iio_dev *indio_dev,
-- 
2.39.2

[PATCH v4 10/10] iio: accel: adxl345: add kfifo with watermark

[Lothar Rubusch]

Add a basic setup for kfifo with configurable watermark, add a handler
for watermark interrupt events and extend the channel for the
scan_index needed for the kfifo. The sensor is configurable to use a
FIFO_BYPASSED mode or a FIFO_STREAM mode. For the FIFO_STREAM mode a
watermark can be configured, or disabled by setting 0. Further features
are based on the FIFO setup.

Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
---
 drivers/iio/accel/adxl345_core.c | 300 +++++++++++++++++++++++++++++++
 1 file changed, 300 insertions(+)

diff --git a/drivers/iio/accel/adxl345_core.c b/drivers/iio/accel/adxl345_core.c
index 3067a70c54e..58ed82d66dc 100644
--- a/drivers/iio/accel/adxl345_core.c
+++ b/drivers/iio/accel/adxl345_core.c
@@ -15,15 +15,28 @@
 
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/events.h>
+#include <linux/iio/kfifo_buf.h>
 
 #include "adxl345.h"
 
+#define ADXL345_FIFO_BYPASS	0
+#define ADXL345_FIFO_FIFO	1
+#define ADXL345_FIFO_STREAM	2
+
+#define ADXL345_DIRS 3
+
 struct adxl345_state {
 	int irq;
 	const struct adxl345_chip_info *info;
 	struct regmap *regmap;
+	__le16 fifo_buf[ADXL345_DIRS * ADXL345_FIFO_SIZE];
 	bool fifo_delay; /* delay: delay is needed for SPI */
 	u8 intio;
+	u8 int_map;
+	u8 watermark;
+	u8 fifo_mode;
 };
 
 #define ADXL345_CHANNEL(index, reg, axis) {					\
@@ -36,6 +49,13 @@ struct adxl345_state {
 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |		\
 		BIT(IIO_CHAN_INFO_SAMP_FREQ),				\
 	.scan_index = (index),				\
+	.scan_type = {					\
+		.sign = 's',				\
+		.realbits = 13,				\
+		.storagebits = 16,			\
+		.shift = 0,				\
+		.endianness = IIO_LE,			\
+	},						\
 }
 
 enum adxl345_chans {
@@ -48,6 +68,25 @@ static const struct iio_chan_spec adxl345_channels[] = {
 	ADXL345_CHANNEL(2, chan_z, Z),
 };
 
+static int adxl345_set_interrupts(struct adxl345_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);
+
+	ret = regmap_write(st->regmap, ADXL345_REG_INT_MAP, int_map);
+	if (ret)
+		return ret;
+
+	return regmap_write(st->regmap, ADXL345_REG_INT_ENABLE, int_enable);
+}
+
 static int adxl345_read_raw(struct iio_dev *indio_dev,
 			    struct iio_chan_spec const *chan,
 			    int *val, int *val2, long mask)
@@ -133,6 +172,31 @@ static int adxl345_write_raw(struct iio_dev *indio_dev,
 	return -EINVAL;
 }
 
+static int adxl345_set_watermark(struct iio_dev *indio_dev, unsigned int value)
+{
+	struct adxl345_state *st = iio_priv(indio_dev);
+	unsigned int fifo_mask = 0x1F;
+	int ret;
+
+	if (value == 0) {
+		st->int_map &= ~ADXL345_INT_WATERMARK;
+		return 0;
+	}
+
+	if (value > ADXL345_FIFO_SIZE)
+		value = ADXL345_FIFO_SIZE;
+
+	ret = regmap_update_bits(st->regmap, ADXL345_REG_FIFO_CTL,
+				 fifo_mask, value);
+	if (ret)
+		return ret;
+
+	st->watermark = value;
+	st->int_map |= ADXL345_INT_WATERMARK;
+
+	return 0;
+}
+
 static int adxl345_write_raw_get_fmt(struct iio_dev *indio_dev,
 				     struct iio_chan_spec const *chan,
 				     long mask)
@@ -188,11 +252,224 @@ static const struct attribute_group adxl345_attrs_group = {
 	.attrs = adxl345_attrs,
 };
 
+static int adxl345_set_fifo(struct adxl345_state *st)
+{
+	u8 fifo_ctl;
+	int ret;
+
+	/* FIFO should only be configured while in standby mode */
+	ret = adxl345_set_measure_en(st, false);
+	if (ret < 0)
+		return ret;
+
+	fifo_ctl = ADXL345_FIFO_CTL_SAMLPES(st->watermark) |
+		ADXL345_FIFO_CTL_TRIGGER(st->intio) |
+		ADXL345_FIFO_CTL_MODE(st->fifo_mode);
+
+	ret = regmap_write(st->regmap, ADXL345_REG_FIFO_CTL, fifo_ctl);
+	if (ret < 0)
+		return ret;
+
+	return adxl345_set_measure_en(st, true);
+}
+
+/**
+ * adxl345_get_samples() - Read number of FIFO entries.
+ * @st: The initialized state instance of this driver.
+ *
+ * The sensor does not support treating any axis individually, or exclude them
+ * from measuring.
+ *
+ * Return: negative error, or value.
+ */
+static int adxl345_get_samples(struct adxl345_state *st)
+{
+	unsigned int regval = 0;
+	int ret;
+
+	ret = regmap_read(st->regmap, ADXL345_REG_FIFO_STATUS, &regval);
+	if (ret < 0)
+		return ret;
+
+	return 0x3f & regval;
+}
+
+/**
+ * adxl345_fifo_transfer() - Read samples number of elements.
+ * @st: The instance of the state object of this sensor.
+ * @samples: 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.
+ *
+ * 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.
+ *
+ * Return: 0 or error value.
+ */
+static int adxl345_fifo_transfer(struct adxl345_state *st, int samples)
+{
+	size_t count;
+	int i, ret;
+
+	count = sizeof(st->fifo_buf[0]) * ADXL345_DIRS;
+	for (i = 0; i < samples; i++) {
+		ret = regmap_noinc_read(st->regmap, ADXL345_REG_XYZ_BASE,
+				st->fifo_buf + (i * count / 2), count);
+		if (ret < 0)
+			return ret;
+	}
+	return ret;
+}
+
+/**
+ * adxl345_fifo_reset() - Empty the FIFO in error condition.
+ * @st: The instance to the state object of the sensor.
+ *
+ * Read all elements of the FIFO. Reading the interrupt source register
+ * resets the sensor.
+ */
+static void adxl345_fifo_reset(struct adxl345_state *st)
+{
+	int regval;
+	int samples;
+
+	adxl345_set_measure_en(st, false);
+
+	samples = adxl345_get_samples(st);
+	if (samples > 0)
+		adxl345_fifo_transfer(st, samples);
+
+	regmap_read(st->regmap, ADXL345_REG_INT_SOURCE, &regval);
+
+	adxl345_set_measure_en(st, true);
+}
+
+static int adxl345_buffer_postenable(struct iio_dev *indio_dev)
+{
+	struct adxl345_state *st = iio_priv(indio_dev);
+	int ret;
+
+	ret = adxl345_set_interrupts(st);
+	if (ret < 0)
+		return ret;
+
+	st->fifo_mode = ADXL345_FIFO_STREAM;
+	return adxl345_set_fifo(st);
+}
+
+static int adxl345_buffer_predisable(struct iio_dev *indio_dev)
+{
+	struct adxl345_state *st = iio_priv(indio_dev);
+	int ret;
+
+	st->int_map = 0x00;
+
+	ret = adxl345_set_interrupts(st);
+	if (ret < 0)
+		return ret;
+
+	st->fifo_mode = ADXL345_FIFO_BYPASS;
+	return adxl345_set_fifo(st);
+}
+
+static const struct iio_buffer_setup_ops adxl345_buffer_ops = {
+	.postenable = adxl345_buffer_postenable,
+	.predisable = adxl345_buffer_predisable,
+};
+
+static int adxl345_get_status(struct adxl345_state *st)
+{
+	int ret;
+	unsigned int regval;
+
+	ret = regmap_read(st->regmap, ADXL345_REG_INT_SOURCE, &regval);
+	if (ret < 0)
+		return ret;
+
+	return (0xff & regval);
+}
+
+static int adxl345_fifo_push(struct iio_dev *indio_dev,
+				  int samples)
+{
+	struct adxl345_state *st = iio_priv(indio_dev);
+	int i, ret;
+
+	if (samples <= 0)
+		return -EINVAL;
+
+	ret = adxl345_fifo_transfer(st, samples);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < ADXL345_DIRS * samples; i += ADXL345_DIRS) {
+		/*
+		 * To ensure that the FIFO has completely popped, there must be at least 5
+		 * us between the end of reading the data registers, signified by the
+		 * transition to register 0x38 from 0x37 or the CS pin going high, and the
+		 * start of new reads of the FIFO or reading the FIFO_STATUS register. For
+		 * SPI operation at 1.5 MHz or lower, the register addressing portion of the
+		 * transmission is sufficient delay to ensure the FIFO has completely
+		 * popped. It is necessary for SPI operation greater than 1.5 MHz to
+		 * de-assert the CS pin to ensure a total of 5 us, which is at most 3.4 us
+		 * at 5 MHz operation.
+		 */
+		if (st->fifo_delay && (samples > 1))
+			udelay(3);
+
+		iio_push_to_buffers(indio_dev, &st->fifo_buf[i]);
+	}
+
+	return 0;
+}
+
+/**
+ * adxl345_event_handler() - Handle events of the ADXL345.
+ * @irq: The irq being handled.
+ * @p: The struct iio_device pointer for the device.
+ *
+ * Return: The interrupt was handled.
+ */
+static irqreturn_t adxl345_event_handler(int irq, void *p)
+{
+	struct iio_dev *indio_dev = p;
+	struct adxl345_state *st = iio_priv(indio_dev);
+	u8 int_stat;
+	int samples;
+
+	int_stat = adxl345_get_status(st);
+	if (int_stat < 0)
+		return IRQ_NONE;
+
+	if (int_stat == 0x0)
+		goto err;
+
+	if (int_stat & ADXL345_INT_OVERRUN)
+		goto err;
+
+	if (int_stat & (ADXL345_INT_DATA_READY | ADXL345_INT_WATERMARK)) {
+		samples = adxl345_get_samples(st);
+		if (samples < 0)
+			goto err;
+
+		if (adxl345_fifo_push(indio_dev, samples) < 0)
+			goto err;
+
+	}
+	return IRQ_HANDLED;
+
+err:
+	adxl345_fifo_reset(st);
+
+	return IRQ_HANDLED;
+}
+
 static const struct iio_info adxl345_info = {
 	.attrs		= &adxl345_attrs_group,
 	.read_raw	= adxl345_read_raw,
 	.write_raw	= adxl345_write_raw,
 	.write_raw_get_fmt	= adxl345_write_raw_get_fmt,
+	.hwfifo_set_watermark = adxl345_set_watermark,
 };
 
 /**
@@ -222,6 +499,7 @@ int adxl345_core_probe(struct device *dev, struct regmap *regmap,
 	unsigned int data_format_mask = (ADXL345_DATA_FORMAT_RANGE |
 					 ADXL345_DATA_FORMAT_FULL_RES |
 					 ADXL345_DATA_FORMAT_SELF_TEST);
+	u8 fifo_ctl;
 	int ret;
 
 	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
@@ -293,6 +571,28 @@ int adxl345_core_probe(struct device *dev, struct regmap *regmap,
 	if (ret < 0)
 		return dev_err_probe(dev, ret, "Failed to add action or reset\n");
 
+	if (st->irq > 0) {
+		dev_dbg(dev, "initialize for FIFO_STREAM mode\n");
+
+		ret = devm_iio_kfifo_buffer_setup(dev, indio_dev, &adxl345_buffer_ops);
+		if (ret)
+			return ret;
+
+		ret = devm_request_threaded_irq(dev, st->irq, NULL, &adxl345_event_handler,
+				IRQF_SHARED | IRQF_ONESHOT,
+				indio_dev->name, indio_dev);
+		if (ret)
+			return dev_err_probe(dev, ret, "Failed to setup triggered buffer\n");
+
+	} else {
+		dev_dbg(dev, "initialize for FIFO_BYPASS mode (fallback)\n");
+
+		fifo_ctl = ADXL345_FIFO_CTL_MODE(ADXL345_FIFO_BYPASS);
+
+		ret = regmap_write(st->regmap, ADXL345_REG_FIFO_CTL, fifo_ctl);
+		if (ret < 0)
+			return ret;
+	}
 	return devm_iio_device_register(dev, indio_dev);
 }
 EXPORT_SYMBOL_NS_GPL(adxl345_core_probe, IIO_ADXL345);
-- 
2.39.2

Re: [PATCH v4 06/10] dt-bindings: iio: accel: add interrupt-names

[Krzysztof Kozlowski]

On Wed, Dec 04, 2024 at 06:24:47PM +0000, Lothar Rubusch wrote:
> Add interrupt-names INT1 and INT2 for the two interrupt lines of the
> sensor. Only one line will be connected for incoming events. The driver
> needs to be configured accordingly. If no interrupt line is set up, the
> sensor will still measure, but no events are possible.
> 
> Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
> ---
>  .../devicetree/bindings/iio/accel/adi,adxl345.yaml    | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/iio/accel/adi,adxl345.yaml b/Documentation/devicetree/bindings/iio/accel/adi,adxl345.yaml
> index 280ed479ef5..a4c2cefe1a4 100644
> --- a/Documentation/devicetree/bindings/iio/accel/adi,adxl345.yaml
> +++ b/Documentation/devicetree/bindings/iio/accel/adi,adxl345.yaml
> @@ -37,6 +37,15 @@ properties:
>    interrupts:
>      maxItems: 1
>  
> +  interrupt-names:
> +    description: Use either INT1 or INT2 for events, or ignore events.
> +    minItems: 1
> +    maxItems: 2

No improvements, no responses and according to commit msg you have only
one item, so instead above and below just:

description: .........
items:
 - enum: [ int1, int2]


Best regards,
Krzysztof

Re: [PATCH v4 06/10] dt-bindings: iio: accel: add interrupt-names

[Lothar Rubusch]

On Thu, Dec 5, 2024 at 9:55 AM Krzysztof Kozlowski <krzk@kernel.org> wrote:
>
> On Wed, Dec 04, 2024 at 06:24:47PM +0000, Lothar Rubusch wrote:
> > Add interrupt-names INT1 and INT2 for the two interrupt lines of the
> > sensor. Only one line will be connected for incoming events. The driver
> > needs to be configured accordingly. If no interrupt line is set up, the
> > sensor will still measure, but no events are possible.
> >
> > Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
> > ---
> >  .../devicetree/bindings/iio/accel/adi,adxl345.yaml    | 11 +++++++++++
> >  1 file changed, 11 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/iio/accel/adi,adxl345.yaml b/Documentation/devicetree/bindings/iio/accel/adi,adxl345.yaml
> > index 280ed479ef5..a4c2cefe1a4 100644
> > --- a/Documentation/devicetree/bindings/iio/accel/adi,adxl345.yaml
> > +++ b/Documentation/devicetree/bindings/iio/accel/adi,adxl345.yaml
> > @@ -37,6 +37,15 @@ properties:
> >    interrupts:
> >      maxItems: 1
> >
> > +  interrupt-names:
> > +    description: Use either INT1 or INT2 for events, or ignore events.
> > +    minItems: 1
> > +    maxItems: 2
>
> No improvements, no responses and according to commit msg you have only

That's not true. Indention was now fixed.

> one item, so instead above and below just:
>
> description: .........
> items:
>  - enum: [ int1, int2]

Yes. Unfortunately you're right. I was not aware of the [] writing. Much better!

Sorry, for wasting your time with that. I learned to not just
copy&paste w/o running the lengthy dt_binding_check. Fixed version is
coming up.

Best,
L

>
> Best regards,
> Krzysztof
>