iio:st_pressure: improvements

Ensure triggered buffering memory accesses are properly aligned on per channel storagebits boundaries.

Signed-off-by Gregor Boirie <[email protected]>

---
 drivers/iio/common/st_sensors/st_sensors_buffer.c | 37 +++++++++++------------
 drivers/iio/common/st_sensors/st_sensors_core.c   |  2 +-
 2 files changed, 19 insertions(+), 20 deletions(-)

drivers/iio/common/st_sensors/st_sensors_buffer.c +18 -19

index 50afc0f..d766643 100644
@@ -24,30 +24,29 @@
 
 static int st_sensors_get_buffer_element(struct iio_dev *indio_dev, u8 *buf)
 {
-	int i, len;
-	int total = 0;
+	int i;
 	struct st_sensor_data *sdata = iio_priv(indio_dev);
 	unsigned int num_data_channels = sdata->num_data_channels;
 
-	for (i = 0; i < num_data_channels; i++) {
-		unsigned int bytes_to_read;
-
-		if (test_bit(i, indio_dev->active_scan_mask)) {
-			bytes_to_read = indio_dev->channels[i].scan_type.storagebits >> 3;
-			len = sdata->tf->read_multiple_byte(&sdata->tb,
-				sdata->dev, indio_dev->channels[i].address,
-				bytes_to_read,
-				buf + total, sdata->multiread_bit);
-
-			if (len < bytes_to_read)
-				return -EIO;
-
-			/* Advance the buffer pointer */
-			total += len;
-		}
+	for_each_set_bit(i, indio_dev->active_scan_mask, num_data_channels) {
+		const struct iio_chan_spec *channel = &indio_dev->channels[i];
+		unsigned int bytes_to_read = channel->scan_type.realbits >> 3;
+		unsigned int storage_bytes =
+			channel->scan_type.storagebits >> 3;
+
+		buf = PTR_ALIGN(buf, storage_bytes);
+		if (sdata->tf->read_multiple_byte(&sdata->tb, sdata->dev,
+						  channel->address,
+						  bytes_to_read, buf,
+						  sdata->multiread_bit) <
+		    bytes_to_read)
+			return -EIO;
+
+		/* Advance the buffer pointer */
+		buf += storage_bytes;
 	}
 
-	return total;
+	return 0;
 }
 
 irqreturn_t st_sensors_trigger_handler(int irq, void *p)

drivers/iio/common/st_sensors/st_sensors_core.c +1 -1

index 6db12ea..df9d5e8 100644
@@ -490,7 +490,7 @@ static int st_sensors_read_axis_data(struct iio_dev *indio_dev,
 	int err;
 	u8 *outdata;
 	struct st_sensor_data *sdata = iio_priv(indio_dev);
-	unsigned int byte_for_channel = ch->scan_type.storagebits >> 3;
+	unsigned int byte_for_channel = ch->scan_type.realbits >> 3;
 
 	outdata = kmalloc(byte_for_channel, GFP_KERNEL);
 	if (!outdata)

Sampled pressure data are 24 bits long and should be stored in a 32 bits word.

Signed-off-by Gregor Boirie <[email protected]>

---
 drivers/iio/pressure/st_pressure_core.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

drivers/iio/pressure/st_pressure_core.c +2 -2

index 56d8f5e..8fa3d81 100644
@@ -146,7 +146,7 @@ static const struct iio_chan_spec st_press_1_channels[] = {
 		.scan_type = {
 			.sign = 'u',
 			.realbits = 24,
-			.storagebits = 24,
+			.storagebits = 32,
 			.endianness = IIO_LE,
 		},
 		.info_mask_separate =

@@ -218,7 +218,7 @@ static const struct iio_chan_spec st_press_lps22hb_channels[] = {
 		.scan_type = {
 			.sign = 'u',
 			.realbits = 24,
-			.storagebits = 24,
+			.storagebits = 32,
 			.endianness = IIO_LE,
 		},
 		.info_mask_separate =

Details scaling factors and offsets applied to raw temperature and pressure samples.

Signed-off-by Gregor Boirie <[email protected]>

Quoted 4 lines · Gregor Boirie

Details scaling factors and offsets applied to raw temperature and pressure samples.

Signed-off-by Gregor Boirie <[email protected]>

I try to apply the patches on top of Jonathan's 4.8a branch, but I fail when I get to this patch like this:

$ git am 03.patch
Applying: iio:st_pressure: document sampling gains
error: patch failed: drivers/iio/pressure/st_pressure_core.c:28
error: drivers/iio/pressure/st_pressure_core.c: patch does not apply
Patch failed at 0001 iio:st_pressure: document sampling gains
The copy of the patch that failed is found in:
    /home/linus/linux-iio/.git/rebase-apply/patch
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".

Can you rebase/make sure they all apply on the 4.8a or so so that I can test them?

Or do you have a git branch I can just pull and test?

Yours,
Linus Walleij

Linus,

Quoted 10 lines · Linus Walleij

Quoted 4 lines · Gregor Boirie

Details scaling factors and offsets applied to raw temperature and pressure samples.

Signed-off-by Gregor Boirie <[email protected]>

I try to apply the patches on top of Jonathan's 4.8a branch, but I fail when I get to this patch like this:

Quoted 10 lines

$ git am 03.patch
Applying: iio:st_pressure: document sampling gains
error: patch failed: drivers/iio/pressure/st_pressure_core.c:28
error: drivers/iio/pressure/st_pressure_core.c: patch does not apply
Patch failed at 0001 iio:st_pressure: document sampling gains
The copy of the patch that failed is found in:
    /home/linus/linux-iio/.git/rebase-apply/patch
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".

yep. it seems the patch "iio:st_pressure: fix sampling gains (bring inline with ABI)" is not applied onto togreg branch.

Quoted 1 line

Quoted 4 lines

Can you rebase/make sure they all apply on the 4.8a or so so that I can test them?

Or do you have a git branch I can just pull and test?

Please, find a rebase onto togreg branch with current interrupts related patches applied (without the "harden interrupt handling" stuff) here :
https://github.com/grgbr/linux-iio/tree/iio-togreg-lps22hb

Quoted 3 lines

Yours,
Linus Walleij

Any luck with testing these? They apply cleanly on the tree now as the fix has worked it's way into staging-next and hence back to iio.git after the last pull.

Quoted 2 lines · Jonathan Cameron

Any luck with testing these? They apply cleanly on the tree now as the fix has worked it's way into staging-next and hence back to iio.git after the last pull.

Just tested and sent my Tested-by on patch 0.
Works like a charm.

Yours,
Linus Walleij

Details scaling factors and offsets applied to raw temperature and pressure samples.

Signed-off-by Gregor Boirie <[email protected]>

---
 drivers/iio/pressure/st_pressure_core.c | 92 +++++++++++++++++++++++++++++++--
 1 file changed, 88 insertions(+), 4 deletions(-)

drivers/iio/pressure/st_pressure_core.c +88 -4

index 8fa3d81..2ab1056 100644
@@ -28,6 +28,72 @@
 #include <linux/iio/common/st_sensors.h>
 #include "st_pressure.h"
 
+/*
+ * About determining pressure scaling factors
+ * ------------------------------------------
+ *
+ * Datasheets specify typical pressure sensitivity so that pressure is computed
+ * according to the following equation :
+ *     pressure[mBar] = raw / sensitivity
+ * where :
+ *     raw          the 24 bits long raw sampled pressure
+ *     sensitivity  a scaling factor specified by the datasheet in LSB/mBar
+ *
+ * IIO ABI expects pressure to be expressed as kPascal, hence pressure should be
+ * computed according to :
+ *     pressure[kPascal] = pressure[mBar] / 10
+ *                       = raw / (sensitivity * 10)                          (1)
+ *
+ * Finally, st_press_read_raw() returns pressure scaling factor as an
+ * IIO_VAL_INT_PLUS_NANO with a zero integral part and "gain" as decimal part.
+ * Therefore, from (1), "gain" becomes :
+ *     gain = 10^9 / (sensitivity * 10)
+ *          = 10^8 / sensitivity
+ *
+ * About determining temperature scaling factors and offsets
+ * ---------------------------------------------------------
+ *
+ * Datasheets specify typical temperature sensitivity and offset so that
+ * temperature is computed according to the following equation :
+ *     temp[Celsius] = offset[Celsius] + (raw / sensitivity)
+ * where :
+ *     raw          the 16 bits long raw sampled temperature
+ *     offset       a constant specified by the datasheet in degree Celsius
+ *                  (sometimes zero)
+ *     sensitivity  a scaling factor specified by the datasheet in LSB/Celsius
+ *
+ * IIO ABI expects temperature to be expressed as milli degree Celsius such as
+ * user space should compute temperature according to :
+ *     temp[mCelsius] = temp[Celsius] * 10^3
+ *                    = (offset[Celsius] + (raw / sensitivity)) * 10^3
+ *                    = ((offset[Celsius] * sensitivity) + raw) *
+ *                      (10^3 / sensitivity)                                 (2)
+ *
+ * IIO ABI expects user space to apply offset and scaling factors to raw samples
+ * according to :
+ *     temp[mCelsius] = (OFFSET + raw) * SCALE
+ * where :
+ *     OFFSET an arbitrary constant exposed by device
+ *     SCALE  an arbitrary scaling factor exposed by device
+ *
+ * Matching OFFSET and SCALE with members of (2) gives :
+ *     OFFSET = offset[Celsius] * sensitivity                                (3)
+ *     SCALE  = 10^3 / sensitivity                                           (4)
+ *
+ * st_press_read_raw() returns temperature scaling factor as an
+ * IIO_VAL_FRACTIONAL with a 10^3 numerator and "gain2" as denominator.
+ * Therefore, from (3), "gain2" becomes :
+ *     gain2 = sensitivity
+ *
+ * When declared within channel, i.e. for a non zero specified offset,
+ * st_press_read_raw() will return the latter as an IIO_VAL_FRACTIONAL such as :
+ *     numerator = OFFSET * 10^3
+ *     denominator = 10^3
+ * giving from (4):
+ *     numerator = offset[Celsius] * 10^3 * sensitivity
+ *               = offset[mCelsius] * gain2
+ */
+
 #define MCELSIUS_PER_CELSIUS			1000
 
 /* Default pressure sensitivity */

@@ -48,7 +114,11 @@
 #define ST_PRESS_1_OUT_XL_ADDR			0x28
 #define ST_TEMP_1_OUT_L_ADDR			0x2b
 
-/* CUSTOM VALUES FOR LPS331AP SENSOR */
+/*
+ * CUSTOM VALUES FOR LPS331AP SENSOR
+ * See LPS331AP datasheet:
+ * http://www2.st.com/resource/en/datasheet/lps331ap.pdf
+ */
 #define ST_PRESS_LPS331AP_WAI_EXP		0xbb
 #define ST_PRESS_LPS331AP_ODR_ADDR		0x20
 #define ST_PRESS_LPS331AP_ODR_MASK		0x70

@@ -71,7 +141,9 @@
 #define ST_PRESS_LPS331AP_OD_IRQ_MASK		0x40
 #define ST_PRESS_LPS331AP_MULTIREAD_BIT		true
 
-/* CUSTOM VALUES FOR LPS001WP SENSOR */
+/*
+ * CUSTOM VALUES FOR THE OBSOLETE LPS001WP SENSOR
+ */
 
 /* LPS001WP pressure resolution */
 #define ST_PRESS_LPS001WP_LSB_PER_MBAR		16UL

@@ -94,7 +166,11 @@
 #define ST_PRESS_LPS001WP_OUT_L_ADDR		0x28
 #define ST_TEMP_LPS001WP_OUT_L_ADDR		0x2a
 
-/* CUSTOM VALUES FOR LPS25H SENSOR */
+/*
+ * CUSTOM VALUES FOR LPS25H SENSOR
+ * See LPS25H datasheet:
+ * http://www2.st.com/resource/en/datasheet/lps25h.pdf
+ */
 #define ST_PRESS_LPS25H_WAI_EXP			0xbd
 #define ST_PRESS_LPS25H_ODR_ADDR		0x20
 #define ST_PRESS_LPS25H_ODR_MASK		0x70

@@ -117,7 +193,11 @@
 #define ST_PRESS_LPS25H_OUT_XL_ADDR		0x28
 #define ST_TEMP_LPS25H_OUT_L_ADDR		0x2b
 
-/* CUSTOM VALUES FOR LPS22HB SENSOR */
+/*
+ * CUSTOM VALUES FOR LPS22HB SENSOR
+ * See LPS22HB datasheet:
+ * http://www2.st.com/resource/en/datasheet/lps22hb.pdf
+ */
 #define ST_PRESS_LPS22HB_WAI_EXP		0xb1
 #define ST_PRESS_LPS22HB_ODR_ADDR		0x10
 #define ST_PRESS_LPS22HB_ODR_MASK		0x70

@@ -413,6 +493,10 @@ static const struct st_sensor_settings st_press_sensors_settings[] = {
 		},
 		.fs = {
 			.fs_avl = {
+				/*
+				 * Sensitivity values as defined in table 3 of
+				 * LPS22HB datasheet.
+				 */
 				[0] = {
 					.num = ST_PRESS_FS_AVL_1260MB,
 					.gain = ST_PRESS_KPASCAL_NANO_SCALE,

Enable support for triggered buffering of temperature samples.

Signed-off-by Gregor Boirie <[email protected]>

---
 drivers/iio/pressure/st_pressure_core.c | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

drivers/iio/pressure/st_pressure_core.c +13 -9

index 2ab1056..ea8241f 100644
@@ -105,8 +105,6 @@
 #define ST_PRESS_LSB_PER_CELSIUS		480UL
 #define ST_PRESS_MILLI_CELSIUS_OFFSET		42500UL
 
-#define ST_PRESS_NUMBER_DATA_CHANNELS		1
-
 /* FULLSCALE */
 #define ST_PRESS_FS_AVL_1100MB			1100
 #define ST_PRESS_FS_AVL_1260MB			1260

@@ -222,7 +220,7 @@ static const struct iio_chan_spec st_press_1_channels[] = {
 		.type = IIO_PRESSURE,
 		.channel2 = IIO_NO_MOD,
 		.address = ST_PRESS_1_OUT_XL_ADDR,
-		.scan_index = ST_SENSORS_SCAN_X,
+		.scan_index = 0,
 		.scan_type = {
 			.sign = 'u',
 			.realbits = 24,

@@ -237,7 +235,7 @@ static const struct iio_chan_spec st_press_1_channels[] = {
 		.type = IIO_TEMP,
 		.channel2 = IIO_NO_MOD,
 		.address = ST_TEMP_1_OUT_L_ADDR,
-		.scan_index = -1,
+		.scan_index = 1,
 		.scan_type = {
 			.sign = 'u',
 			.realbits = 16,

@@ -250,7 +248,7 @@ static const struct iio_chan_spec st_press_1_channels[] = {
 			BIT(IIO_CHAN_INFO_OFFSET),
 		.modified = 0,
 	},
-	IIO_CHAN_SOFT_TIMESTAMP(1)
+	IIO_CHAN_SOFT_TIMESTAMP(2)
 };
 
 static const struct iio_chan_spec st_press_lps001wp_channels[] = {

@@ -258,7 +256,7 @@ static const struct iio_chan_spec st_press_lps001wp_channels[] = {
 		.type = IIO_PRESSURE,
 		.channel2 = IIO_NO_MOD,
 		.address = ST_PRESS_LPS001WP_OUT_L_ADDR,
-		.scan_index = ST_SENSORS_SCAN_X,
+		.scan_index = 0,
 		.scan_type = {
 			.sign = 'u',
 			.realbits = 16,

@@ -274,7 +272,7 @@ static const struct iio_chan_spec st_press_lps001wp_channels[] = {
 		.type = IIO_TEMP,
 		.channel2 = IIO_NO_MOD,
 		.address = ST_TEMP_LPS001WP_OUT_L_ADDR,
-		.scan_index = -1,
+		.scan_index = 1,
 		.scan_type = {
 			.sign = 'u',
 			.realbits = 16,

@@ -286,7 +284,7 @@ static const struct iio_chan_spec st_press_lps001wp_channels[] = {
 			BIT(IIO_CHAN_INFO_SCALE),
 		.modified = 0,
 	},
-	IIO_CHAN_SOFT_TIMESTAMP(1)
+	IIO_CHAN_SOFT_TIMESTAMP(2)
 };
 
 static const struct iio_chan_spec st_press_lps22hb_channels[] = {

@@ -642,7 +640,13 @@ int st_press_common_probe(struct iio_dev *indio_dev)
 	if (err < 0)
 		goto st_press_power_off;
 
-	press_data->num_data_channels = ST_PRESS_NUMBER_DATA_CHANNELS;
+	/*
+	 * Skip timestamping channel while declaring available channels to
+	 * common st_sensor layer. Look at st_sensors_get_buffer_element() to
+	 * see how timestamps are explicitly pushed as last samples block
+	 * element.
+	 */
+	press_data->num_data_channels = press_data->sensor_settings->num_ch - 1;
 	press_data->multiread_bit = press_data->sensor_settings->multi_read_bit;
 	indio_dev->channels = press_data->sensor_settings->ch;
 	indio_dev->num_channels = press_data->sensor_settings->num_ch;

Add support for open drain interrupt line.

Signed-off-by Gregor Boirie <[email protected]>

---
 drivers/iio/pressure/st_pressure_core.c | 5 +++++
 1 file changed, 5 insertions(+)

drivers/iio/pressure/st_pressure_core.c +5 -0

index ea8241f..70230a1 100644
@@ -213,6 +213,8 @@
 #define ST_PRESS_LPS22HB_DRDY_IRQ_INT2_MASK	0x08
 #define ST_PRESS_LPS22HB_IHL_IRQ_ADDR		0x12
 #define ST_PRESS_LPS22HB_IHL_IRQ_MASK		0x80
+#define ST_PRESS_LPS22HB_OD_IRQ_ADDR		0x12
+#define ST_PRESS_LPS22HB_OD_IRQ_MASK		0x40
 #define ST_PRESS_LPS22HB_MULTIREAD_BIT		true
 
 static const struct iio_chan_spec st_press_1_channels[] = {

@@ -511,6 +513,9 @@ static const struct st_sensor_settings st_press_sensors_settings[] = {
 			.mask_int2 = ST_PRESS_LPS22HB_DRDY_IRQ_INT2_MASK,
 			.addr_ihl = ST_PRESS_LPS22HB_IHL_IRQ_ADDR,
 			.mask_ihl = ST_PRESS_LPS22HB_IHL_IRQ_MASK,
+			.addr_od = ST_PRESS_LPS22HB_OD_IRQ_ADDR,
+			.mask_od = ST_PRESS_LPS22HB_OD_IRQ_MASK,
+			.addr_stat_drdy = ST_SENSORS_DEFAULT_STAT_ADDR,
 		},
 		.multi_read_bit = ST_PRESS_LPS22HB_MULTIREAD_BIT,
 	},

Implement lps22hb temperature sampling channel.

Signed-off-by Gregor Boirie <[email protected]>

---
 drivers/iio/pressure/st_pressure_core.c | 26 +++++++++++++++++++++++---
 1 file changed, 23 insertions(+), 3 deletions(-)

drivers/iio/pressure/st_pressure_core.c +23 -3

index 70230a1..274cdec 100644
@@ -196,6 +196,10 @@
  * See LPS22HB datasheet:
  * http://www2.st.com/resource/en/datasheet/lps22hb.pdf
  */
+
+/* LPS22HB temperature sensitivity */
+#define ST_PRESS_LPS22HB_LSB_PER_CELSIUS	100UL
+
 #define ST_PRESS_LPS22HB_WAI_EXP		0xb1
 #define ST_PRESS_LPS22HB_ODR_ADDR		0x10
 #define ST_PRESS_LPS22HB_ODR_MASK		0x70

@@ -307,7 +311,22 @@ static const struct iio_chan_spec st_press_lps22hb_channels[] = {
 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
 		.modified = 0,
 	},
-	IIO_CHAN_SOFT_TIMESTAMP(1)
+	{
+		.type = IIO_TEMP,
+		.address = ST_TEMP_1_OUT_L_ADDR,
+		.scan_index = 1,
+		.scan_type = {
+			.sign = 's',
+			.realbits = 16,
+			.storagebits = 16,
+			.endianness = IIO_LE,
+		},
+		.info_mask_separate =
+			BIT(IIO_CHAN_INFO_RAW) |
+			BIT(IIO_CHAN_INFO_SCALE),
+		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+	},
+	IIO_CHAN_SOFT_TIMESTAMP(2)
 };
 
 static const struct st_sensor_settings st_press_sensors_settings[] = {

@@ -494,12 +513,13 @@ static const struct st_sensor_settings st_press_sensors_settings[] = {
 		.fs = {
 			.fs_avl = {
 				/*
-				 * Sensitivity values as defined in table 3 of
-				 * LPS22HB datasheet.
+				 * Pressure and temperature sensitivity values
+				 * as defined in table 3 of LPS22HB datasheet.
 				 */
 				[0] = {
 					.num = ST_PRESS_FS_AVL_1260MB,
 					.gain = ST_PRESS_KPASCAL_NANO_SCALE,
+					.gain2 = ST_PRESS_LPS22HB_LSB_PER_CELSIUS,
 				},
 			},
 		},

Some static channels are explicitly initialized with default values. Remove them to enhance readability.

Signed-off-by Gregor Boirie <[email protected]>

---
 drivers/iio/pressure/st_pressure_core.c | 10 ----------
 1 file changed, 10 deletions(-)

drivers/iio/pressure/st_pressure_core.c +0 -10

index 274cdec..55df9a7 100644
@@ -224,7 +224,6 @@
 static const struct iio_chan_spec st_press_1_channels[] = {
 	{
 		.type = IIO_PRESSURE,
-		.channel2 = IIO_NO_MOD,
 		.address = ST_PRESS_1_OUT_XL_ADDR,
 		.scan_index = 0,
 		.scan_type = {

@@ -235,11 +234,9 @@ static const struct iio_chan_spec st_press_1_channels[] = {
 		},
 		.info_mask_separate =
 			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
-		.modified = 0,
 	},
 	{
 		.type = IIO_TEMP,
-		.channel2 = IIO_NO_MOD,
 		.address = ST_TEMP_1_OUT_L_ADDR,
 		.scan_index = 1,
 		.scan_type = {

@@ -252,7 +249,6 @@ static const struct iio_chan_spec st_press_1_channels[] = {
 			BIT(IIO_CHAN_INFO_RAW) |
 			BIT(IIO_CHAN_INFO_SCALE) |
 			BIT(IIO_CHAN_INFO_OFFSET),
-		.modified = 0,
 	},
 	IIO_CHAN_SOFT_TIMESTAMP(2)
 };

@@ -260,7 +256,6 @@ static const struct iio_chan_spec st_press_1_channels[] = {
 static const struct iio_chan_spec st_press_lps001wp_channels[] = {
 	{
 		.type = IIO_PRESSURE,
-		.channel2 = IIO_NO_MOD,
 		.address = ST_PRESS_LPS001WP_OUT_L_ADDR,
 		.scan_index = 0,
 		.scan_type = {

@@ -272,11 +267,9 @@ static const struct iio_chan_spec st_press_lps001wp_channels[] = {
 		.info_mask_separate =
 			BIT(IIO_CHAN_INFO_RAW) |
 			BIT(IIO_CHAN_INFO_SCALE),
-		.modified = 0,
 	},
 	{
 		.type = IIO_TEMP,
-		.channel2 = IIO_NO_MOD,
 		.address = ST_TEMP_LPS001WP_OUT_L_ADDR,
 		.scan_index = 1,
 		.scan_type = {

@@ -288,7 +281,6 @@ static const struct iio_chan_spec st_press_lps001wp_channels[] = {
 		.info_mask_separate =
 			BIT(IIO_CHAN_INFO_RAW) |
 			BIT(IIO_CHAN_INFO_SCALE),
-		.modified = 0,
 	},
 	IIO_CHAN_SOFT_TIMESTAMP(2)
 };

@@ -296,7 +288,6 @@ static const struct iio_chan_spec st_press_lps001wp_channels[] = {
 static const struct iio_chan_spec st_press_lps22hb_channels[] = {
 	{
 		.type = IIO_PRESSURE,
-		.channel2 = IIO_NO_MOD,
 		.address = ST_PRESS_1_OUT_XL_ADDR,
 		.scan_index = 0,
 		.scan_type = {

@@ -309,7 +300,6 @@ static const struct iio_chan_spec st_press_lps22hb_channels[] = {
 			BIT(IIO_CHAN_INFO_RAW) |
 			BIT(IIO_CHAN_INFO_SCALE),
 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
-		.modified = 0,
 	},
 	{
 		.type = IIO_TEMP,

Quoted 4 lines · Gregor Boirie

Some static channels are explicitly initialized with default values. Remove them to enhance readability.

Signed-off-by Gregor Boirie <[email protected]>

Applied to the togreg branch of iio.git - initially pushed out as testing for the autobuilders to play with it.

I perhaps got a little carried away with Linus' tested by tag and added it even to those patches with only docs in them. Ah well - I'm sure he tested them by reading the docs :)