Merge tag 'iio-for-5.16a-split-take4' of https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into char-misc-next

Jonathan writes:

First set of IIO new device and feature support for the 5.16 cycle

Counter subsystem changes now sent separately.

This has been a busy cycle, so lots here and a few more stragglers to
come next week.

Big new feature in this cycle is probably output buffer support.
This has been in the works for a very long time so it's great to see
Mihail pick up the challenge and build upon his predecessors work to finally
bring this feature to mainline.

New device support
------------------

* adi,adxl313
  - New driver and dt bindings for this low power accelerometer.
* adi,adxl355
  - New driver and dt bindings for this accelerometer.
  - Later series adds buffer support.
* asahi-kasei,ak8975
  - Minor additions to driver to support ak09916
* aspeed,aspeed-adc
  - Substantial rework plus feature additions to add support for the
    ast2600 including a new dt bindings doc.
* atmel,at91_sama5d2
  - Rework and support introduced for the sama7g5 parts.
* maxim,max31865
  - New driver and bindings for this RTD temperature sensor chip.
* nxp,imx8qxp
  - New driver and bindings for the ADC found on the i.MX 8QuadXPlus Soc.
* senseair,sunrise
  - New driver and bindings for this family of carbon dioxide gas sensors.
* sensiron,scd4x
  - New driver and bindings for this carbon dioxide gas sensor.

New features
------------

* Output buffer support.  Works in a similar fashion to input buffers, but
  in this case userspace pushes data into the kfifo which is then drained
  to the device when a trigger occurs.  Support added to the ad5766 DAC
  driver.
* Core, devm_iio_map_array_register() to avoid need for
  devm_add_action_or_reset() based cleanup in fully managed allocation
  drivers.
* Core iio_push_to_buffers_with_ts_unaligned() function to safely handle a
  few drivers where it really hard to ensure the correct data alignment in
  an iio_push_to_buffers_with_timestamp() call. Note this uses a bounce
  buffer so should be avoided whenever possible.  Used in the ti,adc108s102,
  invense,mpu3050 and adi,adis16400.  This closes the last   known set
  of drivers with alignment issues at this interface.
* maxim,max1027
  - Substantial rework to this driver main target of which was supporting
    use of other triggers than it's own EOC interrupt.
  - Transfer optimization.
* nxp,fxls8962af
  - Threshold even support including using it as a wakeup source.

Cleanups, minor fixes etc
-------------------------

Chances of a common type to multiple drivers:

* devm_ conversion and drop of .remove() callbacks in:
  - adi,ad5064
  - adi,ad7291
  - adi,ad7303
  - adi,ad7746
  - adi,ad9832
  - adi,adis16080
  - dialog,da9150-gpadc
  - intel,mrfld_adc
  - marvell,berlin2
  - maxim,max1363
  - maxim,max44000
  - nuvoton,nau7802
  - st_sensors (includes a lot of rework!)
  - ti,ads8344
  - ti,lp8788

* devm_platform_ioremap_resource() used to reduce boilerplate
  - cirrus,ep93xx
  - rockchip,saradc
  - stm,stm32-dac

* Use dev_err_probe() in more places to both not print on deferred probe and
  ensure a reason for the deferral is available for debug purposes.
  - adi,ad8801
  - capella,cm36651
  - linear,ltc1660
  - maxim,ds4424
  - maxim,max5821
  - microchip,mcp4922
  - nxp,lpc18xx
  - onnn,noa1305
  - st,lsm9ds0
  - st,st_sensors
  - st,stm32-dac
  - ti,afe4403
  - ti,afe4404
  - ti,dac7311

* Drop error returns in SPI and I2C remove() functions as they are ignored and
  long term plan is to change these all over to returning void. In some cases
  these patches just make it 'obvious' they always return 0 where it was the
  case before but not easy to tell.
  - adi,ad5380
  - adi,ad5446
  - adi,ad5686
  - adi,ad5592r
  - bosch,bma400
  - bosch,bmc150
  - fsl,mma7455
  - honeywell,hmc5843
  - kionix,kxsd9
  - maxim,max5487
  - meas,ms5611
  - ti,afe4403

Driver specific changes

* adi,ad5770r
  - Bring driver inline with documented bindings.
* adi,ad7746
  - Trivial style fix
* adi,ad7949
  - Express some magic values as the underlying parts via new #defines.
  - Make it work with SPI controllers that don't support 14 or 16 bit messages
  - Support selection of voltage reference from dt including expanding the
    dt-bindings to cover this new functionality.
* adi,ad799x
  - Implement selection of external reference voltage on AD7991, AD7995 and
    AD7999.
  - Add missing dt-bindings doc for devices supported by this driver.
* adi,adislib
  - Move interrupt startup to better location in startup flow.
  - Handle devices that cannot mask/unmask the drdy pin and must instead mask
    at the interrupt controller.  Applies to the adis16460 and adis16475 from
    which we then drop equivalent code.
* adi,ltc2983
  - Add support for optional reset pin.
  - Fail to probe if no channels specified in dt binding.
* asahi-kasei,ak8975
  - dt-binding additions of missing vid-supply regulator.
* aspeed,aspeed-adc
  - Typo fix.
* fsl,mma7660
  - Mark acpi_device_id table __maybe_unused to avoid build warning.
* fsl,imx25-gcq
  - Avoid initializing regulators that aren't used.
* invensense,mpu3050
  - Drop a dead protection against a clash with the old input driver.
* invensense,mpu6050
  - Rework code to not use strcpy() and hence avoid possibility of wrong sized
    buffers. Note this wasn't a bug, but the new code is a lot more readable.
  - Mark acpi_device_id table __maybe_unused to avoid build warning.
* kionix,kxcjk1013
  - dt-binding addition to note it supports interrupts.
* marvell,berlin2-adc
  - Enable COMPILE_TEST building.
* maxim,max1027
  - Avoid returning success in an error path.
* nxp,imx8qxp
  - Fix warning when runtime pm not enabled via __maybe_unused.
* ricoh,rn5t618
  - Use the new devm_iio_map_array_register() instead of open coding the same.
* samsung,exynos_adc
  - Improve kconfig help text.
* st,lsm6dsx
  - Move max_fifo_size into the fifo_ops structure where the other configuration
    parameters are found.
* st,st_sensors:
  - Reorder to ensure we turn the power off after removing userspace interfaces.
* senseair,sunrise
  - Add missing I2C dependency.
* ti,twl6030
  - Small code tidy up.

* tag 'iio-for-5.16a-split-take4' of https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio: (148 commits)
  iio: imx8qxp-adc: mark PM functions as __maybe_unused
  iio: pressure: ms5611: Make ms5611_remove() return void
  iio: potentiometer: max5487: Don't return an error in .remove()
  iio: magn: hmc5843: Make hmc5843_common_remove() return void
  iio: health: afe4403: Don't return an error in .remove()
  iio: dac: ad5686: Make ad5686_remove() return void
  iio: dac: ad5592r: Make ad5592r_remove() return void
  iio: dac: ad5446: Make ad5446_remove() return void
  iio: dac: ad5380: Make ad5380_remove() return void
  iio: accel: mma7455: Make mma7455_core_remove() return void
  iio: accel: kxsd9: Make kxsd9_common_remove() return void
  iio: accel: bmi088: Make bmi088_accel_core_remove() return void
  iio: accel: bmc150: Make bmc150_accel_core_remove() return void
  iio: accel: bma400: Make bma400_remove() return void
  drivers:iio:dac:ad5766.c: Add trigger buffer
  iio: triggered-buffer: extend support to configure output buffers
  iio: kfifo-buffer: Add output buffer support
  iio: Add output buffer support
  iio: documentation: Document scd4x calibration use
  drivers: iio: chemical: Add support for Sensirion SCD4x CO2 sensor
  ...

1 files changed, 180 insertions, 74 deletions

diff --git a/drivers/iio/adc/ad7949.c b/drivers/iio/adc/ad7949.c
index 1b4b3203e428..44bb5fde83de 100644
--- a/drivers/iio/adc/ad7949.c
+++ b/drivers/iio/adc/ad7949.c
@@ -11,12 +11,41 @@
 #include <linux/module.h>
 #include <linux/regulator/consumer.h>
 #include <linux/spi/spi.h>
+#include <linux/bitfield.h>
 
-#define AD7949_MASK_CHANNEL_SEL		GENMASK(9, 7)
-#define AD7949_MASK_TOTAL		GENMASK(13, 0)
-#define AD7949_OFFSET_CHANNEL_SEL	7
-#define AD7949_CFG_READ_BACK		0x1
-#define AD7949_CFG_REG_SIZE_BITS	14
+#define AD7949_CFG_MASK_TOTAL		GENMASK(13, 0)
+
+/* CFG: Configuration Update */
+#define AD7949_CFG_MASK_OVERWRITE	BIT(13)
+
+/* INCC: Input Channel Configuration */
+#define AD7949_CFG_MASK_INCC		GENMASK(12, 10)
+#define AD7949_CFG_VAL_INCC_UNIPOLAR_GND	7
+#define AD7949_CFG_VAL_INCC_UNIPOLAR_COMM	6
+#define AD7949_CFG_VAL_INCC_UNIPOLAR_DIFF	4
+#define AD7949_CFG_VAL_INCC_TEMP		3
+#define AD7949_CFG_VAL_INCC_BIPOLAR		2
+#define AD7949_CFG_VAL_INCC_BIPOLAR_DIFF	0
+
+/* INX: Input channel Selection in a binary fashion */
+#define AD7949_CFG_MASK_INX		GENMASK(9, 7)
+
+/* BW: select bandwidth for low-pass filter. Full or Quarter */
+#define AD7949_CFG_MASK_BW_FULL		BIT(6)
+
+/* REF: reference/buffer selection */
+#define AD7949_CFG_MASK_REF		GENMASK(5, 3)
+#define AD7949_CFG_VAL_REF_EXT_TEMP_BUF		3
+#define AD7949_CFG_VAL_REF_EXT_TEMP		2
+#define AD7949_CFG_VAL_REF_INT_4096		1
+#define AD7949_CFG_VAL_REF_INT_2500		0
+#define AD7949_CFG_VAL_REF_EXTERNAL		BIT(1)
+
+/* SEQ: channel sequencer. Allows for scanning channels */
+#define AD7949_CFG_MASK_SEQ		GENMASK(2, 1)
+
+/* RB: Read back the CFG register */
+#define AD7949_CFG_MASK_RBN		BIT(0)
 
 enum {
 	ID_AD7949 = 0,
@@ -41,41 +70,51 @@ static const struct ad7949_adc_spec ad7949_adc_spec[] = {
  * @vref: regulator generating Vref
  * @indio_dev: reference to iio structure
  * @spi: reference to spi structure
+ * @refsel: reference selection
  * @resolution: resolution of the chip
  * @cfg: copy of the configuration register
  * @current_channel: current channel in use
  * @buffer: buffer to send / receive data to / from device
+ * @buf8b: be16 buffer to exchange data with the device in 8-bit transfers
  */
 struct ad7949_adc_chip {
 	struct mutex lock;
 	struct regulator *vref;
 	struct iio_dev *indio_dev;
 	struct spi_device *spi;
+	u32 refsel;
 	u8 resolution;
 	u16 cfg;
 	unsigned int current_channel;
 	u16 buffer ____cacheline_aligned;
+	__be16 buf8b;
 };
 
 static int ad7949_spi_write_cfg(struct ad7949_adc_chip *ad7949_adc, u16 val,
 				u16 mask)
 {
 	int ret;
-	int bits_per_word = ad7949_adc->resolution;
-	int shift = bits_per_word - AD7949_CFG_REG_SIZE_BITS;
-	struct spi_message msg;
-	struct spi_transfer tx[] = {
-		{
-			.tx_buf = &ad7949_adc->buffer,
-			.len = 2,
-			.bits_per_word = bits_per_word,
-		},
-	};
 
 	ad7949_adc->cfg = (val & mask) | (ad7949_adc->cfg & ~mask);
-	ad7949_adc->buffer = ad7949_adc->cfg << shift;
-	spi_message_init_with_transfers(&msg, tx, 1);
-	ret = spi_sync(ad7949_adc->spi, &msg);
+
+	switch (ad7949_adc->spi->bits_per_word) {
+	case 16:
+		ad7949_adc->buffer = ad7949_adc->cfg << 2;
+		ret = spi_write(ad7949_adc->spi, &ad7949_adc->buffer, 2);
+		break;
+	case 14:
+		ad7949_adc->buffer = ad7949_adc->cfg;
+		ret = spi_write(ad7949_adc->spi, &ad7949_adc->buffer, 2);
+		break;
+	case 8:
+		/* Here, type is big endian as it must be sent in two transfers */
+		ad7949_adc->buf8b = cpu_to_be16(ad7949_adc->cfg << 2);
+		ret = spi_write(ad7949_adc->spi, &ad7949_adc->buf8b, 2);
+		break;
+	default:
+		dev_err(&ad7949_adc->indio_dev->dev, "unsupported BPW\n");
+		return -EINVAL;
+	}
 
 	/*
 	 * This delay is to avoid a new request before the required time to
@@ -90,16 +129,6 @@ static int ad7949_spi_read_channel(struct ad7949_adc_chip *ad7949_adc, int *val,
 {
 	int ret;
 	int i;
-	int bits_per_word = ad7949_adc->resolution;
-	int mask = GENMASK(ad7949_adc->resolution - 1, 0);
-	struct spi_message msg;
-	struct spi_transfer tx[] = {
-		{
-			.rx_buf = &ad7949_adc->buffer,
-			.len = 2,
-			.bits_per_word = bits_per_word,
-		},
-	};
 
 	/*
 	 * 1: write CFG for sample N and read old data (sample N-2)
@@ -109,8 +138,8 @@ static int ad7949_spi_read_channel(struct ad7949_adc_chip *ad7949_adc, int *val,
 	 */
 	for (i = 0; i < 2; i++) {
 		ret = ad7949_spi_write_cfg(ad7949_adc,
-					   channel << AD7949_OFFSET_CHANNEL_SEL,
-					   AD7949_MASK_CHANNEL_SEL);
+					   FIELD_PREP(AD7949_CFG_MASK_INX, channel),
+					   AD7949_CFG_MASK_INX);
 		if (ret)
 			return ret;
 		if (channel == ad7949_adc->current_channel)
@@ -118,9 +147,11 @@ static int ad7949_spi_read_channel(struct ad7949_adc_chip *ad7949_adc, int *val,
 	}
 
 	/* 3: write something and read actual data */
-	ad7949_adc->buffer = 0;
-	spi_message_init_with_transfers(&msg, tx, 1);
-	ret = spi_sync(ad7949_adc->spi, &msg);
+	if (ad7949_adc->spi->bits_per_word == 8)
+		ret = spi_read(ad7949_adc->spi, &ad7949_adc->buf8b, 2);
+	else
+		ret = spi_read(ad7949_adc->spi, &ad7949_adc->buffer, 2);
+
 	if (ret)
 		return ret;
 
@@ -132,7 +163,25 @@ static int ad7949_spi_read_channel(struct ad7949_adc_chip *ad7949_adc, int *val,
 
 	ad7949_adc->current_channel = channel;
 
-	*val = ad7949_adc->buffer & mask;
+	switch (ad7949_adc->spi->bits_per_word) {
+	case 16:
+		*val = ad7949_adc->buffer;
+		/* Shift-out padding bits */
+		*val >>= 16 - ad7949_adc->resolution;
+		break;
+	case 14:
+		*val = ad7949_adc->buffer & GENMASK(13, 0);
+		break;
+	case 8:
+		/* Here, type is big endian as data was sent in two transfers */
+		*val = be16_to_cpu(ad7949_adc->buf8b);
+		/* Shift-out padding bits */
+		*val >>= 16 - ad7949_adc->resolution;
+		break;
+	default:
+		dev_err(&ad7949_adc->indio_dev->dev, "unsupported BPW\n");
+		return -EINVAL;
+	}
 
 	return 0;
 }
@@ -178,12 +227,26 @@ static int ad7949_spi_read_raw(struct iio_dev *indio_dev,
 		return IIO_VAL_INT;
 
 	case IIO_CHAN_INFO_SCALE:
-		ret = regulator_get_voltage(ad7949_adc->vref);
-		if (ret < 0)
-			return ret;
+		switch (ad7949_adc->refsel) {
+		case AD7949_CFG_VAL_REF_INT_2500:
+			*val = 2500;
+			break;
+		case AD7949_CFG_VAL_REF_INT_4096:
+			*val = 4096;
+			break;
+		case AD7949_CFG_VAL_REF_EXT_TEMP:
+		case AD7949_CFG_VAL_REF_EXT_TEMP_BUF:
+			ret = regulator_get_voltage(ad7949_adc->vref);
+			if (ret < 0)
+				return ret;
+
+			/* convert value back to mV */
+			*val = ret / 1000;
+			break;
+		}
 
-		*val = ret / 5000;
-		return IIO_VAL_INT;
+		*val2 = (1 << ad7949_adc->resolution) - 1;
+		return IIO_VAL_FRACTIONAL;
 	}
 
 	return -EINVAL;
@@ -199,8 +262,8 @@ static int ad7949_spi_reg_access(struct iio_dev *indio_dev,
 	if (readval)
 		*readval = ad7949_adc->cfg;
 	else
-		ret = ad7949_spi_write_cfg(ad7949_adc,
-			writeval & AD7949_MASK_TOTAL, AD7949_MASK_TOTAL);
+		ret = ad7949_spi_write_cfg(ad7949_adc, writeval,
+					   AD7949_CFG_MASK_TOTAL);
 
 	return ret;
 }
@@ -214,10 +277,19 @@ static int ad7949_spi_init(struct ad7949_adc_chip *ad7949_adc)
 {
 	int ret;
 	int val;
+	u16 cfg;
 
-	/* Sequencer disabled, CFG readback disabled, IN0 as default channel */
 	ad7949_adc->current_channel = 0;
-	ret = ad7949_spi_write_cfg(ad7949_adc, 0x3C79, AD7949_MASK_TOTAL);
+
+	cfg = FIELD_PREP(AD7949_CFG_MASK_OVERWRITE, 1) |
+		FIELD_PREP(AD7949_CFG_MASK_INCC, AD7949_CFG_VAL_INCC_UNIPOLAR_GND) |
+		FIELD_PREP(AD7949_CFG_MASK_INX, ad7949_adc->current_channel) |
+		FIELD_PREP(AD7949_CFG_MASK_BW_FULL, 1) |
+		FIELD_PREP(AD7949_CFG_MASK_REF, ad7949_adc->refsel) |
+		FIELD_PREP(AD7949_CFG_MASK_SEQ, 0x0) |
+		FIELD_PREP(AD7949_CFG_MASK_RBN, 1);
+
+	ret = ad7949_spi_write_cfg(ad7949_adc, cfg, AD7949_CFG_MASK_TOTAL);
 
 	/*
 	 * Do two dummy conversions to apply the first configuration setting.
@@ -229,12 +301,19 @@ static int ad7949_spi_init(struct ad7949_adc_chip *ad7949_adc)
 	return ret;
 }
 
+static void ad7949_disable_reg(void *reg)
+{
+	regulator_disable(reg);
+}
+
 static int ad7949_spi_probe(struct spi_device *spi)
 {
+	u32 spi_ctrl_mask = spi->controller->bits_per_word_mask;
 	struct device *dev = &spi->dev;
 	const struct ad7949_adc_spec *spec;
 	struct ad7949_adc_chip *ad7949_adc;
 	struct iio_dev *indio_dev;
+	u32 tmp;
 	int ret;
 
 	indio_dev = devm_iio_device_alloc(dev, sizeof(*ad7949_adc));
@@ -257,16 +336,64 @@ static int ad7949_spi_probe(struct spi_device *spi)
 	indio_dev->num_channels = spec->num_channels;
 	ad7949_adc->resolution = spec->resolution;
 
-	ad7949_adc->vref = devm_regulator_get(dev, "vref");
+	/* Set SPI bits per word */
+	if (spi_ctrl_mask & SPI_BPW_MASK(ad7949_adc->resolution)) {
+		spi->bits_per_word = ad7949_adc->resolution;
+	} else if (spi_ctrl_mask == SPI_BPW_MASK(16)) {
+		spi->bits_per_word = 16;
+	} else if (spi_ctrl_mask == SPI_BPW_MASK(8)) {
+		spi->bits_per_word = 8;
+	} else {
+		dev_err(dev, "unable to find common BPW with spi controller\n");
+		return -EINVAL;
+	}
+
+	/* Setup internal voltage reference */
+	tmp = 4096000;
+	device_property_read_u32(dev, "adi,internal-ref-microvolt", &tmp);
+
+	switch (tmp) {
+	case 2500000:
+		ad7949_adc->refsel = AD7949_CFG_VAL_REF_INT_2500;
+		break;
+	case 4096000:
+		ad7949_adc->refsel = AD7949_CFG_VAL_REF_INT_4096;
+		break;
+	default:
+		dev_err(dev, "unsupported internal voltage reference\n");
+		return -EINVAL;
+	}
+
+	/* Setup external voltage reference, buffered? */
+	ad7949_adc->vref = devm_regulator_get_optional(dev, "vrefin");
 	if (IS_ERR(ad7949_adc->vref)) {
-		dev_err(dev, "fail to request regulator\n");
-		return PTR_ERR(ad7949_adc->vref);
+		ret = PTR_ERR(ad7949_adc->vref);
+		if (ret != -ENODEV)
+			return ret;
+		/* unbuffered? */
+		ad7949_adc->vref = devm_regulator_get_optional(dev, "vref");
+		if (IS_ERR(ad7949_adc->vref)) {
+			ret = PTR_ERR(ad7949_adc->vref);
+			if (ret != -ENODEV)
+				return ret;
+		} else {
+			ad7949_adc->refsel = AD7949_CFG_VAL_REF_EXT_TEMP;
+		}
+	} else {
+		ad7949_adc->refsel = AD7949_CFG_VAL_REF_EXT_TEMP_BUF;
 	}
 
-	ret = regulator_enable(ad7949_adc->vref);
-	if (ret < 0) {
-		dev_err(dev, "fail to enable regulator\n");
-		return ret;
+	if (ad7949_adc->refsel & AD7949_CFG_VAL_REF_EXTERNAL) {
+		ret = regulator_enable(ad7949_adc->vref);
+		if (ret < 0) {
+			dev_err(dev, "fail to enable regulator\n");
+			return ret;
+		}
+
+		ret = devm_add_action_or_reset(dev, ad7949_disable_reg,
+					       ad7949_adc->vref);
+		if (ret)
+			return ret;
 	}
 
 	mutex_init(&ad7949_adc->lock);
@@ -274,36 +401,16 @@ static int ad7949_spi_probe(struct spi_device *spi)
 	ret = ad7949_spi_init(ad7949_adc);
 	if (ret) {
 		dev_err(dev, "enable to init this device: %d\n", ret);
-		goto err;
+		return ret;
 	}
 
-	ret = iio_device_register(indio_dev);
-	if (ret) {
+	ret = devm_iio_device_register(dev, indio_dev);
+	if (ret)
 		dev_err(dev, "fail to register iio device: %d\n", ret);
-		goto err;
-	}
-
-	return 0;
-
-err:
-	mutex_destroy(&ad7949_adc->lock);
-	regulator_disable(ad7949_adc->vref);
 
 	return ret;
 }
 
-static int ad7949_spi_remove(struct spi_device *spi)
-{
-	struct iio_dev *indio_dev = spi_get_drvdata(spi);
-	struct ad7949_adc_chip *ad7949_adc = iio_priv(indio_dev);
-
-	iio_device_unregister(indio_dev);
-	mutex_destroy(&ad7949_adc->lock);
-	regulator_disable(ad7949_adc->vref);
-
-	return 0;
-}
-
 static const struct of_device_id ad7949_spi_of_id[] = {
 	{ .compatible = "adi,ad7949" },
 	{ .compatible = "adi,ad7682" },
@@ -326,7 +433,6 @@ static struct spi_driver ad7949_spi_driver = {
 		.of_match_table	= ad7949_spi_of_id,
 	},
 	.probe	  = ad7949_spi_probe,
-	.remove   = ad7949_spi_remove,
 	.id_table = ad7949_spi_id,
 };
 module_spi_driver(ad7949_spi_driver);