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, 201 insertions, 77 deletions

diff --git a/drivers/iio/adc/max1027.c b/drivers/iio/adc/max1027.c
index b753658bb41e..4daf1d576c4e 100644
--- a/drivers/iio/adc/max1027.c
+++ b/drivers/iio/adc/max1027.c
@@ -60,6 +60,9 @@
 #define MAX1027_NAVG_32   (0x03 << 2)
 #define MAX1027_AVG_EN    BIT(4)
 
+/* Device can achieve 300ksps so we assume a 3.33us conversion delay */
+#define MAX1027_CONVERSION_UDELAY 4
+
 enum max1027_id {
 	max1027,
 	max1029,
@@ -172,18 +175,53 @@ static const struct iio_chan_spec max1231_channels[] = {
 	MAX1X31_CHANNELS(12),
 };
 
+/*
+ * These devices are able to scan from 0 to N, N being the highest voltage
+ * channel requested by the user. The temperature can be included or not,
+ * but cannot be retrieved alone. Based on the below
+ * ->available_scan_masks, the core will select the most appropriate
+ * ->active_scan_mask and the "minimum" number of channels will be
+ * scanned and pushed to the buffers.
+ *
+ * For example, if the user wants channels 1, 4 and 5, all channels from
+ * 0 to 5 will be scanned and pushed to the IIO buffers. The core will then
+ * filter out the unneeded samples based on the ->active_scan_mask that has
+ * been selected and only channels 1, 4 and 5 will be available to the user
+ * in the shared buffer.
+ */
+#define MAX1X27_SCAN_MASK_TEMP BIT(0)
+
+#define MAX1X27_SCAN_MASKS(temp)					\
+	GENMASK(1, 1 - (temp)), GENMASK(2, 1 - (temp)),			\
+	GENMASK(3, 1 - (temp)), GENMASK(4, 1 - (temp)),			\
+	GENMASK(5, 1 - (temp)), GENMASK(6, 1 - (temp)),			\
+	GENMASK(7, 1 - (temp)), GENMASK(8, 1 - (temp))
+
+#define MAX1X29_SCAN_MASKS(temp)					\
+	MAX1X27_SCAN_MASKS(temp),					\
+	GENMASK(9, 1 - (temp)), GENMASK(10, 1 - (temp)),		\
+	GENMASK(11, 1 - (temp)), GENMASK(12, 1 - (temp))
+
+#define MAX1X31_SCAN_MASKS(temp)					\
+	MAX1X29_SCAN_MASKS(temp),					\
+	GENMASK(13, 1 - (temp)), GENMASK(14, 1 - (temp)),		\
+	GENMASK(15, 1 - (temp)), GENMASK(16, 1 - (temp))
+
 static const unsigned long max1027_available_scan_masks[] = {
-	0x000001ff,
+	MAX1X27_SCAN_MASKS(0),
+	MAX1X27_SCAN_MASKS(1),
 	0x00000000,
 };
 
 static const unsigned long max1029_available_scan_masks[] = {
-	0x00001fff,
+	MAX1X29_SCAN_MASKS(0),
+	MAX1X29_SCAN_MASKS(1),
 	0x00000000,
 };
 
 static const unsigned long max1031_available_scan_masks[] = {
-	0x0001ffff,
+	MAX1X31_SCAN_MASKS(0),
+	MAX1X31_SCAN_MASKS(1),
 	0x00000000,
 };
 
@@ -232,10 +270,65 @@ struct max1027_state {
 	struct iio_trigger		*trig;
 	__be16				*buffer;
 	struct mutex			lock;
+	struct completion		complete;
 
 	u8				reg ____cacheline_aligned;
 };
 
+static int max1027_wait_eoc(struct iio_dev *indio_dev)
+{
+	struct max1027_state *st = iio_priv(indio_dev);
+	unsigned int conversion_time = MAX1027_CONVERSION_UDELAY;
+	int ret;
+
+	if (st->spi->irq) {
+		ret = wait_for_completion_timeout(&st->complete,
+						  msecs_to_jiffies(1000));
+		reinit_completion(&st->complete);
+		if (!ret)
+			return -ETIMEDOUT;
+	} else {
+		if (indio_dev->active_scan_mask)
+			conversion_time *= hweight32(*indio_dev->active_scan_mask);
+
+		usleep_range(conversion_time, conversion_time * 2);
+	}
+
+	return 0;
+}
+
+/* Scan from chan 0 to the highest requested channel. Include temperature on demand. */
+static int max1027_configure_chans_and_start(struct iio_dev *indio_dev)
+{
+	struct max1027_state *st = iio_priv(indio_dev);
+
+	st->reg = MAX1027_CONV_REG | MAX1027_SCAN_0_N;
+	st->reg |= MAX1027_CHAN(fls(*indio_dev->active_scan_mask) - 2);
+	if (*indio_dev->active_scan_mask & MAX1X27_SCAN_MASK_TEMP)
+		st->reg |= MAX1027_TEMP;
+
+	return spi_write(st->spi, &st->reg, 1);
+}
+
+static int max1027_enable_trigger(struct iio_dev *indio_dev, bool enable)
+{
+	struct max1027_state *st = iio_priv(indio_dev);
+
+	st->reg = MAX1027_SETUP_REG | MAX1027_REF_MODE2;
+
+	/*
+	 * Start acquisition on:
+	 * MODE0: external hardware trigger wired to the cnvst input pin
+	 * MODE2: conversion register write
+	 */
+	if (enable)
+		st->reg |= MAX1027_CKS_MODE0;
+	else
+		st->reg |= MAX1027_CKS_MODE2;
+
+	return spi_write(st->spi, &st->reg, 1);
+}
+
 static int max1027_read_single_value(struct iio_dev *indio_dev,
 				     struct iio_chan_spec const *chan,
 				     int *val)
@@ -243,19 +336,9 @@ static int max1027_read_single_value(struct iio_dev *indio_dev,
 	int ret;
 	struct max1027_state *st = iio_priv(indio_dev);
 
-	if (iio_buffer_enabled(indio_dev)) {
-		dev_warn(&indio_dev->dev, "trigger mode already enabled");
-		return -EBUSY;
-	}
-
-	/* Start acquisition on conversion register write */
-	st->reg = MAX1027_SETUP_REG | MAX1027_REF_MODE2 | MAX1027_CKS_MODE2;
-	ret = spi_write(st->spi, &st->reg, 1);
-	if (ret < 0) {
-		dev_err(&indio_dev->dev,
-			"Failed to configure setup register\n");
+	ret = iio_device_claim_direct_mode(indio_dev);
+	if (ret)
 		return ret;
-	}
 
 	/* Configure conversion register with the requested chan */
 	st->reg = MAX1027_CONV_REG | MAX1027_CHAN(chan->channel) |
@@ -266,18 +349,24 @@ static int max1027_read_single_value(struct iio_dev *indio_dev,
 	if (ret < 0) {
 		dev_err(&indio_dev->dev,
 			"Failed to configure conversion register\n");
+		iio_device_release_direct_mode(indio_dev);
 		return ret;
 	}
 
 	/*
 	 * For an unknown reason, when we use the mode "10" (write
 	 * conversion register), the interrupt doesn't occur every time.
-	 * So we just wait 1 ms.
+	 * So we just wait the maximum conversion time and deliver the value.
 	 */
-	mdelay(1);
+	ret = max1027_wait_eoc(indio_dev);
+	if (ret)
+		return ret;
 
 	/* Read result */
 	ret = spi_read(st->spi, st->buffer, (chan->type == IIO_TEMP) ? 4 : 2);
+
+	iio_device_release_direct_mode(indio_dev);
+
 	if (ret < 0)
 		return ret;
 
@@ -327,8 +416,8 @@ static int max1027_read_raw(struct iio_dev *indio_dev,
 }
 
 static int max1027_debugfs_reg_access(struct iio_dev *indio_dev,
-				      unsigned reg, unsigned writeval,
-				      unsigned *readval)
+				      unsigned int reg, unsigned int writeval,
+				      unsigned int *readval)
 {
 	struct max1027_state *st = iio_priv(indio_dev);
 	u8 *val = (u8 *)st->buffer;
@@ -343,61 +432,96 @@ static int max1027_debugfs_reg_access(struct iio_dev *indio_dev,
 	return spi_write(st->spi, val, 1);
 }
 
-static int max1027_validate_trigger(struct iio_dev *indio_dev,
-				    struct iio_trigger *trig)
+static int max1027_set_cnvst_trigger_state(struct iio_trigger *trig, bool state)
 {
-	struct max1027_state *st = iio_priv(indio_dev);
+	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+	int ret;
+
+	/*
+	 * In order to disable the convst trigger, start acquisition on
+	 * conversion register write, which basically disables triggering
+	 * conversions upon cnvst changes and thus has the effect of disabling
+	 * the external hardware trigger.
+	 */
+	ret = max1027_enable_trigger(indio_dev, state);
+	if (ret)
+		return ret;
 
-	if (st->trig != trig)
-		return -EINVAL;
+	if (state) {
+		ret = max1027_configure_chans_and_start(indio_dev);
+		if (ret)
+			return ret;
+	}
 
 	return 0;
 }
 
-static int max1027_set_trigger_state(struct iio_trigger *trig, bool state)
+static int max1027_read_scan(struct iio_dev *indio_dev)
 {
-	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
 	struct max1027_state *st = iio_priv(indio_dev);
+	unsigned int scanned_chans;
 	int ret;
 
-	if (state) {
-		/* Start acquisition on cnvst */
-		st->reg = MAX1027_SETUP_REG | MAX1027_CKS_MODE0 |
-			  MAX1027_REF_MODE2;
-		ret = spi_write(st->spi, &st->reg, 1);
-		if (ret < 0)
-			return ret;
+	scanned_chans = fls(*indio_dev->active_scan_mask) - 1;
+	if (*indio_dev->active_scan_mask & MAX1X27_SCAN_MASK_TEMP)
+		scanned_chans++;
 
-		/* Scan from 0 to max */
-		st->reg = MAX1027_CONV_REG | MAX1027_CHAN(0) |
-			  MAX1027_SCAN_N_M | MAX1027_TEMP;
-		ret = spi_write(st->spi, &st->reg, 1);
-		if (ret < 0)
-			return ret;
-	} else {
-		/* Start acquisition on conversion register write */
-		st->reg = MAX1027_SETUP_REG | MAX1027_CKS_MODE2	|
-			  MAX1027_REF_MODE2;
-		ret = spi_write(st->spi, &st->reg, 1);
-		if (ret < 0)
-			return ret;
-	}
+	/* fill buffer with all channel */
+	ret = spi_read(st->spi, st->buffer, scanned_chans * 2);
+	if (ret < 0)
+		return ret;
+
+	iio_push_to_buffers(indio_dev, st->buffer);
 
 	return 0;
 }
 
+static irqreturn_t max1027_handler(int irq, void *private)
+{
+	struct iio_dev *indio_dev = private;
+	struct max1027_state *st = iio_priv(indio_dev);
+
+	/*
+	 * If buffers are disabled (raw read) or when using external triggers,
+	 * we just need to unlock the waiters which will then handle the data.
+	 *
+	 * When using the internal trigger, we must hand-off the choice of the
+	 * handler to the core which will then lookup through the interrupt tree
+	 * for the right handler registered with iio_triggered_buffer_setup()
+	 * to execute, as this trigger might very well be used in conjunction
+	 * with another device. The core will then call the relevant handler to
+	 * perform the data processing step.
+	 */
+	if (!iio_buffer_enabled(indio_dev))
+		complete(&st->complete);
+	else
+		iio_trigger_poll(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
 static irqreturn_t max1027_trigger_handler(int irq, void *private)
 {
 	struct iio_poll_func *pf = private;
 	struct iio_dev *indio_dev = pf->indio_dev;
-	struct max1027_state *st = iio_priv(indio_dev);
+	int ret;
 
-	pr_debug("%s(irq=%d, private=0x%p)\n", __func__, irq, private);
+	if (!iio_trigger_using_own(indio_dev)) {
+		ret = max1027_configure_chans_and_start(indio_dev);
+		if (ret)
+			goto out;
 
-	/* fill buffer with all channel */
-	spi_read(st->spi, st->buffer, indio_dev->masklength * 2);
+		/* This is a threaded handler, it is fine to wait for an IRQ */
+		ret = max1027_wait_eoc(indio_dev);
+		if (ret)
+			goto out;
+	}
 
-	iio_push_to_buffers(indio_dev, st->buffer);
+	ret = max1027_read_scan(indio_dev);
+out:
+	if (ret)
+		dev_err(&indio_dev->dev,
+			"Cannot read scanned values (%d)\n", ret);
 
 	iio_trigger_notify_done(indio_dev->trig);
 
@@ -406,12 +530,11 @@ static irqreturn_t max1027_trigger_handler(int irq, void *private)
 
 static const struct iio_trigger_ops max1027_trigger_ops = {
 	.validate_device = &iio_trigger_validate_own_device,
-	.set_trigger_state = &max1027_set_trigger_state,
+	.set_trigger_state = &max1027_set_cnvst_trigger_state,
 };
 
 static const struct iio_info max1027_info = {
 	.read_raw = &max1027_read_raw,
-	.validate_trigger = &max1027_validate_trigger,
 	.debugfs_reg_access = &max1027_debugfs_reg_access,
 };
 
@@ -421,10 +544,8 @@ static int max1027_probe(struct spi_device *spi)
 	struct iio_dev *indio_dev;
 	struct max1027_state *st;
 
-	pr_debug("%s: probe(spi = 0x%p)\n", __func__, spi);
-
 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
-	if (indio_dev == NULL) {
+	if (!indio_dev) {
 		pr_err("Can't allocate iio device\n");
 		return -ENOMEM;
 	}
@@ -434,6 +555,7 @@ static int max1027_probe(struct spi_device *spi)
 	st->info = &max1027_chip_info_tbl[spi_get_device_id(spi)->driver_data];
 
 	mutex_init(&st->lock);
+	init_completion(&st->complete);
 
 	indio_dev->name = spi_get_device_id(spi)->name;
 	indio_dev->info = &max1027_info;
@@ -443,26 +565,26 @@ static int max1027_probe(struct spi_device *spi)
 	indio_dev->available_scan_masks = st->info->available_scan_masks;
 
 	st->buffer = devm_kmalloc_array(&indio_dev->dev,
-				  indio_dev->num_channels, 2,
-				  GFP_KERNEL);
-	if (st->buffer == NULL) {
-		dev_err(&indio_dev->dev, "Can't allocate buffer\n");
+					indio_dev->num_channels, 2,
+					GFP_KERNEL);
+	if (!st->buffer)
 		return -ENOMEM;
+
+	/* Enable triggered buffers */
+	ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
+					      &iio_pollfunc_store_time,
+					      &max1027_trigger_handler,
+					      NULL);
+	if (ret < 0) {
+		dev_err(&indio_dev->dev, "Failed to setup buffer\n");
+		return ret;
 	}
 
+	/* If there is an EOC interrupt, register the cnvst hardware trigger */
 	if (spi->irq) {
-		ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
-						      &iio_pollfunc_store_time,
-						      &max1027_trigger_handler,
-						      NULL);
-		if (ret < 0) {
-			dev_err(&indio_dev->dev, "Failed to setup buffer\n");
-			return ret;
-		}
-
 		st->trig = devm_iio_trigger_alloc(&spi->dev, "%s-trigger",
 						  indio_dev->name);
-		if (st->trig == NULL) {
+		if (!st->trig) {
 			ret = -ENOMEM;
 			dev_err(&indio_dev->dev,
 				"Failed to allocate iio trigger\n");
@@ -479,12 +601,9 @@ static int max1027_probe(struct spi_device *spi)
 			return ret;
 		}
 
-		ret = devm_request_threaded_irq(&spi->dev, spi->irq,
-						iio_trigger_generic_data_rdy_poll,
-						NULL,
-						IRQF_TRIGGER_FALLING,
-						spi->dev.driver->name,
-						st->trig);
+		ret = devm_request_irq(&spi->dev, spi->irq, max1027_handler,
+				       IRQF_TRIGGER_FALLING,
+				       spi->dev.driver->name, indio_dev);
 		if (ret < 0) {
 			dev_err(&indio_dev->dev, "Failed to allocate IRQ.\n");
 			return ret;
@@ -507,6 +626,11 @@ static int max1027_probe(struct spi_device *spi)
 		return ret;
 	}
 
+	/* Assume conversion on register write for now */
+	ret = max1027_enable_trigger(indio_dev, false);
+	if (ret)
+		return ret;
+
 	return devm_iio_device_register(&spi->dev, indio_dev);
 }