Merge tag 'iio-for-6.9a' of http://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into char-misc-next

Jonathan writes:

IIO: 1st set of new device support, features and cleanup for 6.9

IIO Backend support
===================

New approach from Nuno Sa to the problem of reuse of drivers with
IIO devices that are actually the combination of a highspeed chip
and an FPGA core handling the data capture and flows. It will hopefully
also apply to some other split designs. The ad9467 and axi-adi drivers
are converted over to this framework.

New device support
==================

adi,admfm2000
- New driver for this dual microwave down converter.
ams,as73211
- Add support for as7331 UV sensor.
richtek,rtq6056
- Add support for related parts RTQ6053 and RTQ6059
st,lsm6dsx
- Add ASM330LHHXG1 accelerometer and gyro support (mainly IDs)
ti,ads1298
- New driver for this medical ADC.

Features
========

tests
- Unit tests for the gain-time-scale helper library.
bosch,bmi088
- I2C support.
bosh,bmi160
- Add 10EC5280 ACPI ID. Used in a number of devices that won't get fixed.
  The ID is actually a PCI ID belonging to realtech. No response was received
  to earlier attempts to notify them of this.
  The manufacturers of some devices have replied to say they will not fix
  this incorrect ID. Add the ID and hope it isn't a problem.
bosch,bmi323
- Add BOSC0200 ACPI ID. Note this is a duplicate of one in the bmc150
  driver (it appears these parts share a windows driver).
  Both drivers perform an ID check that is safe on the other part before
  successfully probing.
hid-sensors-als
- Add color temperature and chromaticity support. Note this is a replacement
  for the series reverted in 6.8 that correctly handles all the potential
  channel combinations.
honeywell,hsc030pa
- Triggered buffer support (after driver cleanup).
honeywell,mprls00025pa
- Improved error handling.
- New DT binding to allow use of part number triplet as provided in data sheet
  to specify equivalent of most of the binding more efficiently.
- SPI support.
memsic,mxc4005
- ACPI ID MDA6655 as seen in the Chuwi Minibook X 2023
ti,hdc3020
- Add threshold event support (after some driver cleanup)
veml,vcnl4000
- Switch to high resolution proximity measurement.

Cleanup
=======
Various minor typo fixes and better use of defines etc.

Treewide
- Stop using ACPI_PTR(). The savings in space are small and not worth
  the complexity of __maybe_unused of ifdef guards.  To avoid use in
  new IIO drivers based on copy and paste, clean it out.
- cleanup.h based handling of iio_device_claim_direct_mode()/
  iio_device_release_direct_mode() using scope_cond_guard().
  In many drivers this is combined with other automated cleanup
  to give maximum simplifications.
  An initial set of drivers are converted over to this infrastructure.

Tools
- Use rewinddir() instead of seekdir() to return to start of file.

core
- Make iio_bus_type constant.

adi,ad16475
- Use irq_get_trigger_type() instead of opencoding.
adi,ad16480
- Use irq_get_trigger_type() instead of opencoding.
adi,ad-sigma-delta
- Avoid overwriting IRQ flags if provided by firmware.
ams,as73211
- Use IIO_VAL_FRACTIONAL for scales to simplify the code and potentially
  improve accuracy.
gts-library
- Use a div64_u64() instead of a loop to do a division.
honeywell,mprls00025pa
- Clean up dt-binding doc.
- Drop defaults when DT binding not providing values. Very unlikely
  these were useful given they were wrong for vast majority of supported
  devices.
- Whitespace cleanup
miramems,da280
- Use i2c_get_match_data() to replace hand rolled ACPI matching code.
semtech,sx9324
- Avoid unnecessary copying of property strings.
st,lsm6dsx
- Improve docs, particularly wrt to making addition of new device
  support less noisy.
st,lsm9ds0
- Use dev_err_probe() in all probe() error handling.
- Improved header includes.
- Tidy up termination of ID tables.
ti,ads1014
- Correct upper bound on PGA (wrong value had no actual impact)
ti,afe4403/4404
- devm_ useage to simplify error handling in probe() and allow() remove to
  be dropped.
voltage-divider
- Add dt-binding for io-channel-cells to allow such a device to be both
  an IIO consumer and IIO producer at the same time.

* tag 'iio-for-6.9a' of http://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio: (106 commits)
  iio: imu: bmi323: Add ACPI Match Table
  iio: accel: bmc150: Document duplicate ACPI entries with bmi323 driver
  iio: adc: ti-ads1298: Add driver
  dt-bindings: iio: adc: ti-ads1298: Add bindings
  iio: pressure: hsc030pa add triggered buffer
  iio: pressure: hsc030pa add mandatory delay
  iio: pressure: hsc030pa: update datasheet URLs
  iio: pressure: hsc030pa: include cleanup
  iio: pressure: hsc030pa: use signed type to hold div_64() result
  dt-bindings: iio: pressure: honeywell,hsc030pa.yaml add spi props
  iio: st_sensors: lsm9ds0: Use common style for terminator in ID tables
  iio: st_sensors: lsm9ds0: Don't use "proxy" headers
  iio: st_sensors: lsm9ds0: Use dev_err_probe() everywhere
  iio: adc: adi-axi-adc: move to backend framework
  iio: adc: ad9467: convert to backend framework
  iio: add the IIO backend framework
  iio: buffer-dmaengine: export buffer alloc and free functions
  of: property: add device link support for io-backends
  dt-bindings: adc: axi-adc: update bindings for backend framework
  dt-bindings: adc: ad9467: add new io-backend property
  ...

4 files changed, 104 insertions, 69 deletions

diff --git a/include/linux/iio/adc/adi-axi-adc.h b/include/linux/iio/adc/adi-axi-adc.h
deleted file mode 100644
index b7904992d561..000000000000
--- a/include/linux/iio/adc/adi-axi-adc.h
+++ /dev/null
@@ -1,68 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * Analog Devices Generic AXI ADC IP core driver/library
- * Link: https://wiki.analog.com/resources/fpga/docs/axi_adc_ip
- *
- * Copyright 2012-2020 Analog Devices Inc.
- */
-#ifndef __ADI_AXI_ADC_H__
-#define __ADI_AXI_ADC_H__
-
-struct device;
-struct iio_chan_spec;
-
-/**
- * struct adi_axi_adc_chip_info - Chip specific information
- * @name		Chip name
- * @id			Chip ID (usually product ID)
- * @channels		Channel specifications of type @struct iio_chan_spec
- * @num_channels	Number of @channels
- * @scale_table		Supported scales by the chip; tuples of 2 ints
- * @num_scales		Number of scales in the table
- * @max_rate		Maximum sampling rate supported by the device
- */
-struct adi_axi_adc_chip_info {
-	const char			*name;
-	unsigned int			id;
-
-	const struct iio_chan_spec	*channels;
-	unsigned int			num_channels;
-
-	const unsigned int		(*scale_table)[2];
-	int				num_scales;
-
-	unsigned long			max_rate;
-};
-
-/**
- * struct adi_axi_adc_conv - data of the ADC attached to the AXI ADC
- * @chip_info		chip info details for the client ADC
- * @preenable_setup	op to run in the client before enabling the AXI ADC
- * @reg_access		IIO debugfs_reg_access hook for the client ADC
- * @read_raw		IIO read_raw hook for the client ADC
- * @write_raw		IIO write_raw hook for the client ADC
- * @read_avail		IIO read_avail hook for the client ADC
- */
-struct adi_axi_adc_conv {
-	const struct adi_axi_adc_chip_info		*chip_info;
-
-	int (*preenable_setup)(struct adi_axi_adc_conv *conv);
-	int (*reg_access)(struct adi_axi_adc_conv *conv, unsigned int reg,
-			  unsigned int writeval, unsigned int *readval);
-	int (*read_raw)(struct adi_axi_adc_conv *conv,
-			struct iio_chan_spec const *chan,
-			int *val, int *val2, long mask);
-	int (*write_raw)(struct adi_axi_adc_conv *conv,
-			 struct iio_chan_spec const *chan,
-			 int val, int val2, long mask);
-	int (*read_avail)(struct adi_axi_adc_conv *conv,
-			  struct iio_chan_spec const *chan,
-			  const int **val, int *type, int *length, long mask);
-};
-
-struct adi_axi_adc_conv *devm_adi_axi_adc_conv_register(struct device *dev,
-							size_t sizeof_priv);
-
-void *adi_axi_adc_conv_priv(struct adi_axi_adc_conv *conv);
-
-#endif
diff --git a/include/linux/iio/backend.h b/include/linux/iio/backend.h
new file mode 100644
index 000000000000..a6d79381866e
--- /dev/null
+++ b/include/linux/iio/backend.h
@@ -0,0 +1,72 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef _IIO_BACKEND_H_
+#define _IIO_BACKEND_H_
+
+#include <linux/types.h>
+
+struct fwnode_handle;
+struct iio_backend;
+struct device;
+struct iio_dev;
+
+enum iio_backend_data_type {
+	IIO_BACKEND_TWOS_COMPLEMENT,
+	IIO_BACKEND_OFFSET_BINARY,
+	IIO_BACKEND_DATA_TYPE_MAX
+};
+
+/**
+ * struct iio_backend_data_fmt - Backend data format
+ * @type:		Data type.
+ * @sign_extend:	Bool to tell if the data is sign extended.
+ * @enable:		Enable/Disable the data format module. If disabled,
+ *			not formatting will happen.
+ */
+struct iio_backend_data_fmt {
+	enum iio_backend_data_type type;
+	bool sign_extend;
+	bool enable;
+};
+
+/**
+ * struct iio_backend_ops - operations structure for an iio_backend
+ * @enable:		Enable backend.
+ * @disable:		Disable backend.
+ * @chan_enable:	Enable one channel.
+ * @chan_disable:	Disable one channel.
+ * @data_format_set:	Configure the data format for a specific channel.
+ * @request_buffer:	Request an IIO buffer.
+ * @free_buffer:	Free an IIO buffer.
+ **/
+struct iio_backend_ops {
+	int (*enable)(struct iio_backend *back);
+	void (*disable)(struct iio_backend *back);
+	int (*chan_enable)(struct iio_backend *back, unsigned int chan);
+	int (*chan_disable)(struct iio_backend *back, unsigned int chan);
+	int (*data_format_set)(struct iio_backend *back, unsigned int chan,
+			       const struct iio_backend_data_fmt *data);
+	struct iio_buffer *(*request_buffer)(struct iio_backend *back,
+					     struct iio_dev *indio_dev);
+	void (*free_buffer)(struct iio_backend *back,
+			    struct iio_buffer *buffer);
+};
+
+int iio_backend_chan_enable(struct iio_backend *back, unsigned int chan);
+int iio_backend_chan_disable(struct iio_backend *back, unsigned int chan);
+int devm_iio_backend_enable(struct device *dev, struct iio_backend *back);
+int iio_backend_data_format_set(struct iio_backend *back, unsigned int chan,
+				const struct iio_backend_data_fmt *data);
+int devm_iio_backend_request_buffer(struct device *dev,
+				    struct iio_backend *back,
+				    struct iio_dev *indio_dev);
+
+void *iio_backend_get_priv(const struct iio_backend *conv);
+struct iio_backend *devm_iio_backend_get(struct device *dev, const char *name);
+struct iio_backend *
+__devm_iio_backend_get_from_fwnode_lookup(struct device *dev,
+					  struct fwnode_handle *fwnode);
+
+int devm_iio_backend_register(struct device *dev,
+			      const struct iio_backend_ops *ops, void *priv);
+
+#endif
diff --git a/include/linux/iio/buffer-dmaengine.h b/include/linux/iio/buffer-dmaengine.h
index 5c355be89814..cbb8ba957fad 100644
--- a/include/linux/iio/buffer-dmaengine.h
+++ b/include/linux/iio/buffer-dmaengine.h
@@ -10,6 +10,9 @@
 struct iio_dev;
 struct device;
 
+struct iio_buffer *iio_dmaengine_buffer_alloc(struct device *dev,
+					      const char *channel);
+void iio_dmaengine_buffer_free(struct iio_buffer *buffer);
 int devm_iio_dmaengine_buffer_setup(struct device *dev,
 				    struct iio_dev *indio_dev,
 				    const char *channel);
diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
index c5b36d2c1e73..e370a7bb3300 100644
--- a/include/linux/iio/iio.h
+++ b/include/linux/iio/iio.h
@@ -9,6 +9,7 @@
 
 #include <linux/device.h>
 #include <linux/cdev.h>
+#include <linux/cleanup.h>
 #include <linux/slab.h>
 #include <linux/iio/types.h>
 /* IIO TODO LIST */
@@ -638,10 +639,37 @@ int __devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev,
 int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp);
 int iio_device_claim_direct_mode(struct iio_dev *indio_dev);
 void iio_device_release_direct_mode(struct iio_dev *indio_dev);
+
+/*
+ * This autocleanup logic is normally used via
+ * iio_device_claim_direct_scoped().
+ */
+DEFINE_GUARD(iio_claim_direct, struct iio_dev *, iio_device_claim_direct_mode(_T),
+	     iio_device_release_direct_mode(_T))
+
+DEFINE_GUARD_COND(iio_claim_direct, _try, ({
+			struct iio_dev *dev;
+			int d = iio_device_claim_direct_mode(_T);
+
+			if (d < 0)
+				dev = NULL;
+			else
+				dev = _T;
+			dev;
+		}))
+
+/**
+ * iio_device_claim_direct_scoped() - Scoped call to iio_device_claim_direct.
+ * @fail: What to do on failure to claim device.
+ * @iio_dev: Pointer to the IIO devices structure
+ */
+#define iio_device_claim_direct_scoped(fail, iio_dev) \
+	scoped_cond_guard(iio_claim_direct_try, fail, iio_dev)
+
 int iio_device_claim_buffer_mode(struct iio_dev *indio_dev);
 void iio_device_release_buffer_mode(struct iio_dev *indio_dev);
 
-extern struct bus_type iio_bus_type;
+extern const struct bus_type iio_bus_type;
 
 /**
  * iio_device_put() - reference counted deallocation of struct device