Merge tag 'char-misc-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc and other driver subsystem updates from Greg KH:
 "Here is the big set of char/misc and a number of other driver
  subsystem updates for 6.9-rc1. Included in here are:

   - IIO driver updates, loads of new ones and evolution of existing ones

   - coresight driver updates

   - const cleanups for many driver subsystems

   - speakup driver additions

   - platform remove callback void cleanups

   - mei driver updates

   - mhi driver updates

   - cdx driver updates for MSI interrupt handling

   - nvmem driver updates

   - other smaller driver updates and cleanups, full details in the
    shortlog

  All of these have been in linux-next for a long time with no reported
  issue, other than a build warning for the speakup driver"

The build warning hits clang and is a gcc (and C23) extension, and is
fixed up in the merge.

Link: https://lore.kernel.org/all/20240321134831.GA2762840@dev-arch.thelio-3990X/

* tag 'char-misc-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (279 commits)
  binder: remove redundant variable page_addr
  uio_dmem_genirq: UIO_MEM_DMA_COHERENT conversion
  uio_pruss: UIO_MEM_DMA_COHERENT conversion
  cnic,bnx2,bnx2x: use UIO_MEM_DMA_COHERENT
  uio: introduce UIO_MEM_DMA_COHERENT type
  cdx: add MSI support for CDX bus
  pps: use cflags-y instead of EXTRA_CFLAGS
  speakup: Add /dev/synthu device
  speakup: Fix 8bit characters from direct synth
  parport: sunbpp: Convert to platform remove callback returning void
  parport: amiga: Convert to platform remove callback returning void
  char: xillybus: Convert to platform remove callback returning void
  vmw_balloon: change maintainership
  MAINTAINERS: change the maintainer for hpilo driver
  char: xilinx_hwicap: Fix NULL vs IS_ERR() bug
  hpet: remove hpets::hp_clocksource
  platform: goldfish: move the separate 'default' propery for CONFIG_GOLDFISH
  char: xilinx_hwicap: drop casting to void in dev_set_drvdata
  greybus: move is_gb_* functions out of greybus.h
  greybus: Remove usage of the deprecated ida_simple_xx() API
  ...

1 files changed, 72 insertions, 0 deletions

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