fpga: remove redundant checks for bridge ops

Commit 0d70af3c2530 ("fpga: bridge: Use standard dev_release for class
driver") introduced a check in fpga_bridge_register() that prevents
registering a bridge without ops, making checking on every call
redundant.

Signed-off-by: Marco Pagani <marpagan@redhat.com>
Acked-by: Xu Yilun <yilun.xu@intel.com>
Link: https://lore.kernel.org/r/20240201155713.82898-1-marpagan@redhat.com
Signed-off-by: Xu Yilun <yilun.xu@linux.intel.com>

fpga: bridge: make fpga_bridge_class a static const structure

Now that the driver core allows for struct class to be in read-only
memory, move the fpga_bridge_class structure to be declared at build
time placing it into read-only memory, instead of having to be
dynamically allocated at boot time.

Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Acked-by: Xu Yilun <yilun.xu@intel.com>
Link: https://lore.kernel.org/r/20230811073043.52808-1-ivan.orlov0322@gmail.com
Signed-off-by: Xu Yilun <yilun.xu@intel.com>

fpga: bridge: fix kernel-doc

Fix the following warnings issued by the kernel-doc script:

drivers/fpga/fpga-bridge.c:99: warning: No description found for return value of 'of_fpga_bridge_get'
drivers/fpga/fpga-bridge.c:163: warning: No description found for return value of 'fpga_bridges_enable'
drivers/fpga/fpga-bridge.c:187: warning: No description found for return value of 'fpga_bridges_disable'
drivers/fpga/fpga-bridge.c:238: warning: No description found for return value of 'of_fpga_bridge_get_to_list'
drivers/fpga/fpga-bridge.c:268: warning: No description found for return value of 'fpga_bridge_get_to_list'

- Extend the return description of of_fpga_bridge_get() to include the
case when try_module_get() fails.

Signed-off-by: Marco Pagani <marpagan@redhat.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Xu Yilun <yilun.xu@intel.com>
Link: https://lore.kernel.org/r/20230706142755.124879-3-marpagan@redhat.com
Signed-off-by: Xu Yilun <yilun.xu@intel.com>

driver core: class: remove module * from class_create()

The module pointer in class_create() never actually did anything, and it
shouldn't have been requred to be set as a parameter even if it did
something. So just remove it and fix up all callers of the function in
the kernel tree at the same time.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20230313181843.1207845-4-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fpga: bridge: fix kernel-doc parameter description

Fix the kernel-doc description for the "struct fpga_image_info *info"
parameter of the fpga_bridge_get() function.

Fixes: 060ac5c8fa7b ("fpga: bridge: kernel-doc fixes")
Signed-off-by: Marco Pagani <marpagan@redhat.com>
Reviewed-by: Tom Rix <trix@redhat.com>
Acked-by: Xu Yilun <yilun.xu@intel.com>
Link: https://lore.kernel.org/r/20230301140309.512578-1-marpagan@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fpga: bridge: properly initialize bridge device before populating children

The current code path can lead to warnings because of uninitialized device,
which contains, as a consequence, uninitialized kobject. The uninitialized
device is passed to of_platform_populate, which will at some point, while
creating child device, try to get a reference on uninitialized parent,
resulting in the following warning:

kobject: '(null)' ((ptrval)): is not initialized, yet kobject_get() is
being called.

The warning is observed after migrating a kernel 5.10.x to 6.1.x.
Reverting commit 0d70af3c2530 ("fpga: bridge: Use standard dev_release for
class driver") seems to remove the warning.
This commit aggregates device_initialize() and device_add() into
device_register() but this new call is done AFTER of_platform_populate

Fixes: 0d70af3c2530 ("fpga: bridge: Use standard dev_release for class driver")
Signed-off-by: Alexis Lothoré <alexis.lothore@bootlin.com>
Acked-by: Xu Yilun <yilun.xu@intel.com>
Link: https://lore.kernel.org/r/20230404133102.2837535-2-alexis.lothore@bootlin.com
Signed-off-by: Xu Yilun <yilun.xu@intel.com>

fpga: bridge: return errors in the show() method of the "state" attribute

This patch changes the show() method of the "state" sysfs attribute to
propagate errors returned by the enable_show() op. In this way,
userspace can distinguish between when the bridge is actually "enabled"
(i.e., allowing signals) or "disabled" (i.e., gating signals), or when
there is an error.

Currently, enable_show() returns an integer representing the bridge's
state (enabled or disabled) or an error code. However, this integer
value is interpreted in state_show() as a bool, resulting in the method
printing "enabled" (i.e., the bridge allows signals to pass), without
propagating the error, even when enable_show() returns an error code.

Signed-off-by: Marco Pagani <marpagan@redhat.com>
Acked-by: Xu Yilun <yilun.xu@intel.com>
Link: https://lore.kernel.org/r/20230125140622.176870-1-marpagan@redhat.com
Signed-off-by: Xu Yilun <yilun.xu@intel.com>

fpga: Directly use ida_alloc()/free()

Use ida_alloc()/ida_free() instead of deprecated
ida_simple_get()/ida_simple_remove() .

Signed-off-by: keliu <liuke94@huawei.com>
Link: https://lore.kernel.org/r/20220527085915.2798928-1-liuke94@huawei.com
Signed-off-by: Xu Yilun <yilun.xu@intel.com>

fpga: bridge: Use standard dev_release for class driver

The FPGA bridge class driver data structure is being treated as a
managed resource instead of using the standard dev_release call-back
function to release the class data structure. This change removes
the managed resource code and combines the create() and register()
functions into a single register() function.

Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Reviewed-by: Xu Yilun <yilun.xu@intel.com>
Acked-by: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Moritz Fischer <mdf@kernel.org>

fpga: fpga-bridge: removed repeated word

Removed repeated word and.
Reported by checkpatch.

Signed-off-by: Navin Sankar Velliangiri <navin@linumiz.com>
Signed-off-by: Moritz Fischer <mdf@kernel.org>

fpga: fix spelling mistakes

Run the fpga subsystem through aspell.

Signed-off-by: Tom Rix <trix@redhat.com>
Reviewed-by: Fernando Pacheco <fpacheco@redhat.com>
Signed-off-by: Moritz Fischer <mdf@kernel.org>

fpga: bridge: Rename dev to parent for parent device

Rename variable "dev" to "parent" in cases where it represents the parent
device.

Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Reviewed-by: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Moritz Fischer <mdf@kernel.org>
Link: https://lore.kernel.org/r/20210614170909.232415-5-mdf@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fpga: bridge: change FPGA indirect article to an

Change use of 'a fpga' to 'an fpga'

Signed-off-by: Tom Rix <trix@redhat.com>
Link: https://lore.kernel.org/r/20210608212350.3029742-8-trix@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fpga: Use DEFINE_SPINLOCK() for spinlock

spinlock can be initialized automatically with DEFINE_SPINLOCK()
rather than explicitly calling spin_lock_init().

Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Reviewed-by: Tom Rix <trix@redhat.com>
Signed-off-by: Moritz Fischer <mdf@kernel.org>

fpga: Fix dead store in fpga-bridge.c

Using clang's scan-build/view this issue was flagged
a dead store issue in fpga-bridge.c

warning: Value stored to 'ret' is never read [deadcode.DeadStores]
ret = id;

Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Moritz Fischer <mdf@kernel.org>

drivers: Introduce device lookup variants by of_node

Introduce wrappers for {bus/driver/class}_find_device() to
locate devices by its of_node.

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: dri-devel@lists.freedesktop.org
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: devicetree@vger.kernel.org
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: linux-i2c@vger.kernel.org
Cc: linux-rockchip@lists.infradead.org
Cc: linux-spi@vger.kernel.org
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: Alan Tull <atull@kernel.org>
Cc: linux-fpga@vger.kernel.org
Cc: Peter Rosin <peda@axentia.se>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Thor Thayer <thor.thayer@linux.intel.com>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Peter Rosin <peda@axentia.se>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de> # I2C part
Acked-by: Moritz Fischer <mdf@kernel.org> # For FPGA part
Acked-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20190723221838.12024-3-suzuki.poulose@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fpga: bridge: add devm_fpga_bridge_create

Add devm_fpga_bridge_create() which is the managed
version of fpga_bridge_create().

Change current bridge drivers to use
devm_fpga_bridge_create().

Signed-off-by: Alan Tull <atull@kernel.org>
Suggested-by: Federico Vaga <federico.vaga@cern.ch>
Acked-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fpga: bridge: fix obvious function documentation error

fpga_bridge_dev_match() returns a FPGA bridge struct, not a
FPGA manager struct so s/manager/bridge/.

Signed-off-by: Alan Tull <atull@kernel.org>
Acked-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fpga: clarify that unregister functions also free

The following functions also free the struct. Add that
fact to the function documentation.
- fpga_mgr_free
- fpga_bridge_free
- fpga_region_free

Signed-off-by: Alan Tull <atull@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fpga: bridge: kernel-doc fixes

Fix the following warnings when documentation is built:

./drivers/fpga/fpga-bridge.c:143: warning: Function parameter or
member 'info' not described in 'fpga_bridge_get'

./drivers/fpga/fpga-bridge.c:1: warning: no structured comments found

Signed-off-by: Alan Tull <atull@kernel.org>
Acked-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fpga: use SPDX

Replace GPLv2 boilerplate with SPDX in FPGA code that came from me or
from Altera.

Signed-off-by: Alan Tull <atull@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fpga: bridge: change api, don't use drvdata

Change fpga_bridge_register to not set drvdata. This is to support
the case where a PCIe device can have more than one bridge.

Add API functions to create/free the fpga bridge struct. Change
fpga_bridge_register/unregister to take FPGA bridge struct as
the only parameter.

struct fpga_bridge
*fpga_bridge_create(struct device *dev, const char *name,
const struct fpga_bridge_ops *br_ops,
void *priv);
void fpga_bridge_free(struct fpga_bridge *br);
int fpga_bridge_register(struct fpga_bridge *br);
void fpga_bridge_unregister(struct fpga_bridge *br);

Update the drivers that call fpga_bridge_register with the new API.

Signed-off-by: Alan Tull <atull@kernel.org>
Reported-by: Jiuyue Ma <majiuyue@huawei.com>
Signed-off-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fpga: fpga-bridge: remove unnecessary null check in of_fpga_bridge_get

Notice that bridge = to_fpga_bridge(dev); expands to:

bridge = container_of(dev, struct fpga_bridge, dev);

and container_of is never null, so this null check is
unnecessary.

Addresses-Coverity-ID: 1397912
Reported-by: Alan Tull <atull@kernel.org>
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Reviewed-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Alan Tull <atull@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fpga: add attribute groups

Make it easy to add attributes to low level FPGA drivers the right
way. Add attribute groups pointers to structures that are used when
registering a manager, bridge, or group. When the low level driver
registers, set the device attribute group. The attributes are
created in device_add.

Signed-off-by: Alan Tull <atull@kernel.org>
Acked-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fpga: bridge: support getting bridge from device

Add two functions for getting the FPGA bridge from the device
rather than device tree node. This is to enable writing code
that will support using FPGA bridges without device tree.
Rename one old function to make it clear that it is device
tree-ish. This leaves us with 3 functions for getting a bridge:

* fpga_bridge_get
Get the bridge given the device.

* fpga_bridges_get_to_list
Given the device, get the bridge and add it to a list.

* of_fpga_bridges_get_to_list
Renamed from priviously existing fpga_bridges_get_to_list.
Given the device node, get the bridge and add it to a list.

Signed-off-by: Alan Tull <atull@kernel.org>
Acked-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fpga: bridge: Replace open-coded list_for_each + list_entry

Replaces open-coded list_for_each() + list_entry() with macro
list_for_each_entry()

Signed-off-by: Moritz Fischer <mdf@kernel.org>
Cc: linux-fpga@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Acked-by: Alan Tull <atull@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fpga: fix sparse warnings in fpga-mgr and fpga-bridge

Fix up these sparse warnings:

drivers/fpga/fpga-mgr.c:189:21: warning: symbol '__fpga_mgr_get' was not declared. Should it be static?
drivers/fpga/fpga-bridge.c:30:12: warning: symbol 'bridge_list_lock' was not declared. Should it be static?

Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
Acked-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Alan Tull <atull@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fpga: add fpga bridge framework

This framework adds API functions for enabling/
disabling FPGA bridges under kernel control.

This allows the Linux kernel to disable FPGA bridges
during FPGA reprogramming and to enable FPGA bridges
when FPGA reprogramming is done. This framework is
be manufacturer-agnostic, allowing it to be used in
interfaces that use the FPGA Manager Framework to
reprogram FPGA's.

The functions are:
* of_fpga_bridge_get
* fpga_bridge_put
Get/put an exclusive reference to a FPGA bridge.

* fpga_bridge_enable
* fpga_bridge_disable
Enable/Disable traffic through a bridge.

* fpga_bridge_register
* fpga_bridge_unregister
Register/unregister a device-specific low level FPGA
Bridge driver.

Get an exclusive reference to a bridge and add it to a list:
* fpga_bridge_get_to_list

To enable/disable/put a set of bridges that are on a list:
* fpga_bridges_enable
* fpga_bridges_disable
* fpga_bridges_put

Signed-off-by: Alan Tull <atull@opensource.altera.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>