fpga: altera-hps2fpga: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.

To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Xu Yilun <yilun.xu@intel.com>
Link: https://lore.kernel.org/r/7a56558f7e5aa34bf0b21d22f9036a136a2b7322.1703006638.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Xu Yilun <yilun.xu@linux.intel.com>

fpga: Use device_get_match_data()

Use preferred device_get_match_data() instead of of_match_device() to
get the driver match data. With this, adjust the includes to explicitly
include the correct headers.

Also drop of_match_ptr for xlnx_pr_decoupler_of_match, which is not
necessary because DT is always used for this driver.

Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Xu Yilun <yilun.xu@intel.com>
Link: https://lore.kernel.org/r/20231006224633.445035-1-robh@kernel.org
[yilun.xu@intel.com: merge the fix 20231012192149.1546368-1-robh@kernel.org]
Link: https://lore.kernel.org/r/20231012192149.1546368-1-robh@kernel.org
Signed-off-by: Xu Yilun <yilun.xu@linux.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: 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: 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: altera-hps2fpga: fix multiple init of l3_remap_lock

The global spinlock `l3_remap_lock` is reinitialized every time the
"probe" function `alt_fpga_bridge_probe()` is called. It should only be
initialized once. Use `DEFINE_SPINLOCK()` to initialize it statically.

Fixes: e5f8efa5c8bf ("ARM: socfpga: fpga bridge driver support")
Cc: <stable@vger.kernel.org> # 4.10+
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
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: altera-hps2fpga: add NULL check on of_match_device() return value

Check return value from call to of_match_device()
in order to prevent a NULL pointer dereference.

In case of NULL print error message and return -ENODEV

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>

ARM: socfpga: explicitly request exclusive reset control

Commit a53e35db70d1 ("reset: Ensure drivers are explicit when requesting
reset lines") started to transition the reset control request API calls
to explicitly state whether the driver needs exclusive or shared reset
control behavior. Convert all drivers requesting exclusive resets to the
explicit API call so the temporary transition helpers can be removed.

No functional changes.

Cc: Alan Tull <atull@kernel.org>
Cc: Moritz Fischer <moritz.fischer@ettus.com>
Cc: linux-fpga@vger.kernel.org
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
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 altera-hps2fpga: disable/unprepare clock on error in alt_fpga_bridge_probe()

If either _alt_hps2fpga_enable_set() or fpga_bridge_register() fail in
alt_fpga_bridge_probe(), the clock remains enabled and prepared. Also,
in the error path for _alt_hps2fpga_enable_set() a call to
fpga_bridge_unregister() is made even though the bridge was not
registered yet.

Remove the unnecessary call to fpga_bridge_unregister() and call
clk_disable_unprepare() in both error paths in order to make sure the
clock gets properly disabled and unprepared.

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

ARM: socfpga: fpga bridge driver support

Supports Altera SOCFPGA bridges:
* fpga2sdram
* fpga2hps
* hps2fpga
* lwhps2fpga

Allows enabling/disabling the bridges through the FPGA
Bridge Framework API functions.

The fpga2sdram driver only supports enabling and disabling
of the ports that been configured early on. This is due to
a hardware limitation where the read, write, and command
ports on the fpga2sdram bridge can only be reconfigured
while there are no transactions to the sdram, i.e. when
running out of OCRAM before the kernel boots.

Device tree property 'init-val' configures the driver to
enable or disable the bridge during probe. If the property
does not exist, the driver will leave the bridge in its
current state.

Signed-off-by: Alan Tull <atull@opensource.altera.com>
Signed-off-by: Matthew Gerlach <mgerlach@altera.com>
Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>