[PATCH 0/2] fpga: Xilinx LogiCore PR Decoupler

[PATCH 0/2] fpga: Xilinx LogiCore PR Decoupler

[Alan Tull]

Hi Greg,

Please take these two patches for Xilinx LogiCore
PR Decouper for the FPGA bridge framework.

Thanks,
Alan


Moritz Fischer (2):
  doc: Add bindings document for Xilinx LogiCore PR Decoupler
  fpga: Add support for Xilinx LogiCORE PR Decoupler

 .../bindings/fpga/xilinx-pr-decoupler.txt          |  35 +++++
 drivers/fpga/Kconfig                               |  10 ++
 drivers/fpga/Makefile                              |   1 +
 drivers/fpga/xilinx-pr-decoupler.c                 | 161 +++++++++++++++++++++
 4 files changed, 207 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/fpga/xilinx-pr-decoupler.txt
 create mode 100644 drivers/fpga/xilinx-pr-decoupler.c

-- 
2.11.0

[PATCH 1/2] doc: Add bindings document for Xilinx LogiCore PR Decoupler

[Alan Tull]

From: Moritz Fischer <mdf@kernel.org>

This adds the binding documentation for the Xilinx LogiCORE PR
Decoupler soft core.

Signed-off-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Alan Tull <atull@kernel.org>
Cc: Sören Brinkmann <soren.brinkmann@xilinx.com>
Cc: linux-kernel@vger.kernel.org
Cc: devicetree@vger.kernel.org
---
 .../bindings/fpga/xilinx-pr-decoupler.txt          | 35 ++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/fpga/xilinx-pr-decoupler.txt

diff --git a/Documentation/devicetree/bindings/fpga/xilinx-pr-decoupler.txt b/Documentation/devicetree/bindings/fpga/xilinx-pr-decoupler.txt
new file mode 100644
index 000000000000..2c527ac30398
--- /dev/null
+++ b/Documentation/devicetree/bindings/fpga/xilinx-pr-decoupler.txt
@@ -0,0 +1,35 @@
+Xilinx LogiCORE Partial Reconfig Decoupler Softcore
+
+The Xilinx LogiCORE Partial Reconfig Decoupler manages one or more
+decouplers / fpga bridges.
+The controller can decouple/disable the bridges which prevents signal
+changes from passing through the bridge.  The controller can also
+couple / enable the bridges which allows traffic to pass through the
+bridge normally.
+
+The Driver supports only MMIO handling. A PR region can have multiple
+PR Decouplers which can be handled independently or chained via decouple/
+decouple_status signals.
+
+Required properties:
+- compatible		: Should contain "xlnx,pr-decoupler-1.00" or "xlnx,pr-decoupler"
+- regs			: base address and size for decoupler module
+- clocks		: input clock to IP
+- clock-names		: should contain "aclk"
+
+Optional properties:
+- bridge-enable		: 0 if driver should disable bridge at startup
+			  1 if driver should enable bridge at startup
+			  Default is to leave bridge in current state.
+
+See Documentation/devicetree/bindings/fpga/fpga-region.txt for generic bindings.
+
+Example:
+	fpga-bridge@100000450 {
+		compatible = "xlnx,pr-decoupler-1.00",
+			     "xlnx-pr-decoupler";
+		regs = <0x10000045 0x10>;
+		clocks = <&clkc 15>;
+		clock-names = "aclk";
+		bridge-enable = <0>;
+	};
-- 
2.11.0

Re: [PATCH 1/2] doc: Add bindings document for Xilinx LogiCore PR Decoupler

[Rob Herring]

On Fri, Mar 24, 2017 at 10:33:20AM -0500, Alan Tull wrote:
> From: Moritz Fischer <mdf@kernel.org>

Please use "dt-bindings: fpga: ..." for the subject.


> 
> This adds the binding documentation for the Xilinx LogiCORE PR
> Decoupler soft core.
> 
> Signed-off-by: Moritz Fischer <mdf@kernel.org>
> Signed-off-by: Michal Simek <michal.simek@xilinx.com>
> Acked-by: Alan Tull <atull@kernel.org>

I'm confused why you are sending these instead of Moritz? If it goes 
through you, then it should have your S-o-B too.

> Cc: Sören Brinkmann <soren.brinkmann@xilinx.com>
> Cc: linux-kernel@vger.kernel.org
> Cc: devicetree@vger.kernel.org
> ---
>  .../bindings/fpga/xilinx-pr-decoupler.txt          | 35 ++++++++++++++++++++++
>  1 file changed, 35 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/fpga/xilinx-pr-decoupler.txt
> 
> diff --git a/Documentation/devicetree/bindings/fpga/xilinx-pr-decoupler.txt b/Documentation/devicetree/bindings/fpga/xilinx-pr-decoupler.txt
> new file mode 100644
> index 000000000000..2c527ac30398
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/fpga/xilinx-pr-decoupler.txt
> @@ -0,0 +1,35 @@
> +Xilinx LogiCORE Partial Reconfig Decoupler Softcore
> +
> +The Xilinx LogiCORE Partial Reconfig Decoupler manages one or more
> +decouplers / fpga bridges.
> +The controller can decouple/disable the bridges which prevents signal
> +changes from passing through the bridge.  The controller can also
> +couple / enable the bridges which allows traffic to pass through the
> +bridge normally.
> +
> +The Driver supports only MMIO handling. A PR region can have multiple
> +PR Decouplers which can be handled independently or chained via decouple/
> +decouple_status signals.
> +
> +Required properties:
> +- compatible		: Should contain "xlnx,pr-decoupler-1.00" or "xlnx,pr-decoupler"

I'd drop xlnx,pr-decoupler, but in any case, it should not be OR rather 
"followed by". Plus the example has both.

> +- regs			: base address and size for decoupler module
> +- clocks		: input clock to IP
> +- clock-names		: should contain "aclk"
> +
> +Optional properties:
> +- bridge-enable		: 0 if driver should disable bridge at startup
> +			  1 if driver should enable bridge at startup
> +			  Default is to leave bridge in current state.
> +
> +See Documentation/devicetree/bindings/fpga/fpga-region.txt for generic bindings.
> +
> +Example:
> +	fpga-bridge@100000450 {
> +		compatible = "xlnx,pr-decoupler-1.00",
> +			     "xlnx-pr-decoupler";
> +		regs = <0x10000045 0x10>;
> +		clocks = <&clkc 15>;
> +		clock-names = "aclk";
> +		bridge-enable = <0>;
> +	};
> -- 
> 2.11.0
> 
> --
> To unsubscribe from this list: send the line "unsubscribe devicetree" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH 1/2] doc: Add bindings document for Xilinx LogiCore PR Decoupler

[Moritz Fischer]

On Thu, Mar 30, 2017 at 05:44:29PM -0500, Rob Herring wrote:
> On Fri, Mar 24, 2017 at 10:33:20AM -0500, Alan Tull wrote:
> > From: Moritz Fischer <mdf@kernel.org>
>
> Please use "dt-bindings: fpga: ..." for the subject.
>
>
> >
> > This adds the binding documentation for the Xilinx LogiCORE PR
> > Decoupler soft core.
> >
> > Signed-off-by: Moritz Fischer <mdf@kernel.org>
> > Signed-off-by: Michal Simek <michal.simek@xilinx.com>
> > Acked-by: Alan Tull <atull@kernel.org>
>
> I'm confused why you are sending these instead of Moritz? If it goes
> through you, then it should have your S-o-B too.

Do you want me to resend this Alan (with Rob's suggestions)?
>
> > Cc: Sören Brinkmann <soren.brinkmann@xilinx.com>
> > Cc: linux-kernel@vger.kernel.org
> > Cc: devicetree@vger.kernel.org
> > ---
> >  .../bindings/fpga/xilinx-pr-decoupler.txt          | 35 ++++++++++++++++++++++
> >  1 file changed, 35 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/fpga/xilinx-pr-decoupler.txt
> >
> > diff --git a/Documentation/devicetree/bindings/fpga/xilinx-pr-decoupler.txt b/Documentation/devicetree/bindings/fpga/xilinx-pr-decoupler.txt
> > new file mode 100644
> > index 000000000000..2c527ac30398
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/fpga/xilinx-pr-decoupler.txt
> > @@ -0,0 +1,35 @@
> > +Xilinx LogiCORE Partial Reconfig Decoupler Softcore
> > +
> > +The Xilinx LogiCORE Partial Reconfig Decoupler manages one or more
> > +decouplers / fpga bridges.
> > +The controller can decouple/disable the bridges which prevents signal
> > +changes from passing through the bridge.  The controller can also
> > +couple / enable the bridges which allows traffic to pass through the
> > +bridge normally.
> > +
> > +The Driver supports only MMIO handling. A PR region can have multiple
> > +PR Decouplers which can be handled independently or chained via decouple/
> > +decouple_status signals.
> > +
> > +Required properties:
> > +- compatible : Should contain "xlnx,pr-decoupler-1.00" or "xlnx,pr-decoupler"
>
> I'd drop xlnx,pr-decoupler, but in any case, it should not be OR rather
> "followed by". Plus the example has both.

Michal wanted to have both, so I put both. Personally I don't care. I
think they have some downstream stuff that relied on it.

>
> > +- regs : base address and size for decoupler module
> > +- clocks : input clock to IP
> > +- clock-names : should contain "aclk"
> > +
> > +Optional properties:
> > +- bridge-enable : 0 if driver should disable bridge at startup
> > +  1 if driver should enable bridge at startup
> > +  Default is to leave bridge in current state.
> > +
> > +See Documentation/devicetree/bindings/fpga/fpga-region.txt for generic bindings.
> > +
> > +Example:
> > + fpga-bridge@100000450 {
> > + compatible = "xlnx,pr-decoupler-1.00",
> > +     "xlnx-pr-decoupler";
> > + regs = <0x10000045 0x10>;
> > + clocks = <&clkc 15>;
> > + clock-names = "aclk";
> > + bridge-enable = <0>;
> > + };
> > --
> > 2.11.0
> >
> > --
> > To unsubscribe from this list: send the line "unsubscribe devicetree" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html

Thanks,
Moritz

Re: [PATCH 1/2] doc: Add bindings document for Xilinx LogiCore PR Decoupler

[Michal Simek]

On 5.4.2017 01:36, Moritz Fischer wrote:
> On Thu, Mar 30, 2017 at 05:44:29PM -0500, Rob Herring wrote:
>> On Fri, Mar 24, 2017 at 10:33:20AM -0500, Alan Tull wrote:
>>> From: Moritz Fischer <mdf@kernel.org>
>>
>> Please use "dt-bindings: fpga: ..." for the subject.
>>
>>
>>>
>>> This adds the binding documentation for the Xilinx LogiCORE PR
>>> Decoupler soft core.
>>>
>>> Signed-off-by: Moritz Fischer <mdf@kernel.org>
>>> Signed-off-by: Michal Simek <michal.simek@xilinx.com>
>>> Acked-by: Alan Tull <atull@kernel.org>
>>
>> I'm confused why you are sending these instead of Moritz? If it goes
>> through you, then it should have your S-o-B too.
> 
> Do you want me to resend this Alan (with Rob's suggestions)?
>>
>>> Cc: Sören Brinkmann <soren.brinkmann@xilinx.com>
>>> Cc: linux-kernel@vger.kernel.org
>>> Cc: devicetree@vger.kernel.org
>>> ---
>>>  .../bindings/fpga/xilinx-pr-decoupler.txt          | 35 ++++++++++++++++++++++
>>>  1 file changed, 35 insertions(+)
>>>  create mode 100644 Documentation/devicetree/bindings/fpga/xilinx-pr-decoupler.txt
>>>
>>> diff --git a/Documentation/devicetree/bindings/fpga/xilinx-pr-decoupler.txt b/Documentation/devicetree/bindings/fpga/xilinx-pr-decoupler.txt
>>> new file mode 100644
>>> index 000000000000..2c527ac30398
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/fpga/xilinx-pr-decoupler.txt
>>> @@ -0,0 +1,35 @@
>>> +Xilinx LogiCORE Partial Reconfig Decoupler Softcore
>>> +
>>> +The Xilinx LogiCORE Partial Reconfig Decoupler manages one or more
>>> +decouplers / fpga bridges.
>>> +The controller can decouple/disable the bridges which prevents signal
>>> +changes from passing through the bridge.  The controller can also
>>> +couple / enable the bridges which allows traffic to pass through the
>>> +bridge normally.
>>> +
>>> +The Driver supports only MMIO handling. A PR region can have multiple
>>> +PR Decouplers which can be handled independently or chained via decouple/
>>> +decouple_status signals.
>>> +
>>> +Required properties:
>>> +- compatible : Should contain "xlnx,pr-decoupler-1.00" or "xlnx,pr-decoupler"
>>
>> I'd drop xlnx,pr-decoupler, but in any case, it should not be OR rather
>> "followed by". Plus the example has both.
> 
> Michal wanted to have both, so I put both. Personally I don't care. I
> think they have some downstream stuff that relied on it.

Agree with Rob with using "followed by" instead of or.

M

Re: [PATCH 1/2] doc: Add bindings document for Xilinx LogiCore PR Decoupler

[Alan Tull]

On Tue, Apr 4, 2017 at 6:36 PM, Moritz Fischer <moritz.fischer@ettus.com> wrote:
> On Thu, Mar 30, 2017 at 05:44:29PM -0500, Rob Herring wrote:
>> On Fri, Mar 24, 2017 at 10:33:20AM -0500, Alan Tull wrote:
>> > From: Moritz Fischer <mdf@kernel.org>
>>
>> Please use "dt-bindings: fpga: ..." for the subject.
>>
>>
>> >
>> > This adds the binding documentation for the Xilinx LogiCORE PR
>> > Decoupler soft core.
>> >
>> > Signed-off-by: Moritz Fischer <mdf@kernel.org>
>> > Signed-off-by: Michal Simek <michal.simek@xilinx.com>
>> > Acked-by: Alan Tull <atull@kernel.org>
>>
>> I'm confused why you are sending these instead of Moritz? If it goes
>> through you, then it should have your S-o-B too.

Greg asked me to send patches to him.  I should have started adding my
signed-of-by
at that point.

>
> Do you want me to resend this Alan (with Rob's suggestions)?

I sent a set of patches to Greg on March 24.  Looking back on that I realize
that it didn't have Rob's ack yet (as well as having my ack where it should
have been my signed-of-by).

Yes, please resend this patchset with Rob's feedback.

Thanks,
ALan

>>
>> > Cc: Sören Brinkmann <soren.brinkmann@xilinx.com>
>> > Cc: linux-kernel@vger.kernel.org
>> > Cc: devicetree@vger.kernel.org
>> > ---
>> >  .../bindings/fpga/xilinx-pr-decoupler.txt          | 35 ++++++++++++++++++++++
>> >  1 file changed, 35 insertions(+)
>> >  create mode 100644 Documentation/devicetree/bindings/fpga/xilinx-pr-decoupler.txt
>> >
>> > diff --git a/Documentation/devicetree/bindings/fpga/xilinx-pr-decoupler.txt b/Documentation/devicetree/bindings/fpga/xilinx-pr-decoupler.txt
>> > new file mode 100644
>> > index 000000000000..2c527ac30398
>> > --- /dev/null
>> > +++ b/Documentation/devicetree/bindings/fpga/xilinx-pr-decoupler.txt
>> > @@ -0,0 +1,35 @@
>> > +Xilinx LogiCORE Partial Reconfig Decoupler Softcore
>> > +
>> > +The Xilinx LogiCORE Partial Reconfig Decoupler manages one or more
>> > +decouplers / fpga bridges.
>> > +The controller can decouple/disable the bridges which prevents signal
>> > +changes from passing through the bridge.  The controller can also
>> > +couple / enable the bridges which allows traffic to pass through the
>> > +bridge normally.
>> > +
>> > +The Driver supports only MMIO handling. A PR region can have multiple
>> > +PR Decouplers which can be handled independently or chained via decouple/
>> > +decouple_status signals.
>> > +
>> > +Required properties:
>> > +- compatible : Should contain "xlnx,pr-decoupler-1.00" or "xlnx,pr-decoupler"
>>
>> I'd drop xlnx,pr-decoupler, but in any case, it should not be OR rather
>> "followed by". Plus the example has both.
>
> Michal wanted to have both, so I put both. Personally I don't care. I
> think they have some downstream stuff that relied on it.
>
>>
>> > +- regs : base address and size for decoupler module
>> > +- clocks : input clock to IP
>> > +- clock-names : should contain "aclk"
>> > +
>> > +Optional properties:
>> > +- bridge-enable : 0 if driver should disable bridge at startup
>> > +  1 if driver should enable bridge at startup
>> > +  Default is to leave bridge in current state.
>> > +
>> > +See Documentation/devicetree/bindings/fpga/fpga-region.txt for generic bindings.
>> > +
>> > +Example:
>> > + fpga-bridge@100000450 {
>> > + compatible = "xlnx,pr-decoupler-1.00",
>> > +     "xlnx-pr-decoupler";
>> > + regs = <0x10000045 0x10>;
>> > + clocks = <&clkc 15>;
>> > + clock-names = "aclk";
>> > + bridge-enable = <0>;
>> > + };
>> > --
>> > 2.11.0
>> >
>> > --
>> > To unsubscribe from this list: send the line "unsubscribe devicetree" in
>> > the body of a message to majordomo@vger.kernel.org
>> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
> Thanks,
> Moritz

[PATCH 2/2] fpga: Add support for Xilinx LogiCORE PR Decoupler

[Alan Tull]

From: Moritz Fischer <mdf@kernel.org>

This adds support for the Xilinx LogiCORE PR Decoupler
soft-ip that does decoupling of PR regions in the FPGA
fabric during partial reconfiguration.

Signed-off-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Cc: Sören Brinkmann <soren.brinkmann@xilinx.com>
Cc: linux-kernel@vger.kernel.org
Cc: devicetree@vger.kernel.org
Acked-by: Alan Tull <atull@kernel.org>
---
 drivers/fpga/Kconfig               |  10 +++
 drivers/fpga/Makefile              |   1 +
 drivers/fpga/xilinx-pr-decoupler.c | 161 +++++++++++++++++++++++++++++++++++++
 3 files changed, 172 insertions(+)
 create mode 100644 drivers/fpga/xilinx-pr-decoupler.c

diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
index 116ee92fe034..161ba9dccede 100644
--- a/drivers/fpga/Kconfig
+++ b/drivers/fpga/Kconfig
@@ -95,6 +95,16 @@ config ALTERA_PR_IP_CORE_PLAT
 	  Platform driver support for Altera Partial Reconfiguration IP
 	  component
 
+config XILINX_PR_DECOUPLER
+	tristate "Xilinx LogiCORE PR Decoupler"
+	depends on FPGA_BRIDGE
+	depends on HAS_IOMEM
+	help
+	  Say Y to enable drivers for Xilinx LogiCORE PR Decoupler.
+	  The PR Decoupler exists in the FPGA fabric to isolate one
+	  region of the FPGA from the busses while that region is
+	  being reprogrammed during partial reconfig.
+
 endif # FPGA
 
 endmenu
diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
index 530cf9410dde..2a4f0218145c 100644
--- a/drivers/fpga/Makefile
+++ b/drivers/fpga/Makefile
@@ -19,6 +19,7 @@ obj-$(CONFIG_ALTERA_PR_IP_CORE_PLAT)    += altera-pr-ip-core-plat.o
 obj-$(CONFIG_FPGA_BRIDGE)		+= fpga-bridge.o
 obj-$(CONFIG_SOCFPGA_FPGA_BRIDGE)	+= altera-hps2fpga.o altera-fpga2sdram.o
 obj-$(CONFIG_ALTERA_FREEZE_BRIDGE)	+= altera-freeze-bridge.o
+obj-$(CONFIG_XILINX_PR_DECOUPLER)	+= xilinx-pr-decoupler.o
 
 # High Level Interfaces
 obj-$(CONFIG_FPGA_REGION)		+= fpga-region.o
diff --git a/drivers/fpga/xilinx-pr-decoupler.c b/drivers/fpga/xilinx-pr-decoupler.c
new file mode 100644
index 000000000000..e359930bebc8
--- /dev/null
+++ b/drivers/fpga/xilinx-pr-decoupler.c
@@ -0,0 +1,161 @@
+/*
+ * Copyright (c) 2017, National Instruments Corp.
+ * Copyright (c) 2017, Xilix Inc
+ *
+ * FPGA Bridge Driver for the Xilinx LogiCORE Partial Reconfiguration
+ * Decoupler IP Core.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/of_device.h>
+#include <linux/module.h>
+#include <linux/fpga/fpga-bridge.h>
+
+#define CTRL_CMD_DECOUPLE	BIT(0)
+#define CTRL_CMD_COUPLE		0
+#define CTRL_OFFSET		0
+
+struct xlnx_pr_decoupler_data {
+	void __iomem *io_base;
+	struct clk *clk;
+};
+
+static inline void xlnx_pr_decoupler_write(struct xlnx_pr_decoupler_data *d,
+					   u32 offset, u32 val)
+{
+	writel(val, d->io_base + offset);
+}
+
+static inline u32 xlnx_pr_decouple_read(const struct xlnx_pr_decoupler_data *d,
+					u32 offset)
+{
+	return readl(d->io_base + offset);
+}
+
+static int xlnx_pr_decoupler_enable_set(struct fpga_bridge *bridge, bool enable)
+{
+	int err;
+	struct xlnx_pr_decoupler_data *priv = bridge->priv;
+
+	err = clk_enable(priv->clk);
+	if (err)
+		return err;
+
+	if (enable)
+		xlnx_pr_decoupler_write(priv, CTRL_OFFSET, CTRL_CMD_COUPLE);
+	else
+		xlnx_pr_decoupler_write(priv, CTRL_OFFSET, CTRL_CMD_DECOUPLE);
+
+	clk_disable(priv->clk);
+
+	return 0;
+}
+
+static int xlnx_pr_decoupler_enable_show(struct fpga_bridge *bridge)
+{
+	const struct xlnx_pr_decoupler_data *priv = bridge->priv;
+	u32 status;
+	int err;
+
+	err = clk_enable(priv->clk);
+	if (err)
+		return err;
+
+	status = readl(priv->io_base);
+
+	clk_disable(priv->clk);
+
+	return !status;
+}
+
+static struct fpga_bridge_ops xlnx_pr_decoupler_br_ops = {
+	.enable_set = xlnx_pr_decoupler_enable_set,
+	.enable_show = xlnx_pr_decoupler_enable_show,
+};
+
+static const struct of_device_id xlnx_pr_decoupler_of_match[] = {
+	{ .compatible = "xlnx,pr-decoupler-1.00", },
+	{ .compatible = "xlnx,pr-decoupler", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, xlnx_pr_decoupler_of_match);
+
+static int xlnx_pr_decoupler_probe(struct platform_device *pdev)
+{
+	struct xlnx_pr_decoupler_data *priv;
+	int err;
+	struct resource *res;
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	priv->io_base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(priv->io_base))
+		return PTR_ERR(priv->io_base);
+
+	priv->clk = devm_clk_get(&pdev->dev, "aclk");
+	if (IS_ERR(priv->clk)) {
+		dev_err(&pdev->dev, "input clock not found\n");
+		return PTR_ERR(priv->clk);
+	}
+
+	err = clk_prepare_enable(priv->clk);
+	if (err) {
+		dev_err(&pdev->dev, "unable to enable clock\n");
+		return err;
+	}
+
+	clk_disable(priv->clk);
+
+	err = fpga_bridge_register(&pdev->dev, "Xilinx PR Decoupler",
+				   &xlnx_pr_decoupler_br_ops, priv);
+
+	if (err) {
+		dev_err(&pdev->dev, "unable to register Xilinx PR Decoupler");
+		clk_unprepare(priv->clk);
+		return err;
+	}
+
+	return 0;
+}
+
+static int xlnx_pr_decoupler_remove(struct platform_device *pdev)
+{
+	struct fpga_bridge *bridge = platform_get_drvdata(pdev);
+	struct xlnx_pr_decoupler_data *p = bridge->priv;
+
+	fpga_bridge_unregister(&pdev->dev);
+
+	clk_unprepare(p->clk);
+
+	return 0;
+}
+
+static struct platform_driver xlnx_pr_decoupler_driver = {
+	.probe = xlnx_pr_decoupler_probe,
+	.remove = xlnx_pr_decoupler_remove,
+	.driver = {
+		.name = "xlnx_pr_decoupler",
+		.of_match_table = of_match_ptr(xlnx_pr_decoupler_of_match),
+	},
+};
+
+module_platform_driver(xlnx_pr_decoupler_driver);
+
+MODULE_DESCRIPTION("Xilinx Partial Reconfiguration Decoupler");
+MODULE_AUTHOR("Moritz Fischer <mdf@kernel.org>");
+MODULE_AUTHOR("Michal Simek <michal.simek@xilinx.com>");
+MODULE_LICENSE("GPL v2");
-- 
2.11.0