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@xxxxxxxxxx>
Cc: Michal Simek <michal.simek@xxxxxxxxxx>
Cc: Sören Brinkmann <soren.brinkmann@xxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: devicetree@xxxxxxxxxxxxxxx
---
drivers/fpga/Kconfig | 9 +++
drivers/fpga/Makefile | 1 +
drivers/fpga/xilinx-pr-decoupler.c | 156 +++++++++++++++++++++++++++++++++++++
3 files changed, 166 insertions(+)
create mode 100644 drivers/fpga/xilinx-pr-decoupler.c
diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
index 967cda4..e42c7dc 100644
--- a/drivers/fpga/Kconfig
+++ b/drivers/fpga/Kconfig
@@ -69,6 +69,15 @@ config ALTERA_FREEZE_BRIDGE
isolate one region of the FPGA from the busses while that
region is being reprogrammed.
+config XILINX_PR_DECOUPLER
+ tristate "Xilinx LogiCORE PR Decoupler"
+ depends on FPGA_BRIDGE
+ 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 cc0d364..3f04bcf 100644
--- a/drivers/fpga/Makefile
+++ b/drivers/fpga/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_FPGA_MGR_ZYNQ_FPGA) += zynq-fpga.o
obj-$(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 0000000..07afdd6
--- /dev/null
+++ b/drivers/fpga/xilinx-pr-decoupler.c
@@ -0,0 +1,156 @@
+/*
+ * Copyright (c) 2017, National Instruments Corp.
+ *
+ * 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_OFFSET 0x00
+#define STATUS_OFFSET 0x00
+
+#define CTRL_CMD_MASK BIT(0)
+#define CTRL_CMD_DECOUPLE BIT(0)
+#define CTRL_CMD_COUPLE ~BIT(0)
+
+#define STATUS_STATE_MASK BIT(0)
+#define STATUS_STATE_COUPLED ~BIT(0)
+#define STATUS_STATE_DECOUPLED BIT(0)
+
+struct xlnx_pr_decoupler_data {
+ void __iomem *io_base;
+ struct clk *clk;
+ bool enable;
+};
+
+static inline void xlnx_pr_decoupler_write(struct xlnx_pr_decoupler_data *p,
+ u32 offset, u32 val)
+{
+ writel(val, p->io_base + offset);
+}
+
+static inline u32 xlnx_pr_decoupler_read(const struct xlnx_pr_decoupler_data *p,
+ u32 offset)
+{
+ return readl(p->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;
+
+ if (priv->enable != enable) {
+ err = clk_enable(priv->clk);
+ if (err)
+ return err;
+
+ xlnx_pr_decoupler_write(priv, CTRL_OFFSET,
+ enable ? CTRL_CMD_COUPLE :
+ 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 *p = bridge->priv;
+
+ return p->enable;
+}
+
+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", },
+ {},
+};
+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;
+ u32 status;
+ 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, "ref_clk");
+ 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;
+ }
+
+ status = xlnx_pr_decoupler_read(priv, STATUS_OFFSET);
+ priv->enable = !!(status & STATUS_STATE_MASK);
+
+ 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)
+{
+ fpga_bridge_unregister(&pdev->dev);
+
+ 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@xxxxxxxxxx>");
+MODULE_LICENSE("GPL v2");
--
2.7.4
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