Adds the reset bridge. After the bitstream load the reset
bridge helps in reseting the programable logic. The
reset lines depends on the design.
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx>
---
drivers/fpga/Kconfig | 8 ++++
drivers/fpga/Makefile | 1 +
drivers/fpga/xilinx-rst-bridge.c | 100 +++++++++++++++++++++++++++++++++++++++
3 files changed, 109 insertions(+)
create mode 100644 drivers/fpga/xilinx-rst-bridge.c
diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
index ad5448f..752a907 100644
--- a/drivers/fpga/Kconfig
+++ b/drivers/fpga/Kconfig
@@ -117,4 +117,12 @@ config XILINX_PR_DECOUPLER
region of the FPGA from the busses while that region is
being reprogrammed during partial reconfig.
+config XILINX_RST_BRIDGE
+ tristate "Xilinx Reset bridge"
+ depends on FPGA_BRIDGE
+ help
+ Say Y to enable drivers for Xilinx Reset bridge.
+ After writing the bitstream there has to be a reset.
+ The reset lines are design specific.
+
endif # FPGA
diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
index f98dcf1..c1b0d13 100644
--- a/drivers/fpga/Makefile
+++ b/drivers/fpga/Makefile
@@ -23,6 +23,7 @@ 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
+obj-$(CONFIG_FPGA_MGR_ZYNQMP_FPGA) += xilinx-rst-bridge.o
# High Level Interfaces
obj-$(CONFIG_FPGA_REGION) += fpga-region.o
diff --git a/drivers/fpga/xilinx-rst-bridge.c b/drivers/fpga/xilinx-rst-bridge.c
new file mode 100644
index 0000000..8062283
--- /dev/null
+++ b/drivers/fpga/xilinx-rst-bridge.c
@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Xilinx FPGA reset bridge.
+ * Copyright (c) 2018 Xilinx Inc.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/fpga/fpga-bridge.h>
+#include <linux/reset.h>
+
+struct xlnx_rst_bridge_priv {
+ struct device *dev;
+ bool enable;
+};
+
+static int xlnx_rst_bridge_enable_set(struct fpga_bridge *bridge, bool enable)
+{
+ struct xlnx_rst_bridge_priv *priv = bridge->priv;
+ struct device *dev = priv->dev;
+ struct reset_control *rstc;
+ int ret = 0;
+
+ if (enable) {
+ rstc = of_reset_control_array_get(dev->of_node, false, false);
+ if (IS_ERR(rstc))
+ return PTR_ERR(rstc);
+
+ ret = reset_control_reset(rstc);
+
+ reset_control_put(rstc);
+
+ if (ret)
+ dev_err(dev, "Reset failed\n");
+ } else {
+ dev_dbg(dev, "Bridge disabled\n");
+ }
+
+ if (!ret)
+ priv->enable = enable;
+
+ return ret;
+}
+
+static int xlnx_rst_bridge_enable_show(struct fpga_bridge *bridge)
+{
+ struct xlnx_rst_bridge_priv *priv = bridge->priv;
+
+ return priv->enable;
+}
+
+static struct fpga_bridge_ops xlnx_rst_bridge_ops = {
+ .enable_set = xlnx_rst_bridge_enable_set,
+ .enable_show = xlnx_rst_bridge_enable_show,
+};
+
+static int xlnx_rst_bridge_probe(struct platform_device *pdev)
+{
+ struct xlnx_rst_bridge_priv *priv;
+ struct device *dev = &pdev->dev;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->dev = dev;
+
+ return fpga_bridge_register(dev, "xlnx_rst_bridge",
+ &xlnx_rst_bridge_ops, priv);
+}
+
+static int xlnx_rst_bridge_remove(struct platform_device *pdev)
+{
+ fpga_bridge_unregister(&pdev->dev);
+
+ return 0;
+}
+
+static const struct of_device_id xlnx_rst_bridge_of_match[] = {
+ { .compatible = "xlnx,rst-bridge", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, xlnx_rst_bridge_of_match);
+
+static struct platform_driver xlnx_rst_bridge_driver = {
+ .probe = xlnx_rst_bridge_probe,
+ .remove = xlnx_rst_bridge_remove,
+ .driver = {
+ .name = "xlnx_rst_bridge",
+ .of_match_table = of_match_ptr(xlnx_rst_bridge_of_match),
+ },
+};
+
+module_platform_driver(xlnx_rst_bridge_driver);
+
+MODULE_DESCRIPTION("Xilinx reset Bridge");
+MODULE_AUTHOR("Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx>");
+MODULE_LICENSE("GPL v2");
--
2.1.1
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