[PATCH 5/5] misc: zynqmp: Add afi config driver

[Nava kishore Manne]

This patch adds zynqmp afi config driver.This is useful for
the configuration of the PS-PL interface on Zynq US+ MPSoC
platform.

Signed-off-by: Nava kishore Manne <nava.manne at xilinx.com>
---
 drivers/misc/Kconfig      | 11 ++++++
 drivers/misc/Makefile     |  1 +
 drivers/misc/zynqmp-afi.c | 83 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 95 insertions(+)
 create mode 100644 drivers/misc/zynqmp-afi.c

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 877b43b3377d..d1ea1eeb3ac1 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -456,6 +456,17 @@ config ZYNQ_AFI
 	  between PS and PL, the AXI port data path should be configured
 	  with the proper Bus-width values
 
+config ZYNQMP_AFI
+        tristate "Xilinx ZYNQMP AFI support"
+        help
+	  ZynqMP AFI driver support for writing to the AFI registers for
+	  configuring PS_PL Bus-width. Xilinx Zynq US+ MPSoC connect the
+	  PS to the programmable logic (PL) through the AXI port. This AXI
+	  port helps to establish the data path between the PS and PL.
+	  In-order to establish the proper communication path between
+	  PS and PL, the AXI port data path should be configured with
+	  the proper Bus-width values
+
 source "drivers/misc/c2port/Kconfig"
 source "drivers/misc/eeprom/Kconfig"
 source "drivers/misc/cb710/Kconfig"
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index e9b03843100f..54bd0edc511e 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -57,3 +57,4 @@ obj-$(CONFIG_UACCE)		+= uacce/
 obj-$(CONFIG_XILINX_SDFEC)	+= xilinx_sdfec.o
 obj-$(CONFIG_HISI_HIKEY_USB)	+= hisi_hikey_usb.o
 obj-$(CONFIG_ZYNQ_AFI)		+= zynq-afi.o
+obj-$(CONFIG_ZYNQMP_AFI)	+= zynqmp-afi.o
diff --git a/drivers/misc/zynqmp-afi.c b/drivers/misc/zynqmp-afi.c
new file mode 100644
index 000000000000..a318652576d2
--- /dev/null
+++ b/drivers/misc/zynqmp-afi.c
@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Xilinx FPGA AFI bridge.
+ * Copyright (c) 2018-2021 Xilinx Inc.
+ */
+
+#include <linux/err.h>
+#include <linux/firmware/xlnx-zynqmp.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+/**
+ * struct zynqmp_afi_fpga - AFI register description
+ * @value: value to be written to the register
+ * @regid: Register id for the register to be written
+ */
+struct zynqmp_afi_fpga {
+	u32 value;
+	u32 regid;
+};
+
+static int zynqmp_afi_fpga_probe(struct platform_device *pdev)
+{
+	struct zynqmp_afi_fpga *zynqmp_afi_fpga;
+	struct device_node *np = pdev->dev.of_node;
+	int i, entries, ret;
+	u32 reg, val;
+
+	zynqmp_afi_fpga = devm_kzalloc(&pdev->dev,
+				       sizeof(*zynqmp_afi_fpga), GFP_KERNEL);
+	if (!zynqmp_afi_fpga)
+		return -ENOMEM;
+	platform_set_drvdata(pdev, zynqmp_afi_fpga);
+
+	entries = of_property_count_u32_elems(np, "config-afi");
+	if (!entries || (entries % 2)) {
+		dev_err(&pdev->dev, "Invalid number of registers\n");
+		return -EINVAL;
+	}
+
+	for (i = 0; i < entries / 2; i++) {
+		ret = of_property_read_u32_index(np, "config-afi", i * 2, &reg);
+		if (ret) {
+			dev_err(&pdev->dev, "failed to read register\n");
+			return -EINVAL;
+		}
+		ret = of_property_read_u32_index(np, "config-afi", i * 2 + 1,
+						 &val);
+		if (ret) {
+			dev_err(&pdev->dev, "failed to read value\n");
+			return -EINVAL;
+		}
+		ret = zynqmp_pm_afi(reg, val);
+		if (ret < 0) {
+			dev_err(&pdev->dev, "AFI register write error %d\n",
+				ret);
+			return ret;
+		}
+	}
+	return 0;
+}
+
+static const struct of_device_id zynqmp_afi_fpga_ids[] = {
+	{ .compatible = "xlnx,zynqmp-afi-fpga" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, zynqmp_afi_fpga_ids);
+
+static struct platform_driver zynqmp_afi_fpga_driver = {
+	.driver = {
+		.name = "zynqmp-afi-fpga",
+		.of_match_table = zynqmp_afi_fpga_ids,
+	},
+	.probe = zynqmp_afi_fpga_probe,
+};
+module_platform_driver(zynqmp_afi_fpga_driver);
+
+MODULE_DESCRIPTION("ZYNQMP FPGA afi module");
+MODULE_AUTHOR("Nava kishore Manne <nava.manne at xilinx.com>");
+MODULE_LICENSE("GPL v2");
-- 
2.18.0