[PATCH V4 XRT Alveo 15/20] fpga: xrt: devctl platform driver

[Lizhi Hou]

Add devctl driver. devctl is a type of hardware function which only has
few registers to read or write. They are discovered by walking firmware
metadata. A platform device node will be created for them.

Signed-off-by: Sonal Santan <sonal.santan@xxxxxxxxxx>
Signed-off-by: Max Zhen <max.zhen@xxxxxxxxxx>
Signed-off-by: Lizhi Hou <lizhi.hou@xxxxxxxxxx>
---
 drivers/fpga/xrt/include/xleaf/devctl.h |  40 ++++++
 drivers/fpga/xrt/lib/xleaf/devctl.c     | 183 ++++++++++++++++++++++++
 2 files changed, 223 insertions(+)
 create mode 100644 drivers/fpga/xrt/include/xleaf/devctl.h
 create mode 100644 drivers/fpga/xrt/lib/xleaf/devctl.c

diff --git a/drivers/fpga/xrt/include/xleaf/devctl.h b/drivers/fpga/xrt/include/xleaf/devctl.h
new file mode 100644
index 000000000000..b97f3b6d9326
--- /dev/null
+++ b/drivers/fpga/xrt/include/xleaf/devctl.h
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2021 Xilinx, Inc.
+ *
+ * Authors:
+ *	Lizhi Hou <Lizhi.Hou@xxxxxxxxxx>
+ */
+
+#ifndef _XRT_DEVCTL_H_
+#define _XRT_DEVCTL_H_
+
+#include "xleaf.h"
+
+/*
+ * DEVCTL driver leaf calls.
+ */
+enum xrt_devctl_leaf_cmd {
+	XRT_DEVCTL_READ = XRT_XLEAF_CUSTOM_BASE, /* See comments in xleaf.h */
+};
+
+enum xrt_devctl_id {
+	XRT_DEVCTL_ROM_UUID = 0,
+	XRT_DEVCTL_DDR_CALIB,
+	XRT_DEVCTL_GOLDEN_VER,
+	XRT_DEVCTL_MAX
+};
+
+struct xrt_devctl_rw {
+	u32	xdr_id;
+	void	*xdr_buf;
+	u32	xdr_len;
+	u32	xdr_offset;
+};
+
+struct xrt_devctl_intf_uuid {
+	u32	uuid_num;
+	uuid_t	*uuids;
+};
+
+#endif	/* _XRT_DEVCTL_H_ */
diff --git a/drivers/fpga/xrt/lib/xleaf/devctl.c b/drivers/fpga/xrt/lib/xleaf/devctl.c
new file mode 100644
index 000000000000..ae086d7c431d
--- /dev/null
+++ b/drivers/fpga/xrt/lib/xleaf/devctl.c
@@ -0,0 +1,183 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Xilinx Alveo FPGA devctl Driver
+ *
+ * Copyright (C) 2020-2021 Xilinx, Inc.
+ *
+ * Authors:
+ *      Lizhi Hou<Lizhi.Hou@xxxxxxxxxx>
+ */
+
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/regmap.h>
+#include <linux/io.h>
+#include "metadata.h"
+#include "xleaf.h"
+#include "xleaf/devctl.h"
+
+#define XRT_DEVCTL "xrt_devctl"
+
+struct xrt_name_id {
+	char *ep_name;
+	int id;
+};
+
+static struct xrt_name_id name_id[XRT_DEVCTL_MAX] = {
+	{ XRT_MD_NODE_BLP_ROM, XRT_DEVCTL_ROM_UUID },
+	{ XRT_MD_NODE_GOLDEN_VER, XRT_DEVCTL_GOLDEN_VER },
+};
+
+static const struct regmap_config devctl_regmap_config = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+};
+
+struct xrt_devctl {
+	struct platform_device	*pdev;
+	struct regmap		*regmap[XRT_DEVCTL_MAX];
+	ulong			sizes[XRT_DEVCTL_MAX];
+};
+
+static int xrt_devctl_name2id(struct xrt_devctl *devctl, const char *name)
+{
+	int i;
+
+	for (i = 0; i < XRT_DEVCTL_MAX && name_id[i].ep_name; i++) {
+		if (!strncmp(name_id[i].ep_name, name, strlen(name_id[i].ep_name) + 1))
+			return name_id[i].id;
+	}
+
+	return -EINVAL;
+}
+
+static int
+xrt_devctl_leaf_call(struct platform_device *pdev, u32 cmd, void *arg)
+{
+	struct xrt_devctl *devctl;
+	int ret = 0;
+
+	devctl = platform_get_drvdata(pdev);
+
+	switch (cmd) {
+	case XRT_XLEAF_EVENT:
+		/* Does not handle any event. */
+		break;
+	case XRT_DEVCTL_READ: {
+		struct xrt_devctl_rw *rw_arg = arg;
+
+		if (rw_arg->xdr_len & 0x3) {
+			xrt_err(pdev, "invalid len %d", rw_arg->xdr_len);
+			return -EINVAL;
+		}
+
+		if (rw_arg->xdr_id >= XRT_DEVCTL_MAX) {
+			xrt_err(pdev, "invalid id %d", rw_arg->xdr_id);
+			return -EINVAL;
+		}
+
+		if (!devctl->regmap[rw_arg->xdr_id]) {
+			xrt_err(pdev, "io not found, id %d",
+				rw_arg->xdr_id);
+			return -EINVAL;
+		}
+
+		ret = regmap_bulk_read(devctl->regmap[rw_arg->xdr_id], rw_arg->xdr_offset,
+				       rw_arg->xdr_buf,
+				       rw_arg->xdr_len / devctl_regmap_config.reg_stride);
+		break;
+	}
+	default:
+		xrt_err(pdev, "unsupported cmd %d", cmd);
+		return -EINVAL;
+	}
+
+	return ret;
+}
+
+static int xrt_devctl_probe(struct platform_device *pdev)
+{
+	struct xrt_devctl *devctl = NULL;
+	void __iomem *base = NULL;
+	struct resource *res;
+	int i, id, ret = 0;
+
+	devctl = devm_kzalloc(&pdev->dev, sizeof(*devctl), GFP_KERNEL);
+	if (!devctl)
+		return -ENOMEM;
+
+	devctl->pdev = pdev;
+	platform_set_drvdata(pdev, devctl);
+
+	xrt_info(pdev, "probing...");
+	for (i = 0, res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	    res;
+	    res = platform_get_resource(pdev, IORESOURCE_MEM, ++i)) {
+		struct regmap_config config = devctl_regmap_config;
+
+		id = xrt_devctl_name2id(devctl, res->name);
+		if (id < 0) {
+			xrt_err(pdev, "ep %s not found", res->name);
+			continue;
+		}
+		base = devm_ioremap_resource(&pdev->dev, res);
+		if (IS_ERR(base)) {
+			ret = PTR_ERR(base);
+			break;
+		}
+		config.max_register = res->end - res->start + 1;
+		devctl->regmap[id] = devm_regmap_init_mmio(&pdev->dev, base, &config);
+		if (IS_ERR(devctl->regmap[id])) {
+			xrt_err(pdev, "map base failed %pR", res);
+			ret = PTR_ERR(devctl->regmap[id]);
+			break;
+		}
+		devctl->sizes[id] = res->end - res->start + 1;
+	}
+
+	return ret;
+}
+
+static struct xrt_subdev_endpoints xrt_devctl_endpoints[] = {
+	{
+		.xse_names = (struct xrt_subdev_ep_names[]) {
+			/* add name if ep is in same partition */
+			{ .ep_name = XRT_MD_NODE_BLP_ROM },
+			{ NULL },
+		},
+		.xse_min_ep = 1,
+	},
+	{
+		.xse_names = (struct xrt_subdev_ep_names[]) {
+			{ .ep_name = XRT_MD_NODE_GOLDEN_VER },
+			{ NULL },
+		},
+		.xse_min_ep = 1,
+	},
+	/* adding ep bundle generates devctl device instance */
+	{ 0 },
+};
+
+static struct xrt_subdev_drvdata xrt_devctl_data = {
+	.xsd_dev_ops = {
+		.xsd_leaf_call = xrt_devctl_leaf_call,
+	},
+};
+
+static const struct platform_device_id xrt_devctl_table[] = {
+	{ XRT_DEVCTL, (kernel_ulong_t)&xrt_devctl_data },
+	{ },
+};
+
+static struct platform_driver xrt_devctl_driver = {
+	.driver = {
+		.name = XRT_DEVCTL,
+	},
+	.probe = xrt_devctl_probe,
+	.id_table = xrt_devctl_table,
+};
+
+XRT_LEAF_INIT_FINI_FUNC(XRT_SUBDEV_DEVCTL, devctl);
-- 
2.27.0