[PATCH V4 XRT Alveo 13/20] fpga: xrt: User Clock Subsystem platform driver

[Lizhi Hou]

Add User Clock Subsystem (UCS) driver. UCS is a hardware function
discovered by walking xclbin metadata. A platform device node will be
created for it.  UCS enables/disables the dynamic region clocks.

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/lib/xleaf/ucs.c | 167 +++++++++++++++++++++++++++++++
 1 file changed, 167 insertions(+)
 create mode 100644 drivers/fpga/xrt/lib/xleaf/ucs.c

diff --git a/drivers/fpga/xrt/lib/xleaf/ucs.c b/drivers/fpga/xrt/lib/xleaf/ucs.c
new file mode 100644
index 000000000000..d91ee229e7cb
--- /dev/null
+++ b/drivers/fpga/xrt/lib/xleaf/ucs.c
@@ -0,0 +1,167 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Xilinx Alveo FPGA UCS 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/clock.h"
+
+#define UCS_ERR(ucs, fmt, arg...)   \
+	xrt_err((ucs)->pdev, fmt "\n", ##arg)
+#define UCS_WARN(ucs, fmt, arg...)  \
+	xrt_warn((ucs)->pdev, fmt "\n", ##arg)
+#define UCS_INFO(ucs, fmt, arg...)  \
+	xrt_info((ucs)->pdev, fmt "\n", ##arg)
+#define UCS_DBG(ucs, fmt, arg...)   \
+	xrt_dbg((ucs)->pdev, fmt "\n", ##arg)
+
+#define XRT_UCS		"xrt_ucs"
+
+#define XRT_UCS_CHANNEL1_REG			0
+#define XRT_UCS_CHANNEL2_REG			8
+
+#define CLK_MAX_VALUE			6400
+
+static const struct regmap_config ucs_regmap_config = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+	.max_register = 0x1000,
+};
+
+struct xrt_ucs {
+	struct platform_device	*pdev;
+	struct regmap		*regmap;
+	struct mutex		ucs_lock; /* ucs dev lock */
+};
+
+static void xrt_ucs_event_cb(struct platform_device *pdev, void *arg)
+{
+	struct xrt_event *evt = (struct xrt_event *)arg;
+	enum xrt_events e = evt->xe_evt;
+	struct platform_device *leaf;
+	enum xrt_subdev_id id;
+	int instance;
+
+	id = evt->xe_subdev.xevt_subdev_id;
+	instance = evt->xe_subdev.xevt_subdev_instance;
+
+	if (e != XRT_EVENT_POST_CREATION) {
+		xrt_dbg(pdev, "ignored event %d", e);
+		return;
+	}
+
+	if (id != XRT_SUBDEV_CLOCK)
+		return;
+
+	leaf = xleaf_get_leaf_by_id(pdev, XRT_SUBDEV_CLOCK, instance);
+	if (!leaf) {
+		xrt_err(pdev, "does not get clock subdev");
+		return;
+	}
+
+	xleaf_call(leaf, XRT_CLOCK_VERIFY, NULL);
+	xleaf_put_leaf(pdev, leaf);
+}
+
+static int ucs_enable(struct xrt_ucs *ucs)
+{
+	int ret;
+
+	mutex_lock(&ucs->ucs_lock);
+	ret = regmap_write(ucs->regmap, XRT_UCS_CHANNEL2_REG, 1);
+	mutex_unlock(&ucs->ucs_lock);
+
+	return ret;
+}
+
+static int
+xrt_ucs_leaf_call(struct platform_device *pdev, u32 cmd, void *arg)
+{
+	switch (cmd) {
+	case XRT_XLEAF_EVENT:
+		xrt_ucs_event_cb(pdev, arg);
+		break;
+	default:
+		xrt_err(pdev, "unsupported cmd %d", cmd);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int ucs_probe(struct platform_device *pdev)
+{
+	struct xrt_ucs *ucs = NULL;
+	void __iomem *base = NULL;
+	struct resource *res;
+
+	ucs = devm_kzalloc(&pdev->dev, sizeof(*ucs), GFP_KERNEL);
+	if (!ucs)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, ucs);
+	ucs->pdev = pdev;
+	mutex_init(&ucs->ucs_lock);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -EINVAL;
+
+	base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	ucs->regmap = devm_regmap_init_mmio(&pdev->dev, base, &ucs_regmap_config);
+	if (IS_ERR(ucs->regmap)) {
+		UCS_ERR(ucs, "map base %pR failed", res);
+		return PTR_ERR(ucs->regmap);
+	}
+	ucs_enable(ucs);
+
+	return 0;
+}
+
+static struct xrt_subdev_endpoints xrt_ucs_endpoints[] = {
+	{
+		.xse_names = (struct xrt_subdev_ep_names[]) {
+			{ .ep_name = XRT_MD_NODE_UCS_CONTROL_STATUS },
+			{ NULL },
+		},
+		.xse_min_ep = 1,
+	},
+	{ 0 },
+};
+
+static struct xrt_subdev_drvdata xrt_ucs_data = {
+	.xsd_dev_ops = {
+		.xsd_leaf_call = xrt_ucs_leaf_call,
+	},
+};
+
+static const struct platform_device_id xrt_ucs_table[] = {
+	{ XRT_UCS, (kernel_ulong_t)&xrt_ucs_data },
+	{ },
+};
+
+static struct platform_driver xrt_ucs_driver = {
+	.driver = {
+		.name = XRT_UCS,
+	},
+	.probe = ucs_probe,
+	.id_table = xrt_ucs_table,
+};
+
+XRT_LEAF_INIT_FINI_FUNC(XRT_SUBDEV_UCS, ucs);
-- 
2.27.0