[PATCH V3 XRT Alveo 11/18] fpga: xrt: UCS platform driver

[Lizhi Hou <lizhi.hou@xilinx.com>]

Add 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@xilinx.com>
Signed-off-by: Max Zhen <max.zhen@xilinx.com>
Signed-off-by: Lizhi Hou <lizhih@xilinx.com>
---
 drivers/fpga/xrt/include/xleaf/ucs.h |  24 +++
 drivers/fpga/xrt/lib/xleaf/ucs.c     | 235 +++++++++++++++++++++++++++
 2 files changed, 259 insertions(+)
 create mode 100644 drivers/fpga/xrt/include/xleaf/ucs.h
 create mode 100644 drivers/fpga/xrt/lib/xleaf/ucs.c

diff --git a/drivers/fpga/xrt/include/xleaf/ucs.h b/drivers/fpga/xrt/include/xleaf/ucs.h
new file mode 100644
index 000000000000..a5ef0e100e12
--- /dev/null
+++ b/drivers/fpga/xrt/include/xleaf/ucs.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Header file for XRT UCS Leaf Driver
+ *
+ * Copyright (C) 2020-2021 Xilinx, Inc.
+ *
+ * Authors:
+ *	Lizhi Hou <Lizhi.Hou@xilinx.com>
+ */
+
+#ifndef _XRT_UCS_H_
+#define _XRT_UCS_H_
+
+#include "xleaf.h"
+
+/*
+ * UCS driver IOCTL calls.
+ */
+enum xrt_ucs_ioctl_cmd {
+	XRT_UCS_CHECK = XRT_XLEAF_CUSTOM_BASE, /* See comments in xleaf.h */
+	XRT_UCS_ENABLE,
+};
+
+#endif	/* _XRT_UCS_H_ */
diff --git a/drivers/fpga/xrt/lib/xleaf/ucs.c b/drivers/fpga/xrt/lib/xleaf/ucs.c
new file mode 100644
index 000000000000..ae762c8fddbb
--- /dev/null
+++ b/drivers/fpga/xrt/lib/xleaf/ucs.c
@@ -0,0 +1,235 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Xilinx Alveo FPGA UCS Driver
+ *
+ * Copyright (C) 2020-2021 Xilinx, Inc.
+ *
+ * Authors:
+ *      Lizhi Hou<Lizhi.Hou@xilinx.com>
+ */
+
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include "metadata.h"
+#include "xleaf.h"
+#include "xleaf/ucs.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 CHANNEL1_OFFSET			0
+#define CHANNEL2_OFFSET			8
+
+#define CLK_MAX_VALUE			6400
+
+struct ucs_control_status_ch1 {
+	unsigned int shutdown_clocks_latched:1;
+	unsigned int reserved1:15;
+	unsigned int clock_throttling_average:14;
+	unsigned int reserved2:2;
+};
+
+struct xrt_ucs {
+	struct platform_device	*pdev;
+	void __iomem		*ucs_base;
+	struct mutex		ucs_lock; /* ucs dev lock */
+};
+
+static inline u32 reg_rd(struct xrt_ucs *ucs, u32 offset)
+{
+	return ioread32(ucs->ucs_base + offset);
+}
+
+static inline void reg_wr(struct xrt_ucs *ucs, u32 val, u32 offset)
+{
+	iowrite32(val, ucs->ucs_base + offset);
+}
+
+static void xrt_ucs_event_cb(struct platform_device *pdev, void *arg)
+{
+	struct platform_device	*leaf;
+	struct xrt_event *evt = (struct xrt_event *)arg;
+	enum xrt_events e = evt->xe_evt;
+	enum xrt_subdev_id id = evt->xe_subdev.xevt_subdev_id;
+	int instance = evt->xe_subdev.xevt_subdev_instance;
+
+	switch (e) {
+	case XRT_EVENT_POST_CREATION:
+		break;
+	default:
+		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_ioctl(leaf, XRT_CLOCK_VERIFY, NULL);
+	xleaf_put_leaf(pdev, leaf);
+}
+
+static void ucs_check(struct xrt_ucs *ucs, bool *latched)
+{
+	struct ucs_control_status_ch1 *ucs_status_ch1;
+	u32 status;
+
+	mutex_lock(&ucs->ucs_lock);
+	status = reg_rd(ucs, CHANNEL1_OFFSET);
+	ucs_status_ch1 = (struct ucs_control_status_ch1 *)&status;
+	if (ucs_status_ch1->shutdown_clocks_latched) {
+		UCS_ERR(ucs,
+			"Critical temperature or power event, kernel clocks have been stopped.");
+		UCS_ERR(ucs,
+			"run 'xbutil valiate -q' to continue. See AR 73398 for more details.");
+		/* explicitly indicate reset should be latched */
+		*latched = true;
+	} else if (ucs_status_ch1->clock_throttling_average >
+	    CLK_MAX_VALUE) {
+		UCS_ERR(ucs, "kernel clocks %d exceeds expected maximum value %d.",
+			ucs_status_ch1->clock_throttling_average,
+			CLK_MAX_VALUE);
+	} else if (ucs_status_ch1->clock_throttling_average) {
+		UCS_ERR(ucs, "kernel clocks throttled at %d%%.",
+			(ucs_status_ch1->clock_throttling_average /
+			 (CLK_MAX_VALUE / 100)));
+	}
+	mutex_unlock(&ucs->ucs_lock);
+}
+
+static void ucs_enable(struct xrt_ucs *ucs)
+{
+	reg_wr(ucs, 1, CHANNEL2_OFFSET);
+}
+
+static int
+xrt_ucs_leaf_ioctl(struct platform_device *pdev, u32 cmd, void *arg)
+{
+	struct xrt_ucs		*ucs;
+	int			ret = 0;
+
+	ucs = platform_get_drvdata(pdev);
+
+	switch (cmd) {
+	case XRT_XLEAF_EVENT:
+		xrt_ucs_event_cb(pdev, arg);
+		break;
+	case XRT_UCS_CHECK: {
+		ucs_check(ucs, (bool *)arg);
+		break;
+	}
+	case XRT_UCS_ENABLE:
+		ucs_enable(ucs);
+		break;
+	default:
+		xrt_err(pdev, "unsupported cmd %d", cmd);
+		return -EINVAL;
+	}
+
+	return ret;
+}
+
+static int ucs_remove(struct platform_device *pdev)
+{
+	struct xrt_ucs *ucs;
+
+	ucs = platform_get_drvdata(pdev);
+	if (!ucs) {
+		xrt_err(pdev, "driver data is NULL");
+		return -EINVAL;
+	}
+
+	if (ucs->ucs_base)
+		iounmap(ucs->ucs_base);
+
+	platform_set_drvdata(pdev, NULL);
+	devm_kfree(&pdev->dev, ucs);
+
+	return 0;
+}
+
+static int ucs_probe(struct platform_device *pdev)
+{
+	struct xrt_ucs *ucs = NULL;
+	struct resource *res;
+	int ret;
+
+	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);
+	ucs->ucs_base = ioremap(res->start, res->end - res->start + 1);
+	if (!ucs->ucs_base) {
+		UCS_ERR(ucs, "map base %pR failed", res);
+		ret = -EFAULT;
+		goto failed;
+	}
+	ucs_enable(ucs);
+
+	return 0;
+
+failed:
+	ucs_remove(pdev);
+	return ret;
+}
+
+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_ioctl = xrt_ucs_leaf_ioctl,
+	},
+};
+
+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,
+	.remove = ucs_remove,
+	.id_table = xrt_ucs_table,
+};
+
+void ucs_leaf_init_fini(bool init)
+{
+	if (init)
+		xleaf_register_driver(XRT_SUBDEV_UCS, &xrt_ucs_driver, xrt_ucs_endpoints);
+	else
+		xleaf_unregister_driver(XRT_SUBDEV_UCS);
+}
-- 
2.18.4