[PATCH V3 XRT Alveo 15/18] fpga: xrt: clock frequence counter platform driver

Lizhi Hou
2021-02-18T07:39:06Z

Add clock frequence counter driver. Clock frequence counter is
a hardware function discovered by walking xclbin metadata. A platform
device node will be created for it. Other part of driver can read the
actual clock frequence through clock frequence counter driver.

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/clkfreq.h | 23 +++
drivers/fpga/xrt/lib/xleaf/clkfreq.c | 221 +++++++++++++++++++++++
2 files changed, 244 insertions(+)
create mode 100644 drivers/fpga/xrt/include/xleaf/clkfreq.h
create mode 100644 drivers/fpga/xrt/lib/xleaf/clkfreq.c

diff --git a/drivers/fpga/xrt/include/xleaf/clkfreq.h b/drivers/fpga/xrt/include/xleaf/clkfreq.h
new file mode 100644
index 000000000000..29fc45e8a31b
--- /dev/null
+++ b/drivers/fpga/xrt/include/xleaf/clkfreq.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Header file for XRT Clock Counter Leaf Driver
+ *
+ * Copyright (C) 2020-2021 Xilinx, Inc.
+ *
+ * Authors:
+ * Lizhi Hou <Lizhi.Hou@xilinx.com>
+ */
+
+#ifndef _XRT_CLKFREQ_H_
+#define _XRT_CLKFREQ_H_
+
+#include "xleaf.h"
+
+/*
+ * CLKFREQ driver IOCTL calls.
+ */
+enum xrt_clkfreq_ioctl_cmd {
+ XRT_CLKFREQ_READ = XRT_XLEAF_CUSTOM_BASE, /* See comments in xleaf.h */
+};
+
+#endif /* _XRT_CLKFREQ_H_ */
diff --git a/drivers/fpga/xrt/lib/xleaf/clkfreq.c b/drivers/fpga/xrt/lib/xleaf/clkfreq.c
new file mode 100644
index 000000000000..2482dd2cff47
--- /dev/null
+++ b/drivers/fpga/xrt/lib/xleaf/clkfreq.c
@@ -0,0 +1,221 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Xilinx Alveo FPGA Clock Frequency Counter 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/clkfreq.h"
+
+#define CLKFREQ_ERR(clkfreq, fmt, arg...) \
+ xrt_err((clkfreq)->pdev, fmt "\n", ##arg)
+#define CLKFREQ_WARN(clkfreq, fmt, arg...) \
+ xrt_warn((clkfreq)->pdev, fmt "\n", ##arg)
+#define CLKFREQ_INFO(clkfreq, fmt, arg...) \
+ xrt_info((clkfreq)->pdev, fmt "\n", ##arg)
+#define CLKFREQ_DBG(clkfreq, fmt, arg...) \
+ xrt_dbg((clkfreq)->pdev, fmt "\n", ##arg)
+
+#define XRT_CLKFREQ "xrt_clkfreq"
+
+#define OCL_CLKWIZ_STATUS_MASK 0xffff
+
+#define OCL_CLKWIZ_STATUS_MEASURE_START 0x1
+#define OCL_CLKWIZ_STATUS_MEASURE_DONE 0x2
+#define OCL_CLK_FREQ_COUNTER_OFFSET 0x8
+#define OCL_CLK_FREQ_V5_COUNTER_OFFSET 0x10
+#define OCL_CLK_FREQ_V5_CLK0_ENABLED 0x10000
+
+struct clkfreq {
+ struct platform_device *pdev;
+ void __iomem *clkfreq_base;
+ const char *clkfreq_ep_name;
+ struct mutex clkfreq_lock; /* clock counter dev lock */
+};
+
+static inline u32 reg_rd(struct clkfreq *clkfreq, u32 offset)
+{
+ return ioread32(clkfreq->clkfreq_base + offset);
+}
+
+static inline void reg_wr(struct clkfreq *clkfreq, u32 val, u32 offset)
+{
+ iowrite32(val, clkfreq->clkfreq_base + offset);
+}
+
+static u32 clkfreq_read(struct clkfreq *clkfreq)
+{
+ u32 freq = 0, status;
+ int times = 10;
+
+ mutex_lock(&clkfreq->clkfreq_lock);
+ reg_wr(clkfreq, OCL_CLKWIZ_STATUS_MEASURE_START, 0);
+ while (times != 0) {
+ status = reg_rd(clkfreq, 0);
+ if ((status & OCL_CLKWIZ_STATUS_MASK) ==
+ OCL_CLKWIZ_STATUS_MEASURE_DONE)
+ break;
+ mdelay(1);
+ times--;
+ };
+ if (times > 0) {
+ freq = (status & OCL_CLK_FREQ_V5_CLK0_ENABLED) ?
+ reg_rd(clkfreq, OCL_CLK_FREQ_V5_COUNTER_OFFSET) :
+ reg_rd(clkfreq, OCL_CLK_FREQ_COUNTER_OFFSET);
+ }
+ mutex_unlock(&clkfreq->clkfreq_lock);
+
+ return freq;
+}
+
+static ssize_t freq_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct clkfreq *clkfreq = platform_get_drvdata(to_platform_device(dev));
+ u32 freq;
+ ssize_t count;
+
+ freq = clkfreq_read(clkfreq);
+ count = snprintf(buf, 64, "%d\n", freq);
+
+ return count;
+}
+static DEVICE_ATTR_RO(freq);
+
+static struct attribute *clkfreq_attrs[] = {
+ &dev_attr_freq.attr,
+ NULL,
+};
+
+static struct attribute_group clkfreq_attr_group = {
+ .attrs = clkfreq_attrs,
+};
+
+static int
+xrt_clkfreq_leaf_ioctl(struct platform_device *pdev, u32 cmd, void *arg)
+{
+ struct clkfreq *clkfreq;
+ int ret = 0;
+
+ clkfreq = platform_get_drvdata(pdev);
+
+ switch (cmd) {
+ case XRT_XLEAF_EVENT:
+ /* Does not handle any event. */
+ break;
+ case XRT_CLKFREQ_READ: {
+ *(u32 *)arg = clkfreq_read(clkfreq);
+ break;
+ }
+ default:
+ xrt_err(pdev, "unsupported cmd %d", cmd);
+ return -EINVAL;
+ }
+
+ return ret;
+}
+
+static int clkfreq_remove(struct platform_device *pdev)
+{
+ struct clkfreq *clkfreq;
+
+ clkfreq = platform_get_drvdata(pdev);
+ if (!clkfreq) {
+ xrt_err(pdev, "driver data is NULL");
+ return -EINVAL;
+ }
+
+ platform_set_drvdata(pdev, NULL);
+ devm_kfree(&pdev->dev, clkfreq);
+
+ CLKFREQ_INFO(clkfreq, "successfully removed clkfreq subdev");
+ return 0;
+}
+
+static int clkfreq_probe(struct platform_device *pdev)
+{
+ struct clkfreq *clkfreq = NULL;
+ struct resource *res;
+ int ret;
+
+ clkfreq = devm_kzalloc(&pdev->dev, sizeof(*clkfreq), GFP_KERNEL);
+ if (!clkfreq)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, clkfreq);
+ clkfreq->pdev = pdev;
+ mutex_init(&clkfreq->clkfreq_lock);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ clkfreq->clkfreq_base = ioremap(res->start, res->end - res->start + 1);
+ if (!clkfreq->clkfreq_base) {
+ CLKFREQ_ERR(clkfreq, "map base %pR failed", res);
+ ret = -EFAULT;
+ goto failed;
+ }
+ clkfreq->clkfreq_ep_name = res->name;
+
+ ret = sysfs_create_group(&pdev->dev.kobj, &clkfreq_attr_group);
+ if (ret) {
+ CLKFREQ_ERR(clkfreq, "create clkfreq attrs failed: %d", ret);
+ goto failed;
+ }
+
+ CLKFREQ_INFO(clkfreq, "successfully initialized clkfreq subdev");
+
+ return 0;
+
+failed:
+ clkfreq_remove(pdev);
+ return ret;
+}
+
+static struct xrt_subdev_endpoints xrt_clkfreq_endpoints[] = {
+ {
+ .xse_names = (struct xrt_subdev_ep_names[]) {
+ { .regmap_name = "freq_cnt" },
+ { NULL },
+ },
+ .xse_min_ep = 1,
+ },
+ { 0 },
+};
+
+static struct xrt_subdev_drvdata xrt_clkfreq_data = {
+ .xsd_dev_ops = {
+ .xsd_ioctl = xrt_clkfreq_leaf_ioctl,
+ },
+};
+
+static const struct platform_device_id xrt_clkfreq_table[] = {
+ { XRT_CLKFREQ, (kernel_ulong_t)&xrt_clkfreq_data },
+ { },
+};
+
+static struct platform_driver xrt_clkfreq_driver = {
+ .driver = {
+ .name = XRT_CLKFREQ,
+ },
+ .probe = clkfreq_probe,
+ .remove = clkfreq_remove,
+ .id_table = xrt_clkfreq_table,
+};
+
+void clkfreq_leaf_init_fini(bool init)
+{
+ if (init) {
+ xleaf_register_driver(XRT_SUBDEV_CLKFREQ,
+ &xrt_clkfreq_driver, xrt_clkfreq_endpoints);
+ } else {
+ xleaf_unregister_driver(XRT_SUBDEV_CLKFREQ);
+ }
+}
--
2.18.4