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    Subject[PATCH V5 XRT Alveo 17/20] fpga: xrt: clock frequency counter driver
    Date
    Add clock frequency counter driver. Clock frequency counter is
    a hardware function discovered by walking xclbin metadata. A xrt
    device node will be created for it. Other part of driver can read the
    actual clock frequency through clock frequency 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 <lizhi.hou@xilinx.com>
    ---
    drivers/fpga/xrt/include/xleaf/clkfreq.h | 21 +++
    drivers/fpga/xrt/lib/xleaf/clkfreq.c | 223 +++++++++++++++++++++++
    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..005441d5df78
    --- /dev/null
    +++ b/drivers/fpga/xrt/include/xleaf/clkfreq.h
    @@ -0,0 +1,21 @@
    +/* SPDX-License-Identifier: GPL-2.0 */
    +/*
    + * 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 leaf calls.
    + */
    +enum xrt_clkfreq_leaf_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..3d1f11152375
    --- /dev/null
    +++ b/drivers/fpga/xrt/lib/xleaf/clkfreq.c
    @@ -0,0 +1,223 @@
    +// 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/delay.h>
    +#include <linux/device.h>
    +#include <linux/regmap.h>
    +#include <linux/io.h>
    +#include "metadata.h"
    +#include "xleaf.h"
    +#include "xleaf/clkfreq.h"
    +
    +#define CLKFREQ_ERR(clkfreq, fmt, arg...) \
    + xrt_err((clkfreq)->xdev, fmt "\n", ##arg)
    +#define CLKFREQ_WARN(clkfreq, fmt, arg...) \
    + xrt_warn((clkfreq)->xdev, fmt "\n", ##arg)
    +#define CLKFREQ_INFO(clkfreq, fmt, arg...) \
    + xrt_info((clkfreq)->xdev, fmt "\n", ##arg)
    +#define CLKFREQ_DBG(clkfreq, fmt, arg...) \
    + xrt_dbg((clkfreq)->xdev, fmt "\n", ##arg)
    +
    +#define XRT_CLKFREQ "xrt_clkfreq"
    +
    +#define XRT_CLKFREQ_CONTROL_STATUS_MASK 0xffff
    +
    +#define XRT_CLKFREQ_CONTROL_START 0x1
    +#define XRT_CLKFREQ_CONTROL_DONE 0x2
    +#define XRT_CLKFREQ_V5_CLK0_ENABLED 0x10000
    +
    +#define XRT_CLKFREQ_CONTROL_REG 0
    +#define XRT_CLKFREQ_COUNT_REG 0x8
    +#define XRT_CLKFREQ_V5_COUNT_REG 0x10
    +
    +#define XRT_CLKFREQ_READ_RETRIES 10
    +
    +XRT_DEFINE_REGMAP_CONFIG(clkfreq_regmap_config);
    +
    +struct clkfreq {
    + struct xrt_device *xdev;
    + struct regmap *regmap;
    + const char *clkfreq_ep_name;
    + struct mutex clkfreq_lock; /* clock counter dev lock */
    +};
    +
    +static int clkfreq_read(struct clkfreq *clkfreq, u32 *freq)
    +{
    + int times = XRT_CLKFREQ_READ_RETRIES;
    + u32 status;
    + int ret;
    +
    + *freq = 0;
    + mutex_lock(&clkfreq->clkfreq_lock);
    + ret = regmap_write(clkfreq->regmap, XRT_CLKFREQ_CONTROL_REG, XRT_CLKFREQ_CONTROL_START);
    + if (ret) {
    + CLKFREQ_INFO(clkfreq, "write start to control reg failed %d", ret);
    + goto failed;
    + }
    + while (times != 0) {
    + ret = regmap_read(clkfreq->regmap, XRT_CLKFREQ_CONTROL_REG, &status);
    + if (ret) {
    + CLKFREQ_INFO(clkfreq, "read control reg failed %d", ret);
    + goto failed;
    + }
    + if ((status & XRT_CLKFREQ_CONTROL_STATUS_MASK) == XRT_CLKFREQ_CONTROL_DONE)
    + break;
    + mdelay(1);
    + times--;
    + };
    +
    + if (!times) {
    + ret = -ETIMEDOUT;
    + goto failed;
    + }
    +
    + if (status & XRT_CLKFREQ_V5_CLK0_ENABLED)
    + ret = regmap_read(clkfreq->regmap, XRT_CLKFREQ_V5_COUNT_REG, freq);
    + else
    + ret = regmap_read(clkfreq->regmap, XRT_CLKFREQ_COUNT_REG, freq);
    + if (ret) {
    + CLKFREQ_INFO(clkfreq, "read count failed %d", ret);
    + goto failed;
    + }
    +
    + mutex_unlock(&clkfreq->clkfreq_lock);
    +
    + return 0;
    +
    +failed:
    + mutex_unlock(&clkfreq->clkfreq_lock);
    +
    + return ret;
    +}
    +
    +static ssize_t freq_show(struct device *dev, struct device_attribute *attr, char *buf)
    +{
    + struct clkfreq *clkfreq = xrt_get_drvdata(to_xrt_dev(dev));
    + ssize_t count;
    + u32 freq;
    +
    + if (clkfreq_read(clkfreq, &freq))
    + return -EINVAL;
    +
    + count = snprintf(buf, 64, "%u\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_call(struct xrt_device *xdev, u32 cmd, void *arg)
    +{
    + struct clkfreq *clkfreq;
    + int ret = 0;
    +
    + clkfreq = xrt_get_drvdata(xdev);
    +
    + switch (cmd) {
    + case XRT_XLEAF_EVENT:
    + /* Does not handle any event. */
    + break;
    + case XRT_CLKFREQ_READ:
    + ret = clkfreq_read(clkfreq, arg);
    + break;
    + default:
    + xrt_err(xdev, "unsupported cmd %d", cmd);
    + return -EINVAL;
    + }
    +
    + return ret;
    +}
    +
    +static void clkfreq_remove(struct xrt_device *xdev)
    +{
    + sysfs_remove_group(&xdev->dev.kobj, &clkfreq_attr_group);
    +}
    +
    +static int clkfreq_probe(struct xrt_device *xdev)
    +{
    + struct clkfreq *clkfreq = NULL;
    + void __iomem *base = NULL;
    + struct resource *res;
    + int ret;
    +
    + clkfreq = devm_kzalloc(&xdev->dev, sizeof(*clkfreq), GFP_KERNEL);
    + if (!clkfreq)
    + return -ENOMEM;
    +
    + xrt_set_drvdata(xdev, clkfreq);
    + clkfreq->xdev = xdev;
    + mutex_init(&clkfreq->clkfreq_lock);
    +
    + res = xrt_get_resource(xdev, IORESOURCE_MEM, 0);
    + if (!res) {
    + ret = -EINVAL;
    + goto failed;
    + }
    + base = devm_ioremap_resource(&xdev->dev, res);
    + if (IS_ERR(base)) {
    + ret = PTR_ERR(base);
    + goto failed;
    + }
    +
    + clkfreq->regmap = devm_regmap_init_mmio(&xdev->dev, base, &clkfreq_regmap_config);
    + if (IS_ERR(clkfreq->regmap)) {
    + CLKFREQ_ERR(clkfreq, "regmap %pR failed", res);
    + ret = PTR_ERR(clkfreq->regmap);
    + goto failed;
    + }
    + clkfreq->clkfreq_ep_name = res->name;
    +
    + ret = sysfs_create_group(&xdev->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:
    + return ret;
    +}
    +
    +static struct xrt_dev_endpoints xrt_clkfreq_endpoints[] = {
    + {
    + .xse_names = (struct xrt_dev_ep_names[]) {
    + { .compat = XRT_MD_COMPAT_CLKFREQ },
    + { NULL },
    + },
    + .xse_min_ep = 1,
    + },
    + { 0 },
    +};
    +
    +static struct xrt_driver xrt_clkfreq_driver = {
    + .driver = {
    + .name = XRT_CLKFREQ,
    + },
    + .subdev_id = XRT_SUBDEV_CLKFREQ,
    + .endpoints = xrt_clkfreq_endpoints,
    + .probe = clkfreq_probe,
    + .remove = clkfreq_remove,
    + .leaf_call = xrt_clkfreq_leaf_call,
    +};
    +
    +XRT_LEAF_INIT_FINI_FUNC(clkfreq);
    --
    2.27.0
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      Last update: 2021-04-27 23:02    [W:5.091 / U:0.176 seconds]
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