Re: [PATCH V5 XRT Alveo 13/20] fpga: xrt: User Clock Subsystem driver

[Tom Rix <trix@redhat.com>]

On 4/27/21 1:54 PM, Lizhi Hou wrote:
> Add User Clock Subsystem (UCS) driver. UCS is a hardware function
> discovered by walking xclbin metadata. A xrt 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 <lizhi.hou@xilinx.com>

v4 was ok, please add my Reviewed-by line here, under yours.

Do for the others I have also ok-ed.

Reviewed-by: Tom Rix <trix@redhat.com>

> ---
>   drivers/fpga/xrt/lib/xleaf/ucs.c | 152 +++++++++++++++++++++++++++++++
>   1 file changed, 152 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..a7a96ddde44f
> --- /dev/null
> +++ b/drivers/fpga/xrt/lib/xleaf/ucs.c
> @@ -0,0 +1,152 @@
> +// 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/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)->xdev, fmt "\n", ##arg)
> +#define UCS_WARN(ucs, fmt, arg...)  \
> +	xrt_warn((ucs)->xdev, fmt "\n", ##arg)
> +#define UCS_INFO(ucs, fmt, arg...)  \
> +	xrt_info((ucs)->xdev, fmt "\n", ##arg)
> +#define UCS_DBG(ucs, fmt, arg...)   \
> +	xrt_dbg((ucs)->xdev, 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
> +
> +XRT_DEFINE_REGMAP_CONFIG(ucs_regmap_config);
> +
> +struct xrt_ucs {
> +	struct xrt_device	*xdev;
> +	struct regmap		*regmap;
> +	struct mutex		ucs_lock; /* ucs dev lock */
> +};
> +
> +static void xrt_ucs_event_cb(struct xrt_device *xdev, void *arg)
> +{
> +	struct xrt_event *evt = (struct xrt_event *)arg;
> +	enum xrt_events e = evt->xe_evt;
> +	struct xrt_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(xdev, "ignored event %d", e);
> +		return;
> +	}
> +
> +	if (id != XRT_SUBDEV_CLOCK)
> +		return;
> +
> +	leaf = xleaf_get_leaf_by_id(xdev, XRT_SUBDEV_CLOCK, instance);
> +	if (!leaf) {
> +		xrt_err(xdev, "does not get clock subdev");
> +		return;
> +	}
> +
> +	xleaf_call(leaf, XRT_CLOCK_VERIFY, NULL);
> +	xleaf_put_leaf(xdev, 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 xrt_device *xdev, u32 cmd, void *arg)
> +{
> +	switch (cmd) {
> +	case XRT_XLEAF_EVENT:
> +		xrt_ucs_event_cb(xdev, arg);
> +		break;
> +	default:
> +		xrt_err(xdev, "unsupported cmd %d", cmd);
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static int ucs_probe(struct xrt_device *xdev)
> +{
> +	struct xrt_ucs *ucs = NULL;
> +	void __iomem *base = NULL;
> +	struct resource *res;
> +
> +	ucs = devm_kzalloc(&xdev->dev, sizeof(*ucs), GFP_KERNEL);
> +	if (!ucs)
> +		return -ENOMEM;
> +
> +	xrt_set_drvdata(xdev, ucs);
> +	ucs->xdev = xdev;
> +	mutex_init(&ucs->ucs_lock);
> +
> +	res = xrt_get_resource(xdev, IORESOURCE_MEM, 0);
> +	if (!res)
> +		return -EINVAL;
> +
> +	base = devm_ioremap_resource(&xdev->dev, res);
> +	if (IS_ERR(base))
> +		return PTR_ERR(base);
> +
> +	ucs->regmap = devm_regmap_init_mmio(&xdev->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_dev_endpoints xrt_ucs_endpoints[] = {
> +	{
> +		.xse_names = (struct xrt_dev_ep_names[]) {
> +			{ .ep_name = XRT_MD_NODE_UCS_CONTROL_STATUS },
> +			{ NULL },
> +		},
> +		.xse_min_ep = 1,
> +	},
> +	{ 0 },
> +};
> +
> +static struct xrt_driver xrt_ucs_driver = {
> +	.driver = {
> +		.name = XRT_UCS,
> +	},
> +	.subdev_id = XRT_SUBDEV_UCS,
> +	.endpoints = xrt_ucs_endpoints,
> +	.probe = ucs_probe,
> +	.leaf_call = xrt_ucs_leaf_call,
> +};
> +
> +XRT_LEAF_INIT_FINI_FUNC(ucs);