Re: [PATCH V5 XRT Alveo 15/20] fpga: xrt: devctl xrt driver

From: Tom Rix
Date: Tue May 04 2021 - 10:07:27 EST



On 4/27/21 1:54 PM, Lizhi Hou wrote:
Add devctl driver. devctl is a type of hardware function which only has
few registers to read or write. They are discovered by walking firmware
metadata. A xrt device node will be created for them.

Signed-off-by: Sonal Santan <sonal.santan@xxxxxxxxxx>
Signed-off-by: Max Zhen <max.zhen@xxxxxxxxxx>
Signed-off-by: Lizhi Hou <lizhi.hou@xxxxxxxxxx>

v4 was also ok, please add my Reviwed-by line

Reviewed-by: Tom Rix <trix@xxxxxxxxxx>

---
drivers/fpga/xrt/include/xleaf/devctl.h | 40 ++++++
drivers/fpga/xrt/lib/xleaf/devctl.c | 169 ++++++++++++++++++++++++
2 files changed, 209 insertions(+)
create mode 100644 drivers/fpga/xrt/include/xleaf/devctl.h
create mode 100644 drivers/fpga/xrt/lib/xleaf/devctl.c

diff --git a/drivers/fpga/xrt/include/xleaf/devctl.h b/drivers/fpga/xrt/include/xleaf/devctl.h
new file mode 100644
index 000000000000..b97f3b6d9326
--- /dev/null
+++ b/drivers/fpga/xrt/include/xleaf/devctl.h
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2021 Xilinx, Inc.
+ *
+ * Authors:
+ * Lizhi Hou <Lizhi.Hou@xxxxxxxxxx>
+ */
+
+#ifndef _XRT_DEVCTL_H_
+#define _XRT_DEVCTL_H_
+
+#include "xleaf.h"
+
+/*
+ * DEVCTL driver leaf calls.
+ */
+enum xrt_devctl_leaf_cmd {
+ XRT_DEVCTL_READ = XRT_XLEAF_CUSTOM_BASE, /* See comments in xleaf.h */
+};
+
+enum xrt_devctl_id {
+ XRT_DEVCTL_ROM_UUID = 0,
+ XRT_DEVCTL_DDR_CALIB,
+ XRT_DEVCTL_GOLDEN_VER,
+ XRT_DEVCTL_MAX
+};
+
+struct xrt_devctl_rw {
+ u32 xdr_id;
+ void *xdr_buf;
+ u32 xdr_len;
+ u32 xdr_offset;
+};
+
+struct xrt_devctl_intf_uuid {
+ u32 uuid_num;
+ uuid_t *uuids;
+};
+
+#endif /* _XRT_DEVCTL_H_ */
diff --git a/drivers/fpga/xrt/lib/xleaf/devctl.c b/drivers/fpga/xrt/lib/xleaf/devctl.c
new file mode 100644
index 000000000000..fb2122be7e56
--- /dev/null
+++ b/drivers/fpga/xrt/lib/xleaf/devctl.c
@@ -0,0 +1,169 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Xilinx Alveo FPGA devctl Driver
+ *
+ * Copyright (C) 2020-2021 Xilinx, Inc.
+ *
+ * Authors:
+ * Lizhi Hou<Lizhi.Hou@xxxxxxxxxx>
+ */
+
+#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/devctl.h"
+
+#define XRT_DEVCTL "xrt_devctl"
+
+struct xrt_name_id {
+ char *ep_name;
+ int id;
+};
+
+static struct xrt_name_id name_id[XRT_DEVCTL_MAX] = {
+ { XRT_MD_NODE_BLP_ROM, XRT_DEVCTL_ROM_UUID },
+ { XRT_MD_NODE_GOLDEN_VER, XRT_DEVCTL_GOLDEN_VER },
+};
+
+XRT_DEFINE_REGMAP_CONFIG(devctl_regmap_config);
+
+struct xrt_devctl {
+ struct xrt_device *xdev;
+ struct regmap *regmap[XRT_DEVCTL_MAX];
+ ulong sizes[XRT_DEVCTL_MAX];
+};
+
+static int xrt_devctl_name2id(struct xrt_devctl *devctl, const char *name)
+{
+ int i;
+
+ for (i = 0; i < XRT_DEVCTL_MAX && name_id[i].ep_name; i++) {
+ if (!strncmp(name_id[i].ep_name, name, strlen(name_id[i].ep_name) + 1))
+ return name_id[i].id;
+ }
+
+ return -EINVAL;
+}
+
+static int
+xrt_devctl_leaf_call(struct xrt_device *xdev, u32 cmd, void *arg)
+{
+ struct xrt_devctl *devctl;
+ int ret = 0;
+
+ devctl = xrt_get_drvdata(xdev);
+
+ switch (cmd) {
+ case XRT_XLEAF_EVENT:
+ /* Does not handle any event. */
+ break;
+ case XRT_DEVCTL_READ: {
+ struct xrt_devctl_rw *rw_arg = arg;
+
+ if (rw_arg->xdr_len & 0x3) {
+ xrt_err(xdev, "invalid len %d", rw_arg->xdr_len);
+ return -EINVAL;
+ }
+
+ if (rw_arg->xdr_id >= XRT_DEVCTL_MAX) {
+ xrt_err(xdev, "invalid id %d", rw_arg->xdr_id);
+ return -EINVAL;
+ }
+
+ if (!devctl->regmap[rw_arg->xdr_id]) {
+ xrt_err(xdev, "io not found, id %d",
+ rw_arg->xdr_id);
+ return -EINVAL;
+ }
+
+ ret = regmap_bulk_read(devctl->regmap[rw_arg->xdr_id], rw_arg->xdr_offset,
+ rw_arg->xdr_buf,
+ rw_arg->xdr_len / devctl_regmap_config.reg_stride);
+ break;
+ }
+ default:
+ xrt_err(xdev, "unsupported cmd %d", cmd);
+ return -EINVAL;
+ }
+
+ return ret;
+}
+
+static int xrt_devctl_probe(struct xrt_device *xdev)
+{
+ struct xrt_devctl *devctl = NULL;
+ void __iomem *base = NULL;
+ struct resource *res;
+ int i, id, ret = 0;
+
+ devctl = devm_kzalloc(&xdev->dev, sizeof(*devctl), GFP_KERNEL);
+ if (!devctl)
+ return -ENOMEM;
+
+ devctl->xdev = xdev;
+ xrt_set_drvdata(xdev, devctl);
+
+ xrt_info(xdev, "probing...");
+ for (i = 0, res = xrt_get_resource(xdev, IORESOURCE_MEM, 0);
+ res;
+ res = xrt_get_resource(xdev, IORESOURCE_MEM, ++i)) {
+ struct regmap_config config = devctl_regmap_config;
+
+ id = xrt_devctl_name2id(devctl, res->name);
+ if (id < 0) {
+ xrt_err(xdev, "ep %s not found", res->name);
+ continue;
+ }
+ base = devm_ioremap_resource(&xdev->dev, res);
+ if (IS_ERR(base)) {
+ ret = PTR_ERR(base);
+ break;
+ }
+ config.max_register = res->end - res->start + 1;
+ devctl->regmap[id] = devm_regmap_init_mmio(&xdev->dev, base, &config);
+ if (IS_ERR(devctl->regmap[id])) {
+ xrt_err(xdev, "map base failed %pR", res);
+ ret = PTR_ERR(devctl->regmap[id]);
+ break;
+ }
+ devctl->sizes[id] = res->end - res->start + 1;
+ }
+
+ return ret;
+}
+
+static struct xrt_dev_endpoints xrt_devctl_endpoints[] = {
+ {
+ .xse_names = (struct xrt_dev_ep_names[]) {
+ /* add name if ep is in same partition */
+ { .ep_name = XRT_MD_NODE_BLP_ROM },
+ { NULL },
+ },
+ .xse_min_ep = 1,
+ },
+ {
+ .xse_names = (struct xrt_dev_ep_names[]) {
+ { .ep_name = XRT_MD_NODE_GOLDEN_VER },
+ { NULL },
+ },
+ .xse_min_ep = 1,
+ },
+ /* adding ep bundle generates devctl device instance */
+ { 0 },
+};
+
+static struct xrt_driver xrt_devctl_driver = {
+ .driver = {
+ .name = XRT_DEVCTL,
+ },
+ .subdev_id = XRT_SUBDEV_DEVCTL,
+ .endpoints = xrt_devctl_endpoints,
+ .probe = xrt_devctl_probe,
+ .leaf_call = xrt_devctl_leaf_call,
+};
+
+XRT_LEAF_INIT_FINI_FUNC(devctl);