[PATCH V3 XRT Alveo 16/18] fpga: xrt: DDR calibration platform driver

Lizhi Hou
2021-02-18T07:44:04Z

Add DDR calibration driver. DDR calibration is a hardware function
discovered by walking firmware metadata. A platform device node will
be created for it. Hardware provides DDR calibration status through
this function.

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/calib.h | 30 ++++
drivers/fpga/xrt/lib/xleaf/calib.c | 226 +++++++++++++++++++++++++
2 files changed, 256 insertions(+)
create mode 100644 drivers/fpga/xrt/include/xleaf/calib.h
create mode 100644 drivers/fpga/xrt/lib/xleaf/calib.c

diff --git a/drivers/fpga/xrt/include/xleaf/calib.h b/drivers/fpga/xrt/include/xleaf/calib.h
new file mode 100644
index 000000000000..f8aba4594c58
--- /dev/null
+++ b/drivers/fpga/xrt/include/xleaf/calib.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Header file for XRT DDR Calibration Leaf Driver
+ *
+ * Copyright (C) 2020-2021 Xilinx, Inc.
+ *
+ * Authors:
+ * Cheng Zhen <maxz@xilinx.com>
+ */
+
+#ifndef _XRT_CALIB_H_
+#define _XRT_CALIB_H_
+
+#include "xleaf.h"
+#include <linux/xrt/xclbin.h>
+
+/*
+ * Memory calibration driver IOCTL calls.
+ */
+enum xrt_calib_results {
+ XRT_CALIB_UNKNOWN,
+ XRT_CALIB_SUCCEEDED,
+ XRT_CALIB_FAILED,
+};
+
+enum xrt_calib_ioctl_cmd {
+ XRT_CALIB_RESULT = XRT_XLEAF_CUSTOM_BASE, /* See comments in xleaf.h */
+};
+
+#endif /* _XRT_CALIB_H_ */
diff --git a/drivers/fpga/xrt/lib/xleaf/calib.c b/drivers/fpga/xrt/lib/xleaf/calib.c
new file mode 100644
index 000000000000..fbb813636e76
--- /dev/null
+++ b/drivers/fpga/xrt/lib/xleaf/calib.c
@@ -0,0 +1,226 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Xilinx Alveo FPGA memory calibration driver
+ *
+ * Copyright (C) 2020-2021 Xilinx, Inc.
+ *
+ * memory calibration
+ *
+ * Authors:
+ * Lizhi Hou<Lizhi.Hou@xilinx.com>
+ */
+#include <linux/delay.h>
+#include "xclbin-helper.h"
+#include "metadata.h"
+#include "xleaf/calib.h"
+
+#define XRT_CALIB "xrt_calib"
+
+struct calib_cache {
+ struct list_head link;
+ const char *ep_name;
+ char *data;
+ u32 data_size;
+};
+
+struct calib {
+ struct platform_device *pdev;
+ void *calib_base;
+ struct mutex lock; /* calibration dev lock */
+ struct list_head cache_list;
+ u32 cache_num;
+ enum xrt_calib_results result;
+};
+
+#define CALIB_DONE(calib) \
+ (ioread32((calib)->calib_base) & BIT(0))
+
+static void calib_cache_clean_nolock(struct calib *calib)
+{
+ struct calib_cache *cache, *temp;
+
+ list_for_each_entry_safe(cache, temp, &calib->cache_list, link) {
+ vfree(cache->data);
+ list_del(&cache->link);
+ vfree(cache);
+ }
+ calib->cache_num = 0;
+}
+
+static void calib_cache_clean(struct calib *calib)
+{
+ mutex_lock(&calib->lock);
+ calib_cache_clean_nolock(calib);
+ mutex_unlock(&calib->lock);
+}
+
+static int calib_srsr(struct calib *calib, struct platform_device *srsr_leaf)
+{
+ return -EOPNOTSUPP;
+}
+
+static int calib_calibration(struct calib *calib)
+{
+ int i;
+
+ for (i = 0; i < 20; i++) {
+ if (CALIB_DONE(calib))
+ break;
+ msleep(500);
+ }
+
+ if (i == 20) {
+ xrt_err(calib->pdev,
+ "MIG calibration timeout after bitstream download");
+ return -ETIMEDOUT;
+ }
+
+ xrt_info(calib->pdev, "took %dms", i * 500);
+ return 0;
+}
+
+static void xrt_calib_event_cb(struct platform_device *pdev, void *arg)
+{
+ struct calib *calib = platform_get_drvdata(pdev);
+ 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;
+ struct platform_device *leaf;
+ int ret;
+
+ switch (e) {
+ case XRT_EVENT_POST_CREATION: {
+ if (id == XRT_SUBDEV_SRSR) {
+ leaf = xleaf_get_leaf_by_id(pdev,
+ XRT_SUBDEV_SRSR,
+ instance);
+ if (!leaf) {
+ xrt_err(pdev, "does not get SRSR subdev");
+ return;
+ }
+ ret = calib_srsr(calib, leaf);
+ xleaf_put_leaf(pdev, leaf);
+ calib->result =
+ ret ? XRT_CALIB_FAILED : XRT_CALIB_SUCCEEDED;
+ } else if (id == XRT_SUBDEV_UCS) {
+ ret = calib_calibration(calib);
+ calib->result =
+ ret ? XRT_CALIB_FAILED : XRT_CALIB_SUCCEEDED;
+ }
+ break;
+ }
+ default:
+ break;
+ }
+}
+
+static int xrt_calib_remove(struct platform_device *pdev)
+{
+ struct calib *calib = platform_get_drvdata(pdev);
+
+ calib_cache_clean(calib);
+
+ if (calib->calib_base)
+ iounmap(calib->calib_base);
+
+ platform_set_drvdata(pdev, NULL);
+ devm_kfree(&pdev->dev, calib);
+
+ return 0;
+}
+
+static int xrt_calib_probe(struct platform_device *pdev)
+{
+ struct calib *calib;
+ struct resource *res;
+ int err = 0;
+
+ calib = devm_kzalloc(&pdev->dev, sizeof(*calib), GFP_KERNEL);
+ if (!calib)
+ return -ENOMEM;
+
+ calib->pdev = pdev;
+ platform_set_drvdata(pdev, calib);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ goto failed;
+
+ calib->calib_base = ioremap(res->start, res->end - res->start + 1);
+ if (!calib->calib_base) {
+ err = -EIO;
+ xrt_err(pdev, "Map iomem failed");
+ goto failed;
+ }
+
+ mutex_init(&calib->lock);
+ INIT_LIST_HEAD(&calib->cache_list);
+
+ return 0;
+
+failed:
+ xrt_calib_remove(pdev);
+ return err;
+}
+
+static int
+xrt_calib_leaf_ioctl(struct platform_device *pdev, u32 cmd, void *arg)
+{
+ struct calib *calib = platform_get_drvdata(pdev);
+ int ret = 0;
+
+ switch (cmd) {
+ case XRT_XLEAF_EVENT:
+ xrt_calib_event_cb(pdev, arg);
+ break;
+ case XRT_CALIB_RESULT: {
+ enum xrt_calib_results *r = (enum xrt_calib_results *)arg;
+ *r = calib->result;
+ break;
+ }
+ default:
+ xrt_err(pdev, "unsupported cmd %d", cmd);
+ ret = -EINVAL;
+ }
+ return ret;
+}
+
+static struct xrt_subdev_endpoints xrt_calib_endpoints[] = {
+ {
+ .xse_names = (struct xrt_subdev_ep_names[]) {
+ { .ep_name = XRT_MD_NODE_DDR_CALIB },
+ { NULL },
+ },
+ .xse_min_ep = 1,
+ },
+ { 0 },
+};
+
+static struct xrt_subdev_drvdata xrt_calib_data = {
+ .xsd_dev_ops = {
+ .xsd_ioctl = xrt_calib_leaf_ioctl,
+ },
+};
+
+static const struct platform_device_id xrt_calib_table[] = {
+ { XRT_CALIB, (kernel_ulong_t)&xrt_calib_data },
+ { },
+};
+
+static struct platform_driver xrt_calib_driver = {
+ .driver = {
+ .name = XRT_CALIB,
+ },
+ .probe = xrt_calib_probe,
+ .remove = xrt_calib_remove,
+ .id_table = xrt_calib_table,
+};
+
+void calib_leaf_init_fini(bool init)
+{
+ if (init)
+ xleaf_register_driver(XRT_SUBDEV_CALIB, &xrt_calib_driver, xrt_calib_endpoints);
+ else
+ xleaf_unregister_driver(XRT_SUBDEV_CALIB);
+}
--
2.18.4