[PATCH V5 XRT Alveo 18/20] fpga: xrt: DDR calibration driver

Lizhi Hou
2021-04-27T21:01:54Z

Add DDR calibration driver. DDR calibration is a hardware function
discovered by walking firmware metadata. A xrt 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 <lizhi.hou@xilinx.com>
---
.../fpga/xrt/include/xleaf/ddr_calibration.h | 28 +++
drivers/fpga/xrt/lib/xleaf/ddr_calibration.c | 210 ++++++++++++++++++
2 files changed, 238 insertions(+)
create mode 100644 drivers/fpga/xrt/include/xleaf/ddr_calibration.h
create mode 100644 drivers/fpga/xrt/lib/xleaf/ddr_calibration.c

diff --git a/drivers/fpga/xrt/include/xleaf/ddr_calibration.h b/drivers/fpga/xrt/include/xleaf/ddr_calibration.h
new file mode 100644
index 000000000000..878740c26ca2
--- /dev/null
+++ b/drivers/fpga/xrt/include/xleaf/ddr_calibration.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2021 Xilinx, Inc.
+ *
+ * Authors:
+ * Cheng Zhen <maxz@xilinx.com>
+ */
+
+#ifndef _XRT_DDR_CALIBRATION_H_
+#define _XRT_DDR_CALIBRATION_H_
+
+#include "xleaf.h"
+#include <linux/xrt/xclbin.h>
+
+/*
+ * Memory calibration driver leaf calls.
+ */
+enum xrt_calib_results {
+ XRT_CALIB_UNKNOWN = 0,
+ XRT_CALIB_SUCCEEDED,
+ XRT_CALIB_FAILED,
+};
+
+enum xrt_calib_leaf_cmd {
+ XRT_CALIB_RESULT = XRT_XLEAF_CUSTOM_BASE, /* See comments in xleaf.h */
+};
+
+#endif /* _XRT_DDR_CALIBRATION_H_ */
diff --git a/drivers/fpga/xrt/lib/xleaf/ddr_calibration.c b/drivers/fpga/xrt/lib/xleaf/ddr_calibration.c
new file mode 100644
index 000000000000..36a0937c9195
--- /dev/null
+++ b/drivers/fpga/xrt/lib/xleaf/ddr_calibration.c
@@ -0,0 +1,210 @@
+// 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 <linux/regmap.h>
+#include "xclbin-helper.h"
+#include "metadata.h"
+#include "xleaf/ddr_calibration.h"
+
+#define XRT_CALIB "xrt_calib"
+
+#define XRT_CALIB_STATUS_REG 0
+#define XRT_CALIB_READ_RETRIES 20
+#define XRT_CALIB_READ_INTERVAL 500 /* ms */
+
+XRT_DEFINE_REGMAP_CONFIG(calib_regmap_config);
+
+struct calib_cache {
+ struct list_head link;
+ const char *ep_name;
+ char *data;
+ u32 data_size;
+};
+
+struct calib {
+ struct xrt_device *xdev;
+ struct regmap *regmap;
+ struct mutex lock; /* calibration dev lock */
+ struct list_head cache_list;
+ u32 cache_num;
+ enum xrt_calib_results result;
+};
+
+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_calibration(struct calib *calib)
+{
+ u32 times = XRT_CALIB_READ_RETRIES;
+ u32 status;
+ int ret;
+
+ while (times != 0) {
+ ret = regmap_read(calib->regmap, XRT_CALIB_STATUS_REG, &status);
+ if (ret) {
+ xrt_err(calib->xdev, "failed to read status reg %d", ret);
+ return ret;
+ }
+
+ if (status & BIT(0))
+ break;
+ msleep(XRT_CALIB_READ_INTERVAL);
+ times--;
+ }
+
+ if (!times) {
+ xrt_err(calib->xdev,
+ "MIG calibration timeout after bitstream download");
+ return -ETIMEDOUT;
+ }
+
+ xrt_info(calib->xdev, "took %dms", (XRT_CALIB_READ_RETRIES - times) *
+ XRT_CALIB_READ_INTERVAL);
+ return 0;
+}
+
+static void xrt_calib_event_cb(struct xrt_device *xdev, void *arg)
+{
+ struct calib *calib = xrt_get_drvdata(xdev);
+ struct xrt_event *evt = (struct xrt_event *)arg;
+ enum xrt_events e = evt->xe_evt;
+ enum xrt_subdev_id id;
+ int ret;
+
+ id = evt->xe_subdev.xevt_subdev_id;
+
+ switch (e) {
+ case XRT_EVENT_POST_CREATION:
+ if (id == XRT_SUBDEV_UCS) {
+ ret = calib_calibration(calib);
+ if (ret)
+ calib->result = XRT_CALIB_FAILED;
+ else
+ calib->result = XRT_CALIB_SUCCEEDED;
+ }
+ break;
+ default:
+ xrt_dbg(xdev, "ignored event %d", e);
+ break;
+ }
+}
+
+static void xrt_calib_remove(struct xrt_device *xdev)
+{
+ struct calib *calib = xrt_get_drvdata(xdev);
+
+ calib_cache_clean(calib);
+}
+
+static int xrt_calib_probe(struct xrt_device *xdev)
+{
+ void __iomem *base = NULL;
+ struct resource *res;
+ struct calib *calib;
+ int err = 0;
+
+ calib = devm_kzalloc(&xdev->dev, sizeof(*calib), GFP_KERNEL);
+ if (!calib)
+ return -ENOMEM;
+
+ calib->xdev = xdev;
+ xrt_set_drvdata(xdev, calib);
+
+ res = xrt_get_resource(xdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ err = -EINVAL;
+ goto failed;
+ }
+
+ base = devm_ioremap_resource(&xdev->dev, res);
+ if (IS_ERR(base)) {
+ err = PTR_ERR(base);
+ goto failed;
+ }
+
+ calib->regmap = devm_regmap_init_mmio(&xdev->dev, base, &calib_regmap_config);
+ if (IS_ERR(calib->regmap)) {
+ xrt_err(xdev, "Map iomem failed");
+ err = PTR_ERR(calib->regmap);
+ goto failed;
+ }
+
+ mutex_init(&calib->lock);
+ INIT_LIST_HEAD(&calib->cache_list);
+
+ return 0;
+
+failed:
+ return err;
+}
+
+static int
+xrt_calib_leaf_call(struct xrt_device *xdev, u32 cmd, void *arg)
+{
+ struct calib *calib = xrt_get_drvdata(xdev);
+ int ret = 0;
+
+ switch (cmd) {
+ case XRT_XLEAF_EVENT:
+ xrt_calib_event_cb(xdev, arg);
+ break;
+ case XRT_CALIB_RESULT: {
+ enum xrt_calib_results *r = (enum xrt_calib_results *)arg;
+ *r = calib->result;
+ break;
+ }
+ default:
+ xrt_err(xdev, "unsupported cmd %d", cmd);
+ ret = -EINVAL;
+ }
+ return ret;
+}
+
+static struct xrt_dev_endpoints xrt_calib_endpoints[] = {
+ {
+ .xse_names = (struct xrt_dev_ep_names[]) {
+ { .ep_name = XRT_MD_NODE_DDR_CALIB },
+ { NULL },
+ },
+ .xse_min_ep = 1,
+ },
+ { 0 },
+};
+
+static struct xrt_driver xrt_calib_driver = {
+ .driver = {
+ .name = XRT_CALIB,
+ },
+ .subdev_id = XRT_SUBDEV_CALIB,
+ .endpoints = xrt_calib_endpoints,
+ .probe = xrt_calib_probe,
+ .remove = xrt_calib_remove,
+ .leaf_call = xrt_calib_leaf_call,
+};
+
+XRT_LEAF_INIT_FINI_FUNC(calib);
--
2.27.0