Hi Pavan,
On 8/22/2023 6:09 PM, Pavan Kondeti wrote:
On Tue, Aug 22, 2023 at 05:45:12PM +0530, Ninad Naik wrote:
Qualcomm secondary bootloader (XBL) boot log holds information to
identify various firmware configuration currently set on the SoC.
The XBL log is stored in a predefined reserved memory region.
This drivers provides a way to print XBL logs on the console. To
do so, it provides a debugfs entry which captures the logs stored
in this reserved memory region. This entry can now be used to read
and print the XBL logs to console.
User can use the below command to print XBL log to console:
cat /sys/kernel/debug/xbl_log
Signed-off-by: Ninad Naik <quic_ninanaik@xxxxxxxxxxx>
---
For a single patch, cover letter may not be needed. The under cut
portion (this area) of the patch can be used to present the additional
details.
Ack.
drivers/soc/qcom/Kconfig | 13 +++
drivers/soc/qcom/Makefile | 1 +
drivers/soc/qcom/dump_xbl_log.c | 139 ++++++++++++++++++++++++++++++++
3 files changed, 153 insertions(+)
create mode 100644 drivers/soc/qcom/dump_xbl_log.c
[...]
+static int map_addr_range(struct device_node **parent, const char *name,
+ struct xbl_log_data *xbl_data)
+{
+ struct device_node *node;
+ struct resource res;
+ int ret;
+
+ node = of_find_node_by_name(*parent, name);
+ if (!node)
+ return -ENODEV;
+
+ ret = of_address_to_resource(node, 0, &res);
+ if (ret) {
+ dev_err(xbl_data->dev, "Failed to parse memory region\n");
+ return ret;
+ }
+ of_node_put(node);
+
+ if (!resource_size(&res)) {
+ dev_err(xbl_data->dev, "Failed to parse memory region size\n");
+ return -ENODEV;
+ }
+
+ xbl_data->buf_size = resource_size(&res) - 1;
+ xbl_data->xbl_buf = devm_memremap(xbl_data->dev, res.start,
+ xbl_data->buf_size, MEMREMAP_WB);
+ if (!xbl_data->xbl_buf) {
+ dev_err(xbl_data->dev, "%s: memory remap failed\n", name);
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static int xbl_log_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct xbl_log_data *xbl_data;
+ struct device_node *parent;
+ int ret;
+
+ xbl_data = devm_kzalloc(dev, sizeof(*xbl_data), GFP_KERNEL);
+ if (!xbl_data)
+ return -ENOMEM;
+
+ xbl_data->dev = &pdev->dev;
+ platform_set_drvdata(pdev, xbl_data);
+
+ parent = of_find_node_by_path("/reserved-memory");
+ if (!parent) {
+ dev_err(xbl_data->dev, "reserved-memory node missing\n");
+ return -ENODEV;
+ }
+
You would need to present the Device Tree binding document for this. For
ex: pls see
Documentation/devicetree/bindings/reserved-memory/qcom,cmd-db.yaml
Ack. Will add a corresponding DT binding in the next version
+ ret = map_addr_range(&parent, "uefi-log", xbl_data);
+ if (ret)
+ goto put_node;
+
+ xbl_data->dbg_data.data = xbl_data->xbl_buf;
+ xbl_data->dbg_data.size = xbl_data->buf_size;
+ xbl_data->dbg_file = debugfs_create_blob("xbl_log", 0400, NULL,
+ &xbl_data->dbg_data);
+ if (IS_ERR(xbl_data->dbg_file)) {
+ dev_err(xbl_data->dev, "failed to create debugfs entry\n");
+ ret = PTR_ERR(xbl_data->dbg_file);
+ }
+
+put_node:
+ of_node_put(parent);
+ return ret;
+}
+
+static int xbl_log_remove(struct platform_device *pdev)
+{
+ struct xbl_log_data *xbl_data = platform_get_drvdata(pdev);
+
+ debugfs_remove_recursive(xbl_data->dbg_file);
+ return 0;
+}
+
+static struct platform_driver xbl_log_driver = {
+ .probe = xbl_log_probe,
+ .remove = xbl_log_remove,
+ .driver = {
+ .name = "xbl-log",
+ },
+};
+
+static struct platform_device xbl_log_device = {
+ .name = "xbl-log",
+};
+
+static int __init xbl_log_init(void)
+{
+ int ret = 0;
+
+ ret = platform_driver_register(&xbl_log_driver);
+ if (!ret) {
+ ret = platform_device_register(&xbl_log_device);
+ if (ret)
+ platform_driver_unregister(&xbl_log_driver);
+ }
+ return ret;
+}
+
The platform device registration, the resource parsing can be completely
avoided by adding your compatible entry to reserved_mem_matches
structure defined in drivers/of/platform.c . There are some Qualcomm SoC
devices also present in that list.
Ack. So once the compatible entry is added to reserved_mem_matches
structure here, a platform_device is created for this node to which this
driver can bind to. Thank you for the suggestion, I'll make the
necessary corrections in the next revision.
+static void __exit xbl_log_exit(void)
+{
+ platform_device_unregister(&xbl_log_device);
+ platform_driver_unregister(&xbl_log_driver);
+}
+
+module_init(xbl_log_init);
+module_exit(xbl_log_exit);
+
+MODULE_DESCRIPTION("Qualcomm Technologies, Inc. (QTI) XBL log driver");
+MODULE_LICENSE("GPL");
--
2.41.0
Thanks,
Ninad
