Re: [PATCH v6 03/14] gtrace: Add RISC-V platform driver for the gtrace framework

[Leo Liang]

On Thu, Oct 01, 2026 at 10:52:14AM +0530, Mayuresh Chitale wrote:
> From: Anup Patel <anup.patel@xxxxxxxxxxxxxxxx>
> 
> The RISC-V trace components defined by the RISC-V Trace Control Interface
> Specification are memory mapped devices which are organized in a
> graph-like topology and described in the device tree.
> 
> Add the RISC-V platform driver for the gtrace framework. The driver
> parses the RISC-V component topology from the device tree, discovers the
> type and version of each component from its IMPL register, provides the
> RISC-V register level control ops and registers each component with the
> gtrace core.
> 
> Signed-off-by: Anup Patel <anup.patel@xxxxxxxxxxxxxxxx>
> Co-developed-by: Mayuresh Chitale <mayuresh.chitale@xxxxxxxxxxxxxxxx>
> Signed-off-by: Mayuresh Chitale <mayuresh.chitale@xxxxxxxxxxxxxxxx>
> ---
>  drivers/hwtracing/gtrace/Kconfig            |  15 ++
>  drivers/hwtracing/gtrace/Makefile           |   3 +
>  drivers/hwtracing/gtrace/gtrace-of.c        | 126 +++++++++++++
>  drivers/hwtracing/gtrace/rvtrace-platform.c | 186 ++++++++++++++++++++
>  drivers/hwtracing/gtrace/rvtrace.h          | 121 +++++++++++++
>  include/linux/gtrace.h                      |   3 +
>  6 files changed, 454 insertions(+)
>  create mode 100644 drivers/hwtracing/gtrace/gtrace-of.c
>  create mode 100644 drivers/hwtracing/gtrace/rvtrace-platform.c
>  create mode 100644 drivers/hwtracing/gtrace/rvtrace.h
> 
>
> ...
>
> +
> +/*
> + * Parse the "out-ports" graph of the component's device tree node and allocate

typo: "in-ports"

> + * pdata->inconns.
> + *
> + * Return: 0 on success or when there are no input ports, -ENOMEM otherwise.
> + */
> +int gtrace_of_parse_inconns(struct gtrace_platform_data *pdata)
> +{
> +	struct device_node *parent;
> +	int ret = 0;
> +
> +	parent = of_get_child_by_name(dev_of_node(pdata->dev), "in-ports");
> +	if (!parent)
> +		return 0;
> +
> +	pdata->nr_inconns = of_graph_get_endpoint_count(parent);
> +	pdata->inconns = devm_kcalloc(pdata->dev, pdata->nr_inconns,
> +				      sizeof(*pdata->inconns), GFP_KERNEL);
> +	if (!pdata->inconns)
> +		ret = -ENOMEM;
> +
> +	of_node_put(parent);
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(gtrace_of_parse_inconns);