Re: [PATCH v7 3/7] interconnect: Add of_icc_get_by_index() helper function

Matthias Kaehlcke
2020-04-24T18:02:35Z

Hi,

On Fri, Apr 24, 2020 at 06:54:00PM +0300, Georgi Djakov wrote:
> This is the same as the traditional of_icc_get() function, but the
> difference is that it takes index as an argument, instead of name.
>
> Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
> ---
> v7:
> * Addressed review comments from Sibi.
> * Re-based patch.
>
> v2: https://lore.kernel.org/r/20190423132823.7915-3-georgi.djakov@linaro.org
>
> drivers/interconnect/core.c | 68 +++++++++++++++++++++++++++---------
> include/linux/interconnect.h | 6 ++++
> 2 files changed, 58 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
> index 2c6515e3ecf1..648237f4de49 100644
> --- a/drivers/interconnect/core.c
> +++ b/drivers/interconnect/core.c
> @@ -351,9 +351,9 @@ static struct icc_node *of_icc_get_from_provider(struct of_phandle_args *spec)
> }
>
> /**
> - * of_icc_get() - get a path handle from a DT node based on name
> + * of_icc_get_by_index() - get a path handle from a DT node based on index
> * @dev: device pointer for the consumer device
> - * @name: interconnect path name
> + * @idx: interconnect path index
> *
> * This function will search for a path between two endpoints and return an
> * icc_path handle on success. Use icc_put() to release constraints when they
> @@ -365,13 +365,12 @@ static struct icc_node *of_icc_get_from_provider(struct of_phandle_args *spec)
> * Return: icc_path pointer on success or ERR_PTR() on error. NULL is returned
> * when the API is disabled or the "interconnects" DT property is missing.
> */
> -struct icc_path *of_icc_get(struct device *dev, const char *name)
> +struct icc_path *of_icc_get_by_index(struct device *dev, int idx)
> {
> struct icc_path *path = ERR_PTR(-EPROBE_DEFER);

nit: initialization is not needed. According to the diff this is existing
code, but since we are adding a new function we can as well 'fix' it :)

> struct icc_node *src_node, *dst_node;
> struct device_node *np = NULL;

ditto

> struct of_phandle_args src_args, dst_args;
> - int idx = 0;
> int ret;
>
> if (!dev || !dev->of_node)
> @@ -391,12 +390,6 @@ struct icc_path *of_icc_get(struct device *dev, const char *name)
> * lets support only global ids and extend this in the future if needed
> * without breaking DT compatibility.
> */
> - if (name) {
> - idx = of_property_match_string(np, "interconnect-names", name);
> - if (idx < 0)
> - return ERR_PTR(idx);
> - }
> -
> ret = of_parse_phandle_with_args(np, "interconnects",
> "#interconnect-cells", idx * 2,
> &src_args);
> @@ -439,12 +432,8 @@ struct icc_path *of_icc_get(struct device *dev, const char *name)
> return path;
> }
>
> - if (name)
> - path->name = kstrdup_const(name, GFP_KERNEL);
> - else
> - path->name = kasprintf(GFP_KERNEL, "%s-%s",
> - src_node->name, dst_node->name);
> -
> + path->name = kasprintf(GFP_KERNEL, "%s-%s",
> + src_node->name, dst_node->name);
> if (!path->name) {
> kfree(path);
> return ERR_PTR(-ENOMEM);
> @@ -452,6 +441,53 @@ struct icc_path *of_icc_get(struct device *dev, const char *name)
>
> return path;
> }
> +EXPORT_SYMBOL_GPL(of_icc_get_by_index);
> +
> +/**
> + * of_icc_get() - get a path handle from a DT node based on name
> + * @dev: device pointer for the consumer device
> + * @name: interconnect path name
> + *
> + * This function will search for a path between two endpoints and return an
> + * icc_path handle on success. Use icc_put() to release constraints when they
> + * are not needed anymore.
> + * If the interconnect API is disabled, NULL is returned and the consumer
> + * drivers will still build. Drivers are free to handle this specifically,
> + * but they don't have to.
> + *
> + * Return: icc_path pointer on success or ERR_PTR() on error. NULL is returned
> + * when the API is disabled or the "interconnects" DT property is missing.
> + */
> +struct icc_path *of_icc_get(struct device *dev, const char *name)
> +{
> + struct device_node *np = NULL;

nit: initialization is not needed

> + int idx = 0;
> +
> + if (!dev || !dev->of_node)
> + return ERR_PTR(-ENODEV);
> +
> + np = dev->of_node;
> +
> + /*
> + * When the consumer DT node do not have "interconnects" property
> + * return a NULL path to skip setting constraints.
> + */
> + if (!of_find_property(np, "interconnects", NULL))
> + return NULL;
> +
> + /*
> + * We use a combination of phandle and specifier for endpoint. For now
> + * lets support only global ids and extend this in the future if needed
> + * without breaking DT compatibility.
> + */
> + if (name) {
> + idx = of_property_match_string(np, "interconnect-names", name);
> + if (idx < 0)
> + return ERR_PTR(idx);
> + }
> +
> + return of_icc_get_by_index(dev, idx);
> +}
> EXPORT_SYMBOL_GPL(of_icc_get);
>
> /**
> diff --git a/include/linux/interconnect.h b/include/linux/interconnect.h
> index d70a914cba11..34e97231a6ab 100644
> --- a/include/linux/interconnect.h
> +++ b/include/linux/interconnect.h
> @@ -28,6 +28,7 @@ struct device;
> struct icc_path *icc_get(struct device *dev, const int src_id,
> const int dst_id);
> struct icc_path *of_icc_get(struct device *dev, const char *name);
> +struct icc_path *of_icc_get_by_index(struct device *dev, int idx);
> void icc_put(struct icc_path *path);
> int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw);
> void icc_set_tag(struct icc_path *path, u32 tag);
> @@ -46,6 +47,11 @@ static inline struct icc_path *of_icc_get(struct device *dev,
> return NULL;
> }
>
> +static inline struct icc_path *of_icc_get_by_index(struct device *dev, int idx)
> +{
> + return NULL;
> +}
> +
> static inline void icc_put(struct icc_path *path)
> {
> }

Reviewed-by: Matthias Kaehlcke <mka@chromium.org>