Re: [PATCH v3 6/6] interconnect: Add OPP table support for interconnects

Vincent Guittot
2019-07-03T06:45:39Z

On Wed, 3 Jul 2019 at 03:10, Saravana Kannan <saravanak@google.com> wrote:
>
> Interconnect paths can have different performance points. Now that OPP
> framework supports bandwidth OPP tables, add OPP table support for
> interconnects.
>
> Devices can use the interconnect-opp-table DT property to specify OPP
> tables for interconnect paths. And the driver can obtain the OPP table for
> an interconnect path by calling icc_get_opp_table().

The opp table of a path must come from the aggregation of OPP tables
of the interconnect providers. So such kind of OPP table should be at
provider level but not at path level.

>
> Signed-off-by: Saravana Kannan <saravanak@google.com>
> ---
> drivers/interconnect/core.c | 27 ++++++++++++++++++++++++++-
> include/linux/interconnect.h | 7 +++++++
> 2 files changed, 33 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
> index 871eb4bc4efc..881bac80bc1e 100644
> --- a/drivers/interconnect/core.c
> +++ b/drivers/interconnect/core.c
> @@ -47,6 +47,7 @@ struct icc_req {
> */
> struct icc_path {
> size_t num_nodes;
> + struct opp_table *opp_table;
> struct icc_req reqs[];
> };
>
> @@ -313,7 +314,7 @@ struct icc_path *of_icc_get(struct device *dev, const char *name)
> {
> struct icc_path *path = ERR_PTR(-EPROBE_DEFER);
> struct icc_node *src_node, *dst_node;
> - struct device_node *np = NULL;
> + struct device_node *np = NULL, *opp_node;
> struct of_phandle_args src_args, dst_args;
> int idx = 0;
> int ret;
> @@ -381,10 +382,34 @@ struct icc_path *of_icc_get(struct device *dev, const char *name)
> dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path));
> mutex_unlock(&icc_lock);
>
> + opp_node = of_parse_phandle(np, "interconnect-opp-table", idx);
> + if (opp_node) {
> + path->opp_table = dev_pm_opp_of_find_table_from_node(opp_node);
> + of_node_put(opp_node);
> + }
> +
> +
> return path;
> }
> EXPORT_SYMBOL_GPL(of_icc_get);
>
> +/**
> + * icc_get_opp_table() - Get the OPP table that corresponds to a path
> + * @path: reference to the path returned by icc_get()
> + *
> + * This function will return the OPP table that corresponds to a path handle.
> + * 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: opp_table pointer on success. NULL is returned when the API is
> + * disabled or the OPP table is missing.
> + */
> +struct opp_table *icc_get_opp_table(struct icc_path *path)
> +{
> + return path->opp_table;
> +}
> +
> /**
> * icc_set_bw() - set bandwidth constraints on an interconnect path
> * @path: reference to the path returned by icc_get()
> diff --git a/include/linux/interconnect.h b/include/linux/interconnect.h
> index dc25864755ba..0c0bc55f0e89 100644
> --- a/include/linux/interconnect.h
> +++ b/include/linux/interconnect.h
> @@ -9,6 +9,7 @@
>
> #include <linux/mutex.h>
> #include <linux/types.h>
> +#include <linux/pm_opp.h>
>
> /* macros for converting to icc units */
> #define Bps_to_icc(x) ((x) / 1000)
> @@ -28,6 +29,7 @@ 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 opp_table *icc_get_opp_table(struct icc_path *path);
> void icc_put(struct icc_path *path);
> int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw);
>
> @@ -49,6 +51,11 @@ static inline void icc_put(struct icc_path *path)
> {
> }
>
> +static inline struct opp_table *icc_get_opp_table(struct icc_path *path)
> +{
> + return NULL;
> +}
> +
> static inline int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw)
> {
> return 0;
> --
> 2.22.0.410.gd8fdbe21b5-goog
>