Hi, Absolutely, I like this approach. I think that it is necessary to make the connection between frequencies of devices. But, I have a question on below.
2019년 6월 22일 (토) 오전 9:35, Saravana Kannan <sarava...@google.com>님이 작성: > > Add a function that allows looking up required OPPs given a source OPP > table, destination OPP table and the source OPP. > > Signed-off-by: Saravana Kannan <sarava...@google.com> > --- > drivers/opp/core.c | 54 ++++++++++++++++++++++++++++++++++++++++++ > include/linux/pm_opp.h | 11 +++++++++ > 2 files changed, 65 insertions(+) > > diff --git a/drivers/opp/core.c b/drivers/opp/core.c > index 74c7bdc6f463..4f7870bffbf8 100644 > --- a/drivers/opp/core.c > +++ b/drivers/opp/core.c > @@ -1830,6 +1830,60 @@ void dev_pm_opp_put_genpd_virt_dev(struct opp_table > *opp_table, > dev_err(virt_dev, "Failed to find required device entry\n"); > } > > +/** > + * dev_pm_opp_xlate_opp() - Find required OPP for src_table OPP. > + * @src_table: OPP table which has dst_table as one of its required OPP > table. > + * @dst_table: Required OPP table of the src_table. > + * @pstate: OPP of the src_table. > + * > + * This function returns the OPP (present in @dst_table) pointed out by the > + * "required-opps" property of the OPP (present in @src_table). > + * > + * The callers are required to call dev_pm_opp_put() for the returned OPP > after > + * use. > + * > + * Return: destination table OPP on success, otherwise NULL on errors. > + */ > +struct dev_pm_opp *dev_pm_opp_xlate_opp(struct opp_table *src_table, > + struct opp_table *dst_table, > + struct dev_pm_opp *src_opp) > +{ > + struct dev_pm_opp *opp, *dest_opp = NULL; > + int i; > + > + if (!src_table || !dst_table || !src_opp) > + return NULL; > + > + for (i = 0; i < src_table->required_opp_count; i++) { > + if (src_table->required_opp_tables[i]->np == dst_table->np) > + break; > + } > + > + if (unlikely(i == src_table->required_opp_count)) { > + pr_err("%s: Couldn't find matching OPP table (%p: %p)\n", > + __func__, src_table, dst_table); > + return NULL; > + } > + > + mutex_lock(&src_table->lock); > + > + list_for_each_entry(opp, &src_table->opp_list, node) { > + if (opp == src_opp) { > + dest_opp = opp->required_opps[i]; Correct me if I am wrong. This patch assume that 'i' index is same on between [1] and [2]. But in order to guarantee this assumption, all OPP entries in the same opp_table have to have the same number of 'required-opps' properties and keep the sequence among 'required-opps' entries. [1] src_table->required_opp_tables[i]->np [2] opp->required_opps[I]; For example, three OPP entries in the 'parent_bus_opp' have the different sequence of 'required-opps' and the different number of 'required-opps'. Is it no problem? parent_bus_opp: opp_table { compatible = "operating-points-v2"; opp2 { opp-hz = /bits/ 64 <200000>; required-opps = <&child_bus_a_opp2>, <&child_bus_b_opp2>, <&child_bus_c_opp2>; }; opp1 { opp-hz = /bits/ 64 <200000>; // change the sequence between child_bus_b_opp2 and child_bus_c_opp2 required-opps = <&child_bus_a_opp2>, <&child_bus_c_opp2>, <&child_bus_b_opp2> }; opp0 { opp-hz = /bits/ 64 <200000>; // missing 'child_bus_a_opp2' required-opps = <&child_bus_c_opp2>, <&child_bus_b_opp2> }; } > + dev_pm_opp_get(dest_opp); > + goto unlock; > + } > + } > + > + pr_err("%s: Couldn't find matching OPP (%p: %p)\n", __func__, > src_table, > + dst_table); > + > +unlock: > + mutex_unlock(&src_table->lock); > + > + return dest_opp; > +} > + > /** > * dev_pm_opp_xlate_performance_state() - Find required OPP's pstate for > src_table. > * @src_table: OPP table which has dst_table as one of its required OPP > table. > diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h > index b150fe97ce5a..bc5c68bdfc8d 100644 > --- a/include/linux/pm_opp.h > +++ b/include/linux/pm_opp.h > @@ -134,6 +134,9 @@ void dev_pm_opp_unregister_set_opp_helper(struct > opp_table *opp_table); > struct opp_table *dev_pm_opp_set_genpd_virt_dev(struct device *dev, struct > device *virt_dev, int index); > void dev_pm_opp_put_genpd_virt_dev(struct opp_table *opp_table, struct > device *virt_dev); > int dev_pm_opp_xlate_performance_state(struct opp_table *src_table, struct > opp_table *dst_table, unsigned int pstate); > +struct dev_pm_opp *dev_pm_opp_xlate_opp(struct opp_table *src_table, > + struct opp_table *dst_table, > + struct dev_pm_opp *src_opp); > int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq); > int dev_pm_opp_set_sharing_cpus(struct device *cpu_dev, const struct cpumask > *cpumask); > int dev_pm_opp_get_sharing_cpus(struct device *cpu_dev, struct cpumask > *cpumask); > @@ -307,6 +310,14 @@ static inline int > dev_pm_opp_xlate_performance_state(struct opp_table *src_table > return -ENOTSUPP; > } > > +static inline struct dev_pm_opp *dev_pm_opp_xlate_opp( > + struct opp_table *src_table, > + struct opp_table *dst_table, > + struct dev_pm_opp *src_opp) > +{ > + return NULL; > +} > + > static inline int dev_pm_opp_set_rate(struct device *dev, unsigned long > target_freq) > { > return -ENOTSUPP; > -- > 2.22.0.410.gd8fdbe21b5-goog > -- Best Regards, Chanwoo Choi