From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Lezcano Subject: Re: [PATCH v10 06/27] of: base: Add of_get_cpu_state_node() to get idle states for a CPU node Date: Wed, 19 Dec 2018 12:05:56 +0100 Message-ID: <65605bbd-ceda-2266-615e-20b9d3491bed@linaro.org> References: <20181129174700.16585-1-ulf.hansson@linaro.org> <20181129174700.16585-7-ulf.hansson@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20181129174700.16585-7-ulf.hansson@linaro.org> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Ulf Hansson , "Rafael J . Wysocki" , Sudeep Holla , Lorenzo Pieralisi , Mark Rutland , linux-pm@vger.kernel.org Cc: "Raju P . L . S . S . S . N" , Stephen Boyd , Tony Lindgren , Kevin Hilman , Lina Iyer , Viresh Kumar , Vincent Guittot , Geert Uytterhoeven , linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, Rob Herring , devicetree@vger.kernel.org List-Id: linux-pm@vger.kernel.org On 29/11/2018 18:46, Ulf Hansson wrote: > The CPU's idle state nodes are currently parsed at the common cpuidle DT > library, but also when initializing back-end data for the arch specific CPU > operations, as in the PSCI driver case. > > To avoid open-coding, let's introduce of_get_cpu_state_node(), which takes > the device node for the CPU and the index to the requested idle state node, > as in-parameters. In case a corresponding idle state node is found, it > returns the node with the refcount incremented for it, else it returns > NULL. > > Moreover, for ARM, there are two generic methods, to describe the CPU's > idle states, either via the flattened description through the > "cpu-idle-states" binding [1] or via the hierarchical layout, using the > "power-domains" and the "domain-idle-states" bindings [2]. Hence, let's > take both options into account. > > [1] > Documentation/devicetree/bindings/arm/idle-states.txt > [2] > Documentation/devicetree/bindings/arm/psci.txt > > Cc: Rob Herring > Cc: devicetree@vger.kernel.org > Cc: Lina Iyer > Suggested-by: Sudeep Holla > Co-developed-by: Lina Iyer > Signed-off-by: Ulf Hansson > Reviewed-by: Rob Herring Nitpicking some kerneldoc formatting below. Other than that: Reviewed-by: Daniel Lezcano > --- > > Changes in v10: > - None. > > --- > drivers/of/base.c | 35 +++++++++++++++++++++++++++++++++++ > include/linux/of.h | 8 ++++++++ > 2 files changed, 43 insertions(+) > > diff --git a/drivers/of/base.c b/drivers/of/base.c > index 09692c9b32a7..8f6974a22006 100644 > --- a/drivers/of/base.c > +++ b/drivers/of/base.c > @@ -429,6 +429,41 @@ int of_cpu_node_to_id(struct device_node *cpu_node) > } > EXPORT_SYMBOL(of_cpu_node_to_id); > > +/** > + * of_get_cpu_state_node - Get CPU's idle state node at the given index > + * > + * @cpu_node: The device node for the CPU > + * @index: The index in the list of the idle states > + * > + * Two generic methods can be used to describe a CPU's idle states, either via > + * a flattened description through the "cpu-idle-states" binding or via the > + * hierarchical layout, using the "power-domains" and the "domain-idle-states" > + * bindings. This function check for both and returns the idle state node for > + * the requested index. > + * > + * In case and idle state node is found at index, the refcount incremented for s/and/an/ s/index/@index/ > + * it, so call of_node_put() on it when done. Returns NULL if not found. The Return description must be in a separate section. > + */ > +struct device_node *of_get_cpu_state_node(struct device_node *cpu_node, > + int index) > +{ > + struct of_phandle_args args; > + int err; > + > + err = of_parse_phandle_with_args(cpu_node, "power-domains", > + "#power-domain-cells", 0, &args); > + if (!err) { > + struct device_node *state_node = > + of_parse_phandle(args.np, "domain-idle-states", index); > + > + of_node_put(args.np); > + return state_node; > + } > + > + return of_parse_phandle(cpu_node, "cpu-idle-states", index); > +} > +EXPORT_SYMBOL(of_get_cpu_state_node); > + > /** > * __of_device_is_compatible() - Check if the node matches given constraints > * @device: pointer to node > diff --git a/include/linux/of.h b/include/linux/of.h > index a5aee3c438ad..f9f0c65c095c 100644 > --- a/include/linux/of.h > +++ b/include/linux/of.h > @@ -348,6 +348,8 @@ extern const void *of_get_property(const struct device_node *node, > int *lenp); > extern struct device_node *of_get_cpu_node(int cpu, unsigned int *thread); > extern struct device_node *of_get_next_cpu_node(struct device_node *prev); > +extern struct device_node *of_get_cpu_state_node(struct device_node *cpu_node, > + int index); > > #define for_each_property_of_node(dn, pp) \ > for (pp = dn->properties; pp != NULL; pp = pp->next) > @@ -762,6 +764,12 @@ static inline struct device_node *of_get_next_cpu_node(struct device_node *prev) > return NULL; > } > > +static inline struct device_node *of_get_cpu_state_node(struct device_node *cpu_node, > + int index) > +{ > + return NULL; > +} > + > static inline int of_n_addr_cells(struct device_node *np) > { > return 0; > -- Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog