On Thu, Oct 06 2016 at 03:47 -0600, Ulf Hansson wrote:
On 5 October 2016 at 22:31, Lina Iyer <lina.iyer@xxxxxxxxxx> wrote:This patch allows domains to define idle states in the DT. SoC's can define domain idle states in DT using the "domain-idle-states" property of the domain provider. Calling of_pm_genpd_init() will read the idle states and initialize the genpd for the domain. In addition to the entry and exit latency for idle state, also add residency_ns, param and of_node property to each state. A domain idling in a state is only power effecient if it stays idle for a certain period in that state. The residency provides this minimum time for the idle state to provide power benefits. The param is a state specific u32 value that the platform may use for that idle state. This patch is based on the original patch by Marc Titinger. Signed-off-by: Marc Titinger <mtitinger+renesas@xxxxxxxxxxxx> Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx> Signed-off-by: Lina Iyer <lina.iyer@xxxxxxxxxx> --- drivers/base/power/domain.c | 103 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/pm_domain.h | 8 ++++ 2 files changed, 111 insertions(+) diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 740afa9..368a5b8 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -1895,6 +1895,109 @@ out: return ret ? -EPROBE_DEFER : 0; } EXPORT_SYMBOL_GPL(genpd_dev_pm_attach); + +static const struct of_device_id idle_state_match[] = { + { .compatible = "arm,idle-state", }, + { } +}; + +static int read_genpd_state(struct genpd_power_state *genpd_state,/s/read_genpd_state/genpd_parse_state+ struct device_node *state_node) +{ + int err = 0;No need to assign err to 0.+ u32 latency; + u32 residency; + u32 entry_latency, exit_latency; + const struct of_device_id *match_id; + + match_id = of_match_node(idle_state_match, state_node); + if (!match_id) + return -EINVAL; + + err = of_property_read_u32(state_node, "entry-latency-us", + &entry_latency); + if (err) { + pr_debug(" * %s missing entry-latency-us property\n", + state_node->full_name); + return -EINVAL; + } + + err = of_property_read_u32(state_node, "exit-latency-us", + &exit_latency); + if (err) { + pr_debug(" * %s missing exit-latency-us property\n", + state_node->full_name); + return -EINVAL; + } + + err = of_property_read_u32(state_node, "min-residency-us", &residency); + if (!err) + genpd_state->residency_ns = 1000 * residency; + + latency = entry_latency + exit_latency;Hmm, this is probably not what you want. The genpd governor, via __default_power_down_ok(), already adds the ->power_on_latency_ns and the ->power_off_latency_ns, when it validates which idle state you are allowed to enter.+ genpd_state->power_on_latency_ns = 1000 * latency; + genpd_state->power_off_latency_ns = 1000 * entry_latency; + + return 0; +} + +/** + * of_genpd_parse_idle_states: Return array of idle states for the genpd. + * + * @dn: The genpd device node + * @states: The pointer to which the state array will be saved. + * @n: The count of elements in the array returned from this function. + * + * Returns the device states parsed from the OF node. The memory for the states + * is allocated by this function and is the responsibility of the caller to + * free the memory after use. + */ +int of_genpd_parse_idle_states(struct device_node *dn, + struct genpd_power_state **states, int *n) +{ + struct genpd_power_state *st; + struct device_node *np; + int i, ret = 0; + int count; + + for (count = 0; ; count++) + if (!of_parse_phandle(dn, "domain-idle-states", count)) + break;I think it's better to use of_count_phandle_with_args() to find out the number of phandles.
+ + st = kcalloc(count, sizeof(*st), GFP_KERNEL); + if (!st) + return -ENOMEM; + + for (i = 0; i < count; i++) { + np = of_parse_phandle(dn, "domain-idle-states", i);Isn't this a case of when it would be convenient to use the of_phandle_iterator*() APIs?
Hmm.. But if we move back to static allocation of states, we won't need any of this ;) -- Lina
+ if (!np) { + ret = -EFAULT; + break; + } + + ret = read_genpd_state(&st[i], np); + if (ret) { + pr_err + ("Parsing idle state node %s failed with err %d\n", + np->full_name, ret); + of_node_put(np); + break; + } + of_node_put(np); + } + + if (ret) { + kfree(st); + return ret; + } + + *n = count; + *states = st; + + return 0; +} +EXPORT_SYMBOL(of_genpd_parse_idle_states); + #endif /* CONFIG_PM_GENERIC_DOMAINS_OF */ diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index c113713..4c9152d 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -204,6 +204,8 @@ extern int of_genpd_add_device(struct of_phandle_args *args, extern int of_genpd_add_subdomain(struct of_phandle_args *parent, struct of_phandle_args *new_subdomain); extern struct generic_pm_domain *of_genpd_remove_last(struct device_node *np); +extern int of_genpd_parse_idle_states(struct device_node *dn, + struct genpd_power_state **states, int *n); int genpd_dev_pm_attach(struct device *dev); #else /* !CONFIG_PM_GENERIC_DOMAINS_OF */ @@ -233,6 +235,12 @@ static inline int of_genpd_add_subdomain(struct of_phandle_args *parent, return -ENODEV; } +static inline int of_genpd_parse_idle_states(struct device_node *dn, + struct genpd_power_state **states, int *n) +{ + return -ENODEV; +} + static inline int genpd_dev_pm_attach(struct device *dev) { return -ENODEV; -- 2.7.4Kind regards Uffe
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