diff mbox

[3/8] PM / Domains: Allow domain power states to be read from DT

Message ID 1475699519-109623-4-git-send-email-lina.iyer@linaro.org (mailing list archive)
State Superseded, archived
Headers show

Commit Message

Lina Iyer Oct. 5, 2016, 8:31 p.m. UTC
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@baylibre.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
---
 drivers/base/power/domain.c | 103 ++++++++++++++++++++++++++++++++++++++++++++
 include/linux/pm_domain.h   |   8 ++++
 2 files changed, 111 insertions(+)

Comments

Geert Uytterhoeven Oct. 6, 2016, 8:04 a.m. UTC | #1
Hi Lina,

On Wed, Oct 5, 2016 at 10:31 PM, Lina Iyer <lina.iyer@linaro.org> 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@baylibre.com>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
> ---
>  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", },

Do we want ARM-specific compatible values without an #ifdef in drivers/base/?

I know we already have "samsung,power-domain".
Perhaps that should be protected by #ifdef, too.

> +       { }
> +};

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds
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Ulf Hansson Oct. 6, 2016, 9:47 a.m. UTC | #2
On 5 October 2016 at 22:31, Lina Iyer <lina.iyer@linaro.org> 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@baylibre.com>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
> ---
>  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?

> +               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;
> --
> 2.7.4
>

Kind regards
Uffe
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Lina Iyer Oct. 6, 2016, 3:44 p.m. UTC | #3
On Thu, Oct 06 2016 at 02:04 -0600, Geert Uytterhoeven wrote:
>Hi Lina,
>
>On Wed, Oct 5, 2016 at 10:31 PM, Lina Iyer <lina.iyer@linaro.org> 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@baylibre.com>
>> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
>> Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
>> ---
>>  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", },
>
>Do we want ARM-specific compatible values without an #ifdef in drivers/base/?
>
>I know we already have "samsung,power-domain".
>Perhaps that should be protected by #ifdef, too.
>
The arm,idle-state DT binding is re-used here to describe domain idle
states, because that is exactly what we need here. The binding is not
dependent on the ARM architecture, so we won't need a #ifdef around
this. I do agree that using this compatible is not very intuitive.

Thanks,
Lina

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Lina Iyer Oct. 6, 2016, 3:53 p.m. UTC | #4
On Thu, Oct 06 2016 at 03:47 -0600, Ulf Hansson wrote:
>On 5 October 2016 at 22:31, Lina Iyer <lina.iyer@linaro.org> 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@baylibre.com>
>> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
>> Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
>> ---
>>  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;
>> --
>> 2.7.4
>>
>
>Kind regards
>Uffe
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Lina Iyer Oct. 6, 2016, 3:54 p.m. UTC | #5
On Thu, Oct 06 2016 at 03:47 -0600, Ulf Hansson wrote:
>On 5 October 2016 at 22:31, Lina Iyer <lina.iyer@linaro.org> 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@baylibre.com>
>> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
>> Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
>> ---
>>  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
>
Ok.

>> +                                   struct device_node *state_node)
>> +{
>> +       int err = 0;
>
>No need to assign err to 0.
>
Will fix.
>> +       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.
>
Good catch.
>> +       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?
>
>> +               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;
>> --
>> 2.7.4
>>
>
>Kind regards
>Uffe
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diff mbox

Patch

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,
+				    struct device_node *state_node)
+{
+	int err = 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;
+	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;
+
+	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);
+		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;