2008-08-26 20:10:16

by Matthew Garrett

[permalink] [raw]
Subject: [PATCH] power-supply: Add function to return system-wide power state

(resend, I screwed up the Cc)

Certain drivers benefit from knowing whether the system is on ac or
battery, for instance when determining which backlight registers to
read. This adds a simple call to determine whether there's an online
power supply other than any batteries.

Signed-off-by: Matthew Garrett <[email protected]>

---

The name is a bit odd, but seems to fit in with the existing naming
scheme.

diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c
index cb1ccb4..6a687da 100644
--- a/drivers/power/power_supply_core.c
+++ b/drivers/power/power_supply_core.c
@@ -87,6 +87,31 @@ int power_supply_am_i_supplied(struct power_supply *psy)
return error;
}

+static int __power_supply_is_system_supplied(struct device *dev, void *data)
+{
+ union power_supply_propval ret = {0,};
+ struct power_supply *psy = dev_get_drvdata(dev);
+
+ if (psy->type != POWER_SUPPLY_TYPE_BATTERY) {
+ if (psy->get_property(psy,
+ POWER_SUPPLY_PROP_ONLINE, &ret))
+ return 0;
+ if (ret.intval)
+ return ret.intval;
+ }
+ return 0;
+}
+
+int power_supply_is_system_supplied()
+{
+ int error;
+
+ error = class_for_each_device(power_supply_class, NULL, NULL,
+ __power_supply_is_system_supplied);
+
+ return error;
+}
+
int power_supply_register(struct device *parent, struct power_supply *psy)
{
int rc = 0;
@@ -148,6 +173,7 @@ static void __exit power_supply_class_exit(void)

EXPORT_SYMBOL_GPL(power_supply_changed);
EXPORT_SYMBOL_GPL(power_supply_am_i_supplied);
+EXPORT_SYMBOL_GPL(power_supply_is_system_supplied);
EXPORT_SYMBOL_GPL(power_supply_register);
EXPORT_SYMBOL_GPL(power_supply_unregister);

diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index ea96ead..3e67d0c 100644
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -164,6 +164,7 @@ struct power_supply_info {

extern void power_supply_changed(struct power_supply *psy);
extern int power_supply_am_i_supplied(struct power_supply *psy);
+extern int power_supply_is_system_supplied(void);

extern int power_supply_register(struct device *parent,
struct power_supply *psy);

--
Matthew Garrett | [email protected]


2008-08-26 20:25:52

by Anton Vorontsov

[permalink] [raw]
Subject: Re: [PATCH] power-supply: Add function to return system-wide power state

On Tue, Aug 26, 2008 at 09:09:59PM +0100, Matthew Garrett wrote:
> (resend, I screwed up the Cc)
>
> Certain drivers benefit from knowing whether the system is on ac or
> battery, for instance when determining which backlight registers to
> read. This adds a simple call to determine whether there's an online
> power supply other than any batteries.

I like the patch, much thanks!

One comment below.

> Signed-off-by: Matthew Garrett <[email protected]>
>
> ---
>
> The name is a bit odd, but seems to fit in with the existing naming
> scheme.
>
> diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c
> index cb1ccb4..6a687da 100644
> --- a/drivers/power/power_supply_core.c
> +++ b/drivers/power/power_supply_core.c
> @@ -87,6 +87,31 @@ int power_supply_am_i_supplied(struct power_supply *psy)
> return error;
> }
>
> +static int __power_supply_is_system_supplied(struct device *dev, void *data)
> +{
> + union power_supply_propval ret = {0,};
> + struct power_supply *psy = dev_get_drvdata(dev);
> +
> + if (psy->type != POWER_SUPPLY_TYPE_BATTERY) {
> + if (psy->get_property(psy,
> + POWER_SUPPLY_PROP_ONLINE, &ret))
> + return 0;
> + if (ret.intval)
> + return ret.intval;
> + }
> + return 0;
> +}
> +
> +int power_supply_is_system_supplied()
> +{
> + int error;
> +
> + error = class_for_each_device(power_supply_class, NULL, NULL,
> + __power_supply_is_system_supplied);
> +
> + return error;
> +}
> +
> int power_supply_register(struct device *parent, struct power_supply *psy)
> {
> int rc = 0;
> @@ -148,6 +173,7 @@ static void __exit power_supply_class_exit(void)
>
> EXPORT_SYMBOL_GPL(power_supply_changed);
> EXPORT_SYMBOL_GPL(power_supply_am_i_supplied);
> +EXPORT_SYMBOL_GPL(power_supply_is_system_supplied);
> EXPORT_SYMBOL_GPL(power_supply_register);
> EXPORT_SYMBOL_GPL(power_supply_unregister);
>
> diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
> index ea96ead..3e67d0c 100644
> --- a/include/linux/power_supply.h
> +++ b/include/linux/power_supply.h
> @@ -164,6 +164,7 @@ struct power_supply_info {
>
> extern void power_supply_changed(struct power_supply *psy);
> extern int power_supply_am_i_supplied(struct power_supply *psy);
> +extern int power_supply_is_system_supplied(void);

May I suggest adding
static int power_supply_is_system_supplied(void) { return -ENOSYS; }
in case of !CONFIG_POWER_SUPPLY? This way drivers may not strictly
depend on power supply class.

And "if (power_supply_is_system_supplied())" will assume that we're
always supplied, which good assumption, I think.

Thanks,

--
Anton Vorontsov
email: [email protected]
irc://irc.freenode.net/bd2

2008-08-26 20:33:40

by Matthew Garrett

[permalink] [raw]
Subject: Re: [PATCH] power-supply: Add function to return system-wide power state

Something like this?

diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c
index cb1ccb4..6a687da 100644
--- a/drivers/power/power_supply_core.c
+++ b/drivers/power/power_supply_core.c
@@ -87,6 +87,31 @@ int power_supply_am_i_supplied(struct power_supply *psy)
return error;
}

+static int __power_supply_is_system_supplied(struct device *dev, void *data)
+{
+ union power_supply_propval ret = {0,};
+ struct power_supply *psy = dev_get_drvdata(dev);
+
+ if (psy->type != POWER_SUPPLY_TYPE_BATTERY) {
+ if (psy->get_property(psy,
+ POWER_SUPPLY_PROP_ONLINE, &ret))
+ return 0;
+ if (ret.intval)
+ return ret.intval;
+ }
+ return 0;
+}
+
+int power_supply_is_system_supplied()
+{
+ int error;
+
+ error = class_for_each_device(power_supply_class, NULL, NULL,
+ __power_supply_is_system_supplied);
+
+ return error;
+}
+
int power_supply_register(struct device *parent, struct power_supply *psy)
{
int rc = 0;
@@ -148,6 +173,7 @@ static void __exit power_supply_class_exit(void)

EXPORT_SYMBOL_GPL(power_supply_changed);
EXPORT_SYMBOL_GPL(power_supply_am_i_supplied);
+EXPORT_SYMBOL_GPL(power_supply_is_system_supplied);
EXPORT_SYMBOL_GPL(power_supply_register);
EXPORT_SYMBOL_GPL(power_supply_unregister);

diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index ea96ead..304df22 100644
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -164,11 +164,16 @@ struct power_supply_info {

extern void power_supply_changed(struct power_supply *psy);
extern int power_supply_am_i_supplied(struct power_supply *psy);
-
extern int power_supply_register(struct device *parent,
struct power_supply *psy);
extern void power_supply_unregister(struct power_supply *psy);

+#ifdef CONFIG_POWER_SUPPLY
+extern int power_supply_is_system_supplied(void);
+#else
+static int power_supply_is_system_supplied(void) { return -ENOSYS; }
+#endif
+
/* For APM emulation, think legacy userspace. */
extern struct class *power_supply_class;



--
Matthew Garrett | [email protected]

2008-08-26 21:10:30

by Anton Vorontsov

[permalink] [raw]
Subject: Re: [PATCH] power-supply: Add function to return system-wide power state

On Tue, Aug 26, 2008 at 09:33:27PM +0100, Matthew Garrett wrote:
> Something like this?

Yup, except that I forgot 'inline' in my example. ;-) I'll add it
before applying, thanks!

> diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c
> index cb1ccb4..6a687da 100644
> --- a/drivers/power/power_supply_core.c
> +++ b/drivers/power/power_supply_core.c
> @@ -87,6 +87,31 @@ int power_supply_am_i_supplied(struct power_supply *psy)
> return error;
> }
>
> +static int __power_supply_is_system_supplied(struct device *dev, void *data)
> +{
> + union power_supply_propval ret = {0,};
> + struct power_supply *psy = dev_get_drvdata(dev);
> +
> + if (psy->type != POWER_SUPPLY_TYPE_BATTERY) {
> + if (psy->get_property(psy,
> + POWER_SUPPLY_PROP_ONLINE, &ret))
> + return 0;
> + if (ret.intval)
> + return ret.intval;
> + }
> + return 0;
> +}
> +
> +int power_supply_is_system_supplied()
> +{
> + int error;
> +
> + error = class_for_each_device(power_supply_class, NULL, NULL,
> + __power_supply_is_system_supplied);
> +
> + return error;
> +}
> +
> int power_supply_register(struct device *parent, struct power_supply *psy)
> {
> int rc = 0;
> @@ -148,6 +173,7 @@ static void __exit power_supply_class_exit(void)
>
> EXPORT_SYMBOL_GPL(power_supply_changed);
> EXPORT_SYMBOL_GPL(power_supply_am_i_supplied);
> +EXPORT_SYMBOL_GPL(power_supply_is_system_supplied);
> EXPORT_SYMBOL_GPL(power_supply_register);
> EXPORT_SYMBOL_GPL(power_supply_unregister);
>
> diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
> index ea96ead..304df22 100644
> --- a/include/linux/power_supply.h
> +++ b/include/linux/power_supply.h
> @@ -164,11 +164,16 @@ struct power_supply_info {
>
> extern void power_supply_changed(struct power_supply *psy);
> extern int power_supply_am_i_supplied(struct power_supply *psy);
> -
> extern int power_supply_register(struct device *parent,
> struct power_supply *psy);
> extern void power_supply_unregister(struct power_supply *psy);
>
> +#ifdef CONFIG_POWER_SUPPLY
> +extern int power_supply_is_system_supplied(void);
> +#else
> +static int power_supply_is_system_supplied(void) { return -ENOSYS; }
> +#endif
> +
> /* For APM emulation, think legacy userspace. */
> extern struct class *power_supply_class;

--
Anton Vorontsov
email: [email protected]
irc://irc.freenode.net/bd2

2008-08-31 23:14:32

by Anton Vorontsov

[permalink] [raw]
Subject: Re: [PATCH] power-supply: Add function to return system-wide power state

On Tue, Aug 26, 2008 at 09:33:27PM +0100, Matthew Garrett wrote:
> Something like this?

I just applied it to battery-2.6.git with the following changes:

[...]
> +int power_supply_is_system_supplied()

-()
+(void)

[...]
> +#ifdef CONFIG_POWER_SUPPLY

Added || defined(CONFIG_POWER_SUPPLY_MODULE)

> +extern int power_supply_is_system_supplied(void);
> +#else
> +static int power_supply_is_system_supplied(void) { return -ENOSYS; }

Added inline keyword, otherwise gcc might warn about defined but
not used function.


Please test battery-2.6.git tree (or simply next `-next` tree ;-)
if everything is okay.

Thanks again!

--
Anton Vorontsov
email: [email protected]
irc://irc.freenode.net/bd2