diff mbox series

[v4,2/4] power: supply: core: Add new "charge_types" property

Message ID 20241211174451.355421-3-hdegoede@redhat.com (mailing list archive)
State New
Headers show
Series power: supply: Add new "charge_types" property | expand

Commit Message

Hans de Goede Dec. 11, 2024, 5:44 p.m. UTC
Add a new "charge_types" property, this is identical to "charge_type" but
reading returns a list of supported charge-types with the currently active
type surrounded by square brackets, e.g.:

Fast [Standard] "Long_Life"

This has the advantage over the existing "charge_type" property that this
allows userspace to find out which charge-types are supported for writable
charge_type properties.

Drivers which already support "charge_type" can easily add support for
this by setting power_supply_desc.charge_types to a bitmask representing
valid charge_type values. The existing "charge_type" get_property() and
set_property() code paths can be re-used for "charge_types".

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
Changes in v4:
- Rebase on top of latest sre/linux-power-supply.git/for-next
- Only print current value in uevent using new uevent flag passed to
  power_supply_format_property()
- Put new POWER_SUPPLY_PROP_CHARGE_TYPES enum power_supply_property entry
  directly after the existing POWER_SUPPLY_PROP_CHARGE_TYPE entry

Changes in v2:
- Add "Check charge_types to get the values supported by the battery."
  to Documentation/ABI/testing/sysfs-class-power
- Add a note about labels with spaces having these replaced by '_'
  to Documentation/ABI/testing/sysfs-class-power
- Use power_supply_match_string() in power_supply_charge_types_parse()
---
 Documentation/ABI/testing/sysfs-class-power | 20 ++++++++++++
 drivers/power/supply/power_supply_sysfs.c   | 36 +++++++++++++++++++++
 include/linux/power_supply.h                | 23 ++++++++++++-
 3 files changed, 78 insertions(+), 1 deletion(-)

Comments

Thomas Weißschuh Dec. 11, 2024, 7:27 p.m. UTC | #1
On 2024-12-11 18:44:49+0100, Hans de Goede wrote:
> Add a new "charge_types" property, this is identical to "charge_type" but
> reading returns a list of supported charge-types with the currently active
> type surrounded by square brackets, e.g.:
> 
> Fast [Standard] "Long_Life"
> 
> This has the advantage over the existing "charge_type" property that this
> allows userspace to find out which charge-types are supported for writable
> charge_type properties.
> 
> Drivers which already support "charge_type" can easily add support for
> this by setting power_supply_desc.charge_types to a bitmask representing
> valid charge_type values. The existing "charge_type" get_property() and
> set_property() code paths can be re-used for "charge_types".
> 
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>

Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>

[..]
diff mbox series

Patch

diff --git a/Documentation/ABI/testing/sysfs-class-power b/Documentation/ABI/testing/sysfs-class-power
index 45180b62d426..74050dfb5fc0 100644
--- a/Documentation/ABI/testing/sysfs-class-power
+++ b/Documentation/ABI/testing/sysfs-class-power
@@ -407,10 +407,30 @@  Description:
 
 		Access: Read, Write
 
+		Reading this returns the current active value, e.g. 'Standard'.
+		Check charge_types to get the values supported by the battery.
+
 		Valid values:
 			      "Unknown", "N/A", "Trickle", "Fast", "Standard",
 			      "Adaptive", "Custom", "Long Life", "Bypass"
 
+What:		/sys/class/power_supply/<supply_name>/charge_types
+Date:		December 2024
+Contact:	linux-pm@vger.kernel.org
+Description:
+		Identical to charge_type but reading returns a list of supported
+		charge-types with the currently active type surrounded by square
+		brackets, e.g.: "Fast [Standard] Long_Life".
+
+		power_supply class devices may support both charge_type and
+		charge_types for backward compatibility. In this case both will
+		always have the same active value and the active value can be
+		changed by writing either property.
+
+		Note charge-types which contain a space such as "Long Life" will
+		have the space replaced by a '_' resulting in e.g. "Long_Life".
+		When writing charge-types both variants are accepted.
+
 What:		/sys/class/power_supply/<supply_name>/charge_term_current
 Date:		July 2014
 Contact:	linux-pm@vger.kernel.org
diff --git a/drivers/power/supply/power_supply_sysfs.c b/drivers/power/supply/power_supply_sysfs.c
index b7b29ce61c34..9497bc12f4cc 100644
--- a/drivers/power/supply/power_supply_sysfs.c
+++ b/drivers/power/supply/power_supply_sysfs.c
@@ -182,6 +182,8 @@  static struct power_supply_attr power_supply_attrs[] __ro_after_init = {
 	POWER_SUPPLY_ATTR(CHARGE_CONTROL_START_THRESHOLD),
 	POWER_SUPPLY_ATTR(CHARGE_CONTROL_END_THRESHOLD),
 	POWER_SUPPLY_ENUM_ATTR(CHARGE_BEHAVIOUR),
+	/* Same enum value texts as "charge_type" without the 's' at the end */
+	_POWER_SUPPLY_ENUM_ATTR(CHARGE_TYPES, POWER_SUPPLY_CHARGE_TYPE_TEXT),
 	POWER_SUPPLY_ATTR(INPUT_CURRENT_LIMIT),
 	POWER_SUPPLY_ATTR(INPUT_VOLTAGE_LIMIT),
 	POWER_SUPPLY_ATTR(INPUT_POWER_LIMIT),
@@ -339,6 +341,12 @@  static ssize_t power_supply_format_property(struct device *dev,
 		ret = power_supply_charge_behaviour_show(dev, psy->desc->charge_behaviours,
 							 value.intval, buf);
 		break;
+	case POWER_SUPPLY_PROP_CHARGE_TYPES:
+		if (uevent) /* no possible values in uevents */
+			goto default_format;
+		ret = power_supply_charge_types_show(dev, psy->desc->charge_types,
+						     value.intval, buf);
+		break;
 	case POWER_SUPPLY_PROP_MODEL_NAME ... POWER_SUPPLY_PROP_SERIAL_NUMBER:
 		ret = sysfs_emit(buf, "%s\n", value.strval);
 		break;
@@ -556,3 +564,31 @@  int power_supply_charge_behaviour_parse(unsigned int available_behaviours, const
 	return -EINVAL;
 }
 EXPORT_SYMBOL_GPL(power_supply_charge_behaviour_parse);
+
+ssize_t power_supply_charge_types_show(struct device *dev,
+				       unsigned int available_types,
+				       enum power_supply_charge_type current_type,
+				       char *buf)
+{
+	return power_supply_show_enum_with_available(
+				dev, POWER_SUPPLY_CHARGE_TYPE_TEXT,
+				ARRAY_SIZE(POWER_SUPPLY_CHARGE_TYPE_TEXT),
+				available_types, current_type, buf);
+}
+EXPORT_SYMBOL_GPL(power_supply_charge_types_show);
+
+int power_supply_charge_types_parse(unsigned int available_types, const char *buf)
+{
+	int i = power_supply_match_string(POWER_SUPPLY_CHARGE_TYPE_TEXT,
+					  ARRAY_SIZE(POWER_SUPPLY_CHARGE_TYPE_TEXT),
+					  buf);
+
+	if (i < 0)
+		return i;
+
+	if (available_types & BIT(i))
+		return i;
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(power_supply_charge_types_parse);
diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index b98106e1a90f..a841b814743b 100644
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -40,7 +40,7 @@  enum {
 };
 
 /* What algorithm is the charger using? */
-enum {
+enum power_supply_charge_type {
 	POWER_SUPPLY_CHARGE_TYPE_UNKNOWN = 0,
 	POWER_SUPPLY_CHARGE_TYPE_NONE,
 	POWER_SUPPLY_CHARGE_TYPE_TRICKLE,	/* slow speed */
@@ -99,6 +99,7 @@  enum power_supply_property {
 	/* Properties of type `int' */
 	POWER_SUPPLY_PROP_STATUS = 0,
 	POWER_SUPPLY_PROP_CHARGE_TYPE,
+	POWER_SUPPLY_PROP_CHARGE_TYPES,
 	POWER_SUPPLY_PROP_HEALTH,
 	POWER_SUPPLY_PROP_PRESENT,
 	POWER_SUPPLY_PROP_ONLINE,
@@ -245,6 +246,7 @@  struct power_supply_desc {
 	const char *name;
 	enum power_supply_type type;
 	u8 charge_behaviours;
+	u32 charge_types;
 	u32 usb_types;
 	const enum power_supply_property *properties;
 	size_t num_properties;
@@ -944,6 +946,11 @@  ssize_t power_supply_charge_behaviour_show(struct device *dev,
 					   char *buf);
 
 int power_supply_charge_behaviour_parse(unsigned int available_behaviours, const char *buf);
+ssize_t power_supply_charge_types_show(struct device *dev,
+				       unsigned int available_types,
+				       enum power_supply_charge_type current_type,
+				       char *buf);
+int power_supply_charge_types_parse(unsigned int available_types, const char *buf);
 #else
 static inline
 ssize_t power_supply_charge_behaviour_show(struct device *dev,
@@ -959,6 +966,20 @@  static inline int power_supply_charge_behaviour_parse(unsigned int available_beh
 {
 	return -EOPNOTSUPP;
 }
+
+static inline
+ssize_t power_supply_charge_types_show(struct device *dev,
+				       unsigned int available_types,
+				       enum power_supply_charge_type current_type,
+				       char *buf)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int power_supply_charge_types_parse(unsigned int available_types, const char *buf)
+{
+	return -EOPNOTSUPP;
+}
 #endif
 
 #endif /* __LINUX_POWER_SUPPLY_H__ */