[PATCH v3] power: supply: test-power: implement charge_behaviour property

[Thomas Weißschuh]

To validate the special formatting of the "charge_behaviour" sysfs
property add it to the example driver.

Signed-off-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
---
The original submission of the charge_behaviour property did not
implement proper formatting in the default formatting handler in
power_supply_sysfs.c.

At that time it was not a problem because the only provider of the UAPI,
thinkpad_acpi, did its own formatting.

Now there is an in-tree driver, mm8013, and out-of-tree driver which use
the normal power-supply properties and are affected by the wrong
formatting.
In this revision the handling of CHARGE_BEHAVIOUR in mm8013 is dropped
as it is not the correct API for it to use.
That change was not tested by me as I don't have the hardware.
---
Changes in v3:
- Drop already applied patches
- Validate value in test_power_set_battery_property
- Link to v2: https://lore.kernel.org/r/20240303-power_supply-charge_behaviour_prop-v2-0-8ebb0a7c2409@xxxxxxxxxxxxxx

Changes in v2:
- Simplify the backwards-compatibility logic (adds a preparatory patch)
- Extend test-power to also handle writing of charge_behaviour
- Drop incorrect CHARGE_BEHAVIOUR from mm8013 driver
- Replace special CHARGE_BEHAVIOUR_AVAILABLE property with bitmask in
  struct power_supply_desc
- Link to v1: https://lore.kernel.org/r/20240204-power_supply-charge_behaviour_prop-v1-0-06a20c958f96@xxxxxxxxxxxxxx
---
 drivers/power/supply/test_power.c | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/drivers/power/supply/test_power.c b/drivers/power/supply/test_power.c
index 0d0a77584c5d..442ceb7795e1 100644
--- a/drivers/power/supply/test_power.c
+++ b/drivers/power/supply/test_power.c
@@ -35,6 +35,8 @@ static int battery_capacity		= 50;
 static int battery_voltage		= 3300;
 static int battery_charge_counter	= -1000;
 static int battery_current		= -1600;
+static enum power_supply_charge_behaviour battery_charge_behaviour =
+	POWER_SUPPLY_CHARGE_BEHAVIOUR_AUTO;
 
 static bool module_initialized;
 
@@ -123,6 +125,9 @@ static int test_power_get_battery_property(struct power_supply *psy,
 	case POWER_SUPPLY_PROP_CURRENT_NOW:
 		val->intval = battery_current;
 		break;
+	case POWER_SUPPLY_PROP_CHARGE_BEHAVIOUR:
+		val->intval = battery_charge_behaviour;
+		break;
 	default:
 		pr_info("%s: some properties deliberately report errors.\n",
 			__func__);
@@ -131,6 +136,31 @@ static int test_power_get_battery_property(struct power_supply *psy,
 	return 0;
 }
 
+static int test_power_battery_property_is_writeable(struct power_supply *psy,
+						    enum power_supply_property psp)
+{
+	return psp == POWER_SUPPLY_PROP_CHARGE_BEHAVIOUR;
+}
+
+static int test_power_set_battery_property(struct power_supply *psy,
+					   enum power_supply_property psp,
+					   const union power_supply_propval *val)
+{
+	switch (psp) {
+	case POWER_SUPPLY_PROP_CHARGE_BEHAVIOUR:
+		if (val->intval < 0 ||
+		    val->intval >= BITS_PER_TYPE(typeof(psy->desc->charge_behaviours)) ||
+		    !(BIT(val->intval) & psy->desc->charge_behaviours)) {
+			return -EINVAL;
+		}
+		battery_charge_behaviour = val->intval;
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
 static enum power_supply_property test_power_ac_props[] = {
 	POWER_SUPPLY_PROP_ONLINE,
 };
@@ -156,6 +186,7 @@ static enum power_supply_property test_power_battery_props[] = {
 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
 	POWER_SUPPLY_PROP_CURRENT_AVG,
 	POWER_SUPPLY_PROP_CURRENT_NOW,
+	POWER_SUPPLY_PROP_CHARGE_BEHAVIOUR,
 };
 
 static char *test_power_ac_supplied_to[] = {
@@ -178,6 +209,11 @@ static const struct power_supply_desc test_power_desc[] = {
 		.properties = test_power_battery_props,
 		.num_properties = ARRAY_SIZE(test_power_battery_props),
 		.get_property = test_power_get_battery_property,
+		.set_property = test_power_set_battery_property,
+		.property_is_writeable = test_power_battery_property_is_writeable,
+		.charge_behaviours = BIT(POWER_SUPPLY_CHARGE_BEHAVIOUR_AUTO)
+				   | BIT(POWER_SUPPLY_CHARGE_BEHAVIOUR_INHIBIT_CHARGE)
+				   | BIT(POWER_SUPPLY_CHARGE_BEHAVIOUR_FORCE_DISCHARGE),
 	},
 	[TEST_USB] = {
 		.name = "test_usb",

---
base-commit: 4e61f1e9d58fb0765f59f47d4d1f318b36c14d95
change-id: 20230929-power_supply-charge_behaviour_prop-10ccfd96a666

Best regards,
-- 
Thomas Weißschuh <linux@xxxxxxxxxxxxxx>