[PATCH v2 3/3] adp5061: Add support for charging voltage limit enable

From: Stefan Popa
Date: Tue Apr 10 2018 - 05:51:59 EST


This patch adds the option to activate/deactivate the charging voltage
limit. If activated, the charger prevents charging until the battery
voltage drops below the VCHG_VLIM threshold.

This option is not configurable via the power_supply properties,
therefore, access via sysfs was provided to examine and modify this
attribute on the fly.

Signed-off-by: Stefan Popa <stefan.popa@xxxxxxxxxx>
---
Changes in v2:
- Fixed the kbuild test error by changing the type of the
charging_vlim_enabled_show() and charging_vlim_enabled_store()
functions from int to ssize_t.

.../ABI/testing/sysfs-class-power-adp5061 | 13 ++++++
drivers/power/supply/adp5061.c | 46 ++++++++++++++++++++++
2 files changed, 59 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-class-power-adp5061 b/Documentation/ABI/testing/sysfs-class-power-adp5061
index 0d056aa..25064c1 100644
--- a/Documentation/ABI/testing/sysfs-class-power-adp5061
+++ b/Documentation/ABI/testing/sysfs-class-power-adp5061
@@ -8,3 +8,16 @@ Description:
Valid values:
- 1: enabled
- 0: disabled
+
+What: /sys/class/power_supply/adp5061/charging_vlim_enabled
+Description:
+ Enable/disable charging voltage limit
+
+ The ADP5061 charging voltage limit can be enabled by setting
+ this attribute to 1. When enabled, the charger prevents charging
+ until the battery voltage drops bellow the VCHG_VLIM threshold.
+ See device datasheet for details.
+
+ Valid values:
+ - 1: enabled
+ - 0: disabled
diff --git a/drivers/power/supply/adp5061.c b/drivers/power/supply/adp5061.c
index 99871e6..9716059 100644
--- a/drivers/power/supply/adp5061.c
+++ b/drivers/power/supply/adp5061.c
@@ -84,6 +84,10 @@
#define ADP5061_FUNC_SET_1_EN_CHG_MSK BIT(0)
#define ADP5061_FUNC_SET_1_EN_CHG_MODE(x) (((x) & 0x01) << 0)

+/* ADP5061_FUNC_SET_2 */
+#define ADP5061_FUNC_SET_2_EN_CHG_VLIM_MSK BIT(5)
+#define ADP5061_FUNC_SET_2_EN_CHG_VLIM_MODE(x) (((x) & 0x01) << 5)
+
#define ADP5061_NO_BATTERY 0x01
#define ADP5061_ICHG_MAX 1300 // mA

@@ -737,10 +741,52 @@ static ssize_t charging_enabled_store(struct device *dev,
return count;
}

+static ssize_t charging_vlim_enabled_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct power_supply *psy = dev_get_drvdata(dev);
+ struct adp5061_state *st = power_supply_get_drvdata(psy);
+ unsigned int regval;
+ int ret;
+
+ ret = regmap_read(st->regmap, ADP5061_FUNC_SET_2, &regval);
+ if (ret < 0)
+ return ret;
+
+ regval = (regval & ADP5061_FUNC_SET_2_EN_CHG_VLIM_MSK) >> 5;
+ return sprintf(buf, "%d\n", regval);
+}
+
+static ssize_t charging_vlim_enabled_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct power_supply *psy = dev_get_drvdata(dev);
+ struct adp5061_state *st = power_supply_get_drvdata(psy);
+ u8 chg_vlim_en;
+ int ret;
+
+ ret = kstrtou8(buf, 0, &chg_vlim_en);
+ if (ret < 0)
+ return ret;
+
+ ret = regmap_update_bits(st->regmap, ADP5061_FUNC_SET_2,
+ ADP5061_FUNC_SET_2_EN_CHG_VLIM_MSK,
+ ADP5061_FUNC_SET_2_EN_CHG_VLIM_MODE(!!chg_vlim_en));
+
+ if (ret < 0)
+ return ret;
+
+ return count;
+}
+
static DEVICE_ATTR_RW(charging_enabled);
+static DEVICE_ATTR_RW(charging_vlim_enabled);

static struct attribute *adp5061_attributes[] = {
&dev_attr_charging_enabled.attr,
+ &dev_attr_charging_vlim_enabled.attr,
NULL
};

--
2.7.4