[PATCH 2/2] power: supply: rn5t618: Add input current limit

From: Andreas Kemnade
Date: Fri May 28 2021 - 17:30:25 EST

Adds properties for setting the maximum current to USB, ADP and Battery
supplies. USB and ADP limits are reset to OTP values upon replugging.

Signed-off-by: Andreas Kemnade <andreas@xxxxxxxxxxxx>
---
drivers/power/supply/rn5t618_power.c | 188 +++++++++++++++++++++++++++
1 file changed, 188 insertions(+)

diff --git a/drivers/power/supply/rn5t618_power.c b/drivers/power/supply/rn5t618_power.c
index f8f00f67ce4c..819061918b2a 100644
--- a/drivers/power/supply/rn5t618_power.c
+++ b/drivers/power/supply/rn5t618_power.c
@@ -44,6 +44,20 @@

#define FG_ENABLE 1

+/*
+ * Formula seems accurate for battery current, but for USB current around 70mA
+ * per step was seen on Kobo Clara HD but all sources show the same formula
+ * also fur USB current. To avoid accidentially unwanted high currents we stick
+ * to that formula
+ */
+#define TO_CUR_REG(x) ((x) / 100000 - 1)
+#define FROM_CUR_REG(x) ((((x) & 0x1f) + 1) * 100000)
+#define CHG_MIN_CUR 100000
+#define CHG_MAX_CUR 1800000
+#define ADP_MAX_CUR 2500000
+#define USB_MAX_CUR 1400000
+
+
struct rn5t618_power_info {
struct rn5t618 *rn5t618;
struct platform_device *pdev;
@@ -61,12 +75,16 @@ static enum power_supply_usb_type rn5t618_usb_types[] = {
};

static enum power_supply_property rn5t618_usb_props[] = {
+ /* input current limit is not very accurate */
+ POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT,
POWER_SUPPLY_PROP_STATUS,
POWER_SUPPLY_PROP_USB_TYPE,
POWER_SUPPLY_PROP_ONLINE,
};

static enum power_supply_property rn5t618_adp_props[] = {
+ /* input current limit is not very accurate */
+ POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT,
POWER_SUPPLY_PROP_STATUS,
POWER_SUPPLY_PROP_ONLINE,
};
@@ -82,6 +100,7 @@ static enum power_supply_property rn5t618_battery_props[] = {
POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
POWER_SUPPLY_PROP_TIME_TO_FULL_NOW,
POWER_SUPPLY_PROP_TECHNOLOGY,
+ POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT,
POWER_SUPPLY_PROP_CHARGE_FULL,
POWER_SUPPLY_PROP_CHARGE_NOW,
};
@@ -271,6 +290,36 @@ static int rn5t618_battery_ttf(struct rn5t618_power_info *info,
return 0;
}

+static int rn5t618_battery_set_current_limit(struct rn5t618_power_info *info,
+ const union power_supply_propval *val)
+{
+ if (val->intval < CHG_MIN_CUR)
+ return -EINVAL;
+
+ if (val->intval >= CHG_MAX_CUR)
+ return -EINVAL;
+
+ return regmap_update_bits(info->rn5t618->regmap,
+ RN5T618_CHGISET,
+ 0x1F, TO_CUR_REG(val->intval));
+}
+
+static int rn5t618_battery_get_current_limit(struct rn5t618_power_info *info,
+ union power_supply_propval *val)
+{
+ unsigned int regval;
+ int ret;
+
+ ret = regmap_read(info->rn5t618->regmap, RN5T618_CHGISET,
+ &regval);
+ if (ret < 0)
+ return ret;
+
+ val->intval = FROM_CUR_REG(regval);
+
+ return 0;
+}
+
static int rn5t618_battery_charge_full(struct rn5t618_power_info *info,
union power_supply_propval *val)
{
@@ -336,6 +385,9 @@ static int rn5t618_battery_get_property(struct power_supply *psy,
case POWER_SUPPLY_PROP_TECHNOLOGY:
val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
break;
+ case POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT:
+ ret = rn5t618_battery_get_current_limit(info, val);
+ break;
case POWER_SUPPLY_PROP_CHARGE_FULL:
ret = rn5t618_battery_charge_full(info, val);
break;
@@ -349,12 +401,38 @@ static int rn5t618_battery_get_property(struct power_supply *psy,
return ret;
}

+static int rn5t618_battery_set_property(struct power_supply *psy,
+ enum power_supply_property psp,
+ const union power_supply_propval *val)
+{
+ struct rn5t618_power_info *info = power_supply_get_drvdata(psy);
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT:
+ return rn5t618_battery_set_current_limit(info, val);
+ default:
+ return -EINVAL;
+ }
+}
+
+static int rn5t618_battery_property_is_writeable(struct power_supply *psy,
+ enum power_supply_property psp)
+{
+ switch (psp) {
+ case POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT:
+ return true;
+ default:
+ return false;
+ }
+}
+
static int rn5t618_adp_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
{
struct rn5t618_power_info *info = power_supply_get_drvdata(psy);
unsigned int chgstate;
+ unsigned int regval;
bool online;
int ret;

@@ -377,6 +455,14 @@ static int rn5t618_adp_get_property(struct power_supply *psy,
if (val->intval != POWER_SUPPLY_STATUS_CHARGING)
val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;

+ break;
+ case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+ ret = regmap_read(info->rn5t618->regmap,
+ RN5T618_REGISET1, &regval);
+ if (ret < 0)
+ return ret;
+
+ val->intval = FROM_CUR_REG(regval);
break;
default:
return -EINVAL;
@@ -385,6 +471,45 @@ static int rn5t618_adp_get_property(struct power_supply *psy,
return 0;
}

+static int rn5t618_adp_set_property(struct power_supply *psy,
+ enum power_supply_property psp,
+ const union power_supply_propval *val)
+{
+ struct rn5t618_power_info *info = power_supply_get_drvdata(psy);
+ int ret;
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+ if (val->intval > ADP_MAX_CUR)
+ return -EINVAL;
+
+ if (val->intval < CHG_MIN_CUR)
+ return -EINVAL;
+
+ ret = regmap_write(info->rn5t618->regmap, RN5T618_REGISET1,
+ TO_CUR_REG(val->intval));
+ if (ret < 0)
+ return ret;
+
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int rn5t618_adp_property_is_writeable(struct power_supply *psy,
+ enum power_supply_property psp)
+{
+ switch (psp) {
+ case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+ return true;
+ default:
+ return false;
+ }
+}
+
static int rc5t619_usb_get_type(struct rn5t618_power_info *info,
union power_supply_propval *val)
{
@@ -418,6 +543,7 @@ static int rn5t618_usb_get_property(struct power_supply *psy,
{
struct rn5t618_power_info *info = power_supply_get_drvdata(psy);
unsigned int chgstate;
+ unsigned int regval;
bool online;
int ret;

@@ -446,6 +572,23 @@ static int rn5t618_usb_get_property(struct power_supply *psy,
return -ENODATA;

return rc5t619_usb_get_type(info, val);
+ case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+ ret = regmap_read(info->rn5t618->regmap, RN5T618_CHGCTL1,
+ &regval);
+ if (ret < 0)
+ return ret;
+
+ val->intval = 0;
+ if (regval & 2) {
+ ret = regmap_read(info->rn5t618->regmap,
+ RN5T618_REGISET2,
+ &regval);
+ if (ret < 0)
+ return ret;
+
+ val->intval = FROM_CUR_REG(regval);
+ }
+ break;
default:
return -EINVAL;
}
@@ -453,12 +596,53 @@ static int rn5t618_usb_get_property(struct power_supply *psy,
return 0;
}

+static int rn5t618_usb_set_property(struct power_supply *psy,
+ enum power_supply_property psp,
+ const union power_supply_propval *val)
+{
+ struct rn5t618_power_info *info = power_supply_get_drvdata(psy);
+ int ret;
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+ if (val->intval > USB_MAX_CUR)
+ return -EINVAL;
+
+ if (val->intval < CHG_MIN_CUR)
+ return -EINVAL;
+
+ ret = regmap_write(info->rn5t618->regmap, RN5T618_REGISET2,
+ 0xE0 | TO_CUR_REG(val->intval));
+ if (ret < 0)
+ return ret;
+
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int rn5t618_usb_property_is_writeable(struct power_supply *psy,
+ enum power_supply_property psp)
+{
+ switch (psp) {
+ case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+ return true;
+ default:
+ return false;
+ }
+}
+
static const struct power_supply_desc rn5t618_battery_desc = {
.name = "rn5t618-battery",
.type = POWER_SUPPLY_TYPE_BATTERY,
.properties = rn5t618_battery_props,
.num_properties = ARRAY_SIZE(rn5t618_battery_props),
.get_property = rn5t618_battery_get_property,
+ .set_property = rn5t618_battery_set_property,
+ .property_is_writeable = rn5t618_battery_property_is_writeable,
};

static const struct power_supply_desc rn5t618_adp_desc = {
@@ -467,6 +651,8 @@ static const struct power_supply_desc rn5t618_adp_desc = {
.properties = rn5t618_adp_props,
.num_properties = ARRAY_SIZE(rn5t618_adp_props),
.get_property = rn5t618_adp_get_property,
+ .set_property = rn5t618_adp_set_property,
+ .property_is_writeable = rn5t618_adp_property_is_writeable,
};

static const struct power_supply_desc rn5t618_usb_desc = {
@@ -477,6 +663,8 @@ static const struct power_supply_desc rn5t618_usb_desc = {
.properties = rn5t618_usb_props,
.num_properties = ARRAY_SIZE(rn5t618_usb_props),
.get_property = rn5t618_usb_get_property,
+ .set_property = rn5t618_usb_set_property,
+ .property_is_writeable = rn5t618_usb_property_is_writeable,
};

static irqreturn_t rn5t618_charger_irq(int irq, void *data)
--
2.29.2