[PATCH v2 5/9] power: supply: max77693: Set charge current limits during init

[Artur Weber]

There are two charger current limit registers:

- Fast charge current limit (which controls current going from the
  charger to the battery);
- CHGIN input current limit (which controls current going into the
  charger through the cable).

Add a function for setting both of the values, and set them to a
safe default value of 500mA at initialization.

The default value for the fast charge current limit can be modified
by setting the constant-charge-current-max-ua DT property of the
battery node specified in the monitored-battery charger DT property.

Signed-off-by: Artur Weber <aweber.kernel at gmail.com>
---
Changes in v2:
- Squashed mfd include register additions into this commit
- Changed from custom fast charge current property to monitored-battery
  (devm_power_supply_register call has been moved up as it is needed by
  the DT init function now)
- Changed to adapt to both current limit values being managed by the
  CHARGER regulator
---
 drivers/power/supply/max77693_charger.c | 43 ++++++++++++++++++++++++---------
 include/linux/mfd/max77693-private.h    |  6 +++++
 2 files changed, 38 insertions(+), 11 deletions(-)

diff --git a/drivers/power/supply/max77693_charger.c b/drivers/power/supply/max77693_charger.c
index 0d53f61d58ba..0ddaa03669a2 100644
--- a/drivers/power/supply/max77693_charger.c
+++ b/drivers/power/supply/max77693_charger.c
@@ -28,6 +28,7 @@ struct max77693_charger {
 	u32 min_system_volt;
 	u32 thermal_regulation_temp;
 	u32 batttery_overcurrent;
+	u32 fast_charge_current;
 	u32 charge_input_threshold_volt;
 };
 
@@ -570,6 +571,14 @@ static int max77693_set_batttery_overcurrent(struct max77693_charger *chg,
 			CHG_CNFG_12_B2SOVRC_MASK, data);
 }
 
+static int max77693_set_current_limit(struct max77693_charger *chg,
+		unsigned int uamp)
+{
+	dev_dbg(chg->dev, "Current limit: %u\n", uamp);
+
+	return regulator_set_current_limit(chg->regu, (int)uamp, (int)uamp);
+}
+
 static int max77693_set_charge_input_threshold_volt(struct max77693_charger *chg,
 		unsigned int uvolt)
 {
@@ -647,6 +656,10 @@ static int max77693_reg_init(struct max77693_charger *chg)
 	if (ret)
 		return ret;
 
+	ret = max77693_set_current_limit(chg, DEFAULT_FAST_CHARGE_CURRENT);
+	if (ret)
+		return ret;
+
 	return max77693_set_charge_input_threshold_volt(chg,
 			chg->charge_input_threshold_volt);
 }
@@ -654,6 +667,7 @@ static int max77693_reg_init(struct max77693_charger *chg)
 #ifdef CONFIG_OF
 static int max77693_dt_init(struct device *dev, struct max77693_charger *chg)
 {
+	struct power_supply_battery_info *battery_info;
 	struct device_node *np = dev->of_node;
 
 	if (!np) {
@@ -682,11 +696,20 @@ static int max77693_dt_init(struct device *dev, struct max77693_charger *chg)
 		chg->charge_input_threshold_volt =
 			DEFAULT_CHARGER_INPUT_THRESHOLD_VOLT;
 
+	if (power_supply_get_battery_info(chg->charger, &battery_info) ||
+				!battery_info->constant_charge_current_max_ua)
+		chg->fast_charge_current = DEFAULT_FAST_CHARGE_CURRENT;
+	else
+		chg->fast_charge_current = \
+				battery_info->constant_charge_current_max_ua;
+
 	return 0;
 }
 #else /* CONFIG_OF */
 static int max77693_dt_init(struct device *dev, struct max77693_charger *chg)
 {
+	chg->fast_charge_current = DEFAULT_FAST_CHARGE_CURRENT;
+
 	return 0;
 }
 #endif /* CONFIG_OF */
@@ -712,6 +735,15 @@ static int max77693_charger_probe(struct platform_device *pdev)
 		return dev_err_probe(&pdev->dev, PTR_ERR(chg->regu),
 				     "failed to get charger regulator\n");
 
+	psy_cfg.drv_data = chg;
+
+	chg->charger = devm_power_supply_register(&pdev->dev,
+						  &max77693_charger_desc,
+						  &psy_cfg);
+	if (IS_ERR(chg->charger))
+		return dev_err_probe(&pdev->dev, PTR_ERR(chg->charger),
+				     "failed: power supply register\n");
+
 	ret = max77693_dt_init(&pdev->dev, chg);
 	if (ret)
 		return ret;
@@ -720,8 +752,6 @@ static int max77693_charger_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	psy_cfg.drv_data = chg;
-
 	ret = device_create_file(&pdev->dev, &dev_attr_fast_charge_timer);
 	if (ret) {
 		dev_err(&pdev->dev, "failed: create fast charge timer sysfs entry\n");
@@ -741,15 +771,6 @@ static int max77693_charger_probe(struct platform_device *pdev)
 		goto err;
 	}
 
-	chg->charger = devm_power_supply_register(&pdev->dev,
-						  &max77693_charger_desc,
-						  &psy_cfg);
-	if (IS_ERR(chg->charger)) {
-		dev_err(&pdev->dev, "failed: power supply register\n");
-		ret = PTR_ERR(chg->charger);
-		goto err;
-	}
-
 	return 0;
 
 err:
diff --git a/include/linux/mfd/max77693-private.h b/include/linux/mfd/max77693-private.h
index 54444ff2a5de..4570646e2f33 100644
--- a/include/linux/mfd/max77693-private.h
+++ b/include/linux/mfd/max77693-private.h
@@ -145,6 +145,8 @@ enum max77693_pmic_reg {
 #define DEFAULT_THERMAL_REGULATION_TEMP		100
 /* microamps */
 #define DEFAULT_BATTERY_OVERCURRENT		3500000
+/* microamps */
+#define DEFAULT_FAST_CHARGE_CURRENT		500000
 /* microvolts */
 #define DEFAULT_CHARGER_INPUT_THRESHOLD_VOLT	4300000
 
@@ -217,6 +219,10 @@ enum max77693_charger_battery_state {
 #define CHG_CNFG_01_CHGRSTRT_MASK	(0x3 << CHG_CNFG_01_CHGRSTRT_SHIFT)
 #define CHG_CNFG_01_PQEN_MAKS		BIT(CHG_CNFG_01_PQEN_SHIFT)
 
+/* MAX77693_CHG_REG_CHG_CNFG_02 register */
+#define CHG_CNFG_02_CC_SHIFT		0
+#define CHG_CNFG_02_CC_MASK		0x3F
+
 /* MAX77693_CHG_REG_CHG_CNFG_03 register */
 #define CHG_CNFG_03_TOITH_SHIFT		0
 #define CHG_CNFG_03_TOTIME_SHIFT	3

-- 
2.45.2