[PATCH 2/3] regulator: max77693: Also manipulate the fast charge current

[Wolfgang Wiedmeyer <wolfgit@wiedmeyer.de>]

For MAX77693, the fast charge current also needs to be manipulated for
proper charging. The fast charge current is only set in the case of
the MAX77693 type, as the MAX77843 properly manipulates the fast
charge current.
The fast charge current is set to the next possible value below the
maximum input current.

Signed-off-by: Wolfgang Wiedmeyer <wolfgit@wiedmeyer.de>
---
 drivers/regulator/max77693-regulator.c | 45 +++++++++++++++++++++++++++++++---
 1 file changed, 42 insertions(+), 3 deletions(-)

diff --git a/drivers/regulator/max77693-regulator.c b/drivers/regulator/max77693-regulator.c
index cfbb951..e2f7584 100644
--- a/drivers/regulator/max77693-regulator.c
+++ b/drivers/regulator/max77693-regulator.c
@@ -54,14 +54,19 @@ struct chg_reg_data {
 	unsigned int linear_mask;
 	unsigned int uA_step;
 	unsigned int min_sel;
+
+	bool set_fast;
+	unsigned int fast_reg;
+	unsigned int fast_mask;
 };
 
 /*
  * MAX77693 CHARGER regulator - Min : 20mA, Max : 2580mA, step : 20mA
  * 0x00, 0x01, 0x2, 0x03	= 60 mA
  * 0x04 ~ 0x7E			= (60 + (X - 3) * 20) mA
- * Actually for MAX77693 the driver manipulates the maximum input current,
- * not the fast charge current (output). This should be fixed.
+ * Actually for MAX77693 the driver manipulates the maximum input current
+ * and the fast charge current (output) because the fast charge current
+ * is not set.
  *
  * On MAX77843 the calculation formula is the same (except values).
  * Fortunately it properly manipulates the fast charge current.
@@ -100,6 +105,8 @@ static int max77693_chg_set_current_limit(struct regulator_dev *rdev,
 	const struct chg_reg_data *reg_data = rdev_get_drvdata(rdev);
 	unsigned int chg_min_uA = rdev->constraints->min_uA;
 	int sel = 0;
+	unsigned int data;
+	int ret;
 
 	while (chg_min_uA + reg_data->uA_step * sel < min_uA)
 		sel++;
@@ -110,7 +117,35 @@ static int max77693_chg_set_current_limit(struct regulator_dev *rdev,
 	/* the first four codes for charger current are all 60mA */
 	sel += reg_data->min_sel;
 
-	return regmap_write(rdev->regmap, reg_data->linear_reg, sel);
+	ret = regmap_write(rdev->regmap, reg_data->linear_reg, sel);
+	if (ret < 0)
+		return ret;
+
+	if (reg_data->set_fast) {
+		/* disable fast charge if minimum value */
+		if (sel == reg_data->min_sel)
+			data = 0;
+		else {
+			/*
+			 * set the fast charge current to the closest value
+			 * below the input current
+			 */
+			ret = regmap_read(rdev->regmap, reg_data->fast_reg,
+					  &data);
+			if (ret < 0)
+				return ret;
+
+			sel *= reg_data->uA_step / 1000; /* convert to mA */
+			data &= ~reg_data->fast_mask;
+			data |= sel * 10 / 333; /* 0.1A/3 steps */
+		}
+
+		ret = regmap_write(rdev->regmap, reg_data->fast_reg, data);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
 }
 /* end of CHARGER regulator ops */
 
@@ -197,6 +232,9 @@ static const struct chg_reg_data max77693_chg_reg_data = {
 	.linear_mask	= CHG_CNFG_09_CHGIN_ILIM_MASK,
 	.uA_step	= 20000,
 	.min_sel	= 3,
+	.set_fast	= true,
+	.fast_reg	= MAX77693_CHG_REG_CHG_CNFG_02,
+	.fast_mask	= CHG_CNFG_02_CC_MASK,
 };
 
 #define	max77843_regulator_desc_esafeout(num)	{			\
@@ -237,6 +275,7 @@ static const struct chg_reg_data max77843_chg_reg_data = {
 	.linear_mask	= MAX77843_CHG_FAST_CHG_CURRENT_MASK,
 	.uA_step	= MAX77843_CHG_FAST_CHG_CURRENT_STEP,
 	.min_sel	= 2,
+	.set_fast	= false,
 };
 
 static int max77693_pmic_probe(struct platform_device *pdev)
-- 
2.8.0.rc3