regulator/mfd: max14577: Export symbols for calculating charger current

This patch prepares for changing the max14577 charger driver to allow
configuring battery-dependent settings from DTS.

The patch moves from regulator driver to MFD core driver and exports:
 - function for calculating register value for charger's current;
 - table of limits for chargers (MAX14577, MAX77836).

Previously they were used only by the max14577 regulator driver. In next
patch the charger driver will use them as well. Exporting them will
reduce unnecessary code duplication.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Mark Brown <broonie@linaro.org>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

1 files changed, 4 insertions, 76 deletions

diff --git a/drivers/regulator/max14577.c b/drivers/regulator/max14577.c
index 5d9c605cf53..0ff5a20ac95 100644
--- a/drivers/regulator/max14577.c
+++ b/drivers/regulator/max14577.c
@@ -22,42 +22,6 @@
 #include <linux/mfd/max14577-private.h>
 #include <linux/regulator/of_regulator.h>
 
-/*
- * Valid limits of current for max14577 and max77836 chargers.
- * They must correspond to MBCICHWRCL and MBCICHWRCH fields in CHGCTRL4
- * register for given chipset.
- */
-struct maxim_charger_current {
-	/* Minimal current, set in CHGCTRL4/MBCICHWRCL, uA */
-	unsigned int min;
-	/*
-	 * Minimal current when high setting is active,
-	 * set in CHGCTRL4/MBCICHWRCH, uA
-	 */
-	unsigned int high_start;
-	/* Value of one step in high setting, uA */
-	unsigned int high_step;
-	/* Maximum current of high setting, uA */
-	unsigned int max;
-};
-
-/* Table of valid charger currents for different Maxim chipsets */
-static const struct maxim_charger_current maxim_charger_currents[] = {
-	[MAXIM_DEVICE_TYPE_UNKNOWN] = { 0, 0, 0, 0 },
-	[MAXIM_DEVICE_TYPE_MAX14577] = {
-		.min		= MAX14577_REGULATOR_CURRENT_LIMIT_MIN,
-		.high_start	= MAX14577_REGULATOR_CURRENT_LIMIT_HIGH_START,
-		.high_step	= MAX14577_REGULATOR_CURRENT_LIMIT_HIGH_STEP,
-		.max		= MAX14577_REGULATOR_CURRENT_LIMIT_MAX,
-	},
-	[MAXIM_DEVICE_TYPE_MAX77836] = {
-		.min		= MAX77836_REGULATOR_CURRENT_LIMIT_MIN,
-		.high_start	= MAX77836_REGULATOR_CURRENT_LIMIT_HIGH_START,
-		.high_step	= MAX77836_REGULATOR_CURRENT_LIMIT_HIGH_STEP,
-		.max		= MAX77836_REGULATOR_CURRENT_LIMIT_MAX,
-	},
-};
-
 static int max14577_reg_is_enabled(struct regulator_dev *rdev)
 {
 	int rid = rdev_get_id(rdev);
@@ -103,8 +67,8 @@ static int max14577_reg_get_current_limit(struct regulator_dev *rdev)
 static int max14577_reg_set_current_limit(struct regulator_dev *rdev,
 		int min_uA, int max_uA)
 {
-	int i, current_bits = 0xf;
 	u8 reg_data;
+	int ret;
 	struct max14577 *max14577 = rdev_get_drvdata(rdev);
 	const struct maxim_charger_current *limits =
 		&maxim_charger_currents[max14577->dev_type];
@@ -112,35 +76,9 @@ static int max14577_reg_set_current_limit(struct regulator_dev *rdev,
 	if (rdev_get_id(rdev) != MAX14577_CHARGER)
 		return -EINVAL;
 
-	if (min_uA > limits->max || max_uA < limits->min)
-		return -EINVAL;
-
-	if (max_uA < limits->high_start) {
-		/*
-		 * Less than high_start,
-		 * so set the minimal current (turn only Low Bit off)
-		 */
-		u8 reg_data = 0x0 << CHGCTRL4_MBCICHWRCL_SHIFT;
-		return max14577_update_reg(rdev->regmap,
-				MAX14577_CHG_REG_CHG_CTRL4,
-				CHGCTRL4_MBCICHWRCL_MASK, reg_data);
-	}
-
-	/*
-	 * max_uA is in range: <high_start, inifinite>, so search for
-	 * valid current starting from maximum current.
-	 */
-	for (i = limits->max; i >= limits->high_start; i -= limits->high_step) {
-		if (i <= max_uA)
-			break;
-		current_bits--;
-	}
-	BUG_ON(current_bits < 0); /* Cannot happen */
-
-	/* Turn Low Bit on (use range high_start-max)... */
-	reg_data = 0x1 << CHGCTRL4_MBCICHWRCL_SHIFT;
-	/* and set proper High Bits */
-	reg_data |= current_bits << CHGCTRL4_MBCICHWRCH_SHIFT;
+	ret = maxim_charger_calc_reg_current(limits, min_uA, max_uA, &reg_data);
+	if (ret)
+		return ret;
 
 	return max14577_update_reg(rdev->regmap, MAX14577_CHG_REG_CHG_CTRL4,
 			CHGCTRL4_MBCICHWRCL_MASK | CHGCTRL4_MBCICHWRCH_MASK,
@@ -442,16 +380,6 @@ static struct platform_driver max14577_regulator_driver = {
 
 static int __init max14577_regulator_init(void)
 {
-	/* Check for valid values for charger */
-	BUILD_BUG_ON(MAX14577_REGULATOR_CURRENT_LIMIT_HIGH_START +
-			MAX14577_REGULATOR_CURRENT_LIMIT_HIGH_STEP * 0xf !=
-			MAX14577_REGULATOR_CURRENT_LIMIT_MAX);
-	BUILD_BUG_ON(MAX77836_REGULATOR_CURRENT_LIMIT_HIGH_START +
-			MAX77836_REGULATOR_CURRENT_LIMIT_HIGH_STEP * 0xf !=
-			MAX77836_REGULATOR_CURRENT_LIMIT_MAX);
-	/* Valid charger current values must be provided for each chipset */
-	BUILD_BUG_ON(ARRAY_SIZE(maxim_charger_currents) != MAXIM_DEVICE_TYPE_NUM);
-
 	BUILD_BUG_ON(ARRAY_SIZE(max14577_supported_regulators) != MAX14577_REGULATOR_NUM);
 	BUILD_BUG_ON(ARRAY_SIZE(max77836_supported_regulators) != MAX77836_REGULATOR_NUM);