regulator: s2mps11: Convert ramp rate to uV/us and set default ramp rate

This patch makes driver to use uV/us as units of ramp_delay. It makes driver
in compliance with regulator framework and make ramp rate precise.

This patch also sets default ramp rate in regulator descriptor which can be
used in case if case ramp rate is not set in regulator constraints.

Signed-off-by: Yadwinder Singh Brar <yadi.brar@samsung.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

drivers/regulator/s2mps11.c

@@ -42,7 +42,7 @@ static int get_ramp_delay(int ramp_delay)
 {
 	unsigned char cnt = 0;
 
-	ramp_delay /= 6;
+	ramp_delay /= 6250;
 
 	while (true) {
 		ramp_delay = ramp_delay >> 1;
@@ -113,6 +113,7 @@ static struct regulator_ops s2mps11_buck_ops = {
 	.min_uV		= S2MPS11_BUCK_MIN1,			\
 	.uV_step	= S2MPS11_BUCK_STEP1,			\
 	.n_voltages	= S2MPS11_BUCK_N_VOLTAGES,		\
+	.ramp_delay	= S2MPS11_RAMP_DELAY,			\
 	.vsel_reg	= S2MPS11_REG_B1CTRL2 + (num - 1) * 2,	\
 	.vsel_mask	= S2MPS11_BUCK_VSEL_MASK,		\
 	.enable_reg	= S2MPS11_REG_B1CTRL1 + (num - 1) * 2,	\
@@ -128,6 +129,7 @@ static struct regulator_ops s2mps11_buck_ops = {
 	.min_uV		= S2MPS11_BUCK_MIN1,			\
 	.uV_step	= S2MPS11_BUCK_STEP1,			\
 	.n_voltages	= S2MPS11_BUCK_N_VOLTAGES,		\
+	.ramp_delay	= S2MPS11_RAMP_DELAY,			\
 	.vsel_reg	= S2MPS11_REG_B5CTRL2,			\
 	.vsel_mask	= S2MPS11_BUCK_VSEL_MASK,		\
 	.enable_reg	= S2MPS11_REG_B5CTRL1,			\
@@ -143,6 +145,7 @@ static struct regulator_ops s2mps11_buck_ops = {
 	.min_uV		= S2MPS11_BUCK_MIN1,			\
 	.uV_step	= S2MPS11_BUCK_STEP1,			\
 	.n_voltages	= S2MPS11_BUCK_N_VOLTAGES,		\
+	.ramp_delay	= S2MPS11_RAMP_DELAY,			\
 	.vsel_reg	= S2MPS11_REG_B6CTRL2 + (num - 6) * 2,	\
 	.vsel_mask	= S2MPS11_BUCK_VSEL_MASK,		\
 	.enable_reg	= S2MPS11_REG_B6CTRL1 + (num - 6) * 2,	\
@@ -158,6 +161,7 @@ static struct regulator_ops s2mps11_buck_ops = {
 	.min_uV		= S2MPS11_BUCK_MIN3,			\
 	.uV_step	= S2MPS11_BUCK_STEP3,			\
 	.n_voltages	= S2MPS11_BUCK_N_VOLTAGES,		\
+	.ramp_delay	= S2MPS11_RAMP_DELAY,			\
 	.vsel_reg	= S2MPS11_REG_B9CTRL2,			\
 	.vsel_mask	= S2MPS11_BUCK_VSEL_MASK,		\
 	.enable_reg	= S2MPS11_REG_B9CTRL1,			\
@@ -173,6 +177,7 @@ static struct regulator_ops s2mps11_buck_ops = {
 	.min_uV		= S2MPS11_BUCK_MIN2,			\
 	.uV_step	= S2MPS11_BUCK_STEP2,			\
 	.n_voltages	= S2MPS11_BUCK_N_VOLTAGES,		\
+	.ramp_delay	= S2MPS11_RAMP_DELAY,			\
 	.vsel_reg	= S2MPS11_REG_B10CTRL2,			\
 	.vsel_mask	= S2MPS11_BUCK_VSEL_MASK,		\
 	.enable_reg	= S2MPS11_REG_B10CTRL1,			\

include/linux/mfd/samsung/s2mps11.h

@@ -189,6 +189,7 @@ enum s2mps11_regulators {
 #define S2MPS11_ENABLE_SHIFT	0x06
 #define S2MPS11_LDO_N_VOLTAGES	(S2MPS11_LDO_VSEL_MASK + 1)
 #define S2MPS11_BUCK_N_VOLTAGES (S2MPS11_BUCK_VSEL_MASK + 1)
+#define S2MPS11_RAMP_DELAY	25000		/* uV/us */
 
 #define S2MPS11_PMIC_EN_SHIFT	6
 #define S2MPS11_REGULATOR_MAX (S2MPS11_REG_MAX - 3)