[PATCH v2 1/2] regulator: qcom_spmi: Add slewing delays for all SMPS types

[Stephen Boyd <stephen.boyd@linaro.org>]

Only the FT SMPS type regulators have slewing supported in the
driver, but all types of SMPS regulators need the same support.
The only difference is that some SMPS regulators don't have a
step size and the step delay is typically 20, not 8. Luckily, the
step size reads as 0 for the non-FT types, so we can always read
that, but we need to detect which type of regulator we're using
to figure out what step delay to use. Make these minor
adjustments to the slew rate calculations and add support for the
delay function to the appropriate regulator ops.

Reported-by: Georgi Djakov <georgi.djakov@linaro.org>
Cc: David Collins <collinsd@codeaurora.org>
Signed-off-by: Stephen Boyd <stephen.boyd@linaro.org>
---
 drivers/regulator/qcom_spmi-regulator.c | 29 ++++++++++++++++++++++++-----
 1 file changed, 24 insertions(+), 5 deletions(-)

diff --git a/drivers/regulator/qcom_spmi-regulator.c b/drivers/regulator/qcom_spmi-regulator.c
index 88a5dc88badc..d9cb3a2c99c0 100644
--- a/drivers/regulator/qcom_spmi-regulator.c
+++ b/drivers/regulator/qcom_spmi-regulator.c
@@ -246,6 +246,7 @@ enum spmi_common_control_register_index {
 
 /* Minimum voltage stepper delay for each step. */
 #define SPMI_FTSMPS_STEP_DELAY		8
+#define SPMI_DEFAULT_STEP_DELAY		20
 
 /*
  * The ratio SPMI_FTSMPS_STEP_MARGIN_NUM/SPMI_FTSMPS_STEP_MARGIN_DEN is used to
@@ -1008,6 +1009,7 @@ static struct regulator_ops spmi_smps_ops = {
 	.disable		= spmi_regulator_common_disable,
 	.is_enabled		= spmi_regulator_common_is_enabled,
 	.set_voltage		= spmi_regulator_common_set_voltage,
+	.set_voltage_time_sel	= spmi_regulator_set_voltage_time_sel,
 	.get_voltage		= spmi_regulator_common_get_voltage,
 	.list_voltage		= spmi_regulator_common_list_voltage,
 	.set_mode		= spmi_regulator_common_set_mode,
@@ -1081,6 +1083,7 @@ static struct regulator_ops spmi_ult_lo_smps_ops = {
 	.disable		= spmi_regulator_common_disable,
 	.is_enabled		= spmi_regulator_common_is_enabled,
 	.set_voltage		= spmi_regulator_ult_lo_smps_set_voltage,
+	.set_voltage_time_sel	= spmi_regulator_set_voltage_time_sel,
 	.get_voltage		= spmi_regulator_ult_lo_smps_get_voltage,
 	.list_voltage		= spmi_regulator_common_list_voltage,
 	.set_mode		= spmi_regulator_common_set_mode,
@@ -1094,6 +1097,7 @@ static struct regulator_ops spmi_ult_ho_smps_ops = {
 	.disable		= spmi_regulator_common_disable,
 	.is_enabled		= spmi_regulator_common_is_enabled,
 	.set_voltage		= spmi_regulator_single_range_set_voltage,
+	.set_voltage_time_sel	= spmi_regulator_set_voltage_time_sel,
 	.get_voltage		= spmi_regulator_single_range_get_voltage,
 	.list_voltage		= spmi_regulator_common_list_voltage,
 	.set_mode		= spmi_regulator_common_set_mode,
@@ -1245,11 +1249,11 @@ found:
 	return 0;
 }
 
-static int spmi_regulator_ftsmps_init_slew_rate(struct spmi_regulator *vreg)
+static int spmi_regulator_init_slew_rate(struct spmi_regulator *vreg)
 {
 	int ret;
 	u8 reg = 0;
-	int step, delay, slew_rate;
+	int step, delay, slew_rate, step_delay;
 	const struct spmi_voltage_range *range;
 
 	ret = spmi_vreg_read(vreg, SPMI_COMMON_REG_STEP_CTRL, &reg, 1);
@@ -1262,6 +1266,15 @@ static int spmi_regulator_ftsmps_init_slew_rate(struct spmi_regulator *vreg)
 	if (!range)
 		return -EINVAL;
 
+	switch (vreg->logical_type) {
+	case SPMI_REGULATOR_LOGICAL_TYPE_FTSMPS:
+		step_delay = SPMI_FTSMPS_STEP_DELAY;
+		break;
+	default:
+		step_delay = SPMI_DEFAULT_STEP_DELAY;
+		break;
+	}
+
 	step = reg & SPMI_FTSMPS_STEP_CTRL_STEP_MASK;
 	step >>= SPMI_FTSMPS_STEP_CTRL_STEP_SHIFT;
 
@@ -1270,7 +1283,7 @@ static int spmi_regulator_ftsmps_init_slew_rate(struct spmi_regulator *vreg)
 
 	/* slew_rate has units of uV/us */
 	slew_rate = SPMI_FTSMPS_CLOCK_RATE * range->step_uV * (1 << step);
-	slew_rate /= 1000 * (SPMI_FTSMPS_STEP_DELAY << delay);
+	slew_rate /= 1000 * (step_delay << delay);
 	slew_rate *= SPMI_FTSMPS_STEP_MARGIN_NUM;
 	slew_rate /= SPMI_FTSMPS_STEP_MARGIN_DEN;
 
@@ -1411,10 +1424,16 @@ static int spmi_regulator_of_parse(struct device_node *node,
 		return ret;
 	}
 
-	if (vreg->logical_type == SPMI_REGULATOR_LOGICAL_TYPE_FTSMPS) {
-		ret = spmi_regulator_ftsmps_init_slew_rate(vreg);
+	switch (vreg->logical_type) {
+	case SPMI_REGULATOR_LOGICAL_TYPE_FTSMPS:
+	case SPMI_REGULATOR_LOGICAL_TYPE_ULT_LO_SMPS:
+	case SPMI_REGULATOR_LOGICAL_TYPE_ULT_HO_SMPS:
+	case SPMI_REGULATOR_LOGICAL_TYPE_SMPS:
+		ret = spmi_regulator_init_slew_rate(vreg);
 		if (ret)
 			return ret;
+	default:
+		break;
 	}
 
 	if (vreg->logical_type != SPMI_REGULATOR_LOGICAL_TYPE_VS)
-- 
2.8.0.rc4