regulator: rpm-smd-regulator: add support for load based mode control

Add support to request PWM or AUTO mode for BoB and SMPS type
regulators based upon the aggregated consumer load current.  This can
be used in cases where a consumer needs to force PWM mode operation.

CRs-Fixed: 2054771
Change-Id: Iaf4353fb60468c91f958a968d844b3c1c012e54c
Signed-off-by: David Collins <collinsd@codeaurora.org>
Signed-off-by: Tirupathi Reddy <tirupath@codeaurora.org>

2 files changed, 62 insertions, 3 deletions

diff --git a/Documentation/devicetree/bindings/regulator/rpm-smd-regulator.txt b/Documentation/devicetree/bindings/regulator/rpm-smd-regulator.txt
index 1eb27f4c1c56..559ee5b6fc08 100644
--- a/Documentation/devicetree/bindings/regulator/rpm-smd-regulator.txt
+++ b/Documentation/devicetree/bindings/regulator/rpm-smd-regulator.txt
@@ -104,6 +104,12 @@ Optional properties:
 				parameter. Only one pin may be specified per
 				regulator. This property only applies to BoB
 				type regulators.
+- qcom,pwm-threshold-current:  Minimum current in mA which requires regulator
+				to be in PWM mode.  Load currents below this
+				threshold use AUTO mode.  This property only
+				applies to BoB and SMPS type regulators.
+				If this property is not specified, then the
+				hardware default mode will be used all the time.
 - qcom,always-send-voltage:    Flag which indicates that updates to the
 				voltage, voltage corner or voltage level set
 				point should always be sent immediately to the
diff --git a/drivers/regulator/rpm-smd-regulator.c b/drivers/regulator/rpm-smd-regulator.c
index d26fd3bea788..a5dc1b983bcb 100644
--- a/drivers/regulator/rpm-smd-regulator.c
+++ b/drivers/regulator/rpm-smd-regulator.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2012-2016, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2012-2017, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -207,6 +207,7 @@ struct rpm_regulator {
 	bool			use_pin_ctrl_for_enable;
 	struct rpm_vreg_request	req;
 	int			system_load;
+	int			hpm_threshold_current;
 	int			min_uV;
 	int			max_uV;
 	u32			pin_ctrl_mask[RPM_VREG_PIN_CTRL_STATE_COUNT];
@@ -1030,6 +1031,34 @@ static unsigned int rpm_vreg_get_bob_mode(struct regulator_dev *rdev)
 	return mode;
 }
 
+static unsigned int rpm_vreg_get_optimum_mode(struct regulator_dev *rdev,
+				int input_uV, int output_uV, int load_uA)
+{
+	struct rpm_regulator *reg = rdev_get_drvdata(rdev);
+	u32 mode = REGULATOR_MODE_NORMAL;
+
+	if (reg->hpm_threshold_current > 0) {
+		if (load_uA >= reg->hpm_threshold_current) {
+			/* PWM mode */
+			mode = (reg->rpm_vreg->regulator_type
+				== RPM_REGULATOR_TYPE_BOB)
+					? REGULATOR_MODE_FAST
+					: REGULATOR_MODE_NORMAL;
+		} else {
+			/* AUTO mode */
+			mode = (reg->rpm_vreg->regulator_type
+				== RPM_REGULATOR_TYPE_BOB)
+					? REGULATOR_MODE_NORMAL
+					: REGULATOR_MODE_IDLE;
+		}
+	} else {
+		/* Default to the current mode if no threshold is present. */
+		mode = reg->rdesc.ops->get_mode(rdev);
+	}
+
+	return mode;
+}
+
 static int rpm_vreg_enable_time(struct regulator_dev *rdev)
 {
 	struct rpm_regulator *reg = rdev_get_drvdata(rdev);
@@ -1402,6 +1431,18 @@ static struct regulator_ops smps_ops = {
 	.enable_time		= rpm_vreg_enable_time,
 };
 
+static struct regulator_ops smps_optimum_mode_ops = {
+	.enable			= rpm_vreg_enable,
+	.disable		= rpm_vreg_disable,
+	.is_enabled		= rpm_vreg_is_enabled,
+	.set_voltage		= rpm_vreg_set_voltage,
+	.get_voltage		= rpm_vreg_get_voltage,
+	.set_mode		= rpm_vreg_set_mode,
+	.get_mode		= rpm_vreg_get_mode,
+	.get_optimum_mode	= rpm_vreg_get_optimum_mode,
+	.enable_time		= rpm_vreg_enable_time,
+};
+
 static struct regulator_ops switch_ops = {
 	.enable			= rpm_vreg_enable,
 	.disable		= rpm_vreg_disable,
@@ -1426,6 +1467,7 @@ static struct regulator_ops bob_ops = {
 	.get_voltage		= rpm_vreg_get_voltage,
 	.set_mode		= rpm_vreg_set_bob_mode,
 	.get_mode		= rpm_vreg_get_bob_mode,
+	.get_optimum_mode	= rpm_vreg_get_optimum_mode,
 	.enable_time		= rpm_vreg_enable_time,
 };
 
@@ -1676,6 +1718,12 @@ static int rpm_vreg_device_probe(struct platform_device *pdev)
 	if (of_get_property(node, "parent-supply", NULL))
 		init_data->supply_regulator = "parent";
 
+	of_property_read_u32(node, "qcom,pwm-threshold-current",
+					&reg->hpm_threshold_current);
+	if (reg->hpm_threshold_current > 0
+	    && regulator_type == RPM_REGULATOR_TYPE_SMPS)
+		reg->rdesc.ops = &smps_optimum_mode_ops;
+
 	/*
 	 * Fill in ops and mode masks based on callbacks specified for
 	 * this type of regulator.
@@ -1689,8 +1737,13 @@ static int rpm_vreg_device_probe(struct platform_device *pdev)
 	if (reg->rdesc.ops->get_mode) {
 		init_data->constraints.valid_ops_mask
 			|= REGULATOR_CHANGE_MODE | REGULATOR_CHANGE_DRMS;
-		init_data->constraints.valid_modes_mask
-			|= REGULATOR_MODE_NORMAL | REGULATOR_MODE_IDLE;
+
+		if (regulator_type == RPM_REGULATOR_TYPE_BOB)
+			init_data->constraints.valid_modes_mask
+				= REGULATOR_MODE_FAST | REGULATOR_MODE_NORMAL;
+		else
+			init_data->constraints.valid_modes_mask
+				|= REGULATOR_MODE_NORMAL | REGULATOR_MODE_IDLE;
 	}
 
 	reg->rdesc.name		= init_data->constraints.name;