regulator: cpr3: support LDO handling for different LDO types

An LDO300 regulator is used by the GPU rail on msmfalcon. This LDO
is CPR managed and uses a different configuration/control scheme
compared to Kryo LDO. Add support for this LDO in the CPR3 framework.

CRs-Fixed: 1068294
Change-Id: Ia45152fe211f2ece1028c5cb978beebda86faba3
Signed-off-by: Tirupathi Reddy <tirupath@codeaurora.org>

drivers/regulator/cpr3-hmss-regulator.c

@@ -32,7 +32,7 @@
 #include <linux/regulator/driver.h>
 #include <linux/regulator/machine.h>
 #include <linux/regulator/of_regulator.h>
-#include <linux/regulator/kryo-regulator.h>
+#include <linux/regulator/msm-ldo-regulator.h>
 
 #include "cpr3-regulator.h"
 

drivers/regulator/cpr3-regulator.c

@@ -35,7 +35,7 @@
 #include <linux/regulator/driver.h>
 #include <linux/regulator/machine.h>
 #include <linux/regulator/of_regulator.h>
-#include <linux/regulator/kryo-regulator.h>
+#include <linux/regulator/msm-ldo-regulator.h>
 
 #include <soc/qcom/spm.h>
 
@@ -1761,7 +1761,12 @@ static int cpr3_regulator_config_ldo_retention(struct cpr3_regulator *vreg,
 {
 	struct regulator *ldo_ret_reg = vreg->ldo_ret_regulator;
 	int retention_volt, rc;
-	enum kryo_supply_mode mode;
+	enum msm_ldo_supply_mode mode;
+
+	if (!ldo_ret_reg) {
+		/* LDO retention regulator is not defined */
+		return 0;
+	}
 
 	retention_volt = regulator_get_voltage(ldo_ret_reg);
 	if (retention_volt < 0) {
@@ -1783,8 +1788,8 @@ static int cpr3_regulator_config_ldo_retention(struct cpr3_regulator *vreg,
 }
 
 /**
- * cpr3_regulator_config_ldo_mem_acc() - configure the mem-acc regulator
+ * cpr3_regulator_config_kryo_ldo_mem_acc() - configure the mem-acc regulator
- *		corner based upon a future LDO regulator voltage setpoint
+ *		corner based upon a future Kryo LDO regulator voltage setpoint
  * @vreg:		Pointer to the CPR3 regulator
  * @new_volt:		New voltage in microvolts that the LDO regulator needs
  *			to end up at
@@ -1796,7 +1801,7 @@ static int cpr3_regulator_config_ldo_retention(struct cpr3_regulator *vreg,
  *
  * Return: 0 on success, errno on failure
  */
-static int cpr3_regulator_config_ldo_mem_acc(struct cpr3_regulator *vreg,
+static int cpr3_regulator_config_kryo_ldo_mem_acc(struct cpr3_regulator *vreg,
 					     int new_volt)
 {
 	struct cpr3_controller *ctrl = vreg->thread->ctrl;
@@ -1857,6 +1862,51 @@ static int cpr3_regulator_config_ldo_mem_acc(struct cpr3_regulator *vreg,
 	return 0;
 }
 
+/**
+ * cpr3_regulator_kryo_bhs_prepare() - configure the Kryo LDO regulator
+ *		associated with a CPR3 regulator in preparation for BHS
+ *		mode switch.
+ * @vreg:		Pointer to the CPR3 regulator
+ * @vdd_volt:		Last known settled voltage in microvolts for the VDD
+ *			supply
+ * @vdd_ceiling_volt:	Last known aggregated ceiling voltage in microvolts for
+ *			the VDD supply
+ *
+ * This function performs the necessary steps prior to switching a Kryo LDO
+ * regulator to BHS mode (LDO bypassed mode).
+ *
+ * Return: 0 on success, errno on failure
+ */
+static int cpr3_regulator_kryo_bhs_prepare(struct cpr3_regulator *vreg,
+			       int vdd_volt, int vdd_ceiling_volt)
+{
+	struct regulator *ldo_reg = vreg->ldo_regulator;
+	int bhs_volt, rc;
+
+	bhs_volt = vdd_volt - vreg->ldo_min_headroom_volt;
+	if (bhs_volt > vreg->ldo_max_volt) {
+		cpr3_debug(vreg, "limited to LDO output of %d uV when switching to BHS mode\n",
+			   vreg->ldo_max_volt);
+		bhs_volt = vreg->ldo_max_volt;
+	}
+
+	rc = cpr3_regulator_config_kryo_ldo_mem_acc(vreg, bhs_volt);
+	if (rc) {
+		cpr3_err(vreg, "failed to configure mem-acc settings\n");
+		return rc;
+	}
+
+	rc = regulator_set_voltage(ldo_reg, bhs_volt, min(vdd_ceiling_volt,
+							  vreg->ldo_max_volt));
+	if (rc) {
+		cpr3_err(vreg, "regulator_set_voltage(ldo) == %d failed, rc=%d\n",
+			 bhs_volt, rc);
+		return rc;
+	}
+
+	return rc;
+}
+
 /**
  * cpr3_regulator_set_bhs_mode() - configure the LDO regulator associated with
  *		a CPR3 regulator to BHS mode
@@ -1873,32 +1923,21 @@ static int cpr3_regulator_set_bhs_mode(struct cpr3_regulator *vreg,
 			       int vdd_volt, int vdd_ceiling_volt)
 {
 	struct regulator *ldo_reg = vreg->ldo_regulator;
-	int bhs_volt, rc;
+	int rc;
 
-	bhs_volt = vdd_volt - vreg->ldo_min_headroom_volt;
+	if (vreg->ldo_type == CPR3_LDO_KRYO) {
-	if (bhs_volt > vreg->ldo_max_volt) {
+		rc = cpr3_regulator_kryo_bhs_prepare(vreg, vdd_volt,
-		cpr3_debug(vreg, "limited to LDO output of %d uV when switching to BHS mode\n",
+				vdd_ceiling_volt);
-			   vreg->ldo_max_volt);
+		if (rc) {
-		bhs_volt = vreg->ldo_max_volt;
+			cpr3_err(vreg, "cpr3 regulator bhs mode prepare failed, rc=%d\n",
-	}
+				rc);
-
+			return rc;
-	rc = cpr3_regulator_config_ldo_mem_acc(vreg, bhs_volt);
+		}
-	if (rc) {
-		cpr3_err(vreg, "failed to configure mem-acc settings\n");
-		return rc;
-	}
-
-	rc = regulator_set_voltage(ldo_reg, bhs_volt, min(vdd_ceiling_volt,
-							  vreg->ldo_max_volt));
-	if (rc) {
-		cpr3_err(vreg, "regulator_set_voltage(ldo) == %d failed, rc=%d\n",
-			 bhs_volt, rc);
-		return rc;
 	}
 
 	rc = regulator_allow_bypass(ldo_reg, BHS_MODE);
 	if (rc) {
-		cpr3_err(vreg, "regulator_allow_bypass(ldo) == %s failed, rc=%d\n",
+		cpr3_err(vreg, "regulator_allow_bypass(bhs) == %s failed, rc=%d\n",
 			 BHS_MODE ? "true" : "false", rc);
 		return rc;
 	}
@@ -2009,44 +2048,34 @@ static int cpr3_regulator_ldo_apm_prepare(struct cpr3_controller *ctrl,
 }
 
 /**
- * cpr3_regulator_config_vreg_ldo() - configure the voltage and bypass state for
+ * cpr3_regulator_config_vreg_kryo_ldo() - configure the voltage and bypass
- *		the LDO regulator associated with a single CPR3 regulator.
+ *		state for the Kryo LDO regulator associated with a single CPR3
+ *		regulator.
  *
  * @vreg:		Pointer to the CPR3 regulator
  * @vdd_floor_volt:	Last known aggregated floor voltage in microvolts for
  *			the VDD supply
  * @vdd_ceiling_volt:	Last known aggregated ceiling voltage in microvolts for
  *			the VDD supply
- * @new_volt:		New voltage in microvolts that VDD supply needs to
+ * @ref_volt:		Reference voltage in microvolts corresponds either to
- *			end up at
+ *			the aggregated floor voltage or the next VDD supply
+ *			setpoint.
  * @last_volt:		Last known voltage in microvolts for the VDD supply
  *
- * This function performs all relevant LDO or BHS configurations if an LDO
+ * This function performs all relevant LDO or BHS configurations if a Kryo LDO
  * regulator is specified.
  *
  * Return: 0 on success, errno on failure
  */
-static int cpr3_regulator_config_vreg_ldo(struct cpr3_regulator *vreg,
+static int cpr3_regulator_config_vreg_kryo_ldo(struct cpr3_regulator *vreg,
 			  int vdd_floor_volt, int vdd_ceiling_volt,
-			  int new_volt, int last_volt)
+			  int ref_volt, int last_volt)
 {
 	struct cpr3_controller *ctrl = vreg->thread->ctrl;
 	struct regulator *ldo_reg = vreg->ldo_regulator;
 	struct cpr3_corner *current_corner;
 	enum msm_apm_supply apm_mode;
 	int rc, ldo_volt, final_ldo_volt, bhs_volt, max_volt, safe_volt;
-	int ref_volt;
-
-	ref_volt = ctrl->use_hw_closed_loop ? vdd_floor_volt :
-		new_volt;
-
-	rc = cpr3_regulator_config_ldo_retention(vreg, ref_volt);
-	if (rc)
-		return rc;
-
-	if (!vreg->vreg_enabled || vreg->current_corner
-	    == CPR3_REGULATOR_CORNER_INVALID)
-		return 0;
 
 	current_corner = &vreg->corner[vreg->current_corner];
 	ldo_volt = current_corner->open_loop_volt
@@ -2087,7 +2116,7 @@ static int cpr3_regulator_config_vreg_ldo(struct cpr3_regulator *vreg,
 						bhs_volt),
 					    vreg->ldo_max_volt);
 
-			rc = cpr3_regulator_config_ldo_mem_acc(vreg,
+			rc = cpr3_regulator_config_kryo_ldo_mem_acc(vreg,
 							       safe_volt);
 			if (rc) {
 				cpr3_err(vreg, "failed to configure mem-acc settings\n");
@@ -2119,7 +2148,7 @@ static int cpr3_regulator_config_vreg_ldo(struct cpr3_regulator *vreg,
 		else
 			final_ldo_volt = ldo_volt;
 
-		rc = cpr3_regulator_config_ldo_mem_acc(vreg,
+		rc = cpr3_regulator_config_kryo_ldo_mem_acc(vreg,
 						       final_ldo_volt);
 		if (rc) {
 			cpr3_err(vreg, "failed to configure mem-acc settings\n");
@@ -2145,6 +2174,115 @@ static int cpr3_regulator_config_vreg_ldo(struct cpr3_regulator *vreg,
 	return 0;
 }
 
+/**
+ * cpr3_regulator_config_vreg_ldo300() - configure the voltage and bypass state
+ *		for the LDO300 regulator associated with a single CPR3
+ *		regulator.
+ *
+ * @vreg:		Pointer to the CPR3 regulator
+ * @new_volt:		New voltage in microvolts that VDD supply needs to
+ *			end up at
+ * @vdd_ceiling_volt:	Last known aggregated ceiling voltage in microvolts for
+ *			the VDD supply
+ *
+ * This function performs all relevant LDO or BHS configurations for an LDO300
+ * type regulator.
+ *
+ * Return: 0 on success, errno on failure
+ */
+static int cpr3_regulator_config_vreg_ldo300(struct cpr3_regulator *vreg,
+		int new_volt, int vdd_ceiling_volt)
+{
+	struct regulator *ldo_reg = vreg->ldo_regulator;
+	struct cpr3_corner *corner;
+	bool mode;
+	int rc = 0;
+
+	corner = &vreg->corner[vreg->current_corner];
+	mode = corner->ldo_mode_allowed ? LDO_MODE : BHS_MODE;
+
+	if (mode == LDO_MODE) {
+		rc = regulator_set_voltage(ldo_reg, new_volt, vdd_ceiling_volt);
+		if (rc) {
+			cpr3_err(vreg, "regulator_set_voltage(ldo) == %d failed, rc=%d\n",
+				 new_volt, rc);
+			return rc;
+		}
+	}
+
+	if (vreg->ldo_regulator_bypass != mode) {
+		rc = regulator_allow_bypass(ldo_reg, mode);
+		if (rc) {
+			cpr3_err(vreg, "regulator_allow_bypass(%s) is failed, rc=%d\n",
+				 mode == LDO_MODE ? "ldo" : "bhs", rc);
+			return rc;
+		}
+		vreg->ldo_regulator_bypass = mode;
+	}
+
+	return rc;
+}
+
+/**
+ * cpr3_regulator_config_vreg_ldo() - configure the voltage and bypass state for
+ *		the LDO regulator associated with a single CPR3 regulator.
+ *
+ * @vreg:		Pointer to the CPR3 regulator
+ * @vdd_floor_volt:	Last known aggregated floor voltage in microvolts for
+ *			the VDD supply
+ * @vdd_ceiling_volt:	Last known aggregated ceiling voltage in microvolts for
+ *			the VDD supply
+ * @new_volt:		New voltage in microvolts that VDD supply needs to
+ *			end up at
+ * @last_volt:		Last known voltage in microvolts for the VDD supply
+ *
+ * This function identifies the type of LDO regulator associated with a CPR3
+ * regulator and invokes the LDO specific configuration functions.
+ *
+ * Return: 0 on success, errno on failure
+ */
+static int cpr3_regulator_config_vreg_ldo(struct cpr3_regulator *vreg,
+			  int vdd_floor_volt, int vdd_ceiling_volt,
+			  int new_volt, int last_volt)
+{
+	struct cpr3_controller *ctrl = vreg->thread->ctrl;
+	int ref_volt, rc;
+
+	ref_volt = ctrl->use_hw_closed_loop ? vdd_floor_volt :
+		new_volt;
+
+	rc = cpr3_regulator_config_ldo_retention(vreg, ref_volt);
+	if (rc)
+		return rc;
+
+	if (!vreg->vreg_enabled ||
+		vreg->current_corner == CPR3_REGULATOR_CORNER_INVALID)
+		return 0;
+
+	switch (vreg->ldo_type) {
+	case CPR3_LDO_KRYO:
+		rc = cpr3_regulator_config_vreg_kryo_ldo(vreg, vdd_floor_volt,
+				vdd_ceiling_volt, ref_volt, last_volt);
+		if (rc)
+			cpr3_err(vreg, "kryo ldo regulator config failed, rc=%d\n",
+				rc);
+		break;
+	case CPR3_LDO300:
+		rc = cpr3_regulator_config_vreg_ldo300(vreg, new_volt,
+				vdd_ceiling_volt);
+		if (rc)
+			cpr3_err(vreg, "ldo300 regulator config failed, rc=%d\n",
+				rc);
+		break;
+	default:
+		cpr3_err(vreg, "invalid ldo regulator type = %d\n",
+				vreg->ldo_type);
+		rc = -EINVAL;
+	}
+
+	return rc;
+}
+
 /**
  * cpr3_regulator_config_ldo() - configure the voltage and bypass state for the
  *		LDO regulator associated with each CPR3 regulator of a CPR3
@@ -2529,6 +2667,12 @@ static int cpr3_regulator_scale_vdd_voltage(struct cpr3_controller *ctrl,
 	int rc;
 
 	if (new_volt < last_volt) {
+		if (ctrl->support_ldo300_vreg) {
+			rc = cpr3_regulator_config_mem_acc(ctrl, aggr_corner);
+			if (rc)
+				return rc;
+		}
+
 		/* Decreasing VDD voltage */
 		rc = cpr3_regulator_config_ldo(ctrl, aggr_corner->floor_volt,
 					       ctrl->aggr_corner.ceiling_volt,
@@ -2539,10 +2683,11 @@ static int cpr3_regulator_scale_vdd_voltage(struct cpr3_controller *ctrl,
 			return rc;
 		}
 
-		rc = cpr3_regulator_config_mem_acc(ctrl, aggr_corner);
+		if (!ctrl->support_ldo300_vreg) {
-		if (rc)
+			rc = cpr3_regulator_config_mem_acc(ctrl, aggr_corner);
-			return rc;
+			if (rc)
-
+				return rc;
+		}
 	} else {
 		/* Increasing VDD voltage */
 		if (ctrl->system_regulator) {
@@ -2903,6 +3048,8 @@ static void cpr3_regulator_aggregate_corners(struct cpr3_corner *aggr_corner,
 	aggr_corner->mem_acc_volt
 		= max(aggr_corner->mem_acc_volt, corner->mem_acc_volt);
 	aggr_corner->irq_en |= corner->irq_en;
+	aggr_corner->use_open_loop |= corner->use_open_loop;
+	aggr_corner->ldo_mode_allowed |= corner->ldo_mode_allowed;
 
 	if (aggr_quot) {
 		aggr_corner->ro_mask &= corner->ro_mask;
@@ -3281,7 +3428,8 @@ static int _cpr3_regulator_update_ctrl_state(struct cpr3_controller *ctrl)
 	 * Only enable the CPR controller if it is possible to set more than
 	 * one vdd-supply voltage.
 	 */
-	if (aggr_corner.ceiling_volt > aggr_corner.floor_volt)
+	if (aggr_corner.ceiling_volt > aggr_corner.floor_volt &&
+			!aggr_corner.use_open_loop)
 		cpr3_ctrl_loop_enable(ctrl);
 
 	ctrl->last_corner_was_closed_loop = ctrl->cpr_enabled;

drivers/regulator/cpr3-regulator.h

@@ -141,6 +141,9 @@ struct cpr4_sdelta {
  * @use_open_loop:	Boolean indicating that open-loop (i.e CPR disabled) as
  *			opposed to closed-loop operation must be used for this
  *			corner on CPRh controllers.
+ * @ldo_mode_allowed:	Boolean which indicates if LDO mode is allowed for this
+ *			corner. This field is applicable for CPR4 controllers
+ *			that manage LDO300 supply regulator.
  * @sdelta:		The CPR4 controller specific data for this corner. This
  *			field is applicable for CPR4 controllers.
  *
@@ -174,6 +177,7 @@ struct cpr3_corner {
 	u32			irq_en;
 	int			aging_derate;
 	bool			use_open_loop;
+	bool			ldo_mode_allowed;
 	struct cpr4_sdelta	*sdelta;
 };
 
@@ -192,6 +196,18 @@ struct cprh_corner_band {
 	struct cpr4_sdelta	*sdelta;
 };
 
+/**
+ * enum cpr3_ldo_type - Constants which define the LDO supply regulator
+ *	types used to manage the subsystem component rail voltage.
+ * %CPR3_LDO_KRYO:	Kryo LDO regulator used to sub-regulate the HMSS
+ *			per-cluster voltage.
+ * %CPR3_LDO300:	LDO regulator used to sub-regulate the GFX voltage.
+ */
+enum cpr3_ldo_type {
+	CPR3_LDO_KRYO	= 0,
+	CPR3_LDO300	= 1,
+};
+
 /**
  * struct cpr3_regulator - CPR3 logical regulator instance associated with a
  *			given CPR3 hardware thread
@@ -275,6 +291,7 @@ struct cprh_corner_band {
  *			participated in the last aggregation event
  * @debug_corner:	Index identifying voltage corner used for displaying
  *			corner configuration values in debugfs
+ * @ldo_type:		LDO regulator type.
  * @ldo_min_headroom_volt: Minimum voltage difference in microvolts required
  *			between the VDD supply voltage and the LDO output in
  *			order for the LDO operate
@@ -358,6 +375,7 @@ struct cpr3_regulator {
 	int			last_closed_loop_corner;
 	bool			aggregated;
 	int			debug_corner;
+	enum cpr3_ldo_type	ldo_type;
 	int			ldo_min_headroom_volt;
 	int			ldo_max_headroom_volt;
 	int			ldo_adjust_volt;
@@ -715,6 +733,8 @@ struct cpr3_panic_regs_info {
  * @panic_regs_info:	Array of panic registers information which provides the
  *			list of registers to dump when the device crashes.
  * @panic_notifier:	Notifier block registered to global panic notifier list.
+ * @support_ldo300_vreg: Boolean value which indicates that this CPR controller
+ *			manages an underlying LDO regulator of type LDO300.
  *
  * This structure contains both configuration and runtime state data.  The
  * elements cpr_allowed_sw, use_hw_closed_loop, aggr_corner, cpr_enabled,
@@ -815,6 +835,7 @@ struct cpr3_controller {
 	u32			voltage_settling_time;
 	struct cpr3_panic_regs_info *panic_regs_info;
 	struct notifier_block	panic_notifier;
+	bool			support_ldo300_vreg;
 };
 
 /* Used for rounding voltages to the closest physically available set point. */

drivers/regulator/kryo-regulator.c

@@ -28,7 +28,7 @@
 #include <linux/regulator/driver.h>
 #include <linux/regulator/machine.h>
 #include <linux/regulator/of_regulator.h>
-#include <linux/regulator/kryo-regulator.h>
+#include <linux/regulator/msm-ldo-regulator.h>
 
 #include <soc/qcom/spm.h>
 
@@ -89,9 +89,9 @@ struct kryo_regulator {
 	struct regulator_dev		*retention_rdev;
 	struct regulator_desc		retention_desc;
 	const char			*name;
-	enum kryo_supply_mode		mode;
+	enum msm_ldo_supply_mode	mode;
-	enum kryo_supply_mode		retention_mode;
+	enum msm_ldo_supply_mode	retention_mode;
-	enum kryo_supply_mode		pre_lpm_state_mode;
+	enum msm_ldo_supply_mode	pre_lpm_state_mode;
 	void __iomem			*reg_base;
 	void __iomem			*pm_apcc_base;
 	struct dentry			*debugfs;
@@ -248,7 +248,7 @@ static int kryo_set_ldo_volt(struct kryo_regulator *kvreg, int volt)
 
 /* Locks must be held by the caller */
 static int kryo_configure_mode(struct kryo_regulator *kvreg,
-				enum kryo_supply_mode mode)
+				enum msm_ldo_supply_mode mode)
 {
 	u32 reg;
 	int timeout = PWR_GATE_SWITCH_TIMEOUT_US;

include/linux/regulator/msm-ldo-regulator.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2015-2016, 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
@@ -11,22 +11,22 @@
  * GNU General Public License for more details.
  */
 
-#ifndef __KRYO_REGULATOR_H__
+#ifndef __MSM_LDO_REGULATOR_H__
-#define __KRYO_REGULATOR_H__
+#define __MSM_LDO_REGULATOR_H__
 
 /**
- * enum kryo_supply_mode - supported operating modes by this regulator type.
+ * enum msm_ldo_supply_mode - supported operating modes by this regulator type.
  * Use negative logic to ensure BHS mode is treated as the safe default by the
  * the regulator framework. This is necessary since LDO mode can only be enabled
  * when several constraints are satisfied. Consumers of this regulator are
  * expected to request changes in operating modes through the use of
- * regulator_allow_bypass() passing in the desired Kryo supply mode.
+ * regulator_allow_bypass() passing in the desired LDO supply mode.
  * %BHS_MODE:	to select BHS as operating mode
  * %LDO_MODE:	to select LDO as operating mode
  */
-enum kryo_supply_mode {
+enum msm_ldo_supply_mode {
 	BHS_MODE = false,
 	LDO_MODE = true,
 };
 
-#endif /* __KRYO_REGULATOR_H__ */
+#endif /* __MSM_LDO_REGULATOR_H__ */