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From:   David Collins <collinsd@codeaurora.org>
To:     broonie@kernel.org, lgirdwood@gmail.com, robh+dt@kernel.org,
        mark.rutland@arm.com
Cc:     David Collins <collinsd@codeaurora.org>,
        linux-arm-msm@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-arm@lists.infradead.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, rnayak@codeaurora.org,
        sboyd@kernel.org
Subject: [PATCH 1/2] regulator: add QCOM RPMh regulator driver
Date:   Fri, 16 Mar 2018 18:09:10 -0700
Message-Id: <71fab82672524b95632cdb588c16edfc9711866a.1521246069.git.collinsd@codeaurora.org>
In-Reply-To: <cover.1521246069.git.collinsd@codeaurora.org>
References: <cover.1521246069.git.collinsd@codeaurora.org>
In-Reply-To: <cover.1521246069.git.collinsd@codeaurora.org>
References: <cover.1521246069.git.collinsd@codeaurora.org>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Add the QCOM RPMh regulator driver to manage PMIC regulators
which are controlled via RPMh on some Qualcomm Technologies, Inc.
SoCs.  RPMh is a hardware block which contains several
accelerators which are used to manage various hardware resources
that are shared between the processors of the SoC.  The final
hardware state of a regulator is determined within RPMh by
performing max aggregation of the requests made by all of the
processors.

Add support for PMIC regulator control via the voltage regulator
manager (VRM) and oscillator buffer (XOB) RPMh accelerators.  VRM
supports manipulation of enable state, voltage, mode, and
headroom voltage.  XOB supports manipulation of enable state.

Signed-off-by: David Collins <collinsd@codeaurora.org>
---
 drivers/regulator/Kconfig                          |    9 +
 drivers/regulator/Makefile                         |    1 +
 drivers/regulator/qcom_rpmh-regulator.c            | 1124 ++++++++++++++++++++
 .../dt-bindings/regulator/qcom,rpmh-regulator.h    |   40 +
 4 files changed, 1174 insertions(+)
 create mode 100644 drivers/regulator/qcom_rpmh-regulator.c
 create mode 100644 include/dt-bindings/regulator/qcom,rpmh-regulator.h

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 097f617..e0ecd0a 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -671,6 +671,15 @@ config REGULATOR_QCOM_RPM
 	  Qualcomm RPM as a module. The module will be named
 	  "qcom_rpm-regulator".
 
+config REGULATOR_QCOM_RPMH
+	tristate "Qualcomm Technologies, Inc. RPMh regulator driver"
+	depends on (QCOM_RPMH && QCOM_COMMAND_DB && OF) || COMPILE_TEST
+	help
+	  This driver supports control of PMIC regulators via the RPMh hardware
+	  block found on Qualcomm Technologies Inc. SoCs.  RPMh regulator
+	  control allows for voting on regulator state between multiple
+	  processors within the SoC.
+
 config REGULATOR_QCOM_SMD_RPM
 	tristate "Qualcomm SMD based RPM regulator driver"
 	depends on QCOM_SMD_RPM
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index 590674f..c2274dd 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -77,6 +77,7 @@ obj-$(CONFIG_REGULATOR_MT6323)	+= mt6323-regulator.o
 obj-$(CONFIG_REGULATOR_MT6380)	+= mt6380-regulator.o
 obj-$(CONFIG_REGULATOR_MT6397)	+= mt6397-regulator.o
 obj-$(CONFIG_REGULATOR_QCOM_RPM) += qcom_rpm-regulator.o
+obj-$(CONFIG_REGULATOR_QCOM_RPMH) += qcom_rpmh-regulator.o
 obj-$(CONFIG_REGULATOR_QCOM_SMD_RPM) += qcom_smd-regulator.o
 obj-$(CONFIG_REGULATOR_QCOM_SPMI) += qcom_spmi-regulator.o
 obj-$(CONFIG_REGULATOR_PALMAS) += palmas-regulator.o
diff --git a/drivers/regulator/qcom_rpmh-regulator.c b/drivers/regulator/qcom_rpmh-regulator.c
new file mode 100644
index 0000000..808f949
--- /dev/null
+++ b/drivers/regulator/qcom_rpmh-regulator.c
@@ -0,0 +1,1124 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2018, The Linux Foundation. All rights reserved. */
+
+#define pr_fmt(fmt) "%s: " fmt, __func__
+
+#include <linux/bitops.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include <linux/regulator/of_regulator.h>
+#include <soc/qcom/cmd-db.h>
+#include <soc/qcom/rpmh.h>
+#include <dt-bindings/regulator/qcom,rpmh-regulator.h>
+
+/**
+ * enum rpmh_regulator_type - supported RPMh accelerator types
+ * %RPMH_REGULATOR_TYPE_VRM:	RPMh VRM accelerator which supports voting on
+ *				enable, voltage, mode, and headroom voltage of
+ *				LDO, SMPS, VS, and BOB type PMIC regulators.
+ * %RPMH_REGULATOR_TYPE_XOB:	RPMh XOB accelerator which supports voting on
+ *				the enable state of PMIC regulators.
+ */
+enum rpmh_regulator_type {
+	RPMH_REGULATOR_TYPE_VRM,
+	RPMH_REGULATOR_TYPE_XOB,
+};
+
+/* Min and max limits of VRM resource request parameters */
+#define RPMH_VRM_MIN_UV			0
+#define RPMH_VRM_MAX_UV			8191000
+
+#define RPMH_VRM_HEADROOM_MIN_UV	0
+#define RPMH_VRM_HEADROOM_MAX_UV	511000
+
+#define RPMH_VRM_MODE_MIN		0
+#define RPMH_VRM_MODE_MAX		7
+
+/* Register offsets: */
+#define RPMH_REGULATOR_REG_VRM_VOLTAGE		0x0
+#define RPMH_REGULATOR_REG_ENABLE		0x4
+#define RPMH_REGULATOR_REG_VRM_MODE		0x8
+#define RPMH_REGULATOR_REG_VRM_HEADROOM		0xC
+
+/* Enable register values: */
+#define RPMH_REGULATOR_DISABLE			0x0
+#define RPMH_REGULATOR_ENABLE			0x1
+
+/* Number of unique hardware modes supported: */
+#define RPMH_REGULATOR_MODE_COUNT		5
+
+/**
+ * struct rpmh_regulator_mode - RPMh VRM mode attributes
+ * @pmic_mode:			Raw PMIC mode value written into VRM mode voting
+ *				register (i.e. RPMH_REGULATOR_MODE_*)
+ * @framework_mode:		Regulator framework mode value
+ *				(i.e. REGULATOR_MODE_*)
+ * @min_load_ua:		The minimum load current in microamps which
+ *				would utilize this mode
+ *
+ * Software selects the lowest mode for which aggr_load_ua >= min_load_ua.
+ */
+struct rpmh_regulator_mode {
+	u32				pmic_mode;
+	u32				framework_mode;
+	int				min_load_ua;
+};
+
+/**
+ * struct rpmh_vreg_hw_data - RPMh regulator hardware configurations
+ * @mode_map:			Array of size RPMH_REGULATOR_MODE_COUNT which
+ *				maps RPMH_REGULATOR_MODE_* indices into PMIC
+ *				mode and regulator framework mode that are
+ *				supported by this PMIC regulator type
+ * @voltage_range:		The single range of voltages supported by this
+ *				PMIC regulator type
+ * @n_voltages:			The number of unique voltage set points defined
+ *				by voltage_range
+ * @of_map_mode:		Maps an RPMH_REGULATOR_MODE_* mode value defined
+ *				in device tree to a regulator framework mode
+ */
+struct rpmh_vreg_hw_data {
+	const struct rpmh_regulator_mode	*mode_map;
+	const struct regulator_linear_range	*voltage_range;
+	int					n_voltages;
+	unsigned int			      (*of_map_mode)(unsigned int mode);
+};
+
+struct rpmh_pmic;
+
+/**
+ * struct rpmh_vreg - individual rpmh regulator data structure encapsulating a
+ *		single regulator device
+ * @of_node:			Device tree node pointer of the regulator
+ * @pmic:			Pointer to the PMIC containing the regulator
+ * @resource_name:		Name of the RPMh regulator resource which is
+ *				mapped to an RPMh accelerator address via
+ *				command DB.  This name must match to one that is
+ *				defined by the bootloader.
+ * @addr:			Base address of the regulator resource within
+ *				an RPMh accelerator
+ * @rdesc:			Regulator descriptor
+ * @rdev:			Regulator device pointer returned by
+ *				devm_regulator_register()
+ * @hw_data:			PMIC regulator configuration data for this RPMh
+ *				regulator
+ * @regulator_type:		RPMh accelerator type for this regulator
+ *				resource
+ * @always_wait_for_ack:	Boolean flag indicating if a request must always
+ *				wait for an ACK from RPMh before continuing even
+ *				if it corresponds to a strictly lower power
+ *				state (e.g. enabled --> disabled).
+ * @mode_map:			An array of modes which may be configured at
+ *				runtime by setting the load current
+ * @mode_count:			The number of entries in the mode_map array.
+ * @enabled:			Boolean indicating if the regulator is enabled
+ *				or not
+ * @voltage:			RPMh VRM regulator voltage in microvolts
+ * @mode:			RPMh VRM regulator current framework mode
+ * @headroom_voltage:		RPMh VRM regulator minimum headroom voltage
+ *				required
+ */
+struct rpmh_vreg {
+	struct device_node		*of_node;
+	struct rpmh_pmic		*pmic;
+	const char			*resource_name;
+	u32				addr;
+	struct regulator_desc		rdesc;
+	struct regulator_dev		*rdev;
+	const struct rpmh_vreg_hw_data	*hw_data;
+	enum rpmh_regulator_type	regulator_type;
+	bool				always_wait_for_ack;
+	struct rpmh_regulator_mode	*mode_map;
+	int				mode_count;
+
+	bool				enabled;
+	int				voltage;
+	unsigned int			mode;
+	int				headroom_voltage;
+};
+
+/**
+ * struct rpmh_vreg_init_data - initialization data for an RPMh regulator
+ * @name:			Name for the regulator which also corresponds
+ *				to the device tree subnode name of the regulator
+ * @resource_name_base:		RPMh regulator resource name prefix.  E.g.
+ *				"ldo" for RPMh resource "ldoa1".
+ * @supply_name:		Parent supply regulator name
+ * @id:				Regulator number within the PMIC
+ * @regulator_type:		RPMh accelerator type used to manage this
+ *				regulator
+ * @hw_data:			Configuration data for this PMIC regulator type
+ */
+struct rpmh_vreg_init_data {
+	const char			*name;
+	const char			*resource_name_base;
+	const char			*supply_name;
+	int				id;
+	enum rpmh_regulator_type	regulator_type;
+	const struct rpmh_vreg_hw_data	*hw_data;
+};
+
+/**
+ * struct rpmh_pmic_init_data - initialization data for a PMIC
+ * @name:			PMIC name
+ * @vreg_data:			Array of data for each regulator in the PMIC
+ * @count:			Number of entries in vreg_data
+ */
+struct rpmh_pmic_init_data {
+	const char				*name;
+	const struct rpmh_vreg_init_data	*vreg_data;
+	int					count;
+};
+
+/**
+ * struct rpmh_pmic - top level data structure of all regulators found on a PMIC
+ * @dev:			Device pointer of the PMIC device for the
+ *				regulators
+ * @rpmh_client:		Handle used for rpmh communications
+ * @vreg:			Array of rpmh regulator structs representing the
+ *				individual regulators found on this PMIC chip
+ *				which are configured via device tree.
+ * @vreg_count:			The number of entries in the vreg array.
+ * @pmic_id:			Letter used to identify this PMIC within the
+ *				system.  This is dictated by boot loader
+ *				specifications on a given target.
+ * @init_data:			Pointer to the matched PMIC initialization data
+ */
+struct rpmh_pmic {
+	struct device				*dev;
+	struct rpmh_client			*rpmh_client;
+	struct rpmh_vreg			*vreg;
+	int					vreg_count;
+	const char				*pmic_id;
+	const struct rpmh_pmic_init_data	*init_data;
+};
+
+#define vreg_err(vreg, message, ...) \
+	pr_err("%s %s: " message, (vreg)->pmic->init_data->name, \
+		(vreg)->rdesc.name, ##__VA_ARGS__)
+#define vreg_info(vreg, message, ...) \
+	pr_info("%s %s: " message, (vreg)->pmic->init_data->name, \
+		(vreg)->rdesc.name, ##__VA_ARGS__)
+#define vreg_debug(vreg, message, ...) \
+	pr_debug("%s %s: " message, (vreg)->pmic->init_data->name, \
+		(vreg)->rdesc.name, ##__VA_ARGS__)
+
+/**
+ * rpmh_regulator_send_request() - send the request to RPMh
+ * @vreg:		Pointer to the RPMh regulator
+ * @cmd:		RPMh commands to send
+ * @count:		Size of cmd array
+ * @wait_for_ack:	Boolean indicating if execution must wait until the
+ *			request has been acknowledged as complete
+ *
+ * Return: 0 on success, errno on failure
+ */
+static int rpmh_regulator_send_request(struct rpmh_vreg *vreg,
+			struct tcs_cmd *cmd, int count, bool wait_for_ack)
+{
+	int ret;
+
+	if (wait_for_ack || vreg->always_wait_for_ack)
+		ret = rpmh_write(vreg->pmic->rpmh_client,
+				RPMH_ACTIVE_ONLY_STATE, cmd, count);
+	else
+		ret = rpmh_write_async(vreg->pmic->rpmh_client,
+				RPMH_ACTIVE_ONLY_STATE, cmd, count);
+	if (ret < 0)
+		vreg_err(vreg, "rpmh_write() failed, ret=%d\n", ret);
+
+	return ret;
+}
+
+static int rpmh_regulator_is_enabled(struct regulator_dev *rdev)
+{
+	struct rpmh_vreg *vreg = rdev_get_drvdata(rdev);
+
+	return vreg->enabled;
+}
+
+static int rpmh_regulator_enable(struct regulator_dev *rdev)
+{
+	struct rpmh_vreg *vreg = rdev_get_drvdata(rdev);
+	struct tcs_cmd cmd = {
+		.addr = vreg->addr + RPMH_REGULATOR_REG_ENABLE,
+		.data = RPMH_REGULATOR_ENABLE,
+	};
+	int ret;
+
+	if (vreg->enabled)
+		return 0;
+
+	ret = rpmh_regulator_send_request(vreg, &cmd, 1, true);
+	if (ret < 0) {
+		vreg_err(vreg, "enable failed, ret=%d\n", ret);
+		return ret;
+	}
+
+	vreg->enabled = true;
+
+	return 0;
+}
+
+static int rpmh_regulator_disable(struct regulator_dev *rdev)
+{
+	struct rpmh_vreg *vreg = rdev_get_drvdata(rdev);
+	struct tcs_cmd cmd = {
+		.addr = vreg->addr + RPMH_REGULATOR_REG_ENABLE,
+		.data = RPMH_REGULATOR_DISABLE,
+	};
+	int ret;
+
+	if (!vreg->enabled)
+		return 0;
+
+	ret = rpmh_regulator_send_request(vreg, &cmd, 1, false);
+	if (ret < 0) {
+		vreg_err(vreg, "disable failed, ret=%d\n", ret);
+		return ret;
+	}
+
+	vreg->enabled = false;
+
+	return 0;
+}
+
+static int rpmh_regulator_vrm_set_voltage(struct regulator_dev *rdev,
+				int min_uv, int max_uv, unsigned int *selector)
+{
+	struct rpmh_vreg *vreg = rdev_get_drvdata(rdev);
+	struct tcs_cmd cmd = {
+		.addr = vreg->addr + RPMH_REGULATOR_REG_VRM_VOLTAGE,
+	};
+	const struct regulator_linear_range *range;
+	int mv, uv, ret;
+	bool wait_for_ack;
+
+	mv = DIV_ROUND_UP(min_uv, 1000);
+	uv = mv * 1000;
+	if (uv > max_uv) {
+		vreg_err(vreg, "no set points available in range %d-%d uV\n",
+			min_uv, max_uv);
+		return -EINVAL;
+	}
+
+	range = vreg->hw_data->voltage_range;
+	*selector = DIV_ROUND_UP(uv - range->min_uV, range->uV_step);
+
+	if (uv == vreg->voltage)
+		return 0;
+
+	wait_for_ack = uv > vreg->voltage || max_uv < vreg->voltage;
+	cmd.data = mv;
+
+	ret = rpmh_regulator_send_request(vreg, &cmd, 1, wait_for_ack);
+	if (ret < 0) {
+		vreg_err(vreg, "set voltage=%d uV failed, ret=%d\n", uv, ret);
+		return ret;
+	}
+
+	vreg->voltage = uv;
+
+	return 0;
+}
+
+static int rpmh_regulator_vrm_get_voltage(struct regulator_dev *rdev)
+{
+	struct rpmh_vreg *vreg = rdev_get_drvdata(rdev);
+
+	return vreg->voltage;
+}
+
+static int rpmh_regulator_vrm_set_mode(struct regulator_dev *rdev,
+					unsigned int mode)
+{
+	struct rpmh_vreg *vreg = rdev_get_drvdata(rdev);
+	struct tcs_cmd cmd = {
+		.addr = vreg->addr + RPMH_REGULATOR_REG_VRM_MODE,
+	};
+	int i, ret;
+
+	if (mode == vreg->mode)
+		return 0;
+
+	for (i = 0; i < RPMH_REGULATOR_MODE_COUNT; i++)
+		if (vreg->hw_data->mode_map[i].framework_mode == mode)
+			break;
+	if (i >= RPMH_REGULATOR_MODE_COUNT) {
+		vreg_err(vreg, "invalid mode=%u\n", mode);
+		return -EINVAL;
+	}
+
+	cmd.data = vreg->hw_data->mode_map[i].pmic_mode;
+
+	ret = rpmh_regulator_send_request(vreg, &cmd, 1,
+					  mode < vreg->mode || !vreg->mode);
+	if (ret < 0) {
+		vreg_err(vreg, "set mode=%u failed, ret=%d\n", cmd.data, ret);
+		return ret;
+	}
+
+	vreg->mode = mode;
+
+	return ret;
+}
+
+static unsigned int rpmh_regulator_vrm_get_mode(struct regulator_dev *rdev)
+{
+	struct rpmh_vreg *vreg = rdev_get_drvdata(rdev);
+
+	return vreg->mode;
+}
+
+/**
+ * rpmh_regulator_vrm_set_load() - set the PMIC mode based upon the maximum load
+ *		required from the VRM rpmh-regulator
+ * @rdev:		Regulator device pointer for the rpmh-regulator
+ * @load_ua:		Maximum current required from all consumers in microamps
+ *
+ * This function is passed as a callback function into the regulator ops that
+ * are registered for each VRM rpmh-regulator device.
+ *
+ * This function sets the mode of the regulator to that which has the highest
+ * min support load less than or equal to load_ua.  Example:
+ *	mode_count = 3
+ *	mode_map[].min_load_ua = 0, 100000, 6000000
+ *
+ *	load_ua = 10000   --> i = 0
+ *	load_ua = 250000  --> i = 1
+ *	load_ua = 7000000 --> i = 2
+ *
+ * Return: 0 on success, errno on failure
+ */
+static int rpmh_regulator_vrm_set_load(struct regulator_dev *rdev, int load_ua)
+{
+	struct rpmh_vreg *vreg = rdev_get_drvdata(rdev);
+	int i;
+
+	/* No need to check element 0 as it will be the default. */
+	for (i = vreg->mode_count - 1; i > 0; i--)
+		if (vreg->mode_map[i].min_load_ua <= load_ua)
+			break;
+
+	return rpmh_regulator_vrm_set_mode(rdev,
+					   vreg->mode_map[i].framework_mode);
+}
+
+static const struct regulator_ops rpmh_regulator_vrm_ops = {
+	.enable			= rpmh_regulator_enable,
+	.disable		= rpmh_regulator_disable,
+	.is_enabled		= rpmh_regulator_is_enabled,
+	.set_voltage		= rpmh_regulator_vrm_set_voltage,
+	.get_voltage		= rpmh_regulator_vrm_get_voltage,
+	.list_voltage		= regulator_list_voltage_linear_range,
+	.set_mode		= rpmh_regulator_vrm_set_mode,
+	.get_mode		= rpmh_regulator_vrm_get_mode,
+	.set_load		= rpmh_regulator_vrm_set_load,
+};
+
+static const struct regulator_ops rpmh_regulator_xob_ops = {
+	.enable			= rpmh_regulator_enable,
+	.disable		= rpmh_regulator_disable,
+	.is_enabled		= rpmh_regulator_is_enabled,
+};
+
+static const struct regulator_ops *rpmh_regulator_ops[] = {
+	[RPMH_REGULATOR_TYPE_VRM]	= &rpmh_regulator_vrm_ops,
+	[RPMH_REGULATOR_TYPE_XOB]	= &rpmh_regulator_xob_ops,
+};
+
+/**
+ * rpmh_regulator_parse_vrm_modes() - parse the supported mode configurations
+ *		for a VRM RPMh resource from device tree
+ * vreg:		Pointer to the rpmh regulator resource
+ *
+ * This function initializes the mode[] array of vreg based upon the values
+ * of optional device tree properties.
+ *
+ * Return: 0 on success, errno on failure
+ */
+static int rpmh_regulator_parse_vrm_modes(struct rpmh_vreg *vreg)
+{
+	struct device_node *node = vreg->of_node;
+	const struct rpmh_regulator_mode *map;
+	const char *prop;
+	int i, len, ret;
+	u32 *buf;
+
+	map = vreg->hw_data->mode_map;
+	if (!map)
+		return 0;
+
+	/* qcom,allowed-modes is optional */
+	prop = "qcom,allowed-modes";
+	len = of_property_count_elems_of_size(node, prop, sizeof(u32));
+	if (len < 0)
+		return 0;
+
+	vreg->mode_map = devm_kcalloc(vreg->pmic->dev, len,
+				sizeof(*vreg->mode_map), GFP_KERNEL);
+	if (!vreg->mode_map)
+		return -ENOMEM;
+	vreg->mode_count = len;
+
+	buf = kcalloc(len, sizeof(*buf), GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	ret = of_property_read_u32_array(node, prop, buf, len);
+	if (ret < 0) {
+		vreg_err(vreg, "unable to read %s, ret=%d\n",
+			prop, ret);
+		goto done;
+	}
+
+	for (i = 0; i < len; i++) {
+		if (buf[i] >= RPMH_REGULATOR_MODE_COUNT
+		    || !map[buf[i]].framework_mode) {
+			vreg_err(vreg, "element %d of %s = %u is invalid for this regulator\n",
+				i, prop, buf[i]);
+			ret = -EINVAL;
+			goto done;
+		}
+
+		vreg->mode_map[i].pmic_mode = map[buf[i]].pmic_mode;
+		vreg->mode_map[i].framework_mode = map[buf[i]].framework_mode;
+
+		if (i > 0 && vreg->mode_map[i].pmic_mode
+				<= vreg->mode_map[i - 1].pmic_mode) {
+			vreg_err(vreg, "%s elements are not in ascending order\n",
+				prop);
+			ret = -EINVAL;
+			goto done;
+		}
+	}
+
+	prop = "qcom,mode-threshold-currents";
+	ret = of_property_read_u32_array(node, prop, buf, len);
+	if (ret < 0) {
+		vreg_err(vreg, "unable to read %s, ret=%d\n",
+			prop, ret);
+		goto done;
+	}
+
+	for (i = 0; i < len; i++) {
+		vreg->mode_map[i].min_load_ua = buf[i];
+
+		if (i > 0 && vreg->mode_map[i].min_load_ua
+				<= vreg->mode_map[i - 1].min_load_ua) {
+			vreg_err(vreg, "%s elements are not in ascending order\n",
+				prop);
+			ret = -EINVAL;
+			goto done;
+		}
+	}
+
+done:
+	kfree(buf);
+	return ret;
+}
+
+/**
+ * rpmh_regulator_allocate_vreg() - allocate space for the regulators associated
+ *		with the PMIC and initialize important pointers for each
+ *		regulator
+ * @pmic:		Pointer to the RPMh regulator PMIC
+ *
+ * Return: 0 on success, errno on failure
+ */
+static int rpmh_regulator_allocate_vreg(struct rpmh_pmic *pmic)
+{
+	struct device_node *node;
+	int i;
+
+	pmic->vreg_count = of_get_available_child_count(pmic->dev->of_node);
+	if (pmic->vreg_count == 0) {
+		dev_err(pmic->dev, "could not find any regulator subnodes\n");
+		return -ENODEV;
+	}
+
+	pmic->vreg = devm_kcalloc(pmic->dev, pmic->vreg_count,
+			sizeof(*pmic->vreg), GFP_KERNEL);
+	if (!pmic->vreg)
+		return -ENOMEM;
+
+	i = 0;
+	for_each_available_child_of_node(pmic->dev->of_node, node) {
+		pmic->vreg[i].of_node = node;
+		pmic->vreg[i].pmic = pmic;
+
+		i++;
+	}
+
+	return 0;
+}
+
+/**
+ * rpmh_regulator_load_default_parameters() - initialize the RPMh resource
+ *		request for this regulator based on optional device tree
+ *		properties
+ * @vreg:		Pointer to the RPMh regulator
+ *
+ * Return: 0 on success, errno on failure
+ */
+static int rpmh_regulator_load_default_parameters(struct rpmh_vreg *vreg)
+{
+	struct tcs_cmd cmd[2] = { };
+	const char *prop;
+	int cmd_count = 0;
+	int ret;
+	u32 temp;
+
+	if (vreg->regulator_type == RPMH_REGULATOR_TYPE_VRM) {
+		prop = "qcom,headroom-voltage";
+		ret = of_property_read_u32(vreg->of_node, prop, &temp);
+		if (!ret) {
+			if (temp < RPMH_VRM_HEADROOM_MIN_UV ||
+			    temp > RPMH_VRM_HEADROOM_MAX_UV) {
+				vreg_err(vreg, "%s=%u is invalid\n",
+					prop, temp);
+				return -EINVAL;
+			}
+			vreg->headroom_voltage = temp;
+
+			cmd[cmd_count].addr
+				= vreg->addr + RPMH_REGULATOR_REG_VRM_HEADROOM;
+			cmd[cmd_count++].data
+				= DIV_ROUND_UP(vreg->headroom_voltage, 1000);
+		}
+
+		prop = "qcom,regulator-initial-voltage";
+		ret = of_property_read_u32(vreg->of_node, prop, &temp);
+		if (!ret) {
+			if (temp < RPMH_VRM_MIN_UV || temp > RPMH_VRM_MAX_UV) {
+				vreg_err(vreg, "%s=%u is invalid\n",
+					prop, temp);
+				return -EINVAL;
+			}
+			vreg->voltage = temp;
+
+			cmd[cmd_count].addr
+				= vreg->addr + RPMH_REGULATOR_REG_VRM_VOLTAGE;
+			cmd[cmd_count++].data
+				= DIV_ROUND_UP(vreg->voltage, 1000);
+		}
+	}
+
+	if (cmd_count) {
+		ret = rpmh_regulator_send_request(vreg, cmd, cmd_count, true);
+		if (ret < 0) {
+			vreg_err(vreg, "could not send default config, ret=%d\n",
+				ret);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * rpmh_regulator_init_vreg() - initialize all abbributes of an rpmh-regulator
+ * @vreg:		Pointer to the RPMh regulator
+ *
+ * Return: 0 on success, errno on failure
+ */
+static int rpmh_regulator_init_vreg(struct rpmh_vreg *vreg)
+{
+	struct device *dev = vreg->pmic->dev;
+	struct regulator_config reg_config = {};
+	const struct rpmh_vreg_init_data *rpmh_data = NULL;
+	const char *type_name = NULL;
+	enum rpmh_regulator_type type;
+	struct regulator_init_data *init_data;
+	int ret, i;
+
+	for (i = 0; i < vreg->pmic->init_data->count; i++) {
+		if (!strcmp(vreg->pmic->init_data->vreg_data[i].name,
+			    vreg->of_node->name)) {
+			rpmh_data = &vreg->pmic->init_data->vreg_data[i];
+			break;
+		}
+	}
+
+	if (!rpmh_data) {
+		dev_err(dev, "Unknown regulator %s for %s RPMh regulator PMIC\n",
+			vreg->of_node->name, vreg->pmic->init_data->name);
+		return -EINVAL;
+	}
+
+	vreg->resource_name = devm_kasprintf(dev, GFP_KERNEL, "%s%s%d",
+			rpmh_data->resource_name_base, vreg->pmic->pmic_id,
+			rpmh_data->id);
+	if (!vreg->resource_name)
+		return -ENOMEM;
+
+	vreg->addr = cmd_db_read_addr(vreg->resource_name);
+	if (!vreg->addr) {
+		vreg_err(vreg, "could not find RPMh address for resource %s\n",
+			vreg->resource_name);
+		return -ENODEV;
+	}
+
+	vreg->rdesc.name = rpmh_data->name;
+	vreg->rdesc.supply_name = rpmh_data->supply_name;
+	vreg->regulator_type = rpmh_data->regulator_type;
+	vreg->hw_data = rpmh_data->hw_data;
+
+	if (rpmh_data->hw_data->voltage_range) {
+		vreg->rdesc.linear_ranges = rpmh_data->hw_data->voltage_range;
+		vreg->rdesc.n_linear_ranges = 1;
+		vreg->rdesc.n_voltages = rpmh_data->hw_data->n_voltages;
+	}
+
+	/* Optional override for the default RPMh accelerator type */
+	ret = of_property_read_string(vreg->of_node, "qcom,rpmh-resource-type",
+					&type_name);
+	if (!ret) {
+		if (!strcmp("vrm", type_name)) {
+			vreg->regulator_type = RPMH_REGULATOR_TYPE_VRM;
+		} else if (!strcmp("xob", type_name)) {
+			vreg->regulator_type = RPMH_REGULATOR_TYPE_XOB;
+		} else {
+			vreg_err(vreg, "Unknown RPMh accelerator type %s\n",
+				type_name);
+			return -EINVAL;
+		}
+	}
+
+	type = vreg->regulator_type;
+
+	if (type == RPMH_REGULATOR_TYPE_VRM) {
+		ret = rpmh_regulator_parse_vrm_modes(vreg);
+		if (ret < 0) {
+			vreg_err(vreg, "could not parse vrm mode mapping, ret=%d\n",
+				ret);
+			return ret;
+		}
+	}
+
+	vreg->always_wait_for_ack = of_property_read_bool(vreg->of_node,
+						"qcom,always-wait-for-ack");
+
+	vreg->rdesc.owner	= THIS_MODULE;
+	vreg->rdesc.type	= REGULATOR_VOLTAGE;
+	vreg->rdesc.ops		= rpmh_regulator_ops[type];
+	vreg->rdesc.of_map_mode	= vreg->hw_data->of_map_mode;
+
+	init_data = of_get_regulator_init_data(dev, vreg->of_node,
+						&vreg->rdesc);
+	if (!init_data)
+		return -ENOMEM;
+
+	if (type == RPMH_REGULATOR_TYPE_XOB && init_data->constraints.min_uV) {
+		vreg->rdesc.fixed_uV = init_data->constraints.min_uV;
+		init_data->constraints.apply_uV = 0;
+		vreg->rdesc.n_voltages = 1;
+	}
+
+	if (vreg->hw_data->mode_map) {
+		init_data->constraints.valid_ops_mask |= REGULATOR_CHANGE_MODE;
+		for (i = 0; i < RPMH_REGULATOR_MODE_COUNT; i++)
+			init_data->constraints.valid_modes_mask
+				|= vreg->hw_data->mode_map[i].framework_mode;
+	}
+
+	reg_config.dev			= dev;
+	reg_config.init_data		= init_data;
+	reg_config.of_node		= vreg->of_node;
+	reg_config.driver_data		= vreg;
+
+	ret = rpmh_regulator_load_default_parameters(vreg);
+	if (ret < 0) {
+		vreg_err(vreg, "unable to load default parameters, ret=%d\n",
+			ret);
+		return ret;
+	}
+
+	vreg->rdev = devm_regulator_register(dev, &vreg->rdesc, &reg_config);
+	if (IS_ERR(vreg->rdev)) {
+		ret = PTR_ERR(vreg->rdev);
+		vreg->rdev = NULL;
+		vreg_err(vreg, "devm_regulator_register() failed, ret=%d\n",
+			ret);
+		return ret;
+	}
+
+	vreg_debug(vreg, "registered RPMh resource %s @ 0x%05X\n",
+		vreg->resource_name, vreg->addr);
+
+	return ret;
+}
+
+/*
+ * Mappings from RPMh generic modes to VRM accelerator modes and regulator
+ * framework modes for each regulator type.
+ */
+static const struct rpmh_regulator_mode
+rpmh_regulator_mode_map_pmic4_ldo[RPMH_REGULATOR_MODE_COUNT] = {
+	[RPMH_REGULATOR_MODE_RET] = {
+		.pmic_mode = 4,
+		.framework_mode = REGULATOR_MODE_STANDBY,
+	},
+	[RPMH_REGULATOR_MODE_LPM] = {
+		.pmic_mode = 5,
+		.framework_mode = REGULATOR_MODE_IDLE,
+	},
+	[RPMH_REGULATOR_MODE_HPM] = {
+		.pmic_mode = 7,
+		.framework_mode = REGULATOR_MODE_FAST,
+	},
+};
+
+static const struct rpmh_regulator_mode
+rpmh_regulator_mode_map_pmic4_smps[RPMH_REGULATOR_MODE_COUNT] = {
+	[RPMH_REGULATOR_MODE_RET] = {
+		.pmic_mode = 4,
+		.framework_mode = REGULATOR_MODE_STANDBY,
+	},
+	[RPMH_REGULATOR_MODE_LPM] = {
+		.pmic_mode = 5,
+		.framework_mode = REGULATOR_MODE_IDLE,
+	},
+	[RPMH_REGULATOR_MODE_AUTO] = {
+		.pmic_mode = 6,
+		.framework_mode = REGULATOR_MODE_NORMAL,
+	},
+	[RPMH_REGULATOR_MODE_HPM] = {
+		.pmic_mode = 7,
+		.framework_mode = REGULATOR_MODE_FAST,
+	},
+};
+
+static const struct rpmh_regulator_mode
+rpmh_regulator_mode_map_pmic4_bob[RPMH_REGULATOR_MODE_COUNT] = {
+	[RPMH_REGULATOR_MODE_PASS] = {
+		.pmic_mode = 0,
+		.framework_mode = REGULATOR_MODE_STANDBY,
+	},
+	[RPMH_REGULATOR_MODE_LPM] = {
+		.pmic_mode = 1,
+		.framework_mode = REGULATOR_MODE_IDLE,
+	},
+	[RPMH_REGULATOR_MODE_AUTO] = {
+		.pmic_mode = 2,
+		.framework_mode = REGULATOR_MODE_NORMAL,
+	},
+	[RPMH_REGULATOR_MODE_HPM] = {
+		.pmic_mode = 3,
+		.framework_mode = REGULATOR_MODE_FAST,
+	},
+};
+
+static unsigned int rpmh_regulator_vrm_of_map_mode(unsigned int mode,
+		const struct rpmh_regulator_mode *mode_map)
+{
+	if (mode > RPMH_REGULATOR_MODE_COUNT)
+		return -EINVAL;
+	else if (mode_map[mode].framework_mode == 0)
+		return -EINVAL;
+
+	return mode_map[mode].framework_mode;
+}
+
+static unsigned int rpmh_regulator_pmic4_ldo_of_map_mode(unsigned int mode)
+{
+	return rpmh_regulator_vrm_of_map_mode(mode,
+					rpmh_regulator_mode_map_pmic4_ldo);
+}
+
+static unsigned int rpmh_regulator_pmic4_smps_of_map_mode(unsigned int mode)
+{
+	return rpmh_regulator_vrm_of_map_mode(mode,
+					rpmh_regulator_mode_map_pmic4_smps);
+}
+
+static unsigned int rpmh_regulator_pmic4_bob_of_map_mode(unsigned int mode)
+{
+	return rpmh_regulator_vrm_of_map_mode(mode,
+					rpmh_regulator_mode_map_pmic4_bob);
+}
+
+static const struct rpmh_vreg_hw_data pmic4_pldo_hw_data = {
+	.voltage_range = &(const struct regulator_linear_range)
+			REGULATOR_LINEAR_RANGE(1664000, 0, 255, 8000),
+	.n_voltages = 256,
+	.mode_map = rpmh_regulator_mode_map_pmic4_ldo,
+	.of_map_mode = rpmh_regulator_pmic4_ldo_of_map_mode,
+};
+
+static const struct rpmh_vreg_hw_data pmic4_pldo_lv_hw_data = {
+	.voltage_range = &(const struct regulator_linear_range)
+			REGULATOR_LINEAR_RANGE(1256000, 0, 127, 8000),
+	.n_voltages = 128,
+	.mode_map = rpmh_regulator_mode_map_pmic4_ldo,
+	.of_map_mode = rpmh_regulator_pmic4_ldo_of_map_mode,
+};
+
+static const struct rpmh_vreg_hw_data pmic4_nldo_hw_data = {
+	.voltage_range = &(const struct regulator_linear_range)
+			REGULATOR_LINEAR_RANGE(312000, 0, 127, 8000),
+	.n_voltages = 128,
+	.mode_map = rpmh_regulator_mode_map_pmic4_ldo,
+	.of_map_mode = rpmh_regulator_pmic4_ldo_of_map_mode,
+};
+
+static const struct rpmh_vreg_hw_data pmic4_hfsmps3_hw_data = {
+	.voltage_range = &(const struct regulator_linear_range)
+			REGULATOR_LINEAR_RANGE(320000, 0, 215, 8000),
+	.n_voltages = 216,
+	.mode_map = rpmh_regulator_mode_map_pmic4_smps,
+	.of_map_mode = rpmh_regulator_pmic4_smps_of_map_mode,
+};
+
+static const struct rpmh_vreg_hw_data pmic4_ftsmps426_hw_data = {
+	.voltage_range = &(const struct regulator_linear_range)
+			REGULATOR_LINEAR_RANGE(320000, 0, 258, 4000),
+	.n_voltages = 259,
+	.mode_map = rpmh_regulator_mode_map_pmic4_smps,
+	.of_map_mode = rpmh_regulator_pmic4_smps_of_map_mode,
+};
+
+static const struct rpmh_vreg_hw_data pmic4_bob_hw_data = {
+	.voltage_range = &(const struct regulator_linear_range)
+			REGULATOR_LINEAR_RANGE(1824000, 0, 83, 32000),
+	.n_voltages = 84,
+	.mode_map = rpmh_regulator_mode_map_pmic4_bob,
+	.of_map_mode = rpmh_regulator_pmic4_bob_of_map_mode,
+};
+
+static const struct rpmh_vreg_hw_data pmic4_lvs_hw_data = {
+	/* LVS hardware does not support voltage or mode configuration. */
+};
+
+#define RPMH_VREG(_name, _hw_type, _type, _base_name, _id, _supply_name) \
+{ \
+	.name = #_name, \
+	.hw_data = &_hw_type##_hw_data, \
+	.regulator_type = RPMH_REGULATOR_TYPE_##_type, \
+	.resource_name_base = #_base_name, \
+	.id = _id, \
+	.supply_name = #_supply_name, \
+}
+
+static const struct rpmh_vreg_init_data pm8998_vreg_data[] = {
+	RPMH_VREG(smps1,  pmic4_ftsmps426, VRM, smp,  1, vdd_s1),
+	RPMH_VREG(smps2,  pmic4_ftsmps426, VRM, smp,  2, vdd_s2),
+	RPMH_VREG(smps3,  pmic4_hfsmps3,   VRM, smp,  3, vdd_s3),
+	RPMH_VREG(smps4,  pmic4_hfsmps3,   VRM, smp,  4, vdd_s4),
+	RPMH_VREG(smps5,  pmic4_hfsmps3,   VRM, smp,  5, vdd_s5),
+	RPMH_VREG(smps6,  pmic4_ftsmps426, VRM, smp,  6, vdd_s6),
+	RPMH_VREG(smps7,  pmic4_ftsmps426, VRM, smp,  7, vdd_s7),
+	RPMH_VREG(smps8,  pmic4_ftsmps426, VRM, smp,  8, vdd_s8),
+	RPMH_VREG(smps9,  pmic4_ftsmps426, VRM, smp,  9, vdd_s9),
+	RPMH_VREG(smps10, pmic4_ftsmps426, VRM, smp, 10, vdd_s10),
+	RPMH_VREG(smps11, pmic4_ftsmps426, VRM, smp, 11, vdd_s11),
+	RPMH_VREG(smps12, pmic4_ftsmps426, VRM, smp, 12, vdd_s12),
+	RPMH_VREG(smps13, pmic4_ftsmps426, VRM, smp, 13, vdd_s13),
+	RPMH_VREG(ldo1,   pmic4_nldo,      VRM, ldo,  1, vdd_l1_l27),
+	RPMH_VREG(ldo2,   pmic4_nldo,      VRM, ldo,  2, vdd_l2_l8_l17),
+	RPMH_VREG(ldo3,   pmic4_nldo,      VRM, ldo,  3, vdd_l3_l11),
+	RPMH_VREG(ldo4,   pmic4_nldo,      VRM, ldo,  4, vdd_l4_l5),
+	RPMH_VREG(ldo5,   pmic4_nldo,      VRM, ldo,  5, vdd_l4_l5),
+	RPMH_VREG(ldo6,   pmic4_pldo,      VRM, ldo,  6, vdd_l6),
+	RPMH_VREG(ldo7,   pmic4_pldo_lv,   VRM, ldo,  7, vdd_l7_l12_l14_l15),
+	RPMH_VREG(ldo8,   pmic4_nldo,      VRM, ldo,  8, vdd_l2_l8_l17),
+	RPMH_VREG(ldo9,   pmic4_pldo,      VRM, ldo,  9, vdd_l9),
+	RPMH_VREG(ldo10,  pmic4_pldo,      VRM, ldo, 10, vdd_l10_l23_l25),
+	RPMH_VREG(ldo11,  pmic4_nldo,      VRM, ldo, 11, vdd_l3_l11),
+	RPMH_VREG(ldo12,  pmic4_pldo_lv,   VRM, ldo, 12, vdd_l7_l12_l14_l15),
+	RPMH_VREG(ldo13,  pmic4_pldo,      VRM, ldo, 13, vdd_l13_l19_l21),
+	RPMH_VREG(ldo14,  pmic4_pldo_lv,   VRM, ldo, 14, vdd_l7_l12_l14_l15),
+	RPMH_VREG(ldo15,  pmic4_pldo_lv,   VRM, ldo, 15, vdd_l7_l12_l14_l15),
+	RPMH_VREG(ldo16,  pmic4_pldo,      VRM, ldo, 16, vdd_l16_l28),
+	RPMH_VREG(ldo17,  pmic4_nldo,      VRM, ldo, 17, vdd_l2_l8_l17),
+	RPMH_VREG(ldo18,  pmic4_pldo,      VRM, ldo, 18, vdd_l18_l22),
+	RPMH_VREG(ldo19,  pmic4_pldo,      VRM, ldo, 19, vdd_l13_l19_l21),
+	RPMH_VREG(ldo20,  pmic4_pldo,      VRM, ldo, 20, vdd_l20_l24),
+	RPMH_VREG(ldo21,  pmic4_pldo,      VRM, ldo, 21, vdd_l13_l19_l21),
+	RPMH_VREG(ldo22,  pmic4_pldo,      VRM, ldo, 22, vdd_l18_l22),
+	RPMH_VREG(ldo23,  pmic4_pldo,      VRM, ldo, 23, vdd_l10_l23_l25),
+	RPMH_VREG(ldo24,  pmic4_pldo,      VRM, ldo, 24, vdd_l20_l24),
+	RPMH_VREG(ldo25,  pmic4_pldo,      VRM, ldo, 25, vdd_l10_l23_l25),
+	RPMH_VREG(ldo26,  pmic4_nldo,      VRM, ldo, 26, vdd_l26),
+	RPMH_VREG(ldo27,  pmic4_nldo,      VRM, ldo, 27, vdd_l1_l27),
+	RPMH_VREG(ldo28,  pmic4_pldo,      VRM, ldo, 28, vdd_l16_l28),
+	RPMH_VREG(lvs1,   pmic4_lvs,       XOB, vs,   1, vdd_lvs1_lvs2),
+	RPMH_VREG(lvs2,   pmic4_lvs,       XOB, vs,   2, vdd_lvs1_lvs2),
+};
+
+static const struct rpmh_vreg_init_data pmi8998_vreg_data[] = {
+	RPMH_VREG(bob,    pmic4_bob,       VRM, bob,  1, vdd_bob),
+};
+
+static const struct rpmh_vreg_init_data pm8005_vreg_data[] = {
+	RPMH_VREG(smps1,  pmic4_ftsmps426, VRM, smp,  1, vdd_s1),
+	RPMH_VREG(smps2,  pmic4_ftsmps426, VRM, smp,  2, vdd_s2),
+	RPMH_VREG(smps3,  pmic4_ftsmps426, VRM, smp,  3, vdd_s3),
+	RPMH_VREG(smps4,  pmic4_ftsmps426, VRM, smp,  4, vdd_s4),
+};
+
+static const struct rpmh_pmic_init_data pm8998_pmic_data = {
+	.name		= "PM8998",
+	.vreg_data	= pm8998_vreg_data,
+	.count		= ARRAY_SIZE(pm8998_vreg_data),
+};
+
+static const struct rpmh_pmic_init_data pmi8998_pmic_data = {
+	.name		= "PMI8998",
+	.vreg_data	= pmi8998_vreg_data,
+	.count		= ARRAY_SIZE(pmi8998_vreg_data),
+};
+
+static const struct rpmh_pmic_init_data pm8005_pmic_data = {
+	.name		= "PM8005",
+	.vreg_data	= pm8005_vreg_data,
+	.count		= ARRAY_SIZE(pm8005_vreg_data),
+};
+
+static const struct of_device_id rpmh_regulator_match_table[] = {
+	{
+		.compatible = "qcom,pm8998-rpmh-regulators",
+		.data = &pm8998_pmic_data,
+	},
+	{
+		.compatible = "qcom,pmi8998-rpmh-regulators",
+		.data = &pmi8998_pmic_data,
+	},
+	{
+		.compatible = "qcom,pm8005-rpmh-regulators",
+		.data = &pm8005_pmic_data,
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(of, rpmh_regulator_match_table);
+
+/**
+ * rpmh_regulator_probe() - probe an RPMh PMIC and register regulators for each
+ *		of the regulator nodes associated with it
+ * @pdev:		Pointer to the platform device of the RPMh PMIC
+ *
+ * Return: 0 on success, errno on failure
+ */
+static int rpmh_regulator_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	const struct of_device_id *match;
+	struct rpmh_pmic *pmic;
+	struct device_node *node;
+	int ret, i;
+
+	node = dev->of_node;
+
+	if (!node) {
+		dev_err(dev, "Device tree node is missing\n");
+		return -EINVAL;
+	}
+
+	ret = cmd_db_ready();
+	if (ret < 0) {
+		if (ret != -EPROBE_DEFER)
+			dev_err(dev, "Command DB not available, ret=%d\n", ret);
+		return ret;
+	}
+
+	pmic = devm_kzalloc(dev, sizeof(*pmic), GFP_KERNEL);
+	if (!pmic)
+		return -ENOMEM;
+
+	pmic->dev = dev;
+	platform_set_drvdata(pdev, pmic);
+
+	pmic->rpmh_client = rpmh_get_client(pdev);
+	if (IS_ERR(pmic->rpmh_client)) {
+		ret = PTR_ERR(pmic->rpmh_client);
+		if (ret != -EPROBE_DEFER)
+			dev_err(dev, "failed to request RPMh client, ret=%d\n",
+				ret);
+		return ret;
+	}
+
+	match = of_match_node(rpmh_regulator_match_table, node);
+	if (match) {
+		pmic->init_data = match->data;
+	} else {
+		dev_err(dev, "could not find compatible string match\n");
+		ret = -ENODEV;
+		goto cleanup;
+	}
+
+	ret = of_property_read_string(node, "qcom,pmic-id",
+				     &pmic->pmic_id);
+	if (ret < 0) {
+		dev_err(dev, "qcom,pmic-id missing in DT node\n");
+		goto cleanup;
+	}
+
+	ret = rpmh_regulator_allocate_vreg(pmic);
+	if (ret < 0) {
+		dev_err(dev, "failed to allocate regulator subnode array, ret=%d\n",
+			ret);
+		goto cleanup;
+	}
+
+	for (i = 0; i < pmic->vreg_count; i++) {
+		ret = rpmh_regulator_init_vreg(&pmic->vreg[i]);
+		if (ret < 0) {
+			dev_err(dev, "unable to initialize rpmh-regulator vreg %s, ret=%d\n",
+				pmic->vreg[i].of_node->name, ret);
+			goto cleanup;
+		}
+	}
+
+	dev_dbg(dev, "successfully probed %d %s regulators\n",
+		pmic->vreg_count, pmic->init_data->name);
+
+	return ret;
+
+cleanup:
+	rpmh_release(pmic->rpmh_client);
+
+	return ret;
+}
+
+static int rpmh_regulator_remove(struct platform_device *pdev)
+{
+	struct rpmh_pmic *pmic = platform_get_drvdata(pdev);
+
+	rpmh_release(pmic->rpmh_client);
+
+	return 0;
+}
+
+static struct platform_driver rpmh_regulator_driver = {
+	.driver		= {
+		.name		= "qcom-rpmh-regulator",
+		.of_match_table	= rpmh_regulator_match_table,
+		.owner		= THIS_MODULE,
+	},
+	.probe		= rpmh_regulator_probe,
+	.remove		= rpmh_regulator_remove,
+};
+
+static int rpmh_regulator_init(void)
+{
+	return platform_driver_register(&rpmh_regulator_driver);
+}
+
+static void rpmh_regulator_exit(void)
+{
+	platform_driver_unregister(&rpmh_regulator_driver);
+}
+
+arch_initcall(rpmh_regulator_init);
+module_exit(rpmh_regulator_exit);
+
+MODULE_DESCRIPTION("Qualcomm RPMh regulator driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/dt-bindings/regulator/qcom,rpmh-regulator.h b/include/dt-bindings/regulator/qcom,rpmh-regulator.h
new file mode 100644
index 0000000..f854e0e
--- /dev/null
+++ b/include/dt-bindings/regulator/qcom,rpmh-regulator.h
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2018, The Linux Foundation. All rights reserved. */
+
+#ifndef __QCOM_RPMH_REGULATOR_H
+#define __QCOM_RPMH_REGULATOR_H
+
+/*
+ * These mode constants may be used for qcom,allowed-modes and qcom,init-mode
+ * properties of an RPMh resource.  Each type of regulator supports a subset of
+ * the possible modes.
+ *
+ * %RPMH_REGULATOR_MODE_PASS:	Pass-through mode in which output is directly
+ *				tied to input.  This mode is only supported by
+ *				BOB type regulators.
+ * %RPMH_REGULATOR_MODE_RET:	Retention mode in which only an extremely small
+ *				load current is allowed.  This mode is supported
+ *				by LDO and SMPS type regulators.
+ * %RPMH_REGULATOR_MODE_LPM:	Low power mode in which a small load current is
+ *				allowed.  This mode corresponds to PFM for SMPS
+ *				and BOB type regulators.  This mode is supported
+ *				by LDO, HFSMPS, BOB, and PMIC4 FTSMPS type
+ *				regulators.
+ * %RPMH_REGULATOR_MODE_AUTO:	Auto mode in which the regulator hardware
+ *				automatically switches between LPM and HPM based
+ *				upon the real-time load current.  This mode is
+ *				supported by HFSMPS, BOB, and PMIC4 FTSMPS type
+ *				regulators.
+ * %RPMH_REGULATOR_MODE_HPM:	High power mode in which the full rated current
+ *				of the regulator is allowed.  This mode
+ *				corresponds to PWM for SMPS and BOB type
+ *				regulators.  This mode is supported by all types
+ *				of regulators.
+ */
+#define RPMH_REGULATOR_MODE_PASS	0
+#define RPMH_REGULATOR_MODE_RET		1
+#define RPMH_REGULATOR_MODE_LPM		2
+#define RPMH_REGULATOR_MODE_AUTO	3
+#define RPMH_REGULATOR_MODE_HPM		4
+
+#endif
-- 
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