power: regulator: add qcom-rpmh-regulator

Add a regulator driver for controlling the PMIC rails via the RPMh on
Qualcomm platforms. This driver is restricted to only know about rails
which are required by u-boot.

Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>
diff --git a/drivers/power/regulator/Kconfig b/drivers/power/regulator/Kconfig
index 102ec7b..bc061c2 100644
--- a/drivers/power/regulator/Kconfig
+++ b/drivers/power/regulator/Kconfig
@@ -216,6 +216,14 @@
 	features for gpio regulators. The driver implements get/set for
 	voltage value.
 
+config DM_REGULATOR_QCOM_RPMH
+	bool "Enable driver model for Qualcomm RPMh regulator"
+	depends on DM_REGULATOR && QCOM_RPMH
+	---help---
+	  Enable support for the Qualcomm RPMh regulator. The driver
+	  implements get/set api for a limited set of regulators used
+	  by u-boot.
+
 config SPL_DM_REGULATOR_GPIO
 	bool "Enable Driver Model for GPIO REGULATOR in SPL"
 	depends on DM_REGULATOR_GPIO && SPL_GPIO
diff --git a/drivers/power/regulator/Makefile b/drivers/power/regulator/Makefile
index f79932d..56a5276 100644
--- a/drivers/power/regulator/Makefile
+++ b/drivers/power/regulator/Makefile
@@ -21,6 +21,7 @@
 obj-$(CONFIG_$(SPL_)DM_REGULATOR_COMMON) += regulator_common.o
 obj-$(CONFIG_$(SPL_)DM_REGULATOR_FIXED) += fixed.o
 obj-$(CONFIG_$(SPL_)DM_REGULATOR_GPIO) += gpio-regulator.o
+obj-$(CONFIG_DM_REGULATOR_QCOM_RPMH) += qcom-rpmh-regulator.o
 obj-$(CONFIG_$(SPL_TPL_)REGULATOR_RK8XX) += rk8xx.o
 obj-$(CONFIG_DM_REGULATOR_S2MPS11) += s2mps11_regulator.o
 obj-$(CONFIG_REGULATOR_S5M8767) += s5m8767.o
diff --git a/drivers/power/regulator/qcom-rpmh-regulator.c b/drivers/power/regulator/qcom-rpmh-regulator.c
new file mode 100644
index 0000000..c4a1eb2
--- /dev/null
+++ b/drivers/power/regulator/qcom-rpmh-regulator.c
@@ -0,0 +1,516 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2018-2021, The Linux Foundation. All rights reserved.
+
+#include <linux/err.h>
+#include <dm/device_compat.h>
+#include <dm/device.h>
+#include <dm/devres.h>
+#include <dm/lists.h>
+#include <power/regulator.h>
+#include <log.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
+ * @VRM:	RPMh VRM accelerator which supports voting on enable, voltage,
+ *		and mode of LDO, SMPS, and BOB type PMIC regulators.
+ * @XOB:	RPMh XOB accelerator which supports voting on the enable state
+ *		of PMIC regulators.
+ */
+enum rpmh_regulator_type {
+	VRM,
+	XOB,
+};
+
+enum rpmh_regulator_mode {
+	REGULATOR_MODE_RETENTION,
+	REGULATOR_MODE_LPM,
+	REGULATOR_MODE_AUTO,
+	REGULATOR_MODE_HPM,
+};
+
+#define RPMH_REGULATOR_REG_VRM_VOLTAGE		0x0
+#define RPMH_REGULATOR_REG_ENABLE		0x4
+#define RPMH_REGULATOR_REG_VRM_MODE		0x8
+
+#define PMIC4_LDO_MODE_RETENTION		4
+#define PMIC4_LDO_MODE_LPM			5
+#define PMIC4_LDO_MODE_HPM			7
+
+#define PMIC4_SMPS_MODE_RETENTION		4
+#define PMIC4_SMPS_MODE_PFM			5
+#define PMIC4_SMPS_MODE_AUTO			6
+#define PMIC4_SMPS_MODE_PWM			7
+
+#define PMIC4_BOB_MODE_PASS			0
+#define PMIC4_BOB_MODE_PFM			1
+#define PMIC4_BOB_MODE_AUTO			2
+#define PMIC4_BOB_MODE_PWM			3
+
+#define PMIC5_LDO_MODE_RETENTION		3
+#define PMIC5_LDO_MODE_LPM			4
+#define PMIC5_LDO_MODE_HPM			7
+
+#define PMIC5_SMPS_MODE_RETENTION		3
+#define PMIC5_SMPS_MODE_PFM			4
+#define PMIC5_SMPS_MODE_AUTO			6
+#define PMIC5_SMPS_MODE_PWM			7
+
+#define PMIC5_BOB_MODE_PASS			2
+#define PMIC5_BOB_MODE_PFM			4
+#define PMIC5_BOB_MODE_AUTO			6
+#define PMIC5_BOB_MODE_PWM			7
+
+/**
+ * struct linear_range - table of selector - value pairs
+ *
+ * Define a lookup-table for range of values. Intended to help when looking
+ * for a register value matching certaing physical measure (like voltage).
+ * Usable when increment of one in register always results a constant increment
+ * of the physical measure (like voltage).
+ *
+ * @min:  Lowest value in range
+ * @min_sel: Lowest selector for range
+ * @max_sel: Highest selector for range
+ * @step: Value step size
+ */
+struct linear_range {
+	unsigned int min;
+	unsigned int min_sel;
+	unsigned int max_sel;
+	unsigned int step;
+};
+
+/* Initialize struct linear_range for regulators */
+#define REGULATOR_LINEAR_RANGE(_min_uV, _min_sel, _max_sel, _step_uV)	\
+{									\
+	.min		= _min_uV,					\
+	.min_sel	= _min_sel,					\
+	.max_sel	= _max_sel,					\
+	.step		= _step_uV,					\
+}
+
+/**
+ * struct rpmh_vreg_hw_data - RPMh regulator hardware configurations
+ * @regulator_type:		RPMh accelerator type used to manage this
+ *				regulator
+ * @ops:			Pointer to regulator ops callback structure
+ * @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
+ * @hpm_min_load_uA:		Minimum load current in microamps that requires
+ *				high power mode (HPM) operation.  This is used
+ *				for LDO hardware type regulators only.
+ * @pmic_mode_map:		Array indexed by regulator framework mode
+ *				containing PMIC hardware modes.  Must be large
+ *				enough to index all framework modes supported
+ *				by this regulator hardware type.
+ * @of_map_mode:		Maps an RPMH_REGULATOR_MODE_* mode value defined
+ *				in device tree to a regulator framework mode
+ */
+struct rpmh_vreg_hw_data {
+	enum rpmh_regulator_type		regulator_type;
+	const struct dm_regulator_ops		*ops;
+	struct linear_range			voltage_range;
+	int					n_voltages;
+	int					hpm_min_load_uA;
+	struct dm_regulator_mode		*pmic_mode_map;
+	int					n_modes;
+	unsigned int				(*of_map_mode)(unsigned int mode);
+};
+
+/**
+ * struct rpmh_vreg - individual RPMh regulator data structure encapsulating a
+ *		single regulator device
+ * @dev:			Device pointer for the top-level PMIC RPMh
+ *				regulator parent device.  This is used as a
+ *				handle in RPMh write requests.
+ * @addr:			Base address of the regulator resource within
+ *				an RPMh accelerator
+ * @rdesc:			Regulator descriptor
+ * @hw_data:			PMIC regulator configuration data for this RPMh
+ *				regulator
+ * @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).
+ * @enabled:			Flag indicating if the regulator is enabled or
+ *				not
+ * @bypassed:			Boolean indicating if the regulator is in
+ *				bypass (pass-through) mode or not.  This is
+ *				only used by BOB rpmh-regulator resources.
+ * @uv:				Selector used for get_voltage_sel() and
+ *				set_value() callbacks
+ * @mode:			RPMh VRM regulator current framework mode
+ */
+struct rpmh_vreg {
+	struct udevice			*dev;
+	u32				addr;
+	const struct rpmh_vreg_hw_data	*hw_data;
+	bool				always_wait_for_ack;
+
+	int				enabled;
+	bool				bypassed;
+	int				uv;
+	int			mode;
+};
+
+/**
+ * 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:		RPMh regulator resource name format string.
+ *				This must include exactly one field: '%s' which
+ *				is filled at run-time with the PMIC ID provided
+ *				by device tree property qcom,pmic-id.  Example:
+ *				"ldo%s1" for RPMh resource "ldoa1".
+ * @supply_name:		Parent supply regulator name
+ * @hw_data:			Configuration data for this PMIC regulator type
+ */
+struct rpmh_vreg_init_data {
+	const char			*name;
+	const char			*resource_name;
+	const char			*supply_name;
+	const struct rpmh_vreg_hw_data	*hw_data;
+};
+
+/**
+ * rpmh_regulator_send_request() - send the request to RPMh
+ * @vreg:		Pointer to the RPMh regulator
+ * @cmd:		Pointer to the RPMh command to send
+ * @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, bool wait_for_ack)
+{
+	int ret;
+
+	if (wait_for_ack || vreg->always_wait_for_ack)
+		ret = rpmh_write(vreg->dev->parent, RPMH_ACTIVE_ONLY_STATE, cmd, 1);
+	else
+		ret = rpmh_write_async(vreg->dev->parent, RPMH_ACTIVE_ONLY_STATE, cmd,
+					1);
+
+	return ret;
+}
+
+static int _rpmh_regulator_vrm_set_value(struct udevice *rdev,
+				int uv, bool wait_for_ack)
+{
+	struct rpmh_vreg *vreg = dev_get_priv(rdev);
+	struct tcs_cmd cmd = {
+		.addr = vreg->addr + RPMH_REGULATOR_REG_VRM_VOLTAGE,
+	};
+	int ret;
+
+	/* VRM voltage control register is set with voltage in millivolts. */
+	uv = (uv / vreg->hw_data->voltage_range.step) *
+		(vreg->hw_data->voltage_range.step / 1000);
+	cmd.data = uv; // XXX: CHECKME
+
+	ret = rpmh_regulator_send_request(vreg, &cmd, wait_for_ack);
+	if (!ret)
+		vreg->uv = uv;
+
+	return ret;
+}
+
+static int rpmh_regulator_vrm_set_value(struct udevice *rdev,
+					int uv)
+{
+	struct rpmh_vreg *vreg = dev_get_priv(rdev);
+
+	debug("%s: set_value %d (current %d)\n", rdev->name, uv, vreg->uv);
+
+	if (vreg->enabled == -EINVAL) {
+		/*
+		 * Cache the voltage and send it later when the regulator is
+		 * enabled or disabled.
+		 */
+		vreg->uv = uv;
+		return 0;
+	}
+
+	return _rpmh_regulator_vrm_set_value(rdev, uv,
+					uv > vreg->uv);
+}
+
+static int rpmh_regulator_vrm_get_value(struct udevice *rdev)
+{
+	struct rpmh_vreg *vreg = dev_get_priv(rdev);
+
+	debug("%s: get_value %d\n", rdev->name, vreg->uv);
+
+	return vreg->uv;
+}
+
+static int rpmh_regulator_is_enabled(struct udevice *rdev)
+{
+	struct rpmh_vreg *vreg = dev_get_priv(rdev);
+
+	debug("%s: is_enabled %d\n", rdev->name, vreg->enabled);
+
+	return vreg->enabled;
+}
+
+static int rpmh_regulator_set_enable_state(struct udevice *rdev,
+					bool enable)
+{
+	struct rpmh_vreg *vreg = dev_get_priv(rdev);
+	struct tcs_cmd cmd = {
+		.addr = vreg->addr + RPMH_REGULATOR_REG_ENABLE,
+		.data = enable,
+	};
+	int ret;
+
+	debug("%s: set_enable %d (current %d)\n", rdev->name, enable,
+	       vreg->enabled);
+
+	if (vreg->enabled == -EINVAL &&
+	    vreg->uv != -ENOTRECOVERABLE) {
+		ret = _rpmh_regulator_vrm_set_value(rdev,
+						vreg->uv, true);
+		if (ret < 0)
+			return ret;
+	}
+
+	ret = rpmh_regulator_send_request(vreg, &cmd, enable);
+	if (!ret)
+		vreg->enabled = enable;
+
+	return ret;
+}
+
+static int rpmh_regulator_vrm_set_mode_bypass(struct rpmh_vreg *vreg,
+					unsigned int mode, bool bypassed)
+{
+	struct tcs_cmd cmd = {
+		.addr = vreg->addr + RPMH_REGULATOR_REG_VRM_MODE,
+	};
+	struct dm_regulator_mode *pmic_mode;
+	int i;
+
+	if (mode > REGULATOR_MODE_HPM)
+		return -EINVAL;
+
+	for (i = 0; i < vreg->hw_data->n_modes; i++) {
+		pmic_mode = &vreg->hw_data->pmic_mode_map[i];
+		if (pmic_mode->id == mode)
+			break;
+	}
+	if (pmic_mode->id != mode) {
+		printf("Invalid mode %d\n", mode);
+		return -EINVAL;
+	}
+
+	if (bypassed)
+		cmd.data = PMIC4_BOB_MODE_PASS;
+	else
+		cmd.data = pmic_mode->id;
+
+	return rpmh_regulator_send_request(vreg, &cmd, true);
+}
+
+static int rpmh_regulator_vrm_set_mode(struct udevice *rdev,
+					int mode)
+{
+	struct rpmh_vreg *vreg = dev_get_priv(rdev);
+	int ret;
+
+	debug("%s: set_mode %d (current %d)\n", rdev->name, mode, vreg->mode);
+
+	if (mode == vreg->mode)
+		return 0;
+
+	ret = rpmh_regulator_vrm_set_mode_bypass(vreg, mode, vreg->bypassed);
+	if (!ret)
+		vreg->mode = mode;
+
+	return ret;
+}
+
+static int rpmh_regulator_vrm_get_mode(struct udevice *rdev)
+{
+	struct rpmh_vreg *vreg = dev_get_priv(rdev);
+
+	debug("%s: get_mode %d\n", rdev->name, vreg->mode);
+
+	return vreg->mode;
+}
+
+static const struct dm_regulator_ops rpmh_regulator_vrm_drms_ops = {
+	.get_value = rpmh_regulator_vrm_get_value,
+	.set_value = rpmh_regulator_vrm_set_value,
+	.set_enable = rpmh_regulator_set_enable_state,
+	.get_enable = rpmh_regulator_is_enabled,
+	.set_mode = rpmh_regulator_vrm_set_mode,
+	.get_mode = rpmh_regulator_vrm_get_mode,
+};
+
+static struct dm_regulator_mode pmic_mode_map_pmic5_ldo[] = {
+	{
+		.id = REGULATOR_MODE_RETENTION,
+		.register_value = PMIC5_LDO_MODE_RETENTION,
+		.name = "PMIC5_LDO_MODE_RETENTION"
+	}, {
+		.id = REGULATOR_MODE_LPM,
+		.register_value = PMIC5_LDO_MODE_LPM,
+		.name = "PMIC5_LDO_MODE_LPM"
+	}, {
+		.id = REGULATOR_MODE_HPM,
+		.register_value = PMIC5_LDO_MODE_HPM,
+		.name = "PMIC5_LDO_MODE_HPM"
+	},
+};
+
+static const struct rpmh_vreg_hw_data pmic5_pldo = {
+	.regulator_type = VRM,
+	.ops = &rpmh_regulator_vrm_drms_ops,
+	.voltage_range = REGULATOR_LINEAR_RANGE(1504000, 0, 255, 8000),
+	.n_voltages = 256,
+	.hpm_min_load_uA = 10000,
+	.pmic_mode_map = pmic_mode_map_pmic5_ldo,
+	.n_modes = ARRAY_SIZE(pmic_mode_map_pmic5_ldo),
+};
+
+#define RPMH_VREG(_name, _resource_name, _hw_data, _supply_name) \
+{ \
+	.name		= _name, \
+	.resource_name	= _resource_name, \
+	.hw_data	= _hw_data, \
+	.supply_name	= _supply_name, \
+}
+
+static const struct rpmh_vreg_init_data pm8150l_vreg_data[] = {
+	RPMH_VREG("ldo11",  "ldo%s11", &pmic5_pldo,      "vdd-l7-l11"),
+	{}
+};
+
+/* probe an individual regulator */
+static int rpmh_regulator_probe(struct udevice *dev)
+{
+	const struct rpmh_vreg_init_data *init_data;
+	struct rpmh_vreg *priv;
+	struct dm_regulator_uclass_plat *plat_data;
+
+	init_data = (const struct rpmh_vreg_init_data *)dev_get_driver_data(dev);
+	priv = dev_get_priv(dev);
+	plat_data = dev_get_uclass_plat(dev);
+
+	priv->dev = dev;
+	priv->addr = cmd_db_read_addr(dev->name);
+	if (!priv->addr) {
+		printf("Failed to read RPMh address for %s\n", dev->name);
+		return -ENODEV;
+	}
+
+	priv->hw_data = init_data->hw_data;
+	priv->enabled = -EINVAL;
+	priv->uv = -ENOTRECOVERABLE;
+	if (ofnode_read_u32(dev_ofnode(dev), "regulator-initial-mode", &priv->mode))
+		priv->mode = -EINVAL;
+
+	// handle stepping
+	// almost there!!!
+	plat_data->mode = priv->hw_data->pmic_mode_map;
+	plat_data->mode_count = priv->hw_data->n_modes;
+
+	return 0;
+}
+
+/* for non-drm, xob, or bypass regulators add additional driver definitions */
+U_BOOT_DRIVER(rpmh_regulator_drm) = {
+	.name = "rpmh_regulator_drm",
+	.id = UCLASS_REGULATOR,
+	.probe = rpmh_regulator_probe,
+	.priv_auto = sizeof(struct rpmh_vreg),
+	.ops = &rpmh_regulator_vrm_drms_ops,
+};
+
+/* This driver intentionally only supports a subset of the available regulators.
+ * This function checks to see if a given regulator node in DT matches a regulator
+ * defined in the driver.
+ */
+static const struct rpmh_vreg_init_data *
+vreg_get_init_data(const struct rpmh_vreg_init_data *init_data, ofnode node) {
+        const struct rpmh_vreg_init_data *data;
+
+	for(data = init_data; data->name; data++) {
+		if (!strncmp(data->name, ofnode_get_name(node), strlen(data->name)))
+			return data;
+	}
+
+	return NULL;
+}
+
+static int rpmh_regulators_bind(struct udevice *dev)
+{
+	const struct rpmh_vreg_init_data *init_data, *data;
+	const char *pmic_id;
+	char *name;
+	struct driver *drv;
+	ofnode node;
+	int ret;
+	size_t namelen;
+
+	init_data = (const struct rpmh_vreg_init_data *)dev_get_driver_data(dev);
+	if (!init_data) {
+		printf("No RPMh regulator init data\n");
+		return -ENODEV;
+	}
+
+	pmic_id = ofnode_read_string(dev_ofnode(dev), "qcom,pmic-id");
+	if (!pmic_id) {
+		printf("No PMIC ID\n");
+		return -ENODEV;
+	}
+
+	drv = lists_driver_lookup_name("rpmh_regulator_drm");
+
+	ofnode_for_each_subnode(node, dev_ofnode(dev)) {
+		data = vreg_get_init_data(init_data, node);
+		if (!data)
+			continue;
+
+		/* %s is replaced with pmic_id, so subtract 2, then add 1 for the null terminator */
+		namelen = strlen(data->resource_name) + strlen(pmic_id) - 1;
+		name = devm_kzalloc(dev, namelen, GFP_KERNEL);
+		ret = snprintf(name, namelen, data->resource_name, pmic_id);
+		if (ret < 0 || ret >= namelen) {
+			printf("Failed to create RPMh regulator name\n");
+			return -ENOMEM;
+		}
+
+		ret = device_bind_with_driver_data(dev, drv, name, (ulong)data,
+						   node, NULL);
+	}
+
+	return 0;
+}
+
+static const struct udevice_id rpmh_regulator_ids[] = {
+	{
+		.compatible = "qcom,pm8150l-rpmh-regulators",
+		.data = (ulong)pm8150l_vreg_data,
+	},
+	{ /* sentinal */ },
+};
+
+/* Driver for a 'bank' of regulators. This creates devices for each
+ * individual regulator
+ */
+U_BOOT_DRIVER(rpmh_regulators) = {
+	.name = "rpmh_regulators",
+	.id = UCLASS_MISC,
+	.bind = rpmh_regulators_bind,
+	.of_match = rpmh_regulator_ids,
+	.ops = &rpmh_regulator_vrm_drms_ops,
+};
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..86713dc
--- /dev/null
+++ b/include/dt-bindings/regulator/qcom,rpmh-regulator.h
@@ -0,0 +1,36 @@
+/* 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 to specify modes for various RPMh regulator
+ * device tree properties (e.g. regulator-initial-mode).  Each type of regulator
+ * supports a subset of the possible modes.
+ *
+ * %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_RET		0
+#define RPMH_REGULATOR_MODE_LPM		1
+#define RPMH_REGULATOR_MODE_AUTO	2
+#define RPMH_REGULATOR_MODE_HPM		3
+
+#endif