regulator: Add changes to support AP72200 buck-boost regulator

Add driver for AP72200 buck-boost regulator by vendor
"Diodes Incorporated" so that it can output a specified
voltage between 2.6 to 5.14 V, which can be set via
"regulator-min-voltage" DT property.

Change-Id: If18aae6814e3e5a62f1ec2f611dacac7b035f9f0
Signed-off-by: Umang Chheda <quic_uchheda@quicinc.com>

drivers/regulator/Kconfig

@@ -194,6 +194,16 @@ config REGULATOR_ARM_SCMI
 	  This driver uses SCMI Message Protocol driver to interact with the
 	  firmware providing the device Voltage functionality.
 
+config REGULATOR_AP72200
+	tristate "Diodes Incorporated AP72200 Buck-Boost Regulator Driver"
+	depends on I2C
+	help
+	  This driver provides support for AP72200 buck-boost regulator with
+	  a input range of 2.3 to 5.5 V and output range of 2.6 to 5.14V.
+
+	  Say M here if you want to include support for the regulator as a
+          module. The module will be named "ap72200-regulator".
+
 config REGULATOR_AS3711
 	tristate "AS3711 PMIC"
 	depends on MFD_AS3711

drivers/regulator/Makefile

@@ -26,6 +26,7 @@ obj-$(CONFIG_REGULATOR_ANATOP) += anatop-regulator.o
 obj-$(CONFIG_REGULATOR_ARIZONA_LDO1) += arizona-ldo1.o
 obj-$(CONFIG_REGULATOR_ARIZONA_MICSUPP) += arizona-micsupp.o
 obj-$(CONFIG_REGULATOR_ARM_SCMI) += scmi-regulator.o
+obj-$(CONFIG_REGULATOR_AP72200) += ap72200-regulator.o
 obj-$(CONFIG_REGULATOR_AS3711) += as3711-regulator.o
 obj-$(CONFIG_REGULATOR_AS3722) += as3722-regulator.o
 obj-$(CONFIG_REGULATOR_ATC260X) += atc260x-regulator.o

drivers/regulator/ap72200-regulator.c

@@ -0,0 +1,200 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2023, Qualcomm Innovation Center, Inc. All rights reserved. */
+
+#define pr_fmt(fmt) "ap72200-reg: %s: " fmt, __func__
+
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/regmap.h>
+#include <linux/gpio/consumer.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/debug-regulator.h>
+#include <linux/regulator/machine.h>
+#include <linux/regulator/of_regulator.h>
+#include <linux/regulator/proxy-consumer.h>
+
+#define AP72200_CFG_REG2_ADDR	0x3
+#define AP72200_VSEL_REG_ADDR	0x4
+
+#define AP72200_BB_EN_BIT	BIT(6)
+
+#define AP72200_MIN_UV	2600000
+#define AP72200_MAX_UV	5140000
+#define AP72200_STEP_UV	20000
+
+struct ap72200_vreg {
+	struct device		*dev;
+	struct device_node	*of_node;
+	struct regulator_desc	rdesc;
+	struct regulator_dev	*rdev;
+	struct regmap		*regmap;
+	struct gpio_desc	*ena_gpiod;
+	bool			is_enabled;
+};
+
+static const struct regmap_config ap27700_regmap_config = {
+	.reg_bits		= 8,
+	.val_bits		= 8,
+	.max_register		= 0x4,
+};
+
+static int ap72200_vreg_enable(struct regulator_dev *rdev)
+{
+	struct ap72200_vreg *vreg = rdev_get_drvdata(rdev);
+	int rc, val;
+
+	val = DIV_ROUND_UP(vreg->rdesc.fixed_uV - AP72200_MIN_UV, AP72200_STEP_UV);
+
+	/* Set the voltage */
+	rc = regmap_write(vreg->regmap, AP72200_VSEL_REG_ADDR,
+				val);
+	if (rc) {
+		dev_err(vreg->dev, "Failed to set voltage rc: %d\n", rc);
+		return rc;
+	}
+
+	/* Enable VOUT */
+	rc = regmap_update_bits(vreg->regmap, AP72200_CFG_REG2_ADDR,
+				AP72200_BB_EN_BIT, AP72200_BB_EN_BIT);
+	if (rc) {
+		dev_err(vreg->dev, "Failed to enable VOUT rc :%d\n", rc);
+		return rc;
+	}
+
+	vreg->is_enabled = true;
+
+	return rc;
+}
+
+static int ap72200_vreg_disable(struct regulator_dev *rdev)
+{
+	struct ap72200_vreg *vreg = rdev_get_drvdata(rdev);
+	int rc;
+
+	/* Disable VOUT */
+	rc = regmap_update_bits(vreg->regmap, AP72200_CFG_REG2_ADDR,
+					AP72200_BB_EN_BIT, 0);
+	if (rc) {
+		dev_err(vreg->dev, "Failed to disable VOUT rc :%d\n", rc);
+		return rc;
+	}
+
+	vreg->is_enabled = false;
+
+	return rc;
+}
+
+static int ap72200_is_enabled(struct regulator_dev *rdev)
+{
+	struct ap72200_vreg *vreg = rdev_get_drvdata(rdev);
+
+	return vreg->is_enabled;
+}
+
+static const struct regulator_ops ap72200_ops = {
+	.enable			= ap72200_vreg_enable,
+	.disable		= ap72200_vreg_disable,
+	.is_enabled		= ap72200_is_enabled,
+};
+
+static int ap72200_probe(struct i2c_client *client,
+				const struct i2c_device_id *id)
+{
+	struct ap72200_vreg *vreg;
+	struct regulator_config reg_config = {};
+	struct regulator_init_data *init_data;
+	int ret;
+
+	vreg = devm_kzalloc(&client->dev, sizeof(*vreg), GFP_KERNEL);
+	if (!vreg)
+		return -ENOMEM;
+
+	vreg->regmap = devm_regmap_init_i2c(client, &ap27700_regmap_config);
+	if (IS_ERR(vreg->regmap)) {
+		ret = PTR_ERR(vreg->regmap);
+		dev_err(&client->dev, "regmap init failed, err %d\n", ret);
+		return ret;
+	}
+
+	vreg->dev               = &client->dev;
+	vreg->of_node           = client->dev.of_node;
+	vreg->rdesc.ops         = &ap72200_ops;
+	vreg->rdesc.owner       = THIS_MODULE;
+	vreg->rdesc.type        = REGULATOR_VOLTAGE;
+
+	init_data = of_get_regulator_init_data(vreg->dev,
+						vreg->of_node, &vreg->rdesc);
+	if (init_data == NULL)
+		return -ENODATA;
+
+	if (init_data->constraints.name == NULL) {
+		dev_err(&client->dev, "%s: regulator name not specified\n", __func__);
+		return -EINVAL;
+	}
+
+	if (init_data->constraints.min_uV != init_data->constraints.max_uV) {
+		dev_err(&client->dev,
+			"Fixed regulator specified with variable voltages\n");
+		return -EINVAL;
+	}
+
+	init_data->constraints.min_uV   = max(init_data->constraints.min_uV, AP72200_MIN_UV);
+	init_data->constraints.min_uV   = min(init_data->constraints.min_uV, AP72200_MAX_UV);
+
+	vreg->rdesc.n_voltages	= 1;
+	vreg->rdesc.fixed_uV	= init_data->constraints.min_uV;
+	vreg->rdesc.name	= init_data->constraints.name;
+
+	reg_config.dev		= vreg->dev;
+	reg_config.init_data	= init_data;
+	reg_config.of_node	= vreg->of_node;
+	reg_config.driver_data	= vreg;
+
+	vreg->ena_gpiod = gpiod_get(vreg->dev, "enable", GPIOD_OUT_HIGH);
+	if (IS_ERR(vreg->ena_gpiod)) {
+		dev_err(&client->dev, "Failed to get enable GPIO\n");
+		return PTR_ERR(vreg->ena_gpiod);
+	}
+
+	/* Keep the EN pin of this regulator always high */
+	gpiod_set_value_cansleep(vreg->ena_gpiod, 1);
+
+	vreg->rdev = devm_regulator_register(vreg->dev, &vreg->rdesc, &reg_config);
+	if (IS_ERR(vreg->rdev)) {
+		ret = PTR_ERR(vreg->rdev);
+		dev_err(vreg->dev, "Failed to register regulator: %d\n", ret);
+		return ret;
+	}
+
+	ret = devm_regulator_debug_register(vreg->dev, vreg->rdev);
+	if (ret)
+		dev_err(vreg->dev, "Failed to register debug regulator, rc=%d\n", ret);
+
+	return 0;
+}
+
+static const struct of_device_id ap72200_match_tbl[] = {
+	{ .compatible = "diodes,ap72200", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ap72200_match_tbl);
+
+static const struct i2c_device_id ap72200_id[] = {
+	{ "ap72200", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ap72200_id);
+
+static struct i2c_driver ap72200_i2c_driver = {
+	.driver = {
+		.name		= "ap72200",
+		.of_match_table	= ap72200_match_tbl,
+	},
+	.probe		= ap72200_probe,
+	.id_table	= ap72200_id,
+};
+module_i2c_driver(ap72200_i2c_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("i2c:ap72200-regulator");