[PATCH v2 4/6] regulator: Add support for QCOM PMIC VBUS booster

[Wesley Cheng <wcheng@codeaurora.org>]

Some Qualcomm PMICs have the capability to source the VBUS output to
connected peripherals.  This driver will register a regulator to the
regulator list to enable or disable this source by an external driver.

Signed-off-by: Wesley Cheng <wcheng@codeaurora.org>
---
 drivers/regulator/Kconfig                   |  10 ++
 drivers/regulator/Makefile                  |   1 +
 drivers/regulator/qcom_usb_vbus-regulator.c | 147 ++++++++++++++++++++
 3 files changed, 158 insertions(+)
 create mode 100644 drivers/regulator/qcom_usb_vbus-regulator.c

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 074a2ef55943..f9165f9f9051 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -797,6 +797,16 @@ config REGULATOR_QCOM_SPMI
 	  Qualcomm SPMI PMICs as a module. The module will be named
 	  "qcom_spmi-regulator".
 
+config REGULATOR_QCOM_USB_VBUS
+	tristate "Qualcomm USB Vbus regulator driver"
+	depends on SPMI || COMPILE_TEST
+	help
+	  If you say yes to this option, support will be included for the
+	  regulator used to enable the VBUS output.
+
+	  Say M here if you want to include support for enabling the VBUS output
+	  as a module. The module will be named "qcom_usb-regulator".
+
 config REGULATOR_RC5T583
 	tristate "RICOH RC5T583 Power regulators"
 	depends on MFD_RC5T583
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index c0d6b96ebd78..cbab28aa7b56 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -89,6 +89,7 @@ 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-$(CONFIG_REGULATOR_QCOM_USB_VBUS) += qcom_usb_vbus-regulator.o
 obj-$(CONFIG_REGULATOR_PALMAS) += palmas-regulator.o
 obj-$(CONFIG_REGULATOR_PFUZE100) += pfuze100-regulator.o
 obj-$(CONFIG_REGULATOR_PV88060) += pv88060-regulator.o
diff --git a/drivers/regulator/qcom_usb_vbus-regulator.c b/drivers/regulator/qcom_usb_vbus-regulator.c
new file mode 100644
index 000000000000..2b8129a04684
--- /dev/null
+++ b/drivers/regulator/qcom_usb_vbus-regulator.c
@@ -0,0 +1,147 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2020, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include <linux/regmap.h>
+
+#define CMD_OTG				0x40
+#define OTG_EN				BIT(0)
+#define OTG_CFG				0x53
+#define OTG_EN_SRC_CFG			BIT(1)
+
+struct qcom_vbus {
+	struct device	*dev;
+	u32		base;
+	struct regmap	*regmap;
+	struct regulator_dev *usb_vbus_reg;
+};
+
+static int qcom_usb_vbus_enable(struct regulator_dev *rdev)
+{
+	struct qcom_vbus *vbus_out = rdev_get_drvdata(rdev);
+	int rc;
+
+	rc = regmap_update_bits(vbus_out->regmap, vbus_out->base + CMD_OTG,
+				OTG_EN, OTG_EN);
+	if (rc)
+		dev_err(vbus_out->dev, "failed to enable usb_vbus\n");
+
+	return rc;
+}
+
+static int qcom_usb_vbus_disable(struct regulator_dev *rdev)
+{
+	struct qcom_vbus *vbus_out = rdev_get_drvdata(rdev);
+	int rc;
+
+	rc = regmap_update_bits(vbus_out->regmap, vbus_out->base + CMD_OTG,
+				OTG_EN, 0);
+	if (rc)
+		dev_err(vbus_out->dev, "failed to disable usb_vbus\n");
+
+	return rc;
+}
+
+static int qcom_usb_vbus_is_enabled(struct regulator_dev *rdev)
+{
+	struct qcom_vbus *vbus_out = rdev_get_drvdata(rdev);
+	unsigned int value = 0;
+	int rc;
+
+	rc = regmap_read(vbus_out->regmap, vbus_out->base + CMD_OTG, &value);
+	if (rc)
+		dev_err(vbus_out->dev, "failed to read OTG_CTL\n");
+
+	return !!(value & OTG_EN);
+}
+
+static const struct regulator_ops qcom_usb_vbus_reg_ops = {
+	.enable = qcom_usb_vbus_enable,
+	.disable = qcom_usb_vbus_disable,
+	.is_enabled = qcom_usb_vbus_is_enabled,
+};
+
+static const struct regulator_desc qcom_usb_vbus_rdesc = {
+	.name = "usb_vbus",
+	.ops = &qcom_usb_vbus_reg_ops,
+	.owner = THIS_MODULE,
+	.type = REGULATOR_VOLTAGE,
+};
+
+static const struct of_device_id qcom_usb_vbus_regulator_match[] = {
+	{ .compatible = "qcom,pm8150b-vbus-reg" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, qcom_usb_vbus_regulator_match);
+
+static int qcom_usb_vbus_regulator_probe(struct platform_device *pdev)
+{
+	struct qcom_vbus *vbus_out;
+	struct device *dev = &pdev->dev;
+	struct regulator_config config = { };
+	struct regulator_init_data init_data = { };
+	int ret;
+	u32 reg;
+
+	ret = of_property_read_u32(dev->of_node, "reg", &reg);
+	if (ret < 0) {
+		dev_err(dev, "no base address found\n");
+		return ret;
+	}
+
+	vbus_out = devm_kzalloc(dev, sizeof(vbus_out), GFP_KERNEL);
+	if (!vbus_out)
+		return -ENOMEM;
+	vbus_out->base = reg;
+	vbus_out->dev = dev;
+
+	vbus_out->regmap = dev_get_regmap(dev->parent, NULL);
+	if (!vbus_out->regmap) {
+		dev_err(dev, "Failed to get regmap\n");
+		return -ENOENT;
+	}
+
+	init_data.constraints.valid_ops_mask |= REGULATOR_CHANGE_STATUS;
+	config.dev = dev;
+	config.driver_data = vbus_out;
+	config.init_data = &init_data;
+
+	vbus_out->usb_vbus_reg = devm_regulator_register(dev,
+							 &qcom_usb_vbus_rdesc,
+							 &config);
+	if (IS_ERR(vbus_out->usb_vbus_reg)) {
+		ret = PTR_ERR(vbus_out->usb_vbus_reg);
+		dev_err(dev, "not able to register vbus reg %d\n", ret);
+		return ret;
+	}
+
+	/* Disable HW logic for VBUS enable */
+	regmap_update_bits(vbus_out->regmap, vbus_out->base + OTG_CFG,
+			   OTG_EN_SRC_CFG, 0);
+
+	return 0;
+}
+
+static struct platform_driver qcom_usb_vbus_regulator_driver = {
+	.driver		= {
+		.name	= "qcom-usb-vbus-regulator",
+		.of_match_table = qcom_usb_vbus_regulator_match,
+	},
+	.probe		= qcom_usb_vbus_regulator_probe,
+};
+module_platform_driver(qcom_usb_vbus_regulator_driver);
+
+MODULE_DESCRIPTION("Qualcomm USB vbus regulator driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:qcom-usb-vbus-regulator");
-- 
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