From ee6a678263598b737bbc3f9a6f4932eb2739f5c4 Mon Sep 17 00:00:00 2001
From: Samuel Holland <samuel@sholland.org>
Date: Sun, 22 Jan 2023 17:46:20 -0600
Subject: [PATCH] power: regulator: Add a driver for the AXP USB power supply

This driver reports the presence/absence of voltage on the PMIC's USB
VBUS pin. This information is used by the USB PHY driver. The
corresponding Linux driver uses the power supply class, which does not
exist in U-Boot. UCLASS_REGULATOR seems to be the closest match.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Acked-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
---
 drivers/power/regulator/Kconfig         |  7 ++++
 drivers/power/regulator/Makefile        |  1 +
 drivers/power/regulator/axp_usb_power.c | 49 +++++++++++++++++++++++++
 3 files changed, 57 insertions(+)
 create mode 100644 drivers/power/regulator/axp_usb_power.c

diff --git a/drivers/power/regulator/Kconfig b/drivers/power/regulator/Kconfig
index c346d03507..eb5aa38c1c 100644
--- a/drivers/power/regulator/Kconfig
+++ b/drivers/power/regulator/Kconfig
@@ -57,6 +57,13 @@ config SPL_REGULATOR_AXP
 	  Enable support in SPL for the regulators (DCDCs, LDOs) in the
 	  X-Powers AXP152, AXP2xx, and AXP8xx PMICs.
 
+config REGULATOR_AXP_USB_POWER
+	bool "Enable driver for X-Powers AXP PMIC USB power supply"
+	depends on DM_REGULATOR && PMIC_AXP
+	help
+	  Enable support for reading the USB power supply status from
+	  X-Powers AXP2xx and AXP8xx PMICs.
+
 config DM_REGULATOR_BD71837
 	bool "Enable Driver Model for ROHM BD71837/BD71847 regulators"
 	depends on DM_REGULATOR && DM_PMIC_BD71837
diff --git a/drivers/power/regulator/Makefile b/drivers/power/regulator/Makefile
index 2d97e1033a..d9e0cd5949 100644
--- a/drivers/power/regulator/Makefile
+++ b/drivers/power/regulator/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_$(SPL_)DM_REGULATOR) += regulator-uclass.o
 obj-$(CONFIG_REGULATOR_ACT8846) += act8846.o
 obj-$(CONFIG_REGULATOR_AS3722)	+= as3722_regulator.o
 obj-$(CONFIG_$(SPL_)REGULATOR_AXP) += axp_regulator.o
+obj-$(CONFIG_$(SPL_)REGULATOR_AXP_USB_POWER) += axp_usb_power.o
 obj-$(CONFIG_$(SPL_)DM_REGULATOR_DA9063) += da9063.o
 obj-$(CONFIG_DM_REGULATOR_MAX77686) += max77686.o
 obj-$(CONFIG_DM_REGULATOR_NPCM8XX) += npcm8xx_regulator.o
diff --git a/drivers/power/regulator/axp_usb_power.c b/drivers/power/regulator/axp_usb_power.c
new file mode 100644
index 0000000000..f32fb6a92d
--- /dev/null
+++ b/drivers/power/regulator/axp_usb_power.c
@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <dm/device.h>
+#include <errno.h>
+#include <power/pmic.h>
+#include <power/regulator.h>
+
+#define AXP_POWER_STATUS		0x00
+#define AXP_POWER_STATUS_VBUS_PRESENT		BIT(5)
+
+static int axp_usb_power_get_enable(struct udevice *dev)
+{
+	int ret;
+
+	ret = pmic_reg_read(dev->parent, AXP_POWER_STATUS);
+	if (ret < 0)
+		return ret;
+
+	return !!(ret & AXP_POWER_STATUS_VBUS_PRESENT);
+}
+
+static const struct dm_regulator_ops axp_usb_power_ops = {
+	.get_enable		= axp_usb_power_get_enable,
+};
+
+static int axp_usb_power_probe(struct udevice *dev)
+{
+	struct dm_regulator_uclass_plat *uc_plat = dev_get_uclass_plat(dev);
+
+	uc_plat->type = REGULATOR_TYPE_FIXED;
+
+	return 0;
+}
+
+static const struct udevice_id axp_usb_power_ids[] = {
+	{ .compatible = "x-powers,axp202-usb-power-supply" },
+	{ .compatible = "x-powers,axp221-usb-power-supply" },
+	{ .compatible = "x-powers,axp223-usb-power-supply" },
+	{ .compatible = "x-powers,axp813-usb-power-supply" },
+	{ }
+};
+
+U_BOOT_DRIVER(axp_usb_power) = {
+	.name		= "axp_usb_power",
+	.id		= UCLASS_REGULATOR,
+	.of_match	= axp_usb_power_ids,
+	.probe		= axp_usb_power_probe,
+	.ops		= &axp_usb_power_ops,
+};
-- 
2.39.5