phy: Add support for the Apple Type-C PHY

This is merely a dummy driver that makes sure the DWC3 XHCI driver
finds its reset and PHY controllers.  We rely on iBoot to set up
the PHY for us.

Signed-off-by: Mark Kettenis <kettenis@openbsd.org>

MAINTAINERS

@@ -123,6 +123,7 @@ F:	configs/apple_m1_defconfig
 F:	drivers/iommu/apple_dart.c
 F:	drivers/nvme/nvme_apple.c
 F:	drivers/pci/pcie_apple.c
+F:	drivers/phy/phy-apple-atc.c
 F:	drivers/pinctrl/pinctrl-apple.c
 F:	drivers/watchdog/apple_wdt.c
 F:	include/configs/apple.h

arch/arm/Kconfig

@@ -998,6 +998,7 @@ config ARCH_APPLE
 	select OF_BOARD_SETUP
 	select OF_CONTROL
 	select PCI
+	select PHY
 	select PINCTRL
 	select POSITION_INDEPENDENT
 	select POWER_DOMAIN

configs/apple_m1_defconfig

@@ -16,6 +16,7 @@ CONFIG_NVME_APPLE=y
 CONFIG_USB_XHCI_HCD=y
 CONFIG_USB_XHCI_DWC3=y
 CONFIG_USB_XHCI_PCI=y
+CONFIG_USB_DWC3=y
 CONFIG_USB_KEYBOARD=y
 CONFIG_SYS_WHITE_ON_BLACK=y
 CONFIG_NO_FB_CLEAR=y

drivers/phy/Kconfig

@@ -70,6 +70,16 @@ config AB8500_USB_PHY
 	help
 	  Support for the USB OTG PHY in ST-Ericsson AB8500.
 
+config APPLE_ATCPHY
+       bool "Apple Type-C PHY Driver"
+       depends on PHY && ARCH_APPLE
+       default y
+       help
+         Support for the Apple Type-C PHY.
+
+	 This is a dummy driver since the PHY is initialized
+	 sufficiently by previous stage firmware.
+
 config BCM6318_USBH_PHY
 	bool "BCM6318 USBH PHY support"
 	depends on PHY && ARCH_BMIPS

drivers/phy/Makefile

@@ -12,6 +12,7 @@ obj-$(CONFIG_$(SPL_)PHY) += phy-uclass.o
 obj-$(CONFIG_$(SPL_)NOP_PHY) += nop-phy.o
 obj-$(CONFIG_MIPI_DPHY_HELPERS) += phy-core-mipi-dphy.o
 obj-$(CONFIG_AB8500_USB_PHY) += phy-ab8500-usb.o
+obj-$(CONFIG_APPLE_ATCPHY) += phy-apple-atc.o
 obj-$(CONFIG_BCM6318_USBH_PHY) += bcm6318-usbh-phy.o
 obj-$(CONFIG_BCM6348_USBH_PHY) += bcm6348-usbh-phy.o
 obj-$(CONFIG_BCM6358_USBH_PHY) += bcm6358-usbh-phy.o

drivers/phy/phy-apple-atc.c

@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2022 Mark Kettenis <kettenis@openbsd.org>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <dm/device-internal.h>
+#include <generic-phy.h>
+#include <reset-uclass.h>
+
+static const struct phy_ops apple_atcphy_ops = {
+};
+
+static struct driver apple_atcphy_driver = {
+	.name = "apple-atcphy",
+	.id = UCLASS_PHY,
+	.ops = &apple_atcphy_ops,
+};
+
+static int apple_atcphy_reset_of_xlate(struct reset_ctl *reset_ctl,
+				       struct ofnode_phandle_args *args)
+{
+	if (args->args_count != 0)
+		return -EINVAL;
+
+	return 0;
+}
+
+static const struct reset_ops apple_atcphy_reset_ops = {
+	.of_xlate = apple_atcphy_reset_of_xlate,
+};
+
+static int apple_atcphy_reset_probe(struct udevice *dev)
+{
+	struct udevice *child;
+
+	device_bind(dev, &apple_atcphy_driver, "apple-atcphy", NULL,
+		    dev_ofnode(dev), &child);
+
+	return 0;
+}
+
+static const struct udevice_id apple_atcphy_ids[] = {
+	{ .compatible = "apple,t6000-atcphy" },
+	{ .compatible = "apple,t8103-atcphy" },
+	{ }
+};
+
+U_BOOT_DRIVER(apple_atcphy_reset) = {
+	.name = "apple-atcphy-reset",
+	.id = UCLASS_RESET,
+	.of_match = apple_atcphy_ids,
+	.ops = &apple_atcphy_reset_ops,
+	.probe = apple_atcphy_reset_probe,
+};