[RFC PATCH 2/2] usb: phy: Add platform driver support for ULPI PHYs

From: Subbaraya Sundeep Bhatta
Date: Wed Sep 23 2015 - 09:09:42 EST


Based on board design USB controller needs explicit software
access to ULPI PHY for controlling VBUS. This patch adds platform
driver support for generic ULPI PHYs and provides a USB2 PHY device
to controllers.

Signed-off-by: Subbaraya Sundeep Bhatta <sbhatta@xxxxxxxxxx>
---
drivers/usb/phy/Kconfig | 12 +++
drivers/usb/phy/Makefile | 1 +
drivers/usb/phy/phy-platform-ulpi.c | 143 +++++++++++++++++++++++++++++++++++
3 files changed, 156 insertions(+), 0 deletions(-)
create mode 100644 drivers/usb/phy/phy-platform-ulpi.c

diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
index 7d3beee..2956ad4 100644
--- a/drivers/usb/phy/Kconfig
+++ b/drivers/usb/phy/Kconfig
@@ -201,6 +201,18 @@ config USB_RCAR_PHY
To compile this driver as a module, choose M here: the
module will be called phy-rcar-usb.

+config USB_PLATFORM_ULPI_PHY
+ tristate "Platform driver support for ULPI PHYs"
+ depends on ARCH_ZYNQ || COMPILE_TEST
+ select USB_PHY
+ select USB_ULPI_VIEWPORT
+ help
+ Say Y here to add support for the Platform driver for ULPI PHYs.
+ This adds platform driver support for all generic ULPI PHYs and is
+ typically used if usb controller driver needs explicit access to PHY.
+
+ To compile this driver as a module, choose M here.
+
config USB_ULPI
bool "Generic ULPI Transceiver Driver"
depends on ARM || ARM64
diff --git a/drivers/usb/phy/Makefile b/drivers/usb/phy/Makefile
index 19c0dcc..8431b6b 100644
--- a/drivers/usb/phy/Makefile
+++ b/drivers/usb/phy/Makefile
@@ -24,6 +24,7 @@ obj-$(CONFIG_USB_QCOM_8X16_PHY) += phy-qcom-8x16-usb.o
obj-$(CONFIG_USB_MV_OTG) += phy-mv-usb.o
obj-$(CONFIG_USB_MXS_PHY) += phy-mxs-usb.o
obj-$(CONFIG_USB_RCAR_PHY) += phy-rcar-usb.o
+obj-$(CONFIG_USB_PLATFORM_ULPI_PHY) += phy-platform-ulpi.o
obj-$(CONFIG_USB_ULPI) += phy-ulpi.o
obj-$(CONFIG_USB_ULPI_VIEWPORT) += phy-ulpi-viewport.o
obj-$(CONFIG_KEYSTONE_USB_PHY) += phy-keystone.o
diff --git a/drivers/usb/phy/phy-platform-ulpi.c b/drivers/usb/phy/phy-platform-ulpi.c
new file mode 100644
index 0000000..fb89363
--- /dev/null
+++ b/drivers/usb/phy/phy-platform-ulpi.c
@@ -0,0 +1,143 @@
+/*
+ * Platform driver for generic ULPI PHYs.
+ *
+ * Copyright (C) 2015 Xilinx, Inc.
+ *
+ * Author: Subbaraya Sundeep <sbhatta@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it
+ * and/or modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation;
+ * either version 2 of the License, or (at your option) any
+ * later version.
+ */
+
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/usb/ulpi.h>
+#include <linux/usb/phy.h>
+
+/**
+ * struct ulpi_phy - The ULPI PHY
+ * @usb_phy: pointer to usb phy
+ * @regs: base address of USB controller to which PHY is connected
+ * @vp_offset: ulpi viewport register offset of USB controller
+ * @flags: initial required settings of PHY
+ */
+
+struct ulpi_phy {
+ struct usb_phy *usb_phy;
+ void __iomem *regs;
+ unsigned int vp_offset;
+ unsigned int flags;
+};
+
+/**
+ * usbphy_set_vbus - Sets VBUS by writing to PHY.
+ * @phy: pointer to PHY
+ * @on: 1 - turn on VBUS
+ * 0 - turn off VBUS
+ * Return: 0 for success and error value on failure
+ */
+static int usbphy_set_vbus(struct usb_phy *phy, int on)
+{
+ unsigned int flags = usb_phy_io_read(phy, ULPI_OTG_CTRL);
+
+ flags &= ~(ULPI_OTG_CTRL_DRVVBUS | ULPI_OTG_CTRL_DRVVBUS_EXT);
+
+ if (on) {
+ if (phy->flags & ULPI_OTG_DRVVBUS)
+ flags |= ULPI_OTG_CTRL_DRVVBUS;
+
+ if (phy->flags & ULPI_OTG_DRVVBUS_EXT)
+ flags |= ULPI_OTG_CTRL_DRVVBUS_EXT;
+ }
+
+ return usb_phy_io_write(phy, flags, ULPI_OTG_CTRL);
+}
+
+/**
+ * ulpi_phy_probe - The device probe function for driver initialization.
+ * @pdev: pointer to the platform device structure.
+ *
+ * Return: 0 for success and error value on failure
+ */
+static int ulpi_phy_probe(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct resource *res;
+ struct ulpi_phy *uphy;
+ bool flag;
+ int ret;
+
+ uphy = devm_kzalloc(&pdev->dev, sizeof(*uphy), GFP_KERNEL);
+ if (!uphy)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ uphy->regs = devm_ioremap(&pdev->dev, res->start, resource_size(res));
+ if (IS_ERR(uphy->regs))
+ return PTR_ERR(uphy->regs);
+
+ ret = of_property_read_u32(np, "view-port", &uphy->vp_offset);
+ if (IS_ERR(uphy->regs)) {
+ dev_err(&pdev->dev, "view-port register not specified\n");
+ return PTR_ERR(uphy->regs);
+ }
+
+ flag = of_property_read_bool(np, "drv-vbus");
+ if (flag)
+ uphy->flags |= ULPI_OTG_DRVVBUS | ULPI_OTG_DRVVBUS_EXT;
+
+ uphy->usb_phy = otg_ulpi_create(&ulpi_viewport_access_ops, uphy->flags);
+
+ uphy->usb_phy->set_vbus = usbphy_set_vbus;
+
+ uphy->usb_phy->dev = &pdev->dev;
+
+ uphy->usb_phy->io_priv = uphy->regs + uphy->vp_offset;
+
+ ret = usb_add_phy_dev(uphy->usb_phy);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+/**
+ * ulpi_phy_remove - Releases the resources allocated during the initialization.
+ * @pdev: pointer to the platform device structure.
+ *
+ * Return: 0 always
+ */
+static int ulpi_phy_remove(struct platform_device *pdev)
+{
+ struct ulpi_phy *uphy = platform_get_drvdata(pdev);
+
+ usb_remove_phy(uphy->usb_phy);
+
+ return 0;
+}
+
+/* Match table for of_platform binding */
+static const struct of_device_id ulpi_phy_table[] = {
+ { .compatible = "ulpi-phy" },
+ { /* end of list */},
+};
+MODULE_DEVICE_TABLE(of, ulpi_phy_table);
+
+static struct platform_driver ulpi_phy_driver = {
+ .probe = ulpi_phy_probe,
+ .remove = ulpi_phy_remove,
+ .driver = {
+ .name = "ulpi-platform-phy",
+ .of_match_table = of_match_ptr(ulpi_phy_table),
+ },
+};
+module_platform_driver(ulpi_phy_driver);
+
+MODULE_DESCRIPTION("ULPI PHY platform driver");
+MODULE_AUTHOR("Xilinx, Inc");
+MODULE_LICENSE("GPL v2");
--
1.7.1

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