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From:   Nagarjuna Kristam <nkristam@nvidia.com>
To:     <balbi@kernel.org>, <gregkh@linuxfoundation.org>,
        <thierry.reding@gmail.com>, <jonathanh@nvidia.com>,
        <mark.rutland@arm.com>, <robh+dt@kernel.org>, <kishon@ti.com>
CC:     <devicetree@vger.kernel.org>, <linux-tegra@vger.kernel.org>,
        <linux-usb@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        Nagarjuna Kristam <nkristam@nvidia.com>
Subject: [PATCH 03/18] phy: tegra: xusb: Add usb-role-switch support
Date:   Fri, 6 Dec 2019 16:20:06 +0530
Message-ID: <1575629421-7039-4-git-send-email-nkristam@nvidia.com>
In-Reply-To: <1575629421-7039-1-git-send-email-nkristam@nvidia.com>
References: <1575629421-7039-1-git-send-email-nkristam@nvidia.com>
MIME-Version: 1.0
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Sender: linux-kernel-owner@vger.kernel.org
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If usb-role-switch property is present in USB 2 port, register
usb-role-switch to receive usb role changes.

Signed-off-by: Nagarjuna Kristam <nkristam@nvidia.com>
---
 drivers/phy/tegra/Kconfig |  1 +
 drivers/phy/tegra/xusb.c  | 40 ++++++++++++++++++++++++++++++++++++++++
 drivers/phy/tegra/xusb.h  |  3 +++
 3 files changed, 44 insertions(+)

diff --git a/drivers/phy/tegra/Kconfig b/drivers/phy/tegra/Kconfig
index f9817c3..df07c4d 100644
--- a/drivers/phy/tegra/Kconfig
+++ b/drivers/phy/tegra/Kconfig
@@ -2,6 +2,7 @@
 config PHY_TEGRA_XUSB
 	tristate "NVIDIA Tegra XUSB pad controller driver"
 	depends on ARCH_TEGRA
+	select USB_CONN_GPIO
 	help
 	  Choose this option if you have an NVIDIA Tegra SoC.
 
diff --git a/drivers/phy/tegra/xusb.c b/drivers/phy/tegra/xusb.c
index f98ec39..da60a63 100644
--- a/drivers/phy/tegra/xusb.c
+++ b/drivers/phy/tegra/xusb.c
@@ -523,6 +523,7 @@ static int tegra_xusb_port_init(struct tegra_xusb_port *port,
 	port->dev.type = &tegra_xusb_port_type;
 	port->dev.of_node = of_node_get(np);
 	port->dev.parent = padctl->dev;
+	port->dev.driver = padctl->dev->driver;
 
 	err = dev_set_name(&port->dev, "%s-%u", name, index);
 	if (err < 0)
@@ -532,6 +533,7 @@ static int tegra_xusb_port_init(struct tegra_xusb_port *port,
 	if (err < 0)
 		goto unregister;
 
+	dev_set_drvdata(&port->dev, port);
 	return 0;
 
 unregister:
@@ -541,6 +543,7 @@ static int tegra_xusb_port_init(struct tegra_xusb_port *port,
 
 static void tegra_xusb_port_unregister(struct tegra_xusb_port *port)
 {
+	usb_role_switch_unregister(port->usb_role_sw);
 	device_unregister(&port->dev);
 }
 
@@ -551,11 +554,39 @@ static const char *const modes[] = {
 	[USB_DR_MODE_OTG] = "otg",
 };
 
+static int tegra_xusb_role_sw_set(struct device *dev, enum usb_role role)
+{
+	dev_dbg(dev, "%s calling notifier for role is %d\n", __func__, role);
+
+	return 0;
+}
+
+static int tegra_xusb_setup_usb_role_switch(struct tegra_xusb_port *port)
+{
+	int err = 0;
+	struct usb_role_switch_desc role_sx_desc = {
+					.set = tegra_xusb_role_sw_set,
+					.fwnode = dev_fwnode(&port->dev),
+						   };
+
+	port->usb_role_sw = usb_role_switch_register(&port->dev,
+						&role_sx_desc);
+	if (IS_ERR(port->usb_role_sw)) {
+		err = PTR_ERR(port->usb_role_sw);
+		if (err != EPROBE_DEFER)
+			dev_err(&port->dev, "Failed to register USB role SW: %d",
+				err);
+	}
+
+	return err;
+}
+
 static int tegra_xusb_usb2_port_parse_dt(struct tegra_xusb_usb2_port *usb2)
 {
 	struct tegra_xusb_port *port = &usb2->base;
 	struct device_node *np = port->dev.of_node;
 	const char *mode;
+	int err;
 
 	usb2->internal = of_property_read_bool(np, "nvidia,internal");
 
@@ -572,6 +603,15 @@ static int tegra_xusb_usb2_port_parse_dt(struct tegra_xusb_usb2_port *usb2)
 		usb2->mode = USB_DR_MODE_HOST;
 	}
 
+	if (of_property_read_bool(np, "usb-role-switch")) {
+		/* populate connector entry */
+		of_platform_populate(np, NULL, NULL, &port->dev);
+
+		err = tegra_xusb_setup_usb_role_switch(port);
+		if (err < 0)
+			return err;
+	}
+
 	usb2->supply = devm_regulator_get(&port->dev, "vbus");
 	return PTR_ERR_OR_ZERO(usb2->supply);
 }
diff --git a/drivers/phy/tegra/xusb.h b/drivers/phy/tegra/xusb.h
index da94fcc..9f27899 100644
--- a/drivers/phy/tegra/xusb.h
+++ b/drivers/phy/tegra/xusb.h
@@ -12,6 +12,7 @@
 #include <linux/workqueue.h>
 
 #include <linux/usb/otg.h>
+#include <linux/usb/role.h>
 
 /* legacy entry points for backwards-compatibility */
 int tegra_xusb_padctl_legacy_probe(struct platform_device *pdev);
@@ -266,6 +267,8 @@ struct tegra_xusb_port {
 	struct list_head list;
 	struct device dev;
 
+	struct usb_role_switch *usb_role_sw;
+
 	const struct tegra_xusb_port_ops *ops;
 };
 
-- 
2.7.4