[PATCH 5/5] usb: mtu3: register a USB Role Switch for Dual-Role mode

From: Chunfeng Yun
Date: Fri Mar 08 2019 - 01:15:46 EST


Due to extcon is not allowed for new bindings, and the
Dual-Role switch is supported by USB Role Switch,
especially for Type-C drivers, so register a USB Role
Switch to support the new way

Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
---
drivers/usb/mtu3/mtu3.h | 5 ++++
drivers/usb/mtu3/mtu3_dr.c | 50 +++++++++++++++++++++++++++++++++---
drivers/usb/mtu3/mtu3_plat.c | 3 ++-
3 files changed, 54 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/mtu3/mtu3.h b/drivers/usb/mtu3/mtu3.h
index 87823ac0d120..8f9da03255b6 100644
--- a/drivers/usb/mtu3/mtu3.h
+++ b/drivers/usb/mtu3/mtu3.h
@@ -202,6 +202,9 @@ struct mtu3_gpd_ring {
* @id_nb : notifier for iddig(idpin) detection
* @id_work : work of iddig detection notifier
* @id_event : event of iddig detecion notifier
+* @role_sw : use USB Role Switch to support dual-role switch, can't use
+* extcon at the same time, and extcon is deprecated.
+* @role_sw_used : true when the USB Role Switch is used.
* @is_u3_drd: whether port0 supports usb3.0 dual-role device or not
* @manual_drd_enabled: it's true when supports dual-role device by debugfs
* to switch host/device modes depending on user input.
@@ -215,6 +218,8 @@ struct otg_switch_mtk {
struct notifier_block id_nb;
struct work_struct id_work;
unsigned long id_event;
+ struct usb_role_switch *role_sw;
+ bool role_sw_used;
bool is_u3_drd;
bool manual_drd_enabled;
};
diff --git a/drivers/usb/mtu3/mtu3_dr.c b/drivers/usb/mtu3/mtu3_dr.c
index ac60e9c8564e..b9272295fe2b 100644
--- a/drivers/usb/mtu3/mtu3_dr.c
+++ b/drivers/usb/mtu3/mtu3_dr.c
@@ -14,6 +14,7 @@
#include <linux/pinctrl/consumer.h>
#include <linux/seq_file.h>
#include <linux/uaccess.h>
+#include <linux/usb/role.h>

#include "mtu3.h"
#include "mtu3_dr.h"
@@ -266,7 +267,7 @@ static int ssusb_extcon_register(struct otg_switch_mtk *otg_sx)
* This is useful in special cases, such as uses TYPE-A receptacle but also
* wants to support dual-role mode.
*/
-static void ssusb_mode_manual_switch(struct ssusb_mtk *ssusb, int to_host)
+static void ssusb_mode_switch(struct ssusb_mtk *ssusb, int to_host)
{
struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;

@@ -308,9 +309,9 @@ static ssize_t ssusb_mode_write(struct file *file,
return -EFAULT;

if (!strncmp(buf, "host", 4) && !ssusb->is_host) {
- ssusb_mode_manual_switch(ssusb, 1);
+ ssusb_mode_switch(ssusb, 1);
} else if (!strncmp(buf, "device", 6) && ssusb->is_host) {
- ssusb_mode_manual_switch(ssusb, 0);
+ ssusb_mode_switch(ssusb, 0);
} else {
dev_err(ssusb->dev, "wrong or duplicated setting\n");
return -EINVAL;
@@ -412,6 +413,46 @@ void ssusb_set_force_mode(struct ssusb_mtk *ssusb,
mtu3_writel(ssusb->ippc_base, SSUSB_U2_CTRL(0), value);
}

+static int ssusb_role_sw_set(struct device *dev, enum usb_role role)
+{
+ struct ssusb_mtk *ssusb = dev_get_drvdata(dev);
+ bool to_host = false;
+
+ if (role == USB_ROLE_HOST)
+ to_host = true;
+
+ if (to_host ^ ssusb->is_host)
+ ssusb_mode_switch(ssusb, to_host);
+
+ return 0;
+}
+
+static enum usb_role ssusb_role_sw_get(struct device *dev)
+{
+ struct ssusb_mtk *ssusb = dev_get_drvdata(dev);
+ enum usb_role role;
+
+ role = ssusb->is_host ? USB_ROLE_HOST : USB_ROLE_DEVICE;
+
+ return role;
+}
+
+static int ssusb_role_sw_register(struct otg_switch_mtk *otg_sx)
+{
+ struct usb_role_switch_desc role_sx_desc = { 0 };
+ struct ssusb_mtk *ssusb =
+ container_of(otg_sx, struct ssusb_mtk, otg_switch);
+
+ if (!otg_sx->role_sw_used)
+ return 0;
+
+ role_sx_desc.set = ssusb_role_sw_set;
+ role_sx_desc.get = ssusb_role_sw_get;
+ otg_sx->role_sw = usb_role_switch_register(ssusb->dev, &role_sx_desc);
+
+ return PTR_ERR_OR_ZERO(otg_sx->role_sw);
+}
+
int ssusb_otg_switch_init(struct ssusb_mtk *ssusb)
{
struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
@@ -421,6 +462,8 @@ int ssusb_otg_switch_init(struct ssusb_mtk *ssusb)

if (otg_sx->manual_drd_enabled)
ssusb_debugfs_init(ssusb);
+ else if (otg_sx->role_sw_used)
+ ssusb_role_sw_register(otg_sx);
else
ssusb_extcon_register(otg_sx);

@@ -436,4 +479,5 @@ void ssusb_otg_switch_exit(struct ssusb_mtk *ssusb)

cancel_work_sync(&otg_sx->id_work);
cancel_work_sync(&otg_sx->vbus_work);
+ usb_role_switch_unregister(otg_sx->role_sw);
}
diff --git a/drivers/usb/mtu3/mtu3_plat.c b/drivers/usb/mtu3/mtu3_plat.c
index e086630e41a9..02c288a85989 100644
--- a/drivers/usb/mtu3/mtu3_plat.c
+++ b/drivers/usb/mtu3/mtu3_plat.c
@@ -313,8 +313,9 @@ static int get_ssusb_rscs(struct platform_device *pdev, struct ssusb_mtk *ssusb)
otg_sx->is_u3_drd = of_property_read_bool(node, "mediatek,usb3-drd");
otg_sx->manual_drd_enabled =
of_property_read_bool(node, "enable-manual-drd");
+ otg_sx->role_sw_used = of_property_read_bool(node, "usb-role-switch");

- if (of_property_read_bool(node, "extcon")) {
+ if (!otg_sx->role_sw_used && of_property_read_bool(node, "extcon")) {
otg_sx->edev = extcon_get_edev_by_phandle(ssusb->dev, 0);
if (IS_ERR(otg_sx->edev)) {
dev_err(ssusb->dev, "couldn't get extcon device\n");
--
2.20.1