Introduce gadget opts udc_set_sublink_speed callback to set the lane
count and transfer rate (in lane speed mantissa of Gbps) for SuperSpeed
Plus capable gadgets. In the same way udc_set_speed, this function can
control the gadget's sublink attributes for SuperSpeed Plus.
Signed-off-by: Thinh Nguyen <thinhn@xxxxxxxxxxxx>
---
drivers/usb/gadget/composite.c | 2 ++
drivers/usb/gadget/legacy/mass_storage.c | 2 ++
drivers/usb/gadget/udc/core.c | 38 +++++++++++++++++++++++++++++++-
include/linux/usb/gadget.h | 3 +++
4 files changed, 44 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 3b4f67000315..a4de5a8c0f19 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -2353,6 +2353,8 @@ int usb_composite_probe(struct usb_composite_driver *driver)
gadget_driver->function = (char *) driver->name;
gadget_driver->driver.name = driver->name;
gadget_driver->max_speed = driver->max_speed;
+ gadget_driver->max_lane_count = driver->max_lane_count;
+ gadget_driver->max_lsm = driver->max_lsm;
return usb_gadget_probe_driver(gadget_driver);
}
diff --git a/drivers/usb/gadget/legacy/mass_storage.c b/drivers/usb/gadget/legacy/mass_storage.c
index f18f77584fc2..a0912c5afffc 100644
--- a/drivers/usb/gadget/legacy/mass_storage.c
+++ b/drivers/usb/gadget/legacy/mass_storage.c
@@ -223,6 +223,8 @@ static struct usb_composite_driver msg_driver = {
.name = "g_mass_storage",
.dev = &msg_device_desc,
.max_speed = USB_SPEED_SUPER_PLUS,
+ .max_lane_count = 2,
+ .max_lsm = 10,
.needs_serial = 1,
.strings = dev_strings,
.bind = msg_bind,
diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
index 51fa614b4079..a3b106a22a6e 100644
--- a/drivers/usb/gadget/udc/core.c
+++ b/drivers/usb/gadget/udc/core.c
@@ -1120,6 +1120,35 @@ static inline void usb_gadget_udc_set_speed(struct usb_udc *udc,
}
}
+/**
+ * usb_gadget_udc_set_sublink_attr - tells usb device controller the sublink
+ * attributes supported by the current driver
+ * @udc: The device we want to set maximum speed
+ * @lane_count: The maximum number of lanes to connect
+ * @lsm: The maximum lane speed mantissa in Gbps to run
+ *
+ * In the same way as usb_gadget_udc_set_speed(), this function can set the
+ * gadget's sublink attributes for SuperSpeed Plus.
+ *
+ * This call is issued by the UDC Class driver before calling
+ * usb_gadget_udc_start() in order to make sure that we don't try to
+ * connect on speeds the gadget driver doesn't support.
+ */
+static inline void usb_gadget_udc_set_sublink_attr(struct usb_udc *udc,
+ unsigned int lane_count,
+ unsigned int lsm)
+{
+ if (udc->gadget->ops->udc_set_sublink_attr) {
+ unsigned int rate;
+ unsigned int lanes;
+
+ rate = min(lsm, udc->gadget->max_lsm);
+ lanes = min(lane_count, udc->gadget->max_lane_count);
+ udc->gadget->ops->udc_set_sublink_attr(udc->gadget,
+ lanes, rate);
+ }
+}
+
/**
* usb_udc_release - release the usb_udc struct
* @dev: the dev member within usb_udc
@@ -1353,7 +1382,14 @@ static int udc_bind_to_driver(struct usb_udc *udc, struct usb_gadget_driver *dri
udc->dev.driver = &driver->driver;
udc->gadget->dev.driver = &driver->driver;
- usb_gadget_udc_set_speed(udc, driver->max_speed);
+ if (udc->gadget->ops->udc_set_sublink_attr &&
+ udc->gadget->max_speed == USB_SPEED_SUPER_PLUS &&
+ driver->max_lsm && driver->max_lane_count &&
+ driver->max_speed == USB_SPEED_SUPER_PLUS)
+ usb_gadget_udc_set_sublink_attr(udc, driver->max_lane_count,
+ driver->max_lsm);
+ else
+ usb_gadget_udc_set_speed(udc, driver->max_speed);
ret = driver->bind(udc->gadget, driver);
if (ret)
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index cb7531a6f784..a8ee2480b408 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -319,6 +319,9 @@ struct usb_gadget_ops {
struct usb_gadget_driver *);
int (*udc_stop)(struct usb_gadget *);
void (*udc_set_speed)(struct usb_gadget *, enum usb_device_speed);
+ void (*udc_set_sublink_attr)(struct usb_gadget *,
+ unsigned int lane_count,
+ unsigned int lsm);
struct usb_ep *(*match_ep)(struct usb_gadget *,
struct usb_endpoint_descriptor *,
struct usb_ss_ep_comp_descriptor *);
--
2.11.0
