Commit fb95c7cf authored by Chunfeng Yun's avatar Chunfeng Yun Committed by Greg Kroah-Hartman
Browse files

usb: common: add function to get interval expressed in us unit 



Add a new function to convert bInterval into the time expressed
in 1us unit.

Signed-off-by: default avatarChunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/25c8a09b055f716c1e5bf11fea72c3418f844482.1615170625.git.chunfeng.yun@mediatek.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 14295a15

drivers/usb/common/common.c

+41 −0
Original line number Diff line number Diff line
@@ -165,6 +165,47 @@ enum usb_dr_mode usb_get_dr_mode(struct device *dev) 
}

EXPORT_SYMBOL_GPL(usb_get_dr_mode);



/**

 * usb_decode_interval - Decode bInterval into the time expressed in 1us unit

 * @epd: The descriptor of the endpoint

 * @speed: The speed that the endpoint works as

 *

 * Function returns the interval expressed in 1us unit for servicing

 * endpoint for data transfers.

 */

unsigned int usb_decode_interval(const struct usb_endpoint_descriptor *epd,

				 enum usb_device_speed speed)

{

	unsigned int interval = 0;



	switch (usb_endpoint_type(epd)) {

	case USB_ENDPOINT_XFER_CONTROL:

		/* uframes per NAK */

		if (speed == USB_SPEED_HIGH)

			interval = epd->bInterval;

		break;

	case USB_ENDPOINT_XFER_ISOC:

		interval = 1 << (epd->bInterval - 1);

		break;

	case USB_ENDPOINT_XFER_BULK:

		/* uframes per NAK */

		if (speed == USB_SPEED_HIGH && usb_endpoint_dir_out(epd))

			interval = epd->bInterval;

		break;

	case USB_ENDPOINT_XFER_INT:

		if (speed >= USB_SPEED_HIGH)

			interval = 1 << (epd->bInterval - 1);

		else

			interval = epd->bInterval;

		break;

	}



	interval *= (speed >= USB_SPEED_HIGH) ? 125 : 1000;



	return interval;

}

EXPORT_SYMBOL_GPL(usb_decode_interval);



#ifdef CONFIG_OF

/**

 * of_usb_get_dr_mode_by_phy - Get dual role mode for the controller device

drivers/usb/core/devices.c

+4 −17
Original line number Diff line number Diff line
@@ -157,38 +157,25 @@ static char *usb_dump_endpoint_descriptor(int speed, char *start, char *end, 
	switch (usb_endpoint_type(desc)) {

	case USB_ENDPOINT_XFER_CONTROL:

		type = "Ctrl";

		if (speed == USB_SPEED_HIGH)	/* uframes per NAK */

			interval = desc->bInterval;

		else

			interval = 0;

		dir = 'B';			/* ctrl is bidirectional */

		break;

	case USB_ENDPOINT_XFER_ISOC:

		type = "Isoc";

		interval = 1 << (desc->bInterval - 1);

		break;

	case USB_ENDPOINT_XFER_BULK:

		type = "Bulk";

		if (speed == USB_SPEED_HIGH && dir == 'O') /* uframes per NAK */

			interval = desc->bInterval;

		else

			interval = 0;

		break;

	case USB_ENDPOINT_XFER_INT:

		type = "Int.";

		if (speed == USB_SPEED_HIGH || speed >= USB_SPEED_SUPER)

			interval = 1 << (desc->bInterval - 1);

		else

			interval = desc->bInterval;

		break;

	default:	/* "can't happen" */

		return start;

	}

	interval *= (speed == USB_SPEED_HIGH ||

		     speed >= USB_SPEED_SUPER) ? 125 : 1000;

	if (interval % 1000)



	interval = usb_decode_interval(desc, speed);

	if (interval % 1000) {

		unit = 'u';

	else {

	} else {

		unit = 'm';

		interval /= 1000;

	}

drivers/usb/core/endpoint.c

+4 −31
Original line number Diff line number Diff line
@@ -84,40 +84,13 @@ static ssize_t interval_show(struct device *dev, struct device_attribute *attr, 
			     char *buf)

{

	struct ep_device *ep = to_ep_device(dev);

	unsigned int interval;

	char unit;

	unsigned interval = 0;

	unsigned in;



	in = (ep->desc->bEndpointAddress & USB_DIR_IN);



	switch (usb_endpoint_type(ep->desc)) {

	case USB_ENDPOINT_XFER_CONTROL:

		if (ep->udev->speed == USB_SPEED_HIGH)

			/* uframes per NAK */

			interval = ep->desc->bInterval;

		break;



	case USB_ENDPOINT_XFER_ISOC:

		interval = 1 << (ep->desc->bInterval - 1);

		break;



	case USB_ENDPOINT_XFER_BULK:

		if (ep->udev->speed == USB_SPEED_HIGH && !in)

			/* uframes per NAK */

			interval = ep->desc->bInterval;

		break;



	case USB_ENDPOINT_XFER_INT:

		if (ep->udev->speed == USB_SPEED_HIGH)

			interval = 1 << (ep->desc->bInterval - 1);

		else

			interval = ep->desc->bInterval;

		break;

	}

	interval *= (ep->udev->speed == USB_SPEED_HIGH) ? 125 : 1000;

	if (interval % 1000)

	interval = usb_decode_interval(ep->desc, ep->udev->speed);

	if (interval % 1000) {

		unit = 'u';

	else {

	} else {

		unit = 'm';

		interval /= 1000;

	}

include/linux/usb/ch9.h

+3 −0
Original line number Diff line number Diff line
@@ -90,6 +90,9 @@ extern enum usb_ssp_rate usb_get_maximum_ssp_rate(struct device *dev); 
 */

extern const char *usb_state_string(enum usb_device_state state);



unsigned int usb_decode_interval(const struct usb_endpoint_descriptor *epd,

				 enum usb_device_speed speed);



#ifdef CONFIG_TRACING

/**

 * usb_decode_ctrl - Returns human readable representation of control request.