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

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

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/25c8a09b055f716c1e5bf11fea72c3418f844482.1615170625.git.chunfeng.yun@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Chunfeng Yun 2021-03-08 10:52:05 +08:00 committed by Greg Kroah-Hartman
parent 14295a1500
commit fb95c7cf56
4 changed files with 52 additions and 48 deletions
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41
drivers/usb/common/common.c
View File

@ -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

21
drivers/usb/core/devices.c
View File

@ -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;
}

35
drivers/usb/core/endpoint.c
View File

@ -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;
}

3
include/linux/usb/ch9.h
View File

@ -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.