From 541b6fe63023f3059cf85d47ff2767a3e42a8e44 Mon Sep 17 00:00:00 2001 From: Felipe Balbi Date: Mon, 26 Sep 2016 10:51:18 +0300 Subject: usb: add helper to extract bits 12:11 of wMaxPacketSize According to USB Specification 2.0 table 9-4, wMaxPacketSize is a bitfield. Endpoint's maxpacket is laid out in bits 10:0. For high-speed, high-bandwidth isochronous endpoints, bits 12:11 contain a multiplier to tell us how many transactions we want to try per uframe. This means that if we want an isochronous endpoint to issue 3 transfers of 1024 bytes per uframe, wMaxPacketSize should contain the value: 1024 | (2 << 11) or 5120 (0x1400). In order to make Host and Peripheral controller drivers' life easier, we're adding a helper which returns bits 12:11. Note that no care is made WRT to checking endpoint type and gadget's speed. That's left for drivers to handle. Signed-off-by: Felipe Balbi --- include/uapi/linux/usb/ch9.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'include/uapi') diff --git a/include/uapi/linux/usb/ch9.h b/include/uapi/linux/usb/ch9.h index a8acc24765fe..7628dff5fac3 100644 --- a/include/uapi/linux/usb/ch9.h +++ b/include/uapi/linux/usb/ch9.h @@ -423,6 +423,11 @@ struct usb_endpoint_descriptor { #define USB_ENDPOINT_XFER_INT 3 #define USB_ENDPOINT_MAX_ADJUSTABLE 0x80 +#define USB_EP_MAXP_MULT_SHIFT 11 +#define USB_EP_MAXP_MULT_MASK (3 << USB_EP_MAXP_MULT_SHIFT) +#define USB_EP_MAXP_MULT(m) \ + (((m) & USB_EP_MAXP_MULT_MASK) >> USB_EP_MAXP_MULT_SHIFT) + /* The USB 3.0 spec redefines bits 5:4 of bmAttributes as interrupt ep type. */ #define USB_ENDPOINT_INTRTYPE 0x30 #define USB_ENDPOINT_INTR_PERIODIC (0 << 4) @@ -630,6 +635,20 @@ static inline int usb_endpoint_maxp(const struct usb_endpoint_descriptor *epd) return __le16_to_cpu(epd->wMaxPacketSize); } +/** + * usb_endpoint_maxp_mult - get endpoint's transactional opportunities + * @epd: endpoint to be checked + * + * Return @epd's wMaxPacketSize[12:11] + 1 + */ +static inline int +usb_endpoint_maxp_mult(const struct usb_endpoint_descriptor *epd) +{ + int maxp = __le16_to_cpu(epd->wMaxPacketSize); + + return USB_EP_MAXP_MULT(maxp) + 1; +} + static inline int usb_endpoint_interrupt_type( const struct usb_endpoint_descriptor *epd) { -- cgit v1.2.3 From abb621844f6a0c93bbc934f9a096752c4c1c5722 Mon Sep 17 00:00:00 2001 From: Felipe Balbi Date: Wed, 28 Sep 2016 13:42:17 +0300 Subject: usb: ch9: make usb_endpoint_maxp() return only packet size Now that we have a helper to gather periodic endpoints' multiplier bits from wMaxPacketSize and every driver is using it, we can safely make sure that usb_endpoint_maxp() returns only bits 10:0 of wMaxPacketSize which is where the actual packet size lies. Signed-off-by: Felipe Balbi --- include/uapi/linux/usb/ch9.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'include/uapi') diff --git a/include/uapi/linux/usb/ch9.h b/include/uapi/linux/usb/ch9.h index 7628dff5fac3..2c5d7c4a69e3 100644 --- a/include/uapi/linux/usb/ch9.h +++ b/include/uapi/linux/usb/ch9.h @@ -423,6 +423,7 @@ struct usb_endpoint_descriptor { #define USB_ENDPOINT_XFER_INT 3 #define USB_ENDPOINT_MAX_ADJUSTABLE 0x80 +#define USB_ENDPOINT_MAXP_MASK 0x07ff #define USB_EP_MAXP_MULT_SHIFT 11 #define USB_EP_MAXP_MULT_MASK (3 << USB_EP_MAXP_MULT_SHIFT) #define USB_EP_MAXP_MULT(m) \ @@ -628,11 +629,11 @@ static inline int usb_endpoint_is_isoc_out( * usb_endpoint_maxp - get endpoint's max packet size * @epd: endpoint to be checked * - * Returns @epd's max packet + * Returns @epd's max packet bits [10:0] */ static inline int usb_endpoint_maxp(const struct usb_endpoint_descriptor *epd) { - return __le16_to_cpu(epd->wMaxPacketSize); + return __le16_to_cpu(epd->wMaxPacketSize) & USB_ENDPOINT_MAXP_MASK; } /** -- cgit v1.2.3