From 5624dfd5aa91c244519ec60b40b4a42b4d9a43ca Mon Sep 17 00:00:00 2001 From: Bin Meng Date: Wed, 19 Jul 2017 21:51:16 +0800 Subject: usb: hub: Parse and save TT details from device descriptor A high speed hub has a special responsibility to handle full speed/ low speed devices connected on downstream ports. In this case, the hub must isolate the high speed signaling environment from the full speed/low speed signaling environment with the help of Transaction Translator (TT). TT details are provided by hub descriptors and we parse and save it to hub uclass_priv for later use. Signed-off-by: Bin Meng Reviewed-by: Simon Glass --- include/usb_defs.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'include/usb_defs.h') diff --git a/include/usb_defs.h b/include/usb_defs.h index 273337f46a4..b7f2eada07d 100644 --- a/include/usb_defs.h +++ b/include/usb_defs.h @@ -293,6 +293,7 @@ #define HUB_CHAR_LPSM 0x0003 #define HUB_CHAR_COMPOUND 0x0004 #define HUB_CHAR_OCPM 0x0018 +#define HUB_CHAR_TTTT 0x0060 /* TT Think Time mask */ /* * Hub Status & Hub Change bit masks @@ -309,6 +310,17 @@ /* Hub class request codes */ #define USB_REQ_SET_HUB_DEPTH 0x0c +/* + * As of USB 2.0, full/low speed devices are segregated into trees. + * One type grows from USB 1.1 host controllers (OHCI, UHCI etc). + * The other type grows from high speed hubs when they connect to + * full/low speed devices using "Transaction Translators" (TTs). + */ +struct usb_tt { + bool multi; /* true means one TT per port */ + unsigned think_time; /* think time in ns */ +}; + /* * CBI style */ -- cgit v1.2.3