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 --- common/usb_hub.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) (limited to 'common') diff --git a/common/usb_hub.c b/common/usb_hub.c index 18c366ab7e..bbb1155089 100644 --- a/common/usb_hub.c +++ b/common/usb_hub.c @@ -700,6 +700,56 @@ static int usb_hub_configure(struct usb_device *dev) break; } + switch (dev->descriptor.bDeviceProtocol) { + case USB_HUB_PR_FS: + break; + case USB_HUB_PR_HS_SINGLE_TT: + debug("Single TT\n"); + break; + case USB_HUB_PR_HS_MULTI_TT: + ret = usb_set_interface(dev, 0, 1); + if (ret == 0) { + debug("TT per port\n"); + hub->tt.multi = true; + } else { + debug("Using single TT (err %d)\n", ret); + } + break; + case USB_HUB_PR_SS: + /* USB 3.0 hubs don't have a TT */ + break; + default: + debug("Unrecognized hub protocol %d\n", + dev->descriptor.bDeviceProtocol); + break; + } + + /* Note 8 FS bit times == (8 bits / 12000000 bps) ~= 666ns */ + switch (hubCharacteristics & HUB_CHAR_TTTT) { + case HUB_TTTT_8_BITS: + if (dev->descriptor.bDeviceProtocol != 0) { + hub->tt.think_time = 666; + debug("TT requires at most %d FS bit times (%d ns)\n", + 8, hub->tt.think_time); + } + break; + case HUB_TTTT_16_BITS: + hub->tt.think_time = 666 * 2; + debug("TT requires at most %d FS bit times (%d ns)\n", + 16, hub->tt.think_time); + break; + case HUB_TTTT_24_BITS: + hub->tt.think_time = 666 * 3; + debug("TT requires at most %d FS bit times (%d ns)\n", + 24, hub->tt.think_time); + break; + case HUB_TTTT_32_BITS: + hub->tt.think_time = 666 * 4; + debug("TT requires at most %d FS bit times (%d ns)\n", + 32, hub->tt.think_time); + break; + } + debug("power on to power good time: %dms\n", descriptor->bPwrOn2PwrGood * 2); debug("hub controller current requirement: %dmA\n", -- cgit