Hi, On Wed, Jan 18, 2017 at 4:06 AM, Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx> wrote: > On Wed, Jan 18, 2017 at 12:57:08AM +0800, Icenowy Zheng wrote: >> >> >> 17.01.2017, 16:06, "Maxime Ripard" <maxime.ripard@xxxxxxxxxxxxxxxxxx>: >> > On Tue, Jan 17, 2017 at 03:14:46AM +0800, Icenowy Zheng wrote: >> >> The PHY0 on H3 can be wired either to MUSB controller or OHCI/EHCI >> >> controller. >> >> >> >> The original driver wired it to OHCI/EHCI controller; however, as the >> >> code to use PHY0 as OHCI/EHCI is missing, it makes the PHY fully >> >> unusable. >> >> >> >> Rename the register (according to its function and the name in BSP >> >> driver), and remove the code which wires the PHY0 to OHCI/EHCI, as MUSB >> >> can support both peripheral and host mode (although the host mode of >> >> MUSB is buggy). >> > >> > Can you elaborate on that? What's wrong with it? >> >> The configuration is at bit 0 of register 0x20 in PHY. >> >> When the PHY is reseted, it defaults as MUSB mode. >> >> However, the original author of the H3 PHY code seems to be lack of >> this knowledge (He named it PHY_UNK_H3), and changed the PHY to HCI >> mode. >> >> I just removed the code that wires it to HCI mode, thus it will work >> in MUSB mode, with my sun8i-h3-musb patch. > > I have no idea what you mean by MUSB mode. > > Do you mean that the previous code was only working in host mode, and > now it only works in peripheral? >From what I understand, with the H3, Allwinner has put a mux in front of the MUSB controller. The mux can send the USB data to/from the MUSB controller, or a standard EHCI/OHCI pair. This register controls said mux. This means we can use a proper USB host for host mode, instead of the limited support in MUSB. ChenYu > > Maxime > > -- > Maxime Ripard, Free Electrons > Embedded Linux and Kernel engineering > http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
