On Wed, Jan 18, 2017 at 04:09:32AM +0800, Chen-Yu Tsai wrote: > 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. But musb can still operate as a host, right? Thanks! Maxime -- Maxime Ripard, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com
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