2017-03-03 8:29 GMT+01:00 Mats Karrman <mats.dev.list@xxxxxxxxx>: > On 2017-03-03 04:13, Guenter Roeck wrote: > >> On 03/02/2017 07:22 AM, Mats Karrman wrote: >>> >>> .... >>> Looking forward, one thing I have run into is how to connect the typec >>> driver with a >>> driver for an alternate mode. E.g. the DisplayPort Alternate Mode >>> specification >>> includes the HPD (hot plug) and HPD-INT (hot plug interrupt) signals as >>> bits in the >>> Attention message. These signals are needed by the DisplayPort driver to >>> know when to >>> start negotiation etc. >>> Have you got any thoughts on how to standardize such interfaces? >> >> That really depends on the lower level driver. For Chromebooks, where the >> Type-C >> Protocol Manager runs on the EC, we have an extcon driver which reports >> the pin states >> to the graphics drivers and connects to the Type-C class code using the >> Type-C class >> API. I still need to update, re-test, and publish that code. The published >> code in >> https://chromium.googlesource.com/chromiumos/third_party/kernel/, branch >> chromeos-4.4, >> shows how it can be done, though that code currently still uses the >> Android Type-C >> infrastructure. > On a side note, the cros-ec extcon part for DP is currently discussed here [1]. This driver works together with the cdn-dp driver that just landed in mainline. So comments and feedback are welcome [1] https://lkml.org/lkml/2017/3/1/301 > > OK, thanks! > > My system is a bit different. It's an i.MX6 SoC with the typec phy and DP > controller connected > > directly to the SoC and it's using DTB/OF. > > Using extcon I would have a driver that is both typec class and extcon > driver at the same time > > since I can't share the access to the typec phy. Is this done elsewhere in > the kernel? > > I don't know much about the wcove PMIC and what alternate modes it might > support but I > > guess that driver would end up in the same place. > > Do we need to further standardize attributes under (each) specific alternate > mode to > > include things such as HPD for the DP mode? > > BR // Mats > -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
