Peter Chen <peter.chen@xxxxxxxxxxxxx> writes: > On Thu, Mar 14, 2013 at 09:53:55AM +0100, Marc Kleine-Budde wrote: >> On 03/14/2013 09:34 AM, Peter Chen wrote: >> > Hi Alex and all, >> > >> > Currently, we have two problems to block chipidea driver coming >> > development. >> > >> > As there are so many chipidea versions, we impossible to collect >> > all to make a decision, it is better to cover most of the cases, >> > and using device tree (or platform data) to cover exceptions >> > if they exist. >> > >> > 1. USB Mode Problem >> > How can we decide USB mode (gadget, host and otg) at driver, and >> > how to read OTGSC register? Below is my pinion. >> > >> > - We get gadget or host support from CAP_DCCPARAMS(DCCPARAMS_DC or DCCPARAMS_HC), >> >> IIRC This is broken on mx25. The host only port gets into an error state >> if you read this register. :( > > If there is an exception, you can use DT to override it. Eg: > > if (ci->dccparams_is_error) > do not read DCCPARAMS; /* using DT dr_mode setting */ I know it's tempting to add more phandles to the device tree for every possible exception, but let's try to resist the temptation. Regards, -- Alex -- 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
