> > *That is a good point. To understand how to enable the power and clock for > McASP, look at the Starterware examples for McASP as they do everything you > need to make this work.* >
Probably easier, and more productive to read the TRM for the AM335x processors . . . All address offsets should be listed there as well, and the introduction for hardware module will give a short explanation of what needs doing, in order to bring the module up. On Thu, Dec 17, 2015 at 3:15 PM, John Syne <[email protected]> wrote: > > > > On Dec 17, 2015, at 1:59 PM, Charles Steinkuehler < > [email protected]> wrote: > > > > On 12/17/2015 2:04 PM, [email protected] wrote: > >> I am trying to access the McASP control registers. Reading from the > first > >> one fails with the kernel oops stating "external abort on non-linefetch > >> (0x1028)". I dont know what that means. A minimum failing example of the > >> code is below: > > > > <snip> > > > >> I have also tried request_mem_region around it, but that changes > nothing. > >> The sound drivers are not loaded, and the devicetree entry for the > McASP is > >> disabled, so there shouldn't be any problems with conflicts. > > > > One way to get this error is if the hardware you are talking to is > > disabled. You need to either enable the hardware via the device tree, > > or otherwise manage to setup the low-level SoC registers so the McASP > > is provided a clock, power, and is taken out of reset. > > > > Most of the hardware blocks on the AM335x series can be individually > > enabled or shut-down to save power. > That is a good point. To understand how to enable the power and clock for > McASP, look at the Starterware examples for McASP as they do everything you > need to make this work. > > Regards, > John > > > > -- > > Charles Steinkuehler > > [email protected] > > > > -- > > For more options, visit http://beagleboard.org/discuss > > --- > > You received this message because you are subscribed to the Google > Groups "BeagleBoard" group. > > To unsubscribe from this group and stop receiving emails from it, send > an email to [email protected]. > > For more options, visit https://groups.google.com/d/optout. > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
