On Mon, May 21, 2018 at 11:43 AM, Roger Quadros <rogerq@xxxxxx> wrote: > Hi Kevin, > > On 21/05/18 13:11, Kevin Hilman wrote: >> Hi Roger, >> >> I'm looking at the dra7.dtsi to try to understand the base addresses, >> and I'm rather confused about the node addresses vs the reg addresses >> for both dcan1 and dcan2. >> >> Could you clarify why the reg address and node addresses are so >> different for both, and where I might find the TRM that describes >> these addresses? All I could find was a datasheet that didn't give >> any info about the IP or the base addresses, but I'd really like to >> understand what the *real* addresses are for this. > > From the TRM - http://www.ti.com/lit/pdf/sprui30 > > "Table 2-4. L4_WKUP Memory Map" contains DCAN1. > > "Table 2-6. L4_PER2 Memory Map" contains DCAN2. > > As they are in different domains, the addresses look different. > > Also in Chapter 24.10.5 DCAN Register Manual, > Table 24-1120. DCAN Instance Summary, shows base addresses for both instances. Thanks for the details and pointer to the TRM, that helps. I see now that the "reg =" lines in the DT nodes are correct, and match the TRM. What makes it confusing is that these addresses don't match the DT node addresses. IOW, it's confusing that these addresses are different dcan1: can@481cc000 { reg = <0x4ae3c000 0x2000>; That doesn't have any affect on the code obviously, but it makes reading the DT a bit confusing. Kevin -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
