On 01/05/2024 17:14:43+0800, Jingbao Qiu wrote: > On Wed, May 1, 2024 at 3:43 PM Inochi Amaoto <inochiama@xxxxxxxxxxx> wrote: > > > > On Wed, May 01, 2024 at 01:03:58PM GMT, Jingbao Qiu wrote: > > > Hi, Inochi > > > > > > On Wed, May 1, 2024 at 10:19 AM Inochi Amaoto <inochiama@xxxxxxxxxxx> wrote: > > > > > Another thing is that I do not think is a good way to let the > > > > rtc driver access RTC_CTRL area directly. You have already > > > > know there is a 8051 device in the 0x05025000. It is necessary > > > > to make some room for this device. Maybe you want to implement > > > > them all in the rtc driver? If so, I do think it is a bad idea. > > > > > > > > > Do you mean that RTC drivers should not directly access the 0x05025000 address? > > > Because there is an 8051 subsystem on this address. > > > > Yes. At least we need some mechanism to share these address between > > this devices. > > > > > Firstly, I do not intend to implement 8051 in the RTC driver, > > > but the 8051 subsystem is located within a module independently > > > powered by the RTC. > > > So if we want to implement the 8051 subsystem in the future, it can be > > > used as a node in RTC? I'm not sure. > > > > Yes, this is what I care about. > > > > > Then, Alexandre told me that there are operations related to PM in > > > RTC, such as the following files. > > > This matches the description of address 0x05025000. > > > > > > drivers/rtc/rtc jz4740. c > > > > > > > I do not think this is something related to the PM. 8051 is more > > like remoteproc. So it is necessary to arrange them carefully. > > > > You are right. > I learned from official documents that 8051 works in the RTC domain. > Linux does not provide relevant interfaces to operate 8051, > Just providing a mailbox for communication between them, or through > interruptions. > I don't understand how 8051 works, so I shouldn't write to the > corresponding registers in RTC. > > https://milkv.io/docs/duo/getting-started/8051core Then you will have to have a driver for the 8051 firmware before being able to access registers that are outside of the RTC range. However, I se the firmware is using RTC_INFOx without any form of locking but I guess this just means Linux will have to ensure it never writes to those. > > > > > > > 2.25.1 > > > > > -- Alexandre Belloni, co-owner and COO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com
