Re: [Ltib] Enabling Serial Management Controller (SMC) in MPC8265

[Stuart Hughes]

Hi Andres,

It looks like you're on the right track.  Looking at the Linux kernel 
sources, it seems the tty's should be ttyCPMx:

Documentation/devices.txt:

         45 = /dev/ttyMM1       Marvell MPSC - port 1
         46 = /dev/ttyCPM0      PPC CPM (SCC or SMC) - port 0
            ...
         47 = /dev/ttyCPM5      PPC CPM (SCC or SMC) - port 5
         50 = /dev/ttyIOC0      Altix serial card

And you will need the appropriate entries in your dts file to be used by 
 the bootloader to tell the kernel about your hardware:

Documentation/powerpc/dts-bindings/fsl/cpm_qe/serial.txt

Currently defined compatibles:
- fsl,cpm1-smc-uart
- fsl,cpm2-smc-uart
- fsl,cpm1-scc-uart
- fsl,cpm2-scc-uart
- fsl,qe-uart


Your best bet is probably to ask on one of the ppc kernel mailing lists. 
 I'd be very interested in what you find when you managed to resolve 
this, so if you could post that to the list I think it would be of great 
help to others.

Regards, Stuart

Andres F Marquez wrote:
> Hello,
>
>      I am working with a MPC8265 processor for which I am compiling a
> Kernel using LTIB. I just came to a point in my project in which I need
> an additional serial port to interface my CPU with a FPGA. Since I am
> going to use the UTOPIA interface (which uses several serial ports), the
> only option that I find available is to use a Serial Management
> Controller (SMC) port (SMC1 or SMC2).
>
>      I enabled both of them through the Kernel (2.6.25) configuration
> tool using LTIB. I am able to run my system and execute minicom to try
> to configure the needed serial port. I have not been able to find the
> tty port that refers to either one of the two SMC ports. I have tried
> all the tty's that I get when I do ls /dev/tty* but none of them seem to
> work. Below, I provide the list of tty's that I am getting. ttyCPM0 is
> being used for the console. ttyCPM1 is the only one that I am allowed to
> configure through minicom (for the rest it says device not found). But
> even after configuring ttyCPM1 I don't see anything through the serial
> lines.
>
> -sh-2.05b# ls /dev/tty*
> Using fallback suid method
> /dev/tty      /dev/tty7     /dev/ttyP1    /dev/ttyPSC5  /dev/ttyp3
> /dev/tty0     /dev/ttyAM0   /dev/ttyP2    /dev/ttyS0    /dev/ttyp4
> /dev/tty1     /dev/ttyAM1   /dev/ttyP3    /dev/ttyS1    /dev/ttyp5
> /dev/tty2     /dev/ttyAM2   /dev/ttyPSC0  /dev/ttyS2    /dev/ttyp6
> /dev/tty3     /dev/ttyAM3   /dev/ttyPSC1  /dev/ttyS3    /dev/ttyp7
> /dev/tty4     /dev/ttyCPM0  /dev/ttyPSC2  /dev/ttyp0    /dev/ttyp8
> /dev/tty5     /dev/ttyCPM1  /dev/ttyPSC3  /dev/ttyp1    /dev/ttyp9
> /dev/tty6     /dev/ttyP0    /dev/ttyPSC4  /dev/ttyp2
> -sh-2.05b# 
>
> I am not sure how to know which one of them belongs to the SMC serial
> controllers. 
>
>      After doing some research online, I added an entry in my
> mpc8272ads.dts file for the smc serial controller (see below). However,
> this didn't work. In fact, I was not able to boot the kernel (it stopped
> after loading ttyCPM0 and ttyCPM1). I guess there might be some conflict
> with the entry I added.Below I provide the entries for the serial ports
> (two SCC and one SMC):
>
> address@hidden {                  device_type = "serial";
>                                 compatible = "fsl,mpc8280-scc-uart",
>                                              "fsl,cpm2-scc-uart";
>                                 reg = <11a00 20 8000 100>;
>                                 interrupts = <28 8>;
>                                 interrupt-parent = <&PIC>;
>                                 fsl,cpm-brg = <1>;
>                                 fsl,cpm-command = <00800000>;
>                         };
>
> address@hidden {                  device_type = "serial";
>                                 compatible = "fsl,mpc8280-scc-uart",
>                                              "fsl,cpm2-scc-uart";
>                                 reg = <11a20 20 8100 100>;
>                                 interrupts = <29 8>;
>                                 interrupt-parent = <&PIC>;
>                                 fsl,cpm-brg = <2>;
>                                 fsl,cpm-command = <04a00000>;
>                         }; 
>
> address@hidden
>         device_type = "serial";
>         compatible = "fsl,mpc8280-smc-uart",
>                      "fsl,cpm2-smc-uart";
>         reg = <11a80 10 0 40>;
>         interrupts = <4 8>;
>         interrupt-parent = <&PIC>;
>         fsl,cpm-brg = <7>;
>         fsl,cpm-command = <1d000000>;
> };
>
>      I am kind of confused about what I could be missing in order to use
> the SMC. Does it correspond to any of the listed tty's? or should I
> create one using the mknod command?
>
> Thank you in advance for any help.
>
> Bye.
>  
>
> ANDRES
>
>
>
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