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

[Andres F Marquez]

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