Subject: Re: [PATCH] [POWERPC] MPC8360E-RDK: Device tree and board file

From: Timur Tabi <[email-masked]>
Date: Thu, 27 Dec 2007 09:38:23 -0600

Anton Vorontsov wrote:

> I wonder what are the symptoms if microcode is at fault? According
> to errata description, hang isn't something I should get on the
> transmit attempt.

Well, if the microcode fails, you'll never know.  I tried to explain the 
need for a unified microcode validation mechanism to the QE microcode 
developers, but I didn't get very far.

> Well. All I've found is: QERAMPTCH.zip ("RAM Microcode Patches for
> PowerQUICC II Pro Family QE Errata"), which should fix QE_UART5 errata
> for MPC8323 Rev 1.1. 

I don't know what that is, but it doesn't apply.  I'm talking about the 
QE and QE UART patches I've posted to this mailing list over the past 
month.  Once Kumar applies them to them to his for-2.6.25 branch, it'll 
make life easier for everyone.

Can I assume it works for MPC8360 too?

No.  Microcode is very sensitive to the processor and the revision.  A 
microcode for 8360 2.1 won't work on 8360 2.0.

I forgot to give you the actual microcode. :-)  I'll email it to you later.

> Here are dts entries I use:
> 
> 		firmware {
> 			id = "Soft-UART";
> 			extended_modes = <0 0>;
> 			virtual_traps = <0 0 0 0 0 0 0 0>;
> 		};

This entry is created by U-Boot only if it uploads the microcode.  This 
should not be in the DTS.

> 
> 		ucc@2400 {
> 			device_type = "serial";
> 			compatible = "ucc_uart";
> 			reg = <0x2400 0x200>;
> 			device-id = <5>;
> 			port-number = <0>;
> 			rx-clock-name = "brg7";
> 			tx-clock-name = "brg8";
> 			interrupts = <40>;
> 			interrupt-parent = <&qeic>;
> 			soft-uart;
> 		};
> 
> 		ucc@3400 {
> 			device_type = "serial";
> 			compatible = "ucc_uart";
> 			reg = <0x3400 0x200>;
> 			device-id = <6>;
> 			port-number = <1>;
> 			rx-clock-name = "brg14";
> 			tx-clock-name = "brg14";
> 			interrupts = <41>;
> 			interrupt-parent = <&qeic>;
> 		};

You need to have separate BRGs for TX and RX when using soft-uart mode, 
and you MUST use soft-uart mode on the 8360.