Fwd: UART #1 access on Sequoia board

2 messages, 2 authors, 2011-05-23 · open the first message on its own page

Fwd: UART #1 access on Sequoia board

From: Muhammad Waseem <hidden>
Date: 2011-05-23 19:22:39

I am using kernel version 2.6.23 which came with the Sequoia support CD. So
that means UART # 1 BSP would probably not there?  But device file
/dev/ttyS1 is present in rootfs when listed using 'ls'. Do you think
updating the kernel might solve the problem?

BTW where can I see the board's DTS file?

--
Waseem




On Mon, May 23, 2011 at 5:40 PM, Josh Boyer [off-list ref]wrote:
On Mon, May 23, 2011 at 11:34:26AM +0500, Muhammad Waseem wrote:
quoted
Hello,
  I am working on PPC440EPx (Sequoia) to access its UART # 1 port for
data
quoted
transfer, while UART # 0 is connected to remote terminal access on host.
However there is no module/driver listed for UART # 1 using 'lsmod'. The
kernel version is 2.6.23. How can I access the UART # 1 in user space
and/or
quoted
kernel space? Do I need to develop own BSP for this? please help.
The driver is normally built into the kernel.  If the board DTS file has
both UARTs listed, and you have /dev/ttyS1 on your rootfs you should be
able to use it.  However, Sequoia wasn't added until 2.6.24, so I'm not
really sure what kernel flavor you are using.

josh

Re: Fwd: UART #1 access on Sequoia board

From: Josh Boyer <hidden>
Date: 2011-05-23 20:41:09

On Tue, May 24, 2011 at 12:22:14AM +0500, Muhammad Waseem wrote:

Please don't top post.
I am using kernel version 2.6.23 which came with the Sequoia support CD. So
that means UART # 1 BSP would probably not there?  But device file
/dev/ttyS1 is present in rootfs when listed using 'ls'. Do you think
updating the kernel might solve the problem?
Not necessarily.  You can create device nodes on the rootfs without
anything being bound to them.  One of the easiest ways to see if
something discovered the serial port is to look in the boot output.  You
should see something like:

serial8250.0: ttyS0 at MMIO 0x1ef600300 (irq = 17) is a 16550A                  
console [ttyS0] enabled, bootconsole disabled                                   
console [ttyS0] enabled, bootconsole disabled                                   
serial8250.0: ttyS1 at MMIO 0x1ef600400 (irq = 18) is a 16550A                  
serial8250.0: ttyS2 at MMIO 0x1ef600500 (irq = 19) is a 16550A                  
serial8250.0: ttyS3 at MMIO 0x1ef600600 (irq = 20) is a 16550A   

or:

1ef600300.serial: ttyS0 at MMIO 0x1ef600300 (irq = 17) is a 16550               
1ef600400.serial: ttyS1 at MMIO 0x1ef600400 (irq = 18) is a 16550               
1ef600500.serial: ttyS2 at MMIO 0x1ef600500 (irq = 19) is a 16550               
1ef600600.serial: ttyS3 at MMIO 0x1ef600600 (irq = 20) is a 16550      
BTW where can I see the board's DTS file?
arch/powerpc/boot/dts/sequoia.dts

josh
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