Writing to CPLD mapped to EBC Port of AMCC440EP

I am attempting to write to a CPLD mapped to the EBC port of a AMCC 440EP.  When I attempt to write using an unsigned variable
ie. unsigned *pbase = (unsigned char *)ioremap64(0x8F000000,0x1000000);
I get a kernel access of bad area, sig: 11 fault.  However, if I change to an unsigned char ie. unsigned char *pbase = (unsigned char *)ioremap64(0x8F000000,
0x1000000); The system doesn't crash.  I need to write using an unsigned.  Does any one have any ideas what I am doing wrong?

I am using 2.6.24 Xenomai Denx. 4.2.  I am porting a working 2.6.14 project that was developed with FSM Labs RT Linux (now owned by WindRiver).




//-----------------------------------------------------------------------
// initialize module -- this what is called when you do insmod ./ubus.ko
//-----------------------------------------------------------------------
static int __init ubus_init_module (void) 
{
  int i;
  unsigned ofs[20] =
{0x400000,0x400100,0x500000,0x500100,0x600000,0x600100,0x700000,0x700100,

0x608000,0x608100,0x708000,0x708100,0x610000,0x610100,0x710000,0x710100,
                        0x618000,0x618100,0x718000,0x718100};
  unsigned *pbase = (unsigned *)ioremap64(0x8F000000,
0x1000000);
  unsigned *p;
  for( i = 0; i < 20;i++)
  {
    p = pbase + ofs[i] + 0x34;
    *p = 0x25500;
    printk(KERN_ALERT "p = %X\r\n",p);
  }
  iounmap(pbase);
  PRINTK("initializing module ubus\n");
  i = register_chrdev (UBUS_MAJOR, UBUS_NAME, &ubus_fops);
  if (i != 0) return - EIO;

  return 0;
}


-bash-3.2# insmod
ubus.ko                                                                                            
Oops: kernel access of bad area, sig: 11
[#1]                                                                        
NIP: d1068054 LR: d1068038 CTR:
00000000                                                                             
REGS: cf489d70 TRAP: 0300   Not tainted
(2.6.24.2)                                                                  
MSR: 00029000 <EE,ME>  CR: 08004022  XER:
00000004                                                                   
DEAR: d61000d0, ESR:
00800000                                                                                        
TASK = cf45c410[309] 'insmod' THREAD:
cf488000                                                                       
GPR00: d1068038 cf489e20 cf45c410 d5100000 d6100000 00000000 00000000
cf4467f8                                       
GPR08: 000007f8 d1060000 8ffff000 00000000 28004028 1004950c 00000000
d509c1e4                                       
GPR16: cffe1ce0 d5093a04 00000000 00000036 00000036 d5093310 c003cb00
d5081000                                       
GPR24: 00000026 00000026 d5093464 cf489e28 d1


0664c4 00025500 00000026 d1066a60                                       
NIP [d1068054] ubus_init_module+0x54/0x190
[ubus]                                                                    
LR [d1068038] ubus_init_module+0x38/0x190
[ubus]                                                                     
Call
Trace:                                                                                                          
[cf489e20] [d1068038] ubus_init_module+0x38/0x190 [ubus]
(unreliable)                                                
[cf489e90] [c003df74] sys_init_module
+0x174/0x15e0                                                                   
[cf489f40] [c0001ac4] ret_from_syscall
+0x0/0x3c                                                                      
Instruction
dump:                                                                                                    
480000cd 3c808f00 3ca00100 38600000 480000cd 80810008 3fa00002
5484103a                                              
7c841a14 3d20d106 63bd5500 3b8964c4 <93a400d0> 7c7e1b78 388400d0
7f83e378                                            
Segmentation fault   


-bash-3.2# insmod
ubus.ko                                                                                            
p = D5500034                                                                                                         
p = D5500134                                                                                                         
p = D5600034                                                                                                         
p = D5600134                                                                                                         
p = D5700034                                                                                                         
p = D5700134                                                                                                         
p = D5800034                                                                                                         
p = D5800134                                                                                                         
p = D5708034                                                                                                         
p = D5708134                                                                                                          
p = D5808034                                                                                                         
p = D5808134                                                                                                         
p = D5710034                                                                                                         
p = D5710134                                                                                                         
p = D5810034                                                                                                         
p = D5810134                                                                                                         
p = D5718034                                                                                                         
p = D5718134                                                                                                         
p = D5818034                                                                                                         
p = D5818134                                                                                                         
initializing module ubus  

On Mon, 28 Jul 2008 16:40:35 -0700
"Henry Bausley" [off-list ref] wrote:

I am attempting to write to a CPLD mapped to the EBC port of a AMCC 440EP.  When I attempt to write using an unsigned variable
ie. unsigned *pbase = (unsigned char *)ioremap64(0x8F000000,0x1000000);
I get a kernel access of bad area, sig: 11 fault.  However, if I change to an unsigned char ie. unsigned char *pbase = (unsigned char *)ioremap64(0x8F000000,
0x1000000); The system doesn't crash.  I need to write using an unsigned.  Does any one have any ideas what I am doing wrong?

The documentation I have for the Bamboo board says the EPLD is at
address 0x80002000 and is only 8 bytes in size.  Similarly, the
Yosemite board CPLD is at 0x80002000 and is only 16 bytes in size.  Why
you are ioremapping 16MiB at 0x8F000000 I have no idea.

Also, the individual registers of the EPLD/CPLD on both boards are only
8 bits, so an unsigned char seems appropriate.  If you have a custom
board that does something totally different from how the eval boards
are set up, then I'm not sure many people will be able to help you
without documentation for that board.

josh

Our board is based upon the Yosemite.  But we have modified the CPLD and 
made our own custom hardware, thats why the parameters for ioremap are 
different.  The system is based on the 2.6.14-rtl that has worked absolutely 
perfect for a couple of years which we got from FSM Labs.

I am porting to the 2.6.24 kernel Denx with xenomai and had the problem.  It 
turns out the default value if the EBC0_CFG register  was 0x84400000 in the 
system and we needed to change it to 0xBC400000 to increase the Ready 
Timeout.  We were getting a machine check error.

Thank's a lot for your input!!!



----- Original Message ----- 
From: "Josh Boyer" <redacted>
To: "Henry Bausley" <redacted>
Cc: <redacted>
Sent: Tuesday, July 29, 2008 5:02 PM
Subject: Re: Writing to CPLD mapped to EBC Port of AMCC440EP

On Mon, 28 Jul 2008 16:40:35 -0700
"Henry Bausley" [off-list ref] wrote:

quoted

I am attempting to write to a CPLD mapped to the EBC port of a AMCC 
440EP.  When I attempt to write using an unsigned variable
ie. unsigned *pbase = (unsigned char *)ioremap64(0x8F000000,0x1000000);
I get a kernel access of bad area, sig: 11 fault.  However, if I change 
to an unsigned char ie. unsigned char *pbase = (unsigned char 
*)ioremap64(0x8F000000,
0x1000000); The system doesn't crash.  I need to write using an unsigned. 
Does any one have any ideas what I am doing wrong?

The documentation I have for the Bamboo board says the EPLD is at
address 0x80002000 and is only 8 bytes in size.  Similarly, the
Yosemite board CPLD is at 0x80002000 and is only 16 bytes in size.  Why
you are ioremapping 16MiB at 0x8F000000 I have no idea.

Also, the individual registers of the EPLD/CPLD on both boards are only
8 bits, so an unsigned char seems appropriate.  If you have a custom
board that does something totally different from how the eval boards
are set up, then I'm not sure many people will be able to help you
without documentation for that board.

josh 

test - please ignore
--------------------------------------------------------

CONFIDENTIALITY NOTICE: This e-mail message, including any attachments, =
is for the sole use of the intended recipient(s) and contains =
information that is confidential and proprietary to Applied Micro =
Circuits Corporation or its subsidiaries. It is to be used solely for =
the purpose of furthering the parties' business relationship. All =
unauthorized review, use, disclosure or distribution is prohibited. If =
you are not the intended recipient, please contact the sender by reply =
e-mail and destroy all copies of the original message.