Problems with MPC8xx I2C (RTC)

U-Boot-Users Steven Scholz 2 participants 3 messages Apr 11, 2003 – Apr 14, 2003

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Steven Scholz

author

2003-04-11 10:40 UTC #0 lore raw

Hi there,

I am using u-boot-0.3.0, linuxppc-2.4.20 and a DS1338 I2C RTC with MPC8xx CPM I2C (CONFIG_HARD_I2C and i2c-algo-8xx).

To avoid the discribed I2C edge condition I changed u-boot form HARD to SOFT_I2C. Now when booting linux I get:

----------------------------------------------------------------------
i2c-core.o: i2c core module
i2c-dev.o: i2c /dev entries driver module
i2c-algo-8xx.o: i2c mpc8xx algorithm module version 2.6.1 (20010830) i2c-rpx.o: i2c RPX Lite module
i2c-dev.o: Registered 'rpx' as minor 0
Machine check in kernel mode.
Caused by (from SRR1=9032): Transfer error ack signal

Oops: machine check, sig: 7
NIP: C00D9320 XER: 80007E29 LR: C00D9ECC SP: C0FFDF50 REGS: c0ffdea0

TRAP: 0200 Not tainted
MSR: 00009032 EE: 1 PR: 0 FP: 0 ME: 1 IR/DR: 11
TASK = c0ffc000[1] 'swapper' Last syscall: 120
last math 00000000 last altivec 00000000
GPR00: 00000000 C0FFDF50 C0FFC000 C0176C40 00001032 00000001 C0191DFE 00000027
GPR08: 000004FA C0190000 00000000 C0FFDE40 00000001 10000000 00FE5E00 007FFF2D
GPR16: 00000000 00000001 007FFF00 FFFFFFFF 00FE1A30 00000000 00FA0790 00000001
GPR24: 00000000 007FFEC0 00000000 007FFF2D C018EA70 C0176C40 FFF00860 FFF06C3A
Call backtrace:
C0190000 C00D9ECC C0188804 C0188630 C0185CEC C0180588 C01805D0 C000227C C0004C60

Kernel panic: Attempted to kill init!
----------------------------------------------------------------------

Backtrace tells me

0xc0190000 -- 0xc018cb2c + 0x34d4   init_sunrpc
0xc00d9ecc -- 0xc00d9e68 + 0x0064   i2c_8xx_add_bus
0xc0188804 -- 0xc01887d4 + 0x0030   i2c_rpx_init
0xc0188630 -- 0xc0188614 + 0x001c   i2c_init_all
0xc0185cec -- 0xc0185ca4 + 0x0048   chr_dev_init
0xc0180588 -- 0xc0180558 + 0x0030   do_initcalls
0xc01805d0 -- 0xc01805a8 + 0x0028   do_basic_setup
0xc000227c -- 0xc0002268 + 0x0014   init
0xc0004c60 -- 0xc0004c34 + 0x002c   kernel_thread

Did that happen to anyone else?

Do I actually need the I2C_UCODE_PATCH for something?

Thanks,

Steven

Steven Scholz

author

2003-04-11 12:44 UTC #1 lore raw

Quoted 6 lines · I wrote:

I am using u-boot-0.3.0, linuxppc-2.4.20 and a DS1338 I2C RTC with MPC8xx CPM I2C (CONFIG_HARD_I2C and i2c-algo-8xx).
To avoid the discribed I2C edge condition I changed u-boot form HARD to SOFT_I2C. Now when booting linux I get:
...

I just cut & pasted the code from i2c-rpc.c. Apparently the lines

/* Check for and use a microcode relocation patch. */
if ((data->reloc = data->iip->iic_rpbase))

	data->iip = (iic_t *)&cp->cp_dpmem[data->iip->iic_rpbase];

caused the problem! Since I don't use the I added a #ifdef USE_IIC_PATCH around this line just like DENX did in their i2c-r360.c.

Now everything seems to be fine again! :o)

So sorry for the noise!

But again:

What do I need the UCODE_PATCH for?

Thanks,

Steven

Joakim Tjernlund

2003-04-14 09:47 UTC #2 lore raw

Quoted 9 lines

Quoted 6 lines · I wrote:
I am using u-boot-0.3.0, linuxppc-2.4.20 and a DS1338 I2C RTC with MPC8xx CPM I2C (CONFIG_HARD_I2C and i2c-algo-8xx).
To avoid the discribed I2C edge condition I changed u-boot form HARD to SOFT_I2C. Now when booting linux I get:
...

Quoted 8 lines

I just cut & pasted the code from i2c-rpc.c. Apparently the lines
/* Check for and use a microcode relocation patch. */
if ((data->reloc = data->iip->iic_rpbase))
	data->iip = (iic_t *)&cp->cp_dpmem[data->iip->iic_rpbase];
caused the problem! Since I don't use the I added a #ifdef USE_IIC_PATCH around this line just like DENX did in their i2c-r360.c.

This is not the only change needed. You should set data->reloc/iic_rpbase to zero if you don't use the IIC_PATCH.

Quoted 8 lines

Now everything seems to be fine again! :o)
So sorry for the noise!
But again:
What do I need the UCODE_PATCH for?

You need it if you run ethernet on SCC1 and I2C simultaneously.

Jocke