Re: [PATCH V2] CAN: Add Flexcan CAN controller driver

[Sascha Hauer <s.hauer@pengutronix.de>]

On Tue, Jul 28, 2009 at 04:12:10PM +0200, Oliver Hartkopp wrote:
> Oliver Hartkopp wrote:
> > Sascha Hauer wrote:
> 
> >>>> +
> >>>> +	if (frame->can_id & CAN_RTR_FLAG)
> >>>> +		dlc |= MB_CNT_RTR;
> >>>> +
> >>>> +	writel(dlc, &regs->cantxfg[TX_BUF_ID].can_dlc);
> >>>> +	writel(can_id, &regs->cantxfg[TX_BUF_ID].can_id);
> 
> Are you sure, that this is correct?

Yes, I am sure, at least on my hardware.

> 
> Indeed i wonder, if it would make sense to skip the entire struct flexcan_mb
> approach and fiddle byte-by-byte inside the registers ...

You'll have to to 32 bit accesses to get it right on little and big
endian.

what we can do is:

writel(can_data[0] << 24 | can_data[1] << 16 | can_data[2] << 8 | can_data[3],
	msg_buf + 0x8);

Sascha


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