Re: [PATCH] socfpga: Initialize emac physels to RGMII correctly

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

On Tue, Nov 10, 2015 at 11:37:07PM +0000, Trent Piepho wrote:
> A comment in the socfpga init said that it was "Clearing emac0 PHY
> interface select to 0", but this was doubly incorrect.  It was setting
> physel for emac1, not emac0, and it was setting physel to 1 (RGMII)
> not 0 (GMII).  All supported socfpga boards use RGMII, and use emac1,
> so fix the comment to reflect the code.  But then extend the code to
> set the physel for both emac0 and emac1, so it can work on boards that
> use either or both emacs (which are called gmac0/1 in the dts).
> 
> The Cyclone V datasheet, page 17-60 "EMAC HPS Interface
> Initialization", says to set physel while the EMAC is in reset.  So
> place the EMAC in reset while changing physel.  The emacs are not in
> reset as code earlier in the boot has already taken most of the
> modules out of reset.  So put them back in reset while the physel is
> changed.  The Linux kernel does it this way too.
> 
> If barebox has no network support, there is not much point in
> configuring the emac physel lines.  This would be the case for the
> xloader pre-bootloader config, which configures physel, doesn't use
> the network, loads the main barebox, which then reconfigures physel
> again.  Make this code depend on CONFIG_NET so it's just done in the
> main barebox.  The Linux kernel does not need barebox to do this
> initialization to use networking.
> 
> Signed-off-by: Trent Piepho <tpiepho@kymetacorp.com>
> ---
>  arch/arm/mach-socfpga/generic.c | 35 ++++++++++++++++++++++++++++++++---
>  1 file changed, 32 insertions(+), 3 deletions(-)

Applied with a small change.

> -static int socfpga_init(void)
> +#if defined(CONFIG_NET)
> +/* Some initialization for the EMAC */
> +static void socfpga_init_emac(void)
>  {
> -	uint32_t val;
> +	uint32_t rst, val;

Dropped the #ifdef in favour for a:

	if (!IS_ENABLED(CONFIG_NET))
		return;

The binary result will be the same but the code looks nicer and the
compile coverage is better.

Sascha


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