[U-Boot] [U-Boot PATCH v2 10/12] keystone2: net: add keystone ethernet driver

[Tom Rini]

On Wed, Mar 12, 2014 at 03:04:04PM -0400, Murali Karicheri wrote:
> On 2/25/2014 5:11 PM, Rini, Tom wrote:
> >On Thu, Feb 20, 2014 at 12:55:12PM -0500, Murali Karicheri wrote:
> >
> >>From: Vitaly Andrianov <vitalya at ti.com>
> >>
> >>Ethernet driver configures the CPSW, SGMI and Phy and uses
> >>the the Navigator APIs. The driver supports 4 Ethernet ports and
> >>can work with only one port at a time.
> >First, can we just use things in a "dumb" mode and use the existing CPSW
> >driver?  Or are there use cases we need to worry about here with a
> >bigger / more robust network driver?
> 
> First of all we believe the CPSW driver in u-boot is for  tnetv107x
> CPSW hardware and

No, it's for the am335x and DRA7xx HW.

> keystone CPSW is different and more complex. We need to support
> different modes
> such as MAC to PHY, MAC to MAC and MAC to MAC forced. Also we are
> using a SGMII
> with up to 8 ports in the newer K2 devices. So we don't think we can
> re-use the CPSW
> driver.

How many of these modes do we actually need to support in U-Boot?  What
usecase(s) do you have for networking in U-Boot?  And I assume you're
having similar conversations upstreaming the kernel networking driver
(which does support am33xx/dra7xx and tnetv107x)..

> >>+++ b/drivers/net/keystone_net.c
> >Generic problem, please use phylib.
> 
> Vitaly has done some prototyping with phy lib and  found that this
> adds tons of code and
> huge time to change the active port.  It doesn't give any advantage
> of using phylib as the
> driver make only very few reads from standard generic phy registers.

OK.

> >>+void sgmii_serdes_setup_156p25mhz()
> >>+{
> >>+	unsigned int cnt;
> >>+
> >>+	reg_rmw(0x0232a000, 0x00800000, 0xffff0000);
> >Please comment on what we're doing here, and why we aren't using a
> >struct to describe whatever is at 0x0232a000 ?
> >
> >>+void sgmii_serdes_shutdown()
> >>+{
> >>+	reg_rmw(0x0232bfe0, 0, 3 << 29 | 3 << 13);
> >Same.
> 
> We will add comment here as we are using third party SERDES IP and
> the register
> names are not published by the vendor.

Please check what you are and are not allowed to say.  It's usually the
case with NDA'd docs that if you can release code based on the docs it
doesn't have to be heavily obsucred and you can say what you're doing.

-- 
Tom
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