Re: [PATCH net-next v3 1/4] net: mdio: Introduce a regmap-based mdio driver

[Maxime Chevallier <maxime.chevallier@bootlin.com>]

Hello Vlad,

On Fri, 26 May 2023 13:21:39 +0300
Vladimir Oltean <vladimir.oltean@nxp.com> wrote:

> >  M:	William Breathitt Gray <william.gray@linaro.org>
> >  L:	linux-iio@vger.kernel.org
> > diff --git a/drivers/net/ethernet/altera/Kconfig
> > b/drivers/net/ethernet/altera/Kconfig index
> > dd7fd41ccde5..0a7c0a217536 100644 ---
> > a/drivers/net/ethernet/altera/Kconfig +++
> > b/drivers/net/ethernet/altera/Kconfig @@ -5,6 +5,8 @@ config
> > ALTERA_TSE select PHYLIB
> >  	select PHYLINK
> >  	select PCS_ALTERA_TSE
> > +	select MDIO_REGMAP
> > +	depends on REGMAP  
> 
> I don't think this bit belongs in this patch.
> Also: depends on REGMAP or select REGMAP?

Ugh sorry about that... I'll address both the dependency and the wrong
patch splitting in next revision.

> >  	help
> >  	  This driver supports the Altera Triple-Speed (TSE)
> > Ethernet MAC. 
> > diff --git a/drivers/net/mdio/Kconfig b/drivers/net/mdio/Kconfig
> > index 9ff2e6f22f3f..aef39c89cf44 100644
> > --- a/drivers/net/mdio/Kconfig
> > +++ b/drivers/net/mdio/Kconfig
> > @@ -185,6 +185,16 @@ config MDIO_IPQ8064
> >  	  This driver supports the MDIO interface found in the
> > network interface units of the IPQ8064 SoC
> >  
> > +config MDIO_REGMAP
> > +	tristate
> > +	help
> > +	  This driver allows using MDIO devices that are not
> > sitting on a
> > +	  regular MDIO bus, but still exposes the standard 802.3
> > register
> > +	  layout. It's regmap-based so that it can be used on
> > integrated,
> > +	  memory-mapped PHYs, SPI PHYs and so on. A new virtual
> > MDIO bus is
> > +	  created, and its read/write operations are mapped to the
> > underlying
> > +	  regmap.  
> 
> It would probably be helpful to state that those who select this
> option should also explicitly select REGMAP.

You're right, I'll update this

> > +
> >  config MDIO_THUNDER
> >  	tristate "ThunderX SOCs MDIO buses"
> >  	depends on 64BIT
> > diff --git a/drivers/net/mdio/Makefile b/drivers/net/mdio/Makefile
> > index 7d4cb4c11e4e..1015f0db4531 100644
> > --- a/drivers/net/mdio/Makefile
> > +++ b/drivers/net/mdio/Makefile
> > @@ -19,6 +19,7 @@ obj-$(CONFIG_MDIO_MOXART)		+=
> > mdio-moxart.o obj-$(CONFIG_MDIO_MSCC_MIIM)		+=
> > mdio-mscc-miim.o obj-$(CONFIG_MDIO_MVUSB)		+=
> > mdio-mvusb.o obj-$(CONFIG_MDIO_OCTEON)		+=
> > mdio-octeon.o +obj-$(CONFIG_MDIO_REGMAP)		+=
> > mdio-regmap.o obj-$(CONFIG_MDIO_SUN4I)		+=
> > mdio-sun4i.o obj-$(CONFIG_MDIO_THUNDER)		+=
> > mdio-thunder.o obj-$(CONFIG_MDIO_XGENE)		+=
> > mdio-xgene.o diff --git a/include/linux/mdio/mdio-regmap.h
> > b/include/linux/mdio/mdio-regmap.h new file mode 100644
> > index 000000000000..b8508f152552
> > --- /dev/null
> > +++ b/include/linux/mdio/mdio-regmap.h
> > @@ -0,0 +1,24 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +/* Driver for MMIO-Mapped MDIO devices. Some IPs expose internal
> > PHYs or PCS
> > + * within the MMIO-mapped area
> > + *
> > + * Copyright (C) 2023 Maxime Chevallier
> > <maxime.chevallier@bootlin.com>
> > + */
> > +#ifndef MDIO_REGMAP_H
> > +#define MDIO_REGMAP_H
> > +
> > +struct device;
> > +struct regmap;
> > +
> > +struct mdio_regmap_config {
> > +	struct device *parent;
> > +	struct regmap *regmap;
> > +	char name[MII_BUS_ID_SIZE];  
> 
> don't we need a header included for the MII_BUS_ID_SIZE macro?
> An empty C file which includes just <linux/mdio/mdio-regmap.h> must
> build without errors.

You're correct, I'll include the proper header.

Thanks,

Maxime