[PATCH net-next 14/15] net: dsa: mt7530: introduce driver for MT7988 built-in switch
Daniel Golle
daniel at makrotopia.org
Fri Mar 31 13:33:50 PDT 2023
On Fri, Mar 31, 2023 at 11:07:51PM +0300, Arınç ÜNAL wrote:
> On 31.03.2023 16:18, Arınç ÜNAL wrote:
> > On 31.03.2023 15:06, Arınç ÜNAL wrote:
> > > On 31.03.2023 13:16, Daniel Golle wrote:
> > > > On Fri, Mar 31, 2023 at 08:50:28AM +0300, Arınç ÜNAL wrote:
> > > > > On 30.03.2023 18:23, Daniel Golle wrote:
> > > > > > Add driver for the built-in Gigabit Ethernet switch which can be found
> > > > > > in the MediaTek MT7988 SoC.
> > > > > >
> > > > > > The switch shares most of its design with MT7530 and MT7531, but has
> > > > > > it's registers mapped into the SoCs register space rather than being
> > > > > > connected externally or internally via MDIO.
> > > > > >
> > > > > > Introduce a new platform driver to support that.
> > > > > >
> > > > > > Signed-off-by: Daniel Golle <daniel at makrotopia.org>
> > > > > > ---
> > > > > > MAINTAINERS | 2 +
> > > > > > drivers/net/dsa/Kconfig | 12 ++++
> > > > > > drivers/net/dsa/Makefile | 1 +
> > > > > > drivers/net/dsa/mt7530-mmio.c | 101
> > > > > > ++++++++++++++++++++++++++++++++++
> > > > > > drivers/net/dsa/mt7530.c | 86 ++++++++++++++++++++++++++++-
> > > > > > drivers/net/dsa/mt7530.h | 12 ++--
> > > > > > 6 files changed, 206 insertions(+), 8 deletions(-)
> > > > > > create mode 100644 drivers/net/dsa/mt7530-mmio.c
> > > > > >
> > > > > > diff --git a/MAINTAINERS b/MAINTAINERS
> > > > > > index 14924aed15ca7..674673dbdfd8b 100644
> > > > > > --- a/MAINTAINERS
> > > > > > +++ b/MAINTAINERS
> > > > > > @@ -13174,9 +13174,11 @@ MEDIATEK SWITCH DRIVER
> > > > > > M: Sean Wang <sean.wang at mediatek.com>
> > > > > > M: Landen Chao <Landen.Chao at mediatek.com>
> > > > > > M: DENG Qingfang <dqfext at gmail.com>
> > > > > > +M: Daniel Golle <daniel at makrotopia.org>
> > > > > > L: netdev at vger.kernel.org
> > > > > > S: Maintained
> > > > > > F: drivers/net/dsa/mt7530-mdio.c
> > > > > > +F: drivers/net/dsa/mt7530-mmio.c
> > > > > > F: drivers/net/dsa/mt7530.*
> > > > > > F: net/dsa/tag_mtk.c
> > > > > > diff --git a/drivers/net/dsa/Kconfig b/drivers/net/dsa/Kconfig
> > > > > > index c2551b13324c2..de4d86e37973f 100644
> > > > > > --- a/drivers/net/dsa/Kconfig
> > > > > > +++ b/drivers/net/dsa/Kconfig
> > > > > > @@ -52,6 +52,18 @@ config NET_DSA_MT7530
> > > > > > Multi-chip module MT7530 in MT7621AT, MT7621DAT, MT7621ST and
> > > > > > MT7623AI SoCs is supported as well.
> > > > > > +config NET_DSA_MT7988
> > > > > > + tristate "MediaTek MT7988 built-in Ethernet switch support"
> > > > > > + select NET_DSA_MT7530_COMMON
> > > > > > + depends on HAS_IOMEM
> > > > > > + help
> > > > > > + This enables support for the built-in Ethernet switch found
> > > > > > + in the MediaTek MT7988 SoC.
> > > > > > + The switch is a similar design as MT7531, however, unlike
> > > > > > + other MT7530 and MT7531 the switch registers are directly
> > > > > > + mapped into the SoCs register space rather than
> > > > > > being accessible
> > > > > > + via MDIO.
> > > > > > +
> > > > > > config NET_DSA_MV88E6060
> > > > > > tristate "Marvell 88E6060 ethernet switch chip support"
> > > > > > select NET_DSA_TAG_TRAILER
> > > > > > diff --git a/drivers/net/dsa/Makefile b/drivers/net/dsa/Makefile
> > > > > > index 71250d7dd41af..103a33e20de4b 100644
> > > > > > --- a/drivers/net/dsa/Makefile
> > > > > > +++ b/drivers/net/dsa/Makefile
> > > > > > @@ -8,6 +8,7 @@ endif
> > > > > > obj-$(CONFIG_NET_DSA_LANTIQ_GSWIP) += lantiq_gswip.o
> > > > > > obj-$(CONFIG_NET_DSA_MT7530_COMMON) += mt7530.o
> > > > > > obj-$(CONFIG_NET_DSA_MT7530) += mt7530-mdio.o
> > > > > > +obj-$(CONFIG_NET_DSA_MT7988) += mt7530-mmio.o
> > > > >
> > > > > I'm not fond of this way. Wouldn't it be better if we split
> > > > > the mdio and
> > > > > mmio drivers to separate modules and kept switch hardware support on
> > > > > mt7530.c?
> > > >
> > > > You mean this in terms of Kconfig symbols?
> > > > Because the way you describe is basically what I'm doing here:
> > > > * mt7530.c is the shared/common switch hardware driver
> > > > * mt7530-mdio.c contains the MDIO accessors and MDIO device
> > > > drivers for
> > > > MT7530, MT7531, MT7621, MT7623, ...
> > > > * mt7530-mmio.c contains the platform device driver for in-SoC
> > > > switches
> > > > which are accessed via MMIO, ie. MT7988 (and yes, this could be
> > > > extended to also support MT7620A/N).
> > >
> > > Ok great.
> > >
> > > >
> > > > In early drafts I also named the Kconfig symbols
> > > > CONFIG_NET_DSA_MT7530 for mt7530.c (ie. the common part)
> > > > CONFIG_NET_DSA_MT7530_MDIO for the MDIO driver
> > > > CONFIG_NET_DSA_MT7530_MMIO for the MMIO driver
> > > >
> > > > However, as existing kernel configurations expect
> > > > CONFIG_NET_DSA_MT7530 to
> > > > select the MDIO driver, I decided it would be better to hide the
> > > > symbol of
> > > > the common part and have CONFIG_NET_DSA_MT7530 select the MDIO
> > > > driver like
> > > > it was before.
> > >
> > > You can "imply NET_DSA_MT7530_MDIO" from NET_DSA_MT7530 so the MDIO
> > > driver is also enabled when NET_DSA_MT7530 is selected. For example,
> > > on Realtek, both MDIO and SMI drivers are enabled by default when
> > > either of the main drivers are selected.
> > >
> > > config NET_DSA_MT7530
> > > tristate "MediaTek MT7530 and MT7531 Ethernet switch support"
> > > select NET_DSA_TAG_MTK
> > > select MEDIATEK_GE_PHY
> > > select PCS_MTK_LYNXI
> > > imply NET_DSA_MT7530_MDIO
> > > imply NET_DSA_MT7530_MMIO
> >
> > The final kconfig should look like this:
> >
> > config NET_DSA_MT7530
> > tristate "MediaTek MT7530 and MT7531 Ethernet switch support"
> > select NET_DSA_TAG_MTK
> > select MEDIATEK_GE_PHY
> > select PCS_MTK_LYNXI
>
> Looks like PCS_MTK_LYNXI is used on NET_DSA_MT7530_MDIO instead now. I also
> see '#include <linux/pcs/pcs-mtk-lynxi.h>' on mt7530.c but don't see any
> functions called on it. Leftover?
Yes, you are right, it's only used in mt7530-mdio.c and the #include in
mt7530.c is a left-over which I shall remove.
>
> > imply NET_DSA_MT7530_MDIO
> > imply NET_DSA_MT7530_MMIO
> > help
> > This enables support for the MediaTek MT7530 and MT7531 Ethernet
> > switch chips. Multi-chip module MT7530 in MT7621AT, MT7621DAT,
> > MT7621ST and MT7623AI SoCs, and built-in switch in MT7688 SoC is
> > supported.
> >
> > config NET_DSA_MT7530_MDIO
> > tristate "MediaTek MT7530 MDIO interface driver"
>
> Should go here:
>
> select PCS_MTK_LYNXI
Yeah, in Kconfig I had taken care of this already, but forgot to remove
the include in mt7530.c...
Thank you for spotting this. I'll soon post v2 which includes these fixes.
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