| Message ID | 20240216184237.259954-3-florian.fainelli@broadcom.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | Rework GENET MDIO controller clocking | expand |
On 2/16/2024 10:42 AM, Florian Fainelli wrote: > GENET has historically had to create a MDIO platform device for its > controller and pass some auxiliary data to it, like a MDIO completion > callback. Now we also pass the "main" clock to allow for the MDIO bus > controller to manage that clock adequately around I/O accesses. > > Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com> > --- > drivers/net/ethernet/broadcom/genet/bcmmii.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/net/ethernet/broadcom/genet/bcmmii.c b/drivers/net/ethernet/broadcom/genet/bcmmii.c > index cbbe004621bc..7a21950da77c 100644 > --- a/drivers/net/ethernet/broadcom/genet/bcmmii.c > +++ b/drivers/net/ethernet/broadcom/genet/bcmmii.c > @@ -476,6 +476,10 @@ static int bcmgenet_mii_register(struct bcmgenet_priv *priv) > ppd.wait_func = bcmgenet_mii_wait; > ppd.wait_func_data = priv; > ppd.bus_name = "bcmgenet MII bus"; > + /* Pass a reference to our "main" clock which is used for MDIO > + * transfers > + */ > + ppd.clk = priv->clk; > > /* Unimac MDIO bus controller starts at UniMAC offset + MDIO_CMD > * and is 2 * 32-bits word long, 8 bytes total. Is this missing a modification of the header file to add the clk field to struct unimac_mdio_pdata? I don't see that field in the include/linux/platform_data/mdio-bcm-unimac.h header currently... Oh. you included that in the first patch of the series. I see. It feels like the series would be more natural of this was 1/3 instead of 2/3, since the current 1/3 patch depends on this clk value being set, no? The result of the series makes sense tho: Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
On 2/16/24 14:41, Jacob Keller wrote: > > > On 2/16/2024 10:42 AM, Florian Fainelli wrote: >> GENET has historically had to create a MDIO platform device for its >> controller and pass some auxiliary data to it, like a MDIO completion >> callback. Now we also pass the "main" clock to allow for the MDIO bus >> controller to manage that clock adequately around I/O accesses. >> >> Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com> >> --- >> drivers/net/ethernet/broadcom/genet/bcmmii.c | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/drivers/net/ethernet/broadcom/genet/bcmmii.c b/drivers/net/ethernet/broadcom/genet/bcmmii.c >> index cbbe004621bc..7a21950da77c 100644 >> --- a/drivers/net/ethernet/broadcom/genet/bcmmii.c >> +++ b/drivers/net/ethernet/broadcom/genet/bcmmii.c >> @@ -476,6 +476,10 @@ static int bcmgenet_mii_register(struct bcmgenet_priv *priv) >> ppd.wait_func = bcmgenet_mii_wait; >> ppd.wait_func_data = priv; >> ppd.bus_name = "bcmgenet MII bus"; >> + /* Pass a reference to our "main" clock which is used for MDIO >> + * transfers >> + */ >> + ppd.clk = priv->clk; >> >> /* Unimac MDIO bus controller starts at UniMAC offset + MDIO_CMD >> * and is 2 * 32-bits word long, 8 bytes total. > > Is this missing a modification of the header file to add the clk field > to struct unimac_mdio_pdata? I don't see that field in the > include/linux/platform_data/mdio-bcm-unimac.h header currently... > > Oh. you included that in the first patch of the series. I see. I suppose I could have included it in patch #1, and have introduced in patch #2 the hunk that dealt with fetching pdata->clk, but since I was re-organizing the mdio-bcm-unimac.c driver's probe function, it felt more natural to arrange it that way. > > It feels like the series would be more natural of this was 1/3 instead > of 2/3, since the current 1/3 patch depends on this clk value being set, no? I sort of debated that with myself, and ended up going with: put the plumbing first, wire it later, rather than the opposite. If someone was to run a bisection there would not be any difference in behavior until patch #2 regardless of their ordering. > > The result of the series makes sense tho: > > Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Thanks Jacob!
On Fri, Feb 16, 2024 at 10:42:36AM -0800, Florian Fainelli wrote: > GENET has historically had to create a MDIO platform device for its > controller and pass some auxiliary data to it, like a MDIO completion > callback. Now we also pass the "main" clock to allow for the MDIO bus > controller to manage that clock adequately around I/O accesses. I guess this code comes from before the times of DT? I would normally expect to see a clock added to the DT node for the MDIO bus. But if there is no node, because it is not in DT.... Andrew
Hi Andrew, On 2/17/2024 7:21 AM, Andrew Lunn wrote: > On Fri, Feb 16, 2024 at 10:42:36AM -0800, Florian Fainelli wrote: >> GENET has historically had to create a MDIO platform device for its >> controller and pass some auxiliary data to it, like a MDIO completion >> callback. Now we also pass the "main" clock to allow for the MDIO bus >> controller to manage that clock adequately around I/O accesses. > > I guess this code comes from before the times of DT? I would normally > expect to see a clock added to the DT node for the MDIO bus. But if > there is no node, because it is not in DT.... The driver started being DT-only from the get go, however it was also my group's first attempt at upstreaming a driver and we did not get everything right in terms of the DT binding. In particular there was no "mdio" sub-node initially, but we still wanted to be able to split up the MDIO controller part since we knew it was going to be re-used in other designs (bcm_sf2 and later asp2). The platform device was the best we could come up with at the time. All of our DTBs deployed out there do not have a "clocks" property within the "mdio" sub-mode of the GENET Ethernet node, so that is why we are doing this. Thanks!
diff --git a/drivers/net/ethernet/broadcom/genet/bcmmii.c b/drivers/net/ethernet/broadcom/genet/bcmmii.c index cbbe004621bc..7a21950da77c 100644 --- a/drivers/net/ethernet/broadcom/genet/bcmmii.c +++ b/drivers/net/ethernet/broadcom/genet/bcmmii.c @@ -476,6 +476,10 @@ static int bcmgenet_mii_register(struct bcmgenet_priv *priv) ppd.wait_func = bcmgenet_mii_wait; ppd.wait_func_data = priv; ppd.bus_name = "bcmgenet MII bus"; + /* Pass a reference to our "main" clock which is used for MDIO + * transfers + */ + ppd.clk = priv->clk; /* Unimac MDIO bus controller starts at UniMAC offset + MDIO_CMD * and is 2 * 32-bits word long, 8 bytes total.
GENET has historically had to create a MDIO platform device for its controller and pass some auxiliary data to it, like a MDIO completion callback. Now we also pass the "main" clock to allow for the MDIO bus controller to manage that clock adequately around I/O accesses. Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com> --- drivers/net/ethernet/broadcom/genet/bcmmii.c | 4 ++++ 1 file changed, 4 insertions(+)