[PATCH net-next v3 0/2] net: dsa: microchip: enable setting rmii reference

[PATCH net-next v3 0/2] net: dsa: microchip: enable setting rmii reference

[Ante Knezic]

KSZ88X3 devices can select between internal and external RMII reference clock.
This patch series introduces new device tree property for setting reference
clock to internal.

---
V3: 
  - move ksz_cfg from global switch config to port config as suggested by Vladimir
    Oltean
  - reverse patch order as suggested by Vladimir Oltean
  - adapt dt schema as suggested by Conor Dooley
V2: 
  - don't rely on default register settings - enforce set/clear property as
    suggested by Andrew Lunn
  - enforce dt schema as suggested by Conor Dooley

Ante Knezic (2):
  dt-bindings: net: microchip,ksz: document microchip,rmii-clk-internal
  net:dsa:microchip: add property to select internal RMII reference
    clock

 .../devicetree/bindings/net/dsa/microchip,ksz.yaml      | 17 +++++++++++++++++
 drivers/net/dsa/microchip/ksz8795.c                     | 10 +++++++++-
 drivers/net/dsa/microchip/ksz8795_reg.h                 |  3 +++
 drivers/net/dsa/microchip/ksz_common.h                  |  1 +
 4 files changed, 30 insertions(+), 1 deletion(-)

-- 
2.11.0

[PATCH net-next v3 1/2] dt-bindings: net: microchip,ksz: document microchip,rmii-clk-internal

[Ante Knezic]

Add documentation for selecting reference rmii clock on KSZ88X3 devices

Signed-off-by: Ante Knezic <ante.knezic@helmholz.de>
---
 .../devicetree/bindings/net/dsa/microchip,ksz.yaml      | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml b/Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml
index 41014f5c01c4..624feb1bb9be 100644
--- a/Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml
+++ b/Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml
@@ -72,6 +72,23 @@ properties:
   interrupts:
     maxItems: 1
 
+  microchip,rmii-clk-internal:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description:
+      Set if the RMII reference clock is provided internally. Otherwise
+      reference clock should be provided externally.
+
+if:
+  not:
+    properties:
+      compatible:
+        enum:
+          - microchip,ksz8863
+          - microchip,ksz8873
+then:
+  properties:
+    microchip,rmii-clk-internal: false
+
 required:
   - compatible
   - reg
-- 
2.11.0

[PATCH net-next v3 2/2] net:dsa:microchip: add property to select internal RMII reference clock

[Ante Knezic]

Microchip KSZ8863/KSZ8873 have the ability to select between internal
and external RMII reference clock. By default, reference clock
needs to be provided via REFCLKI_3 pin. If required, device can be
setup to provide RMII clock internally so that REFCLKI_3 pin can be
left unconnected.
Add a new "microchip,rmii-clk-internal" property which will set
RMII clock reference to internal. If property is not set, reference
clock needs to be provided externally.

Signed-off-by: Ante Knezic <ante.knezic@helmholz.de>
---
 drivers/net/dsa/microchip/ksz8795.c     | 10 +++++++++-
 drivers/net/dsa/microchip/ksz8795_reg.h |  3 +++
 drivers/net/dsa/microchip/ksz_common.h  |  1 +
 3 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/net/dsa/microchip/ksz8795.c b/drivers/net/dsa/microchip/ksz8795.c
index 91aba470fb2f..b50ad9552c65 100644
--- a/drivers/net/dsa/microchip/ksz8795.c
+++ b/drivers/net/dsa/microchip/ksz8795.c
@@ -1312,8 +1312,16 @@ void ksz8_port_setup(struct ksz_device *dev, int port, bool cpu_port)
 	ksz_port_cfg(dev, port, P_PRIO_CTRL, PORT_802_1P_ENABLE, true);
 
 	if (cpu_port) {
-		if (!ksz_is_ksz88x3(dev))
+		if (!ksz_is_ksz88x3(dev)) {
 			ksz8795_cpu_interface_select(dev, port);
+		} else {
+			dev->rmii_clk_internal = of_property_read_bool(dev->dev->of_node,
+								       "microchip,rmii-clk-internal");
+
+			ksz_cfg(dev, KSZ88X3_REG_FVID_AND_HOST_MODE,
+				KSZ88X3_PORT3_RMII_CLK_INTERNAL,
+				dev->rmii_clk_internal);
+		}
 
 		member = dsa_user_ports(ds);
 	} else {
diff --git a/drivers/net/dsa/microchip/ksz8795_reg.h b/drivers/net/dsa/microchip/ksz8795_reg.h
index 3c9dae53e4d8..beca974e0171 100644
--- a/drivers/net/dsa/microchip/ksz8795_reg.h
+++ b/drivers/net/dsa/microchip/ksz8795_reg.h
@@ -22,6 +22,9 @@
 #define KSZ8863_GLOBAL_SOFTWARE_RESET	BIT(4)
 #define KSZ8863_PCS_RESET		BIT(0)
 
+#define KSZ88X3_REG_FVID_AND_HOST_MODE  0xC6
+#define KSZ88X3_PORT3_RMII_CLK_INTERNAL BIT(3)
+
 #define REG_SW_CTRL_0			0x02
 
 #define SW_NEW_BACKOFF			BIT(7)
diff --git a/drivers/net/dsa/microchip/ksz_common.h b/drivers/net/dsa/microchip/ksz_common.h
index 8842efca0871..e5b0445fe2ca 100644
--- a/drivers/net/dsa/microchip/ksz_common.h
+++ b/drivers/net/dsa/microchip/ksz_common.h
@@ -163,6 +163,7 @@ struct ksz_device {
 	phy_interface_t compat_interface;
 	bool synclko_125;
 	bool synclko_disable;
+	bool rmii_clk_internal;
 
 	struct vlan_table *vlan_cache;
 
-- 
2.11.0

Re: [PATCH net-next v3 2/2] net:dsa:microchip: add property to select internal RMII reference clock

[Andrew Lunn]

On Wed, Oct 18, 2023 at 11:24:14AM +0200, Ante Knezic wrote:
> Microchip KSZ8863/KSZ8873 have the ability to select between internal
> and external RMII reference clock. By default, reference clock
> needs to be provided via REFCLKI_3 pin. If required, device can be
> setup to provide RMII clock internally so that REFCLKI_3 pin can be
> left unconnected.
> Add a new "microchip,rmii-clk-internal" property which will set
> RMII clock reference to internal. If property is not set, reference
> clock needs to be provided externally.
> 
> Signed-off-by: Ante Knezic <ante.knezic@helmholz.de>
> ---
>  drivers/net/dsa/microchip/ksz8795.c     | 10 +++++++++-
>  drivers/net/dsa/microchip/ksz8795_reg.h |  3 +++
>  drivers/net/dsa/microchip/ksz_common.h  |  1 +
>  3 files changed, 13 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/dsa/microchip/ksz8795.c b/drivers/net/dsa/microchip/ksz8795.c
> index 91aba470fb2f..b50ad9552c65 100644
> --- a/drivers/net/dsa/microchip/ksz8795.c
> +++ b/drivers/net/dsa/microchip/ksz8795.c
> @@ -1312,8 +1312,16 @@ void ksz8_port_setup(struct ksz_device *dev, int port, bool cpu_port)
>  	ksz_port_cfg(dev, port, P_PRIO_CTRL, PORT_802_1P_ENABLE, true);
>  
>  	if (cpu_port) {
> -		if (!ksz_is_ksz88x3(dev))
> +		if (!ksz_is_ksz88x3(dev)) {
>  			ksz8795_cpu_interface_select(dev, port);
> +		} else {
> +			dev->rmii_clk_internal = of_property_read_bool(dev->dev->of_node,
> +								       "microchip,rmii-clk-internal");
> +
> +			ksz_cfg(dev, KSZ88X3_REG_FVID_AND_HOST_MODE,
> +				KSZ88X3_PORT3_RMII_CLK_INTERNAL,
> +				dev->rmii_clk_internal);
> +		}

It looks like this is the only use of dev->rmii_clk_internal? So does
it actually need to be a member of ksz_device? 

   Andrew

Re: [PATCH net-next v3 2/2] net:dsa:microchip: add property to select

[Ante Knezic]

On Wed, 18 Oct 2023 15:52:27 +0200, Andrew Lunn wrote:

> It looks like this is the only use of dev->rmii_clk_internal? So does
> it actually need to be a member of ksz_device? 

Yes, I guess you are right, sorry about that, it probably won't be used later
on and should be removed from ksz_device.
I will repost if the rest of the patch is ok?

Re: [PATCH net-next v3 2/2] net:dsa:microchip: add property to select

[Andrew Lunn]

On Wed, Oct 18, 2023 at 04:06:28PM +0200, Ante Knezic wrote:
> On Wed, 18 Oct 2023 15:52:27 +0200, Andrew Lunn wrote:
> 
> > It looks like this is the only use of dev->rmii_clk_internal? So does
> > it actually need to be a member of ksz_device? 
> 
> Yes, I guess you are right, sorry about that, it probably won't be used later
> on and should be removed from ksz_device.
> I will repost if the rest of the patch is ok?

The rest looks O.K. to me.

    Andrew

---
pw-bot: cr

Re: [PATCH net-next v3 2/2] net:dsa:microchip: add property to select internal RMII reference clock

[Vladimir Oltean]

On Wed, Oct 18, 2023 at 11:24:14AM +0200, Ante Knezic wrote:
> Microchip KSZ8863/KSZ8873 have the ability to select between internal
> and external RMII reference clock. By default, reference clock
> needs to be provided via REFCLKI_3 pin. If required, device can be
> setup to provide RMII clock internally so that REFCLKI_3 pin can be
> left unconnected.
> Add a new "microchip,rmii-clk-internal" property which will set
> RMII clock reference to internal. If property is not set, reference
> clock needs to be provided externally.
> 
> Signed-off-by: Ante Knezic <ante.knezic@helmholz.de>
> ---
>  drivers/net/dsa/microchip/ksz8795.c     | 10 +++++++++-
>  drivers/net/dsa/microchip/ksz8795_reg.h |  3 +++
>  drivers/net/dsa/microchip/ksz_common.h  |  1 +
>  3 files changed, 13 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/dsa/microchip/ksz8795.c b/drivers/net/dsa/microchip/ksz8795.c
> index 91aba470fb2f..b50ad9552c65 100644
> --- a/drivers/net/dsa/microchip/ksz8795.c
> +++ b/drivers/net/dsa/microchip/ksz8795.c
> @@ -1312,8 +1312,16 @@ void ksz8_port_setup(struct ksz_device *dev, int port, bool cpu_port)
>  	ksz_port_cfg(dev, port, P_PRIO_CTRL, PORT_802_1P_ENABLE, true);
>  
>  	if (cpu_port) {
> -		if (!ksz_is_ksz88x3(dev))
> +		if (!ksz_is_ksz88x3(dev)) {
>  			ksz8795_cpu_interface_select(dev, port);
> +		} else {
> +			dev->rmii_clk_internal = of_property_read_bool(dev->dev->of_node,
> +								       "microchip,rmii-clk-internal");
> +
> +			ksz_cfg(dev, KSZ88X3_REG_FVID_AND_HOST_MODE,
> +				KSZ88X3_PORT3_RMII_CLK_INTERNAL,
> +				dev->rmii_clk_internal);

Odd code placement, and it looks too crammed/shifted to the right due to indentation.

The calling pattern is as follows: ksz8_port_setup() has 2 callers.

One is from
ds->ops->port_setup()
-> ksz_port_setup()
   -> filters out everything except user ports
   -> dev->dev_ops->port_setup()
      -> ksz8_port_setup()

and the other is from
ds->ops->setup() // switch-wide
-> dev->dev_ops->config_cpu_port()
   -> ksz8_config_cpu_port()
      -> ksz8_port_setup()

So user ports and CPU ports meet at ksz8_port_setup() from different
call paths, but I think it's strange to continue this coding pattern for
port stuff that's not common between user ports and CPU ports. For that
reason, the placement of the existing ksz8795_cpu_interface_select() is
also weird, when it could have been directly placed under
ksz8_config_cpu_port(), and it would have not confusingly shared a code
path with user ports.

Could you please add a dedicated ksz88x3_config_rmii_clk(), called
directly from ksz8_config_cpu_port()? It can have this as first step:

	if (!ksz_is_ksz88x3(dev))
		return 0;

and then the rest of the code can have a single level of indentation,
which would look much more natural.

> +		}
>  
>  		member = dsa_user_ports(ds);
>  	} else {
> 

Re: [PATCH net-next v3 2/2] net:dsa:microchip: add property to select

[Ante Knezic]

On Thu, 19 Oct 2023 19:54:09 +0300, Vladimir Oltean wrote:

> So user ports and CPU ports meet at ksz8_port_setup() from different
> call paths, but I think it's strange to continue this coding pattern for
> port stuff that's not common between user ports and CPU ports. For that
> reason, the placement of the existing ksz8795_cpu_interface_select() is
> also weird, when it could have been directly placed under
> ksz8_config_cpu_port(), and it would have not confusingly shared a code
> path with user ports.
> 
> Could you please add a dedicated ksz88x3_config_rmii_clk(), called
> directly from ksz8_config_cpu_port()? It can have this as first step:
> 
> 	if (!ksz_is_ksz88x3(dev))
> 		return 0;
> 
> and then the rest of the code can have a single level of indentation,
> which would look much more natural.

Ok, will do. I am guessing I should leave the existing 
ksz8795_cpu_interface_select() as it is?

Re: [PATCH net-next v3 2/2] net:dsa:microchip: add property to select

[Vladimir Oltean]

On Fri, Oct 20, 2023 at 10:46:20AM +0200, Ante Knezic wrote:
> Ok, will do. I am guessing I should leave the existing 
> ksz8795_cpu_interface_select() as it is?

I would encourage moving it to the simpler call path as well, but
ultimately this is up to you.

Re: [PATCH net-next v3 2/2] net:dsa:microchip: add property to select

[Vladimir Oltean]

On Fri, Oct 20, 2023 at 12:27:29PM +0300, Vladimir Oltean wrote:
> On Fri, Oct 20, 2023 at 10:46:20AM +0200, Ante Knezic wrote:
> > Ok, will do. I am guessing I should leave the existing 
> > ksz8795_cpu_interface_select() as it is?
> 
> I would encourage moving it to the simpler call path as well, but
> ultimately this is up to you.

Also, could you please put spaces in the commit prefix ("net: dsa: microchip: ")?

Re: [PATCH net-next v3 2/2] net:dsa:microchip: add property to select

[Vladimir Oltean]

+Oleksij

On Fri, Oct 20, 2023 at 01:00:53PM +0300, Vladimir Oltean wrote:
> On Fri, Oct 20, 2023 at 12:27:29PM +0300, Vladimir Oltean wrote:
> > On Fri, Oct 20, 2023 at 10:46:20AM +0200, Ante Knezic wrote:
> > > Ok, will do. I am guessing I should leave the existing 
> > > ksz8795_cpu_interface_select() as it is?
> > 
> > I would encourage moving it to the simpler call path as well, but
> > ultimately this is up to you.
> 
> Also, could you please put spaces in the commit prefix ("net: dsa: microchip: ")?

One more thing. You two are working on separate things on the KSZ
driver (Oleksij on
https://patchwork.kernel.org/project/netdevbpf/cover/20231019122850.1199821-1-o.rempel@pengutronix.de/),
and this creates conflicts in the DT schema and in ksz_common.h.
For the most part, those are avoidable. Could you coordinate so that
both of your next submissions do not conflict with each other? That
means that each of your series can be applied independently of the other
(Ante's first, or Oleksij's first).

For example, the dt-schema properties do not seem alphabetically sorted
(microchip,synclko-125 comes after reset-gpios), so putting
wakeup-source after reset-gpios, and leaving microchip,rmii-clk-internal
at the end, seems a viable strategy in avoiding that conflict.

The conflict in ksz_common.h will be automatically avoided when
rmii_clk_internal stops being stored in struct ksz_device.