[PATCH net-next v2 0/2] Add Half Duplex support for ICSSG Driver

[PATCH net-next v2 0/2] Add Half Duplex support for ICSSG Driver

[MD Danish Anwar]

This series adds support for half duplex operation for ICSSG driver.

In order to support half-duplex operation at 10M and 100M link speeds, the
PHY collision detection signal (COL) should be routed to ICSSG GPIO pin
(PRGx_PRU0/1_GPI10) so that firmware can detect collision signal and apply
the CSMA/CD algorithm applicable for half duplex operation. A DT property,
"ti,half-duplex-capable" is introduced for this purpose in the first patch
of the series. If board has PHY COL pin conencted to PRGx_PRU1_GPIO10,
this DT property can be added to eth node of ICSSG, MII port to support
half duplex operation at that port.

Second patch of the series configures driver to support half-duplex
operation if the DT property "ti,half-duplex-capable" is enabled.

This series addresses comments on [v1] (which was posted as RFC).
This series is based on the latest net-next/main. This series has no
dependency.

Changes from v1 to v2:
*) Dropped the RFC tag.
*) Added RB tags of Andrew and Roger.

[1] https://lore.kernel.org/all/20230830113134.1226970-1-danishanwar@ti.com/

Thanks and Regards,
Md Danish Anwar

MD Danish Anwar (2):
  dt-bindings: net: Add documentation for Half duplex support.
  net: ti: icssg-prueth: Add support for half duplex operation

 .../bindings/net/ti,icssg-prueth.yaml           |  7 +++++++
 drivers/net/ethernet/ti/icssg/icssg_config.c    | 14 ++++++++++++++
 drivers/net/ethernet/ti/icssg/icssg_prueth.c    | 17 +++++++++++++++--
 drivers/net/ethernet/ti/icssg/icssg_prueth.h    |  2 ++
 4 files changed, 38 insertions(+), 2 deletions(-)


base-commit: 73be7fb14e83d24383f840a22f24d3ed222ca319
-- 
2.34.1

[PATCH net-next v2 1/2] dt-bindings: net: Add documentation for Half duplex support.

[MD Danish Anwar]

In order to support half-duplex operation at 10M and 100M link speeds, the
PHY collision detection signal (COL) should be routed to ICSSG
GPIO pin (PRGx_PRU0/1_GPI10) so that firmware can detect collision signal
and apply the CSMA/CD algorithm applicable for half duplex operation. A DT
property, "ti,half-duplex-capable" is introduced for this purpose. If
board has PHY COL pin conencted to PRGx_PRU1_GPIO10, this DT property can
be added to eth node of ICSSG, MII port to support half duplex operation at
that port.

Reviewed-by: Roger Quadros <rogerq@kernel.org>
Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
---
 Documentation/devicetree/bindings/net/ti,icssg-prueth.yaml | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/ti,icssg-prueth.yaml b/Documentation/devicetree/bindings/net/ti,icssg-prueth.yaml
index 311c570165f9..bba17d4d5874 100644
--- a/Documentation/devicetree/bindings/net/ti,icssg-prueth.yaml
+++ b/Documentation/devicetree/bindings/net/ti,icssg-prueth.yaml
@@ -106,6 +106,13 @@ properties:
               phandle to system controller node and register offset
               to ICSSG control register for RGMII transmit delay
 
+          ti,half-duplex-capable:
+            type: boolean
+            description:
+              Enable half duplex operation on ICSSG MII port. This requires
+              PHY output pin (COL) to be routed to ICSSG GPIO pin
+              (PRGx_PRU0/1_GPIO10) as input.
+
         required:
           - reg
     anyOf:
-- 
2.34.1

Re: [PATCH net-next v2 1/2] dt-bindings: net: Add documentation for Half duplex support.

[Rob Herring]

On Mon, Sep 11, 2023 at 11:31:59AM +0530, MD Danish Anwar wrote:
> In order to support half-duplex operation at 10M and 100M link speeds, the
> PHY collision detection signal (COL) should be routed to ICSSG
> GPIO pin (PRGx_PRU0/1_GPI10) so that firmware can detect collision signal
> and apply the CSMA/CD algorithm applicable for half duplex operation. A DT
> property, "ti,half-duplex-capable" is introduced for this purpose. If
> board has PHY COL pin conencted to PRGx_PRU1_GPIO10, this DT property can
> be added to eth node of ICSSG, MII port to support half duplex operation at
> that port.
> 
> Reviewed-by: Roger Quadros <rogerq@kernel.org>
> Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
> ---
>  Documentation/devicetree/bindings/net/ti,icssg-prueth.yaml | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/net/ti,icssg-prueth.yaml b/Documentation/devicetree/bindings/net/ti,icssg-prueth.yaml
> index 311c570165f9..bba17d4d5874 100644
> --- a/Documentation/devicetree/bindings/net/ti,icssg-prueth.yaml
> +++ b/Documentation/devicetree/bindings/net/ti,icssg-prueth.yaml
> @@ -106,6 +106,13 @@ properties:
>                phandle to system controller node and register offset
>                to ICSSG control register for RGMII transmit delay
>  
> +          ti,half-duplex-capable:
> +            type: boolean
> +            description:
> +              Enable half duplex operation on ICSSG MII port. This requires

Still have capable vs. enable confusion. Please reword the description.

> +              PHY output pin (COL) to be routed to ICSSG GPIO pin
> +              (PRGx_PRU0/1_GPIO10) as input.
> +
>          required:
>            - reg
>      anyOf:
> -- 
> 2.34.1
> 

Re: [PATCH net-next v2 1/2] dt-bindings: net: Add documentation for Half duplex support.

[MD Danish Anwar]

On 11/09/23 22:16, Rob Herring wrote:
> On Mon, Sep 11, 2023 at 11:31:59AM +0530, MD Danish Anwar wrote:
>> In order to support half-duplex operation at 10M and 100M link speeds, the
>> PHY collision detection signal (COL) should be routed to ICSSG
>> GPIO pin (PRGx_PRU0/1_GPI10) so that firmware can detect collision signal
>> and apply the CSMA/CD algorithm applicable for half duplex operation. A DT
>> property, "ti,half-duplex-capable" is introduced for this purpose. If
>> board has PHY COL pin conencted to PRGx_PRU1_GPIO10, this DT property can
>> be added to eth node of ICSSG, MII port to support half duplex operation at
>> that port.
>>
>> Reviewed-by: Roger Quadros <rogerq@kernel.org>
>> Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
>> ---
>>  Documentation/devicetree/bindings/net/ti,icssg-prueth.yaml | 7 +++++++
>>  1 file changed, 7 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/net/ti,icssg-prueth.yaml b/Documentation/devicetree/bindings/net/ti,icssg-prueth.yaml
>> index 311c570165f9..bba17d4d5874 100644
>> --- a/Documentation/devicetree/bindings/net/ti,icssg-prueth.yaml
>> +++ b/Documentation/devicetree/bindings/net/ti,icssg-prueth.yaml
>> @@ -106,6 +106,13 @@ properties:
>>                phandle to system controller node and register offset
>>                to ICSSG control register for RGMII transmit delay
>>  
>> +          ti,half-duplex-capable:
>> +            type: boolean
>> +            description:
>> +              Enable half duplex operation on ICSSG MII port. This requires
> 
> Still have capable vs. enable confusion. Please reword the description.
> 

Sure Rob, I will change the description to below.

    description:
      Indicates that the PHY output pin (COL) is routed to ICSSG GPIO
      pin (PRGx_PRU0/1_GPIO10) as input and ICSSG MII port is capable
      of half duplex operations.

Please let me know if this looks OK or if any other change is required.

>> +              PHY output pin (COL) to be routed to ICSSG GPIO pin
>> +              (PRGx_PRU0/1_GPIO10) as input.
>> +
>>          required:
>>            - reg
>>      anyOf:
>> -- 
>> 2.34.1
>>

-- 
Thanks and Regards,
Danish

Re: [PATCH net-next v2 1/2] dt-bindings: net: Add documentation for Half duplex support.

[Andrew Lunn]

> Sure Rob, I will change the description to below.
> 
>     description:
>       Indicates that the PHY output pin (COL) is routed to ICSSG GPIO

The PHY has multiple output pins, so i would not put COL in brackets,
but make it explicit which pin you are referring to.

>       pin (PRGx_PRU0/1_GPIO10) as input and ICSSG MII port is capable
>       of half duplex operations.

"input and so the ICSSG MII port is"

       Andrew

Re: [EXTERNAL] Re: [PATCH net-next v2 1/2] dt-bindings: net: Add documentation for Half duplex support.

[MD Danish Anwar]

On 12/09/23 20:46, Andrew Lunn wrote:
>> Sure Rob, I will change the description to below.
>>
>>     description:
>>       Indicates that the PHY output pin (COL) is routed to ICSSG GPIO
> 
> The PHY has multiple output pins, so i would not put COL in brackets,
> but make it explicit which pin you are referring to.
> 

Sure, I will remove the brackets and make it explicit.

>>       pin (PRGx_PRU0/1_GPIO10) as input and ICSSG MII port is capable
>>       of half duplex operations.
> 
> "input and so the ICSSG MII port is"
> 

I think "input so that the ICSSG MII port is" will be better.

The description would look something like below,

  description:
    Indicates that the PHY output pin COL is routed to ICSSG GPIO pin
    (PRGx_PRU0/1_GPIO10) as input so that the ICSSG MII port is
    capable of half duplex operations.

I will post the next version with this change.

>        Andrew

-- 
Thanks and Regards,
Danish

Re: [PATCH net-next v2 1/2] dt-bindings: net: Add documentation for Half duplex support.

[Simon Horman]

On Mon, Sep 11, 2023 at 11:31:59AM +0530, MD Danish Anwar wrote:
> In order to support half-duplex operation at 10M and 100M link speeds, the
> PHY collision detection signal (COL) should be routed to ICSSG
> GPIO pin (PRGx_PRU0/1_GPI10) so that firmware can detect collision signal
> and apply the CSMA/CD algorithm applicable for half duplex operation. A DT
> property, "ti,half-duplex-capable" is introduced for this purpose. If
> board has PHY COL pin conencted to PRGx_PRU1_GPIO10, this DT property can

nit: connected

...

[PATCH net-next v2 2/2] net: ti: icssg-prueth: Add support for half duplex operation

[MD Danish Anwar]

This patch adds support for half duplex operation at 10M and 100M link
speeds for AM654x/AM64x devices.
- Driver configures rand_seed, a random number, in DMEM HD_RAND_SEED_OFFSET
field, which will be used by firmware for Back off time calculation.
- Driver informs FW about half duplex link operation in DMEM
PORT_LINK_SPEED_OFFSET field by setting bit 7 for 10/100M HD.

Hence, the half duplex operation depends on board design the
"ti,half-duplex-capable" property has to be enabled for ICSS-G ports if HW
is capable to perform half duplex.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Roger Quadros <rogerq@kernel.org>
Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
---
 drivers/net/ethernet/ti/icssg/icssg_config.c | 14 ++++++++++++++
 drivers/net/ethernet/ti/icssg/icssg_prueth.c | 17 +++++++++++++++--
 drivers/net/ethernet/ti/icssg/icssg_prueth.h |  2 ++
 3 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/ti/icssg/icssg_config.c b/drivers/net/ethernet/ti/icssg/icssg_config.c
index 933b84666574..c1da70f247d4 100644
--- a/drivers/net/ethernet/ti/icssg/icssg_config.c
+++ b/drivers/net/ethernet/ti/icssg/icssg_config.c
@@ -433,6 +433,17 @@ int emac_set_port_state(struct prueth_emac *emac,
 	return ret;
 }
 
+void icssg_config_half_duplex(struct prueth_emac *emac)
+{
+	u32 val;
+
+	if (!emac->half_duplex)
+		return;
+
+	val = get_random_u32();
+	writel(val, emac->dram.va + HD_RAND_SEED_OFFSET);
+}
+
 void icssg_config_set_speed(struct prueth_emac *emac)
 {
 	u8 fw_speed;
@@ -453,5 +464,8 @@ void icssg_config_set_speed(struct prueth_emac *emac)
 		return;
 	}
 
+	if (emac->duplex == DUPLEX_HALF)
+		fw_speed |= FW_LINK_SPEED_HD;
+
 	writeb(fw_speed, emac->dram.va + PORT_LINK_SPEED_OFFSET);
 }
diff --git a/drivers/net/ethernet/ti/icssg/icssg_prueth.c b/drivers/net/ethernet/ti/icssg/icssg_prueth.c
index 410612f43cbd..e736652567cd 100644
--- a/drivers/net/ethernet/ti/icssg/icssg_prueth.c
+++ b/drivers/net/ethernet/ti/icssg/icssg_prueth.c
@@ -1029,6 +1029,8 @@ static void emac_adjust_link(struct net_device *ndev)
 		 * values
 		 */
 		if (emac->link) {
+			if (emac->duplex == DUPLEX_HALF)
+				icssg_config_half_duplex(emac);
 			/* Set the RGMII cfg for gig en and full duplex */
 			icssg_update_rgmii_cfg(prueth->miig_rt, emac);
 
@@ -1147,9 +1149,13 @@ static int emac_phy_connect(struct prueth_emac *emac)
 		return -ENODEV;
 	}
 
+	if (!emac->half_duplex) {
+		dev_dbg(prueth->dev, "half duplex mode is not supported\n");
+		phy_remove_link_mode(ndev->phydev, ETHTOOL_LINK_MODE_10baseT_Half_BIT);
+		phy_remove_link_mode(ndev->phydev, ETHTOOL_LINK_MODE_100baseT_Half_BIT);
+	}
+
 	/* remove unsupported modes */
-	phy_remove_link_mode(ndev->phydev, ETHTOOL_LINK_MODE_10baseT_Half_BIT);
-	phy_remove_link_mode(ndev->phydev, ETHTOOL_LINK_MODE_100baseT_Half_BIT);
 	phy_remove_link_mode(ndev->phydev, ETHTOOL_LINK_MODE_1000baseT_Half_BIT);
 	phy_remove_link_mode(ndev->phydev, ETHTOOL_LINK_MODE_Pause_BIT);
 	phy_remove_link_mode(ndev->phydev, ETHTOOL_LINK_MODE_Asym_Pause_BIT);
@@ -2113,6 +2119,10 @@ static int prueth_probe(struct platform_device *pdev)
 				      eth0_node->name);
 			goto exit_iep;
 		}
+
+		if (of_find_property(eth0_node, "ti,half-duplex-capable", NULL))
+			prueth->emac[PRUETH_MAC0]->half_duplex = 1;
+
 		prueth->emac[PRUETH_MAC0]->iep = prueth->iep0;
 	}
 
@@ -2124,6 +2134,9 @@ static int prueth_probe(struct platform_device *pdev)
 			goto netdev_exit;
 		}
 
+		if (of_find_property(eth1_node, "ti,half-duplex-capable", NULL))
+			prueth->emac[PRUETH_MAC1]->half_duplex = 1;
+
 		prueth->emac[PRUETH_MAC1]->iep = prueth->iep0;
 	}
 
diff --git a/drivers/net/ethernet/ti/icssg/icssg_prueth.h b/drivers/net/ethernet/ti/icssg/icssg_prueth.h
index 3fe80a8758d3..8b6d6b497010 100644
--- a/drivers/net/ethernet/ti/icssg/icssg_prueth.h
+++ b/drivers/net/ethernet/ti/icssg/icssg_prueth.h
@@ -145,6 +145,7 @@ struct prueth_emac {
 	struct icss_iep *iep;
 	unsigned int rx_ts_enabled : 1;
 	unsigned int tx_ts_enabled : 1;
+	unsigned int half_duplex : 1;
 
 	/* DMA related */
 	struct prueth_tx_chn tx_chns[PRUETH_MAX_TX_QUEUES];
@@ -271,6 +272,7 @@ int icssg_config(struct prueth *prueth, struct prueth_emac *emac,
 int emac_set_port_state(struct prueth_emac *emac,
 			enum icssg_port_state_cmd state);
 void icssg_config_set_speed(struct prueth_emac *emac);
+void icssg_config_half_duplex(struct prueth_emac *emac);
 
 /* Buffer queue helpers */
 int icssg_queue_pop(struct prueth *prueth, u8 queue);
-- 
2.34.1