diff mbox series

[net-next,v4,5/5] ravb: Add support for explicit internal clock delay configuration

Message ID 20200917135707.12563-6-geert+renesas@glider.be
State Superseded
Headers show
Series net/ravb: Add support for explicit internal clock delay configuration | expand

Commit Message

Geert Uytterhoeven Sept. 17, 2020, 1:57 p.m. UTC
Some EtherAVB variants support internal clock delay configuration, which
can add larger delays than the delays that are typically supported by
the PHY (using an "rgmii-*id" PHY mode, and/or "[rt]xc-skew-ps"
properties).

Historically, the EtherAVB driver configured these delays based on the
"rgmii-*id" PHY mode.  This caused issues with PHY drivers that
implement PHY internal delays properly[1].  Hence a backwards-compatible
workaround was added by masking the PHY mode[2].

Add proper support for explicit configuration of the MAC internal clock
delays using the new "[rt]x-internal-delay-ps" properties.
Fall back to the old handling if none of these properties is present.

[1] Commit bcf3440c6dd78bfe ("net: phy: micrel: add phy-mode support for
    the KSZ9031 PHY")
[2] Commit 9b23203c32ee02cd ("ravb: Mask PHY mode to avoid inserting
    delays twice").

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
---
v4:
  - Add Reviewed-by,

v3:
  - No changes,

v2:
  - Add Reviewed-by,
  - Split long line,
  - Replace "renesas,[rt]xc-delay-ps" by "[rt]x-internal-delay-ps",
  - Use 1 instead of true when assigning to a single-bit bitfield.
---
 drivers/net/ethernet/renesas/ravb.h      |  1 +
 drivers/net/ethernet/renesas/ravb_main.c | 36 ++++++++++++++++++------
 2 files changed, 28 insertions(+), 9 deletions(-)

Comments

Dan Murphy Sept. 17, 2020, 6:49 p.m. UTC | #1
Geert

On 9/17/20 8:57 AM, Geert Uytterhoeven wrote:
> Some EtherAVB variants support internal clock delay configuration, which
> can add larger delays than the delays that are typically supported by
> the PHY (using an "rgmii-*id" PHY mode, and/or "[rt]xc-skew-ps"
> properties).
>
> Historically, the EtherAVB driver configured these delays based on the
> "rgmii-*id" PHY mode.  This caused issues with PHY drivers that
> implement PHY internal delays properly[1].  Hence a backwards-compatible
> workaround was added by masking the PHY mode[2].
>
> Add proper support for explicit configuration of the MAC internal clock
> delays using the new "[rt]x-internal-delay-ps" properties.
> Fall back to the old handling if none of these properties is present.
>
> [1] Commit bcf3440c6dd78bfe ("net: phy: micrel: add phy-mode support for
>      the KSZ9031 PHY")
> [2] Commit 9b23203c32ee02cd ("ravb: Mask PHY mode to avoid inserting
>      delays twice").
>
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> Reviewed-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
> ---
> v4:
>    - Add Reviewed-by,
>
> v3:
>    - No changes,
>
> v2:
>    - Add Reviewed-by,
>    - Split long line,
>    - Replace "renesas,[rt]xc-delay-ps" by "[rt]x-internal-delay-ps",
>    - Use 1 instead of true when assigning to a single-bit bitfield.
> ---
>   drivers/net/ethernet/renesas/ravb.h      |  1 +
>   drivers/net/ethernet/renesas/ravb_main.c | 36 ++++++++++++++++++------
>   2 files changed, 28 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/net/ethernet/renesas/ravb.h b/drivers/net/ethernet/renesas/ravb.h
> index e5ca12ce93c730a9..7453b17a37a2c8d0 100644
> --- a/drivers/net/ethernet/renesas/ravb.h
> +++ b/drivers/net/ethernet/renesas/ravb.h
> @@ -1038,6 +1038,7 @@ struct ravb_private {
>   	unsigned wol_enabled:1;
>   	unsigned rxcidm:1;		/* RX Clock Internal Delay Mode */
>   	unsigned txcidm:1;		/* TX Clock Internal Delay Mode */
> +	unsigned rgmii_override:1;	/* Deprecated rgmii-*id behavior */
>   	int num_tx_desc;		/* TX descriptors per packet */
>   };
>   
> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
> index 59dadd971345e0d1..aa120e3f1e4d4da5 100644
> --- a/drivers/net/ethernet/renesas/ravb_main.c
> +++ b/drivers/net/ethernet/renesas/ravb_main.c
> @@ -1034,11 +1034,8 @@ static int ravb_phy_init(struct net_device *ndev)
>   		pn = of_node_get(np);
>   	}
>   
> -	iface = priv->phy_interface;
> -	if (priv->chip_id != RCAR_GEN2 && phy_interface_mode_is_rgmii(iface)) {
> -		/* ravb_set_delay_mode() takes care of internal delay mode */
> -		iface = PHY_INTERFACE_MODE_RGMII;
> -	}
> +	iface = priv->rgmii_override ? PHY_INTERFACE_MODE_RGMII
> +				     : priv->phy_interface;
>   	phydev = of_phy_connect(ndev, pn, ravb_adjust_link, 0, iface);
>   	of_node_put(pn);
>   	if (!phydev) {
> @@ -1989,20 +1986,41 @@ static const struct soc_device_attribute ravb_delay_mode_quirk_match[] = {
>   };
>   
>   /* Set tx and rx clock internal delay modes */
> -static void ravb_parse_delay_mode(struct net_device *ndev)
> +static void ravb_parse_delay_mode(struct device_node *np, struct net_device *ndev)
>   {
>   	struct ravb_private *priv = netdev_priv(ndev);
> +	bool explicit_delay = false;
> +	u32 delay;
> +
> +	if (!of_property_read_u32(np, "rx-internal-delay-ps", &delay)) {
> +		/* Valid values are 0 and 1800, according to DT bindings */
> +		priv->rxcidm = !!delay;
> +		explicit_delay = true;
> +	}
> +	if (!of_property_read_u32(np, "tx-internal-delay-ps", &delay)) {
> +		/* Valid values are 0 and 2000, according to DT bindings */
> +		priv->txcidm = !!delay;
> +		explicit_delay = true;
> +	}
There are helper functions for this

s32 phy_get_internal_delay(struct phy_device *phydev, struct device 
*dev, const int *delay_values, int size, bool is_rx)
Geert Uytterhoeven Sept. 18, 2020, 9:04 a.m. UTC | #2
Hi Dan,

On Thu, Sep 17, 2020 at 8:50 PM Dan Murphy <dmurphy@ti.com> wrote:
> On 9/17/20 8:57 AM, Geert Uytterhoeven wrote:
> > Some EtherAVB variants support internal clock delay configuration, which
> > can add larger delays than the delays that are typically supported by
> > the PHY (using an "rgmii-*id" PHY mode, and/or "[rt]xc-skew-ps"
> > properties).
> >
> > Historically, the EtherAVB driver configured these delays based on the
> > "rgmii-*id" PHY mode.  This caused issues with PHY drivers that
> > implement PHY internal delays properly[1].  Hence a backwards-compatible
> > workaround was added by masking the PHY mode[2].
> >
> > Add proper support for explicit configuration of the MAC internal clock
> > delays using the new "[rt]x-internal-delay-ps" properties.
> > Fall back to the old handling if none of these properties is present.
> >
> > [1] Commit bcf3440c6dd78bfe ("net: phy: micrel: add phy-mode support for
> >      the KSZ9031 PHY")
> > [2] Commit 9b23203c32ee02cd ("ravb: Mask PHY mode to avoid inserting
> >      delays twice").
> >
> > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> > Reviewed-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
> > Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>

> > @@ -1989,20 +1986,41 @@ static const struct soc_device_attribute ravb_delay_mode_quirk_match[] = {
> >   };
> >
> >   /* Set tx and rx clock internal delay modes */
> > -static void ravb_parse_delay_mode(struct net_device *ndev)
> > +static void ravb_parse_delay_mode(struct device_node *np, struct net_device *ndev)
> >   {
> >       struct ravb_private *priv = netdev_priv(ndev);
> > +     bool explicit_delay = false;
> > +     u32 delay;
> > +
> > +     if (!of_property_read_u32(np, "rx-internal-delay-ps", &delay)) {
> > +             /* Valid values are 0 and 1800, according to DT bindings */
> > +             priv->rxcidm = !!delay;
> > +             explicit_delay = true;
> > +     }
> > +     if (!of_property_read_u32(np, "tx-internal-delay-ps", &delay)) {
> > +             /* Valid values are 0 and 2000, according to DT bindings */
> > +             priv->txcidm = !!delay;
> > +             explicit_delay = true;
> > +     }
> There are helper functions for this
>
> s32 phy_get_internal_delay(struct phy_device *phydev, struct device
> *dev, const int *delay_values, int size, bool is_rx)

That helper operates on the PHY device, not on the MAC device.
Cfr. what I stated in the cover letter:

    This can be considered the MAC counterpart of commit 9150069bf5fc0e86
    ("dt-bindings: net: Add tx and rx internal delays"), which applies to
    the PHY.  Note that unlike commit 92252eec913b2dd5 ("net: phy: Add a
    helper to return the index for of the internal delay"), no helpers are
    provided to parse the DT properties, as so far there is a single user
    only, which supports only zero or a single fixed value.  Of course such
    helpers can be added later, when the need arises, or when deemed useful
    otherwise.

Gr{oetje,eeting}s,

                        Geert
diff mbox series

Patch

diff --git a/drivers/net/ethernet/renesas/ravb.h b/drivers/net/ethernet/renesas/ravb.h
index e5ca12ce93c730a9..7453b17a37a2c8d0 100644
--- a/drivers/net/ethernet/renesas/ravb.h
+++ b/drivers/net/ethernet/renesas/ravb.h
@@ -1038,6 +1038,7 @@  struct ravb_private {
 	unsigned wol_enabled:1;
 	unsigned rxcidm:1;		/* RX Clock Internal Delay Mode */
 	unsigned txcidm:1;		/* TX Clock Internal Delay Mode */
+	unsigned rgmii_override:1;	/* Deprecated rgmii-*id behavior */
 	int num_tx_desc;		/* TX descriptors per packet */
 };
 
diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 59dadd971345e0d1..aa120e3f1e4d4da5 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -1034,11 +1034,8 @@  static int ravb_phy_init(struct net_device *ndev)
 		pn = of_node_get(np);
 	}
 
-	iface = priv->phy_interface;
-	if (priv->chip_id != RCAR_GEN2 && phy_interface_mode_is_rgmii(iface)) {
-		/* ravb_set_delay_mode() takes care of internal delay mode */
-		iface = PHY_INTERFACE_MODE_RGMII;
-	}
+	iface = priv->rgmii_override ? PHY_INTERFACE_MODE_RGMII
+				     : priv->phy_interface;
 	phydev = of_phy_connect(ndev, pn, ravb_adjust_link, 0, iface);
 	of_node_put(pn);
 	if (!phydev) {
@@ -1989,20 +1986,41 @@  static const struct soc_device_attribute ravb_delay_mode_quirk_match[] = {
 };
 
 /* Set tx and rx clock internal delay modes */
-static void ravb_parse_delay_mode(struct net_device *ndev)
+static void ravb_parse_delay_mode(struct device_node *np, struct net_device *ndev)
 {
 	struct ravb_private *priv = netdev_priv(ndev);
+	bool explicit_delay = false;
+	u32 delay;
+
+	if (!of_property_read_u32(np, "rx-internal-delay-ps", &delay)) {
+		/* Valid values are 0 and 1800, according to DT bindings */
+		priv->rxcidm = !!delay;
+		explicit_delay = true;
+	}
+	if (!of_property_read_u32(np, "tx-internal-delay-ps", &delay)) {
+		/* Valid values are 0 and 2000, according to DT bindings */
+		priv->txcidm = !!delay;
+		explicit_delay = true;
+	}
 
+	if (explicit_delay)
+		return;
+
+	/* Fall back to legacy rgmii-*id behavior */
 	if (priv->phy_interface == PHY_INTERFACE_MODE_RGMII_ID ||
-	    priv->phy_interface == PHY_INTERFACE_MODE_RGMII_RXID)
+	    priv->phy_interface == PHY_INTERFACE_MODE_RGMII_RXID) {
 		priv->rxcidm = 1;
+		priv->rgmii_override = 1;
+	}
 
 	if (priv->phy_interface == PHY_INTERFACE_MODE_RGMII_ID ||
 	    priv->phy_interface == PHY_INTERFACE_MODE_RGMII_TXID) {
 		if (!WARN(soc_device_match(ravb_delay_mode_quirk_match),
 			  "phy-mode %s requires TX clock internal delay mode which is not supported by this hardware revision. Please update device tree",
-			  phy_modes(priv->phy_interface)))
+			  phy_modes(priv->phy_interface))) {
 			priv->txcidm = 1;
+			priv->rgmii_override = 1;
+		}
 	}
 }
 
@@ -2148,7 +2166,7 @@  static int ravb_probe(struct platform_device *pdev)
 	ravb_modify(ndev, GCCR, GCCR_LTI, GCCR_LTI);
 
 	if (priv->chip_id != RCAR_GEN2) {
-		ravb_parse_delay_mode(ndev);
+		ravb_parse_delay_mode(np, ndev);
 		ravb_set_delay_mode(ndev);
 	}