From: Nicolas Ferre <nicolas.ferre@atmel.com>
To: Appana Durga Kedareswara Rao <appana.durga.rao@xilinx.com>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
Michal Simek <michal.simek@xilinx.com>
Cc: Punnaiah Choudary Kalluri <punnaia@xilinx.com>,
Harini Katakam <harinik@xilinx.com>,
Anirudha Sarangi <anirudh@xilinx.com>,
"Appana Durga Kedareswara Rao" <appanad@xilinx.com>
Subject: Re: GMII2RGMII Converter support in macb driver
Date: Tue, 12 Apr 2016 15:21:39 +0200 [thread overview]
Message-ID: <570CF663.4000908@atmel.com> (raw)
In-Reply-To: <C246CAC1457055469EF09E3A7AC4E11A4A57592E@XAP-PVEXMBX01.xlnx.xilinx.com>
Le 12/04/2016 15:03, Appana Durga Kedareswara Rao a écrit :
> Hi All,
>
>
>
>
>
> There is a Xilinx custom IP for GMII to RGMII conversion
> data sheet here
> (http://www.xilinx.com/support/documentation/ip_documentation/gmii_to_rgmii/v4_0/pg160-gmii-to-rgmii.pdf
> )
>
>
>
>
>
> Unlike other Phy’s this IP won’t support auto negotiation
> and other features that usually normal Phy’s support.
>
> This IP has only one register (Control register) which needs to be
> programmed based on the external phy auto negotiation
>
> (Based on the external phy negotiated speed).
>
>
>
> I am able to make it work for GEM driver by doing the below changes in
> the driver (drivers/net/ethernet/cadence/macb.c).
>
>
>
> +#define XEMACPS_GMII2RGMII_FULLDPLX BMCR_FULLDPLX
>
> +#define XEMACPS_GMII2RGMII_SPEED1000 BMCR_SPEED1000
>
> +#define XEMACPS_GMII2RGMII_SPEED100 BMCR_SPEED100
>
> +#define
> XEMACPS_GMII2RGMII_REG_NUM 0x10
>
> +
>
> /*
>
> * Graceful stop timeouts in us. We should allow up to
>
> * 1 frame time (10 Mbits/s, full-duplex, ignoring collisions)
>
> @@ -311,8 +317,10 @@ static void macb_handle_link_change(struct
> net_device *dev)
>
> {
>
> struct macb *bp = netdev_priv(dev);
>
> struct phy_device *phydev = bp->phy_dev;
>
> + struct phy_device *gmii2rgmii_phydev = bp->gmii2rgmii_phy_dev;
>
> unsigned long flags;
>
> int status_change = 0;
>
> + u16 gmii2rgmii_reg = 0;
>
> spin_lock_irqsave(&bp->lock, flags);
>
> @@ -326,15 +334,27 @@ static void macb_handle_link_change(struct
> net_device *dev)
>
> if (macb_is_gem(bp))
>
> reg &=
> ~GEM_BIT(GBE);
>
> - if (phydev->duplex)
>
> + if (phydev->duplex) {
>
> reg |=
> MACB_BIT(FD);
>
> - if (phydev->speed == SPEED_100)
>
> +
> gmii2rgmii_reg |= XEMACPS_GMII2RGMII_FULLDPLX;
>
> + }
>
> + if (phydev->speed ==
> SPEED_100) {
>
> reg |=
> MACB_BIT(SPD);
>
> +
> gmii2rgmii_reg |= XEMACPS_GMII2RGMII_SPEED100;
>
> + }
>
> if (phydev->speed ==
> SPEED_1000 &&
>
> - bp->caps &
> MACB_CAPS_GIGABIT_MODE_AVAILABLE)
>
> + bp->caps &
> MACB_CAPS_GIGABIT_MODE_AVAILABLE) {
>
> reg |=
> GEM_BIT(GBE);
>
> +
> gmii2rgmii_reg |= XEMACPS_GMII2RGMII_SPEED1000;
>
> + }
>
> macb_or_gem_writel(bp,
> NCFGR, reg);
>
> + if (gmii2rgmii_phydev != NULL) {
>
> +
> macb_mdio_write(bp->mii_bus,
>
> + gmii2rgmii_phydev->addr,
>
> + XEMACPS_GMII2RGMII_REG_NUM,
>
> + gmii2rgmii_reg);
>
> + }
>
> bp->speed = phydev->speed;
>
> bp->duplex = phydev->duplex;
>
> @@ -382,6 +402,19 @@ static int macb_mii_probe(struct net_device *dev)
>
> int phy_irq;
>
> int ret;
>
> + if (bp->gmii2rgmii_phy_node) {
>
> + phydev = of_phy_attach(bp->dev,
>
> + bp->gmii2rgmii_phy_node,
>
> + 0,
> 0);
>
> + if (!phydev) {
>
> + dev_err(&bp->pdev->dev, "%s:
> no gmii to rgmii converter found\n",
>
> + dev->name);
>
> + return -1;
>
> + }
>
> + bp->gmii2rgmii_phy_dev = phydev;
>
> + } else
>
> + bp->gmii2rgmii_phy_dev = NULL;
>
> +
>
> phydev = phy_find_first(bp->mii_bus);
>
> if (!phydev) {
>
> netdev_err(dev, "no PHY found\n");
>
> @@ -402,6 +435,8 @@ static int macb_mii_probe(struct net_device *dev)
>
>
> bp->phy_interface);
>
> if (ret) {
>
> netdev_err(dev, "Could not attach to PHY\n");
>
> + if (bp->gmii2rgmii_phy_dev)
>
> +
> phy_disconnect(bp->gmii2rgmii_phy_dev);
>
> return ret;
>
> }
>
> @@ -3368,6 +3403,9 @@ static int macb_probe(struct platform_device *pdev)
>
> bp->phy_interface = err;
>
> }
>
> + bp->gmii2rgmii_phy_node =
> of_parse_phandle(bp->pdev->dev.of_node,
>
> +
> "gmii2rgmii-phy-handle", 0);
>
> +
>
> macb_reset_phy(pdev);
>
> /* IP specific init */
>
> @@ -3422,6 +3460,8 @@ static int macb_remove(struct platform_device *pdev)
>
> bp = netdev_priv(dev);
>
> if (bp->phy_dev)
>
> phy_disconnect(bp->phy_dev);
>
> + if (bp->gmii2rgmii_phy_dev)
>
> +
> phy_disconnect(bp->gmii2rgmii_phy_dev);
>
>
>
> But doing above changes making driver looks odd.
>
> could you please suggest any better option to add support for this IP in
> the macb driver?
Appana,
I certainly can't prototype the solution based on your datasheet and the
code sent... do a sensible proposal, then we can evaluate.
As the IP is separated from the Eth controller, make it a separate
driver (an emulated phy one for instance... even if I don't know if it
makes sense).
I don't know if others have already made such an adaptation layer
between GMII to RGMII but I'm pretty sure it can't be inserted into the
macb driver.
Bye,
--
Nicolas Ferre
next parent reply other threads:[~2016-04-12 13:21 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <C246CAC1457055469EF09E3A7AC4E11A4A57592E@XAP-PVEXMBX01.xlnx.xilinx.com>
2016-04-12 13:21 ` Nicolas Ferre [this message]
2016-04-12 13:31 ` GMII2RGMII Converter support in macb driver Appana Durga Kedareswara Rao
2016-04-12 13:37 ` Phil Reid
2016-06-16 7:18 ` Appana Durga Kedareswara Rao
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