From: Phil Reid <preid@electromag.com.au>
To: Nicolas Ferre <nicolas.ferre@atmel.com>,
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 21:37:30 +0800 [thread overview]
Message-ID: <570CFA1A.80702@electromag.com.au> (raw)
In-Reply-To: <570CF663.4000908@atmel.com>
On 12/04/2016 9:21 PM, Nicolas Ferre wrote:
> 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,
>
This sounds very similar to the altera emac-splitter.
See stmmac driver for how they handled this.
--
Regards
Phil Reid
next prev parent reply other threads:[~2016-04-12 13:37 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 ` GMII2RGMII Converter support in macb driver Nicolas Ferre
2016-04-12 13:31 ` Appana Durga Kedareswara Rao
2016-04-12 13:37 ` Phil Reid [this message]
2016-06-16 7:18 ` Appana Durga Kedareswara Rao
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