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[net-next,0/3] enetc: Add mdio bus driver for the PCIe MDIO endpoint

Message ID 1563894955-545-1-git-send-email-claudiu.manoil@nxp.com
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Series enetc: Add mdio bus driver for the PCIe MDIO endpoint | expand

Message

Claudiu Manoil July 23, 2019, 3:15 p.m. UTC
First patch just registers the PCIe endpoint device containing
the MDIO registers as a standalone MDIO bus driver, to allow
an alternative way to control the MDIO bus.  The same code used
by the ENETC ports (eth controllers) to manage MDIO via local
registers applies and is reused.

Bindings are provided for the new MDIO node, similarly to ENETC
port nodes bindings.

Last patch enables the ENETC port 1 and its RGMII PHY on the
LS1028A QDS board, where the MDIO muxing configuration relies
on the MDIO support provided in the first patch.


Claudiu Manoil (3):
  enetc: Add mdio bus driver for the PCIe MDIO endpoint
  dt-bindings: net: fsl: enetc: Add bindings for the central MDIO PCIe
    endpoint
  arm64: dts: ls1028a: Enable eth port1 on the ls1028a QDS board

 .../devicetree/bindings/net/fsl-enetc.txt     | 42 ++++++++-
 .../boot/dts/freescale/fsl-ls1028a-qds.dts    | 40 +++++++++
 .../arm64/boot/dts/freescale/fsl-ls1028a.dtsi |  6 ++
 .../net/ethernet/freescale/enetc/enetc_mdio.c | 90 +++++++++++++++++++
 .../net/ethernet/freescale/enetc/enetc_pf.c   |  5 +-
 5 files changed, 179 insertions(+), 4 deletions(-)

Comments

Saeed Mahameed July 23, 2019, 8:49 p.m. UTC | #1
On Tue, 2019-07-23 at 18:15 +0300, Claudiu Manoil wrote:
> ENETC ports can manage the MDIO bus via local register
> interface.  However there's also a centralized way
> to manage the MDIO bus, via the MDIO PCIe endpoint
> device integrated by the same root complex that also
> integrates the ENETC ports (eth controllers).
> 
> Depending on board design and use case, centralized
> access to MDIO may be better than using local ENETC
> port registers.  For instance, on the LS1028A QDS board
> where MDIO muxing is requiered.  Also, the LS1028A on-chip
> switch doesn't have a local MDIO register interface.
> 
> The current patch registers the above PCIe enpoint as a
> separate MDIO bus and provides a driver for it by re-using
> the code used for local MDIO access.  It also allows the
> ENETC port PHYs to be managed by this driver if the local
> "mdio" node is missing from the ENETC port node.
> 
> Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
> ---
>  .../net/ethernet/freescale/enetc/enetc_mdio.c | 90
> +++++++++++++++++++
>  .../net/ethernet/freescale/enetc/enetc_pf.c   |  5 +-
>  2 files changed, 94 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/freescale/enetc/enetc_mdio.c
> b/drivers/net/ethernet/freescale/enetc/enetc_mdio.c
> index 77b9cd10ba2b..efa8a29f463d 100644
> --- a/drivers/net/ethernet/freescale/enetc/enetc_mdio.c
> +++ b/drivers/net/ethernet/freescale/enetc/enetc_mdio.c
> @@ -197,3 +197,93 @@ void enetc_mdio_remove(struct enetc_pf *pf)
>  		mdiobus_free(pf->mdio);
>  	}
>  }
> +
> +#define ENETC_MDIO_DEV_ID	0xee01
> +#define ENETC_MDIO_DEV_NAME	"FSL PCIe IE Central MDIO"
> +#define ENETC_MDIO_BUS_NAME	ENETC_MDIO_DEV_NAME " Bus"
> +#define ENETC_MDIO_DRV_NAME	ENETC_MDIO_DEV_NAME " driver"
> +#define ENETC_MDIO_DRV_ID	"fsl_enetc_mdio"
> +
> +static int enetc_pci_mdio_probe(struct pci_dev *pdev,
> +				const struct pci_device_id *ent)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct mii_bus *bus;
> +	int err;
> +
> +	bus = mdiobus_alloc_size(sizeof(u32 *));
> +	if (!bus)
> +		return -ENOMEM;
> +
> +	bus->name = ENETC_MDIO_BUS_NAME;
> +	bus->read = enetc_mdio_read;
> +	bus->write = enetc_mdio_write;
> +	bus->parent = dev;
> +	snprintf(bus->id, MII_BUS_ID_SIZE, "%s", dev_name(dev));
> +
> +	pcie_flr(pdev);
> +	err = pci_enable_device_mem(pdev);
> +	if (err) {
> +		dev_err(dev, "device enable failed\n");

mdiobus_free(bus) is missing here and in every error path.

> +		return err;
> +	}
> +
> +	err = pci_request_mem_regions(pdev, ENETC_MDIO_DRV_ID);
> +	if (err) {
> +		dev_err(dev, "pci_request_regions failed\n");
> +		goto err_pci_mem_reg;
> +	}
> +
> +	bus->priv = pci_iomap_range(pdev, 0, ENETC_MDIO_REG_OFFSET, 0);
> +	if (!bus->priv) {
> +		err = -ENXIO;
> +		dev_err(dev, "ioremap failed\n");
> +		goto err_ioremap;
> +	}
> +
> +	err = of_mdiobus_register(bus, dev->of_node);
> +	if (err)
> +		goto err_mdiobus_reg;
> +
> +	pci_set_drvdata(pdev, bus);
> +
> +	return 0;
> +
> +err_mdiobus_reg:
> +	iounmap(bus->priv);
> +err_ioremap:
> +	pci_release_mem_regions(pdev);
> +err_pci_mem_reg:
> +	pci_disable_device(pdev);
> +
> +	return err;
> +}
> +
> +static void enetc_pci_mdio_remove(struct pci_dev *pdev)
> +{
> +	struct mii_bus *bus = pci_get_drvdata(pdev);
> +
> +	mdiobus_unregister(bus);
> +	iounmap(bus->priv);
> +	mdiobus_free(bus);
> +

this should come last to be symmetrical with probe flow.

> +	pci_release_mem_regions(pdev);
> +	pci_disable_device(pdev);
> +}
> +
> +static const struct pci_device_id enetc_pci_mdio_id_table[] = {
> +	{ PCI_DEVICE(PCI_VENDOR_ID_FREESCALE, ENETC_MDIO_DEV_ID) },
> +	{ 0, } /* End of table. */
> +};
> +MODULE_DEVICE_TABLE(pci, enetc_mdio_id_table);
> +
> +static struct pci_driver enetc_pci_mdio_driver = {
> +	.name = ENETC_MDIO_DRV_ID,
> +	.id_table = enetc_pci_mdio_id_table,
> +	.probe = enetc_pci_mdio_probe,
> +	.remove = enetc_pci_mdio_remove,
> +};
> +module_pci_driver(enetc_pci_mdio_driver);
> +
> +MODULE_DESCRIPTION(ENETC_MDIO_DRV_NAME);
> +MODULE_LICENSE("Dual BSD/GPL");
> diff --git a/drivers/net/ethernet/freescale/enetc/enetc_pf.c
> b/drivers/net/ethernet/freescale/enetc/enetc_pf.c
> index 258b3cb38a6f..7d6513ff8507 100644
> --- a/drivers/net/ethernet/freescale/enetc/enetc_pf.c
> +++ b/drivers/net/ethernet/freescale/enetc/enetc_pf.c
> @@ -750,6 +750,7 @@ static int enetc_of_get_phy(struct
> enetc_ndev_priv *priv)
>  {
>  	struct enetc_pf *pf = enetc_si_priv(priv->si);
>  	struct device_node *np = priv->dev->of_node;
> +	struct device_node *mdio_np;
>  	int err;
>  
>  	if (!np) {
> @@ -773,7 +774,9 @@ static int enetc_of_get_phy(struct
> enetc_ndev_priv *priv)
>  		priv->phy_node = of_node_get(np);
>  	}
>  
> -	if (!of_phy_is_fixed_link(np)) {
> +	mdio_np = of_get_child_by_name(np, "mdio");
> +	if (mdio_np) {
> +		of_node_put(mdio_np);
>  		err = enetc_mdio_probe(pf);
>  		if (err) {
>  			of_node_put(priv->phy_node);
Andrew Lunn July 23, 2019, 10:24 p.m. UTC | #2
> +	bus = mdiobus_alloc_size(sizeof(u32 *));
> +	if (!bus)
> +		return -ENOMEM;
> +

> +	bus->priv = pci_iomap_range(pdev, 0, ENETC_MDIO_REG_OFFSET, 0);

This got me confused for a while. You allocate space for a u32
pointer. bus->priv will point to this space. However, you are not
using this space, you {ab}use the pointer to directly hold the return
from pci_iomap_range(). This works, but sparse is probably unhappy,
and you are wasting the space the u32 pointer takes.

    Andrew
Claudiu Manoil July 24, 2019, 9:53 a.m. UTC | #3
>-----Original Message-----
>From: Andrew Lunn <andrew@lunn.ch>
>Sent: Wednesday, July 24, 2019 1:25 AM
>To: Claudiu Manoil <claudiu.manoil@nxp.com>
>Cc: David S . Miller <davem@davemloft.net>; devicetree@vger.kernel.org;
>netdev@vger.kernel.org; Alexandru Marginean
><alexandru.marginean@nxp.com>; linux-kernel@vger.kernel.org; Leo Li
><leoyang.li@nxp.com>; Rob Herring <robh+dt@kernel.org>; linux-arm-
>kernel@lists.infradead.org
>Subject: Re: [PATCH net-next 1/3] enetc: Add mdio bus driver for the PCIe MDIO
>endpoint
>
>> +	bus = mdiobus_alloc_size(sizeof(u32 *));
>> +	if (!bus)
>> +		return -ENOMEM;
>> +
>
>> +	bus->priv = pci_iomap_range(pdev, 0, ENETC_MDIO_REG_OFFSET, 0);
>
>This got me confused for a while. You allocate space for a u32
>pointer. bus->priv will point to this space. However, you are not
>using this space, you {ab}use the pointer to directly hold the return
>from pci_iomap_range(). This works, but sparse is probably unhappy,
>and you are wasting the space the u32 pointer takes.
>

Thanks Andrew,
This is not what I wanted to do, don't ask me how I got to this, it's
confusing indeed.
What's needed here is mdiobus_alloc() or better, devm_mdiobus_alloc().
I've got to do some cleanup in the local mdio bus probing too.
Will send v2.

Thanks,
Claudiu
Claudiu Manoil July 24, 2019, 9:55 a.m. UTC | #4
>-----Original Message-----
>From: Saeed Mahameed <saeedm@mellanox.com>
[...]
>
>mdiobus_free(bus) is missing here and in every error path.
>
[...]
>
>this should come last to be symmetrical with probe flow.
>

Will clean these up too. Thanks.
Claudiu Manoil July 24, 2019, 12:57 p.m. UTC | #5
>-----Original Message-----
>From: netdev-owner@vger.kernel.org <netdev-owner@vger.kernel.org> On
>Behalf Of Claudiu Manoil
>Sent: Wednesday, July 24, 2019 12:53 PM
>To: Andrew Lunn <andrew@lunn.ch>
>Cc: David S . Miller <davem@davemloft.net>; devicetree@vger.kernel.org;
>netdev@vger.kernel.org; Alexandru Marginean
><alexandru.marginean@nxp.com>; linux-kernel@vger.kernel.org; Leo Li
><leoyang.li@nxp.com>; Rob Herring <robh+dt@kernel.org>; linux-arm-
>kernel@lists.infradead.org
>Subject: RE: [PATCH net-next 1/3] enetc: Add mdio bus driver for the PCIe MDIO
>endpoint
>
>>-----Original Message-----
>>From: Andrew Lunn <andrew@lunn.ch>
>>Sent: Wednesday, July 24, 2019 1:25 AM
>>To: Claudiu Manoil <claudiu.manoil@nxp.com>
>>Cc: David S . Miller <davem@davemloft.net>; devicetree@vger.kernel.org;
>>netdev@vger.kernel.org; Alexandru Marginean
>><alexandru.marginean@nxp.com>; linux-kernel@vger.kernel.org; Leo Li
>><leoyang.li@nxp.com>; Rob Herring <robh+dt@kernel.org>; linux-arm-
>>kernel@lists.infradead.org
>>Subject: Re: [PATCH net-next 1/3] enetc: Add mdio bus driver for the
>>PCIe MDIO endpoint
>>
>>> +	bus = mdiobus_alloc_size(sizeof(u32 *));
>>> +	if (!bus)
>>> +		return -ENOMEM;
>>> +
>>
>>> +	bus->priv = pci_iomap_range(pdev, 0, ENETC_MDIO_REG_OFFSET, 0);
>>
>>This got me confused for a while. You allocate space for a u32 pointer.
>>bus->priv will point to this space. However, you are not using this
>>space, you {ab}use the pointer to directly hold the return from
>>pci_iomap_range(). This works, but sparse is probably unhappy, and you
>>are wasting the space the u32 pointer takes.
>>
>
>Thanks Andrew,
>This is not what I wanted to do, don't ask me how I got to this, it's confusing
>indeed.
>What's needed here is mdiobus_alloc() or better, devm_mdiobus_alloc().
>I've got to do some cleanup in the local mdio bus probing too.
>Will send v2.
>

This is tricky actually, mdiobus_alloc won't do it, I still need to allocate space
for the pointer.
So it's not ok to store the register space pointer directly into priv
(even if iomap returns void *), it's unusual.
Looks like I will have to use double pointers!