Re: [RFC 1/2] net: bcmgenet: Initial bcmgenet ACPI support

[Florian Fainelli <f.fainelli@gmail.com>]

On 1/22/20 10:08 PM, Jeremy Linton wrote:
> The rpi4 is capable of booting in ACPI mode with the latest
> edk2-platform commits. As such, it would be helpful if the genet
> platform device were usable.
> 
> To achive this we convert some of the of_ calls to device_ and
> add the ACPI id module table, and tweak the phy connection code
> to use phy_connect() in the ACPI path.

This seems reasonable to me at first glance, although I would be
splitting the bcmgenet.c changes from the bcmmii.c for clarity.

There are some more specific comments below.

> 
> Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
> ---
>  .../net/ethernet/broadcom/genet/bcmgenet.c    | 19 +++--
>  drivers/net/ethernet/broadcom/genet/bcmmii.c  | 76 ++++++++++++-------
>  2 files changed, 63 insertions(+), 32 deletions(-)
> 
> diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
> index 120fa05a39ff..c736700f829e 100644
> --- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
> +++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
> @@ -7,6 +7,7 @@
>  
>  #define pr_fmt(fmt)				"bcmgenet: " fmt
>  
> +#include <linux/acpi.h>
>  #include <linux/kernel.h>
>  #include <linux/module.h>
>  #include <linux/sched.h>
> @@ -3476,7 +3477,7 @@ static int bcmgenet_probe(struct platform_device *pdev)
>  	const struct bcmgenet_plat_data *pdata;
>  	struct bcmgenet_priv *priv;
>  	struct net_device *dev;
> -	const void *macaddr;
> +	const void *macaddr = NULL;
>  	unsigned int i;
>  	int err = -EIO;
>  	const char *phy_mode_str;
> @@ -3510,7 +3511,7 @@ static int bcmgenet_probe(struct platform_device *pdev)
>  
>  	if (dn)
>  		macaddr = of_get_mac_address(dn);
> -	else
> +	else if (pd)
>  		macaddr = pd->mac_address;
>  
>  	priv->base = devm_platform_ioremap_resource(pdev, 0);
> @@ -3555,8 +3556,9 @@ static int bcmgenet_probe(struct platform_device *pdev)
>  
>  	priv->dev = dev;
>  	priv->pdev = pdev;
> -	if (of_id) {
> -		pdata = of_id->data;
> +
> +	pdata = device_get_match_data(&pdev->dev);
> +	if (pdata) {
>  		priv->version = pdata->version;
>  		priv->dma_max_burst_length = pdata->dma_max_burst_length;
>  	} else {
> @@ -3595,7 +3597,7 @@ static int bcmgenet_probe(struct platform_device *pdev)
>  	/* If this is an internal GPHY, power it on now, before UniMAC is
>  	 * brought out of reset as absolutely no UniMAC activity is allowed
>  	 */
> -	if (dn && !of_property_read_string(dn, "phy-mode", &phy_mode_str) &&
> +	if (!device_property_read_string(&pdev->dev, "phy-mode", &phy_mode_str) &&
>  	    !strcasecmp(phy_mode_str, "internal"))
>  		bcmgenet_power_up(priv, GENET_POWER_PASSIVE);
>  
> @@ -3768,6 +3770,12 @@ static int bcmgenet_suspend(struct device *d)
>  
>  static SIMPLE_DEV_PM_OPS(bcmgenet_pm_ops, bcmgenet_suspend, bcmgenet_resume);
>  
> +static const struct acpi_device_id genet_acpi_match[] = {
> +	{ "BCM6E4E", (kernel_ulong_t)&bcm2711_plat_data },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(acpi, genet_acpi_match);
> +
>  static struct platform_driver bcmgenet_driver = {
>  	.probe	= bcmgenet_probe,
>  	.remove	= bcmgenet_remove,
> @@ -3776,6 +3784,7 @@ static struct platform_driver bcmgenet_driver = {
>  		.name	= "bcmgenet",
>  		.of_match_table = bcmgenet_match,
>  		.pm	= &bcmgenet_pm_ops,
> +		.acpi_match_table = ACPI_PTR(genet_acpi_match),
>  	},
>  };
>  module_platform_driver(bcmgenet_driver);
> diff --git a/drivers/net/ethernet/broadcom/genet/bcmmii.c b/drivers/net/ethernet/broadcom/genet/bcmmii.c
> index 6392a2530183..054be1eaa1ae 100644
> --- a/drivers/net/ethernet/broadcom/genet/bcmmii.c
> +++ b/drivers/net/ethernet/broadcom/genet/bcmmii.c
> @@ -5,7 +5,7 @@
>   * Copyright (c) 2014-2017 Broadcom
>   */
>  
> -
> +#include <linux/acpi.h>
>  #include <linux/types.h>
>  #include <linux/delay.h>
>  #include <linux/wait.h>
> @@ -308,10 +308,21 @@ int bcmgenet_mii_config(struct net_device *dev, bool init)
>  	return 0;
>  }
>  
> +static void bcmgenet_phy_name(char *phy_name, int mdid, int phid)
> +{
> +	char mdio_bus_id[MII_BUS_ID_SIZE];
> +
> +	snprintf(mdio_bus_id, MII_BUS_ID_SIZE, "%s-%d",
> +		 UNIMAC_MDIO_DRV_NAME, mdid);
> +	snprintf(phy_name, MII_BUS_ID_SIZE, PHY_ID_FMT, mdio_bus_id, phid);
> +}
> +
>  int bcmgenet_mii_probe(struct net_device *dev)
>  {
>  	struct bcmgenet_priv *priv = netdev_priv(dev);
> -	struct device_node *dn = priv->pdev->dev.of_node;
> +	struct device *kdev = &priv->pdev->dev;
> +	struct device_node *dn = kdev->of_node;
> +
>  	struct phy_device *phydev;
>  	u32 phy_flags = 0;
>  	int ret;
> @@ -333,6 +344,16 @@ int bcmgenet_mii_probe(struct net_device *dev)
>  			pr_err("could not attach to PHY\n");
>  			return -ENODEV;
>  		}
> +	} else if (has_acpi_companion(kdev)) {
> +		char phy_name[MII_BUS_ID_SIZE + 3];
> +
> +		bcmgenet_phy_name(phy_name,  priv->pdev->id, 1);

There is no guarantee that 1 is valid other than for the current
Raspberry Pi 4 design that we have in the wild, would ACPI be used in
the future with other designs, this would likely be different. Can you
find a way to communicate that address via appropriate firmware properties?

> +		phydev = phy_connect(dev, phy_name, bcmgenet_mii_setup,
> +				     priv->phy_interface);
> +		if (!IS_ERR(phydev))
> +			phydev->dev_flags = phy_flags;
> +		else
> +			return -ENODEV;
>  	} else {
>  		phydev = dev->phydev;
>  		phydev->dev_flags = phy_flags;
> @@ -435,6 +456,7 @@ static int bcmgenet_mii_register(struct bcmgenet_priv *priv)
>  	ppd.wait_func = bcmgenet_mii_wait;
>  	ppd.wait_func_data = priv;
>  	ppd.bus_name = "bcmgenet MII bus";
> +	ppd.phy_mask = ~0;

This is going to be breaking PHY scanning for the platform_data case, so
maybe something like:

	if (acpi_has_companion())
		ppd.phy_mask = ~BIT(acpi_phy_id);

or something like that?

>  
>  	/* Unimac MDIO bus controller starts at UniMAC offset + MDIO_CMD
>  	 * and is 2 * 32-bits word long, 8 bytes total.
> @@ -477,12 +499,28 @@ static int bcmgenet_mii_register(struct bcmgenet_priv *priv)
>  	return ret;
>  }
>  
> +static int bcmgenet_mii_phy_init(struct bcmgenet_priv *priv)
> +{

Maybe name that phy_interface_init(), there is not strictly much PHY
initialization going on here, just property fetching and internal book
keeping.
-- 
Florian