Commit d39f339d authored by Oleksij Rempel's avatar Oleksij Rempel Committed by David S. Miller
Browse files

net: usb: lan78xx: refactor PHY init to separate detection and MAC configuration 



Split out PHY detection into lan78xx_get_phy() and MAC-side setup into
lan78xx_mac_prepare_for_phy(), making the main lan78xx_phy_init() cleaner
and easier to follow.

This improves separation of concerns and prepares the code for a future
transition to phylink. Fixed PHY registration and interface selection
are now handled in lan78xx_get_phy(), while MAC-side delay configuration
is done in lan78xx_mac_prepare_for_phy().

The fixed PHY fallback is preserved for setups like EVB-KSZ9897-1,
where LAN7801 connects directly to a KSZ switch without a standard PHY
or device tree support.

No functional changes intended.

Signed-off-by: default avatarOleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: default avatarThangaraj Samynathan <thangaraj.s@microchip.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 3da0ae52

drivers/net/usb/lan78xx.c

+128 −46
Original line number Diff line number Diff line
@@ -2508,53 +2508,145 @@ static void lan78xx_remove_irq_domain(struct lan78xx_net *dev) 
	dev->domain_data.irqdomain = NULL;

}



static struct phy_device *lan7801_phy_init(struct lan78xx_net *dev)

/**

 * lan78xx_register_fixed_phy() - Register a fallback fixed PHY

 * @dev: LAN78xx device

 *

 * Registers a fixed PHY with 1 Gbps full duplex. This is used in special cases

 * like EVB-KSZ9897-1, where LAN7801 acts as a USB-to-Ethernet interface to a

 * switch without a visible PHY.

 *

 * Return: pointer to the registered fixed PHY, or ERR_PTR() on error.

 */

static struct phy_device *lan78xx_register_fixed_phy(struct lan78xx_net *dev)

{

	struct fixed_phy_status fphy_status = {

		.link = 1,

		.speed = SPEED_1000,

		.duplex = DUPLEX_FULL,

	};



	netdev_info(dev->net,

		    "No PHY found on LAN7801 – registering fixed PHY (e.g. EVB-KSZ9897-1)\n");



	return fixed_phy_register(PHY_POLL, &fphy_status, NULL);

}



/**

 * lan78xx_get_phy() - Probe or register PHY device and set interface mode

 * @dev: LAN78xx device structure

 *

 * This function attempts to find a PHY on the MDIO bus. If no PHY is found

 * and the chip is LAN7801, it registers a fixed PHY as fallback. It also

 * sets dev->interface based on chip ID and detected PHY type.

 *

 * Return: a valid PHY device pointer, or ERR_PTR() on failure.

 */

static struct phy_device *lan78xx_get_phy(struct lan78xx_net *dev)

{

	struct phy_device *phydev;

	int ret;



	/* Attempt to locate a PHY on the MDIO bus */

	phydev = phy_find_first(dev->mdiobus);

	if (!phydev) {

		netdev_dbg(dev->net, "PHY Not Found!! Registering Fixed PHY\n");

		phydev = fixed_phy_register(PHY_POLL, &fphy_status, NULL);

		if (IS_ERR(phydev)) {

			netdev_err(dev->net, "No PHY/fixed_PHY found\n");

			return ERR_PTR(-ENODEV);



	switch (dev->chipid) {

	case ID_REV_CHIP_ID_7801_:

		if (phydev) {

			/* External RGMII PHY detected */

			dev->interface = PHY_INTERFACE_MODE_RGMII_ID;

			phydev->is_internal = false;



			if (!phydev->drv)

				netdev_warn(dev->net,

					    "PHY driver not found – assuming RGMII delays are on PCB or strapped for the PHY\n");



			return phydev;

		}

		netdev_dbg(dev->net, "Registered FIXED PHY\n");



		dev->interface = PHY_INTERFACE_MODE_RGMII;

		/* No PHY found – fallback to fixed PHY (e.g. KSZ switch board) */

		return lan78xx_register_fixed_phy(dev);



	case ID_REV_CHIP_ID_7800_:

	case ID_REV_CHIP_ID_7850_:

		if (!phydev)

			return ERR_PTR(-ENODEV);



		/* These use internal GMII-connected PHY */

		dev->interface = PHY_INTERFACE_MODE_GMII;

		phydev->is_internal = true;

		return phydev;



	default:

		netdev_err(dev->net, "Unknown CHIP ID: 0x%08x\n", dev->chipid);

		return ERR_PTR(-ENODEV);

	}

}



/**

 * lan78xx_mac_prepare_for_phy() - Preconfigure MAC-side interface settings

 * @dev: LAN78xx device

 *

 * Configure MAC-side registers according to dev->interface, which should be

 * set by lan78xx_get_phy().

 *

 * - For PHY_INTERFACE_MODE_RGMII:

 *   Enable MAC-side TXC delay. This mode seems to be used in a special setup

 *   without a real PHY, likely on EVB-KSZ9897-1. In that design, LAN7801 is

 *   connected to the KSZ9897 switch, and the link timing is expected to be

 *   hardwired (e.g. via strapping or board layout). No devicetree support is

 *   assumed here.

 *

 * - For PHY_INTERFACE_MODE_RGMII_ID:

 *   Disable MAC-side delay and rely on the PHY driver to provide delay.

 *

 * - For GMII, no MAC-specific config is needed.

 *

 * Return: 0 on success or a negative error code.

 */

static int lan78xx_mac_prepare_for_phy(struct lan78xx_net *dev)

{

	int ret;



	switch (dev->interface) {

	case PHY_INTERFACE_MODE_RGMII:

		/* Enable MAC-side TX clock delay */

		ret = lan78xx_write_reg(dev, MAC_RGMII_ID,

					MAC_RGMII_ID_TXC_DELAY_EN_);

		if (ret < 0)

			return ERR_PTR(ret);

			return ret;



		ret = lan78xx_write_reg(dev, RGMII_TX_BYP_DLL, 0x3D00);

		if (ret < 0)

			return ERR_PTR(ret);

			return ret;



		ret = lan78xx_update_reg(dev, HW_CFG, HW_CFG_CLK125_EN_ |

					 HW_CFG_REFCLK25_EN_,

		ret = lan78xx_update_reg(dev, HW_CFG,

					 HW_CFG_CLK125_EN_ | HW_CFG_REFCLK25_EN_,

					 HW_CFG_CLK125_EN_ | HW_CFG_REFCLK25_EN_);

		if (ret < 0)

			return ERR_PTR(ret);

	} else {

		dev->interface = PHY_INTERFACE_MODE_RGMII_ID;

		/* The PHY driver is responsible to configure proper RGMII

		 * interface delays. Disable RGMII delays on MAC side.

		 */

			return ret;



		break;



	case PHY_INTERFACE_MODE_RGMII_ID:

		/* Disable MAC-side TXC delay, PHY provides it */

		ret = lan78xx_write_reg(dev, MAC_RGMII_ID, 0);

		if (ret < 0)

			return ERR_PTR(ret);

			return ret;



		phydev->is_internal = false;

		break;



	case PHY_INTERFACE_MODE_GMII:

		/* No MAC-specific configuration required */

		break;



	default:

		netdev_warn(dev->net, "Unsupported interface mode: %d\n",

			    dev->interface);

		break;

	}



	return phydev;

	return 0;

}



static int lan78xx_phy_init(struct lan78xx_net *dev)
@@ -2564,31 +2656,13 @@ static int lan78xx_phy_init(struct lan78xx_net *dev) 
	u32 mii_adv;

	struct phy_device *phydev;



	switch (dev->chipid) {

	case ID_REV_CHIP_ID_7801_:

		phydev = lan7801_phy_init(dev);

		if (IS_ERR(phydev)) {

			netdev_err(dev->net, "lan7801: failed to init PHY: %pe\n",

				   phydev);

	phydev = lan78xx_get_phy(dev);

	if (IS_ERR(phydev))

		return PTR_ERR(phydev);

		}

		break;



	case ID_REV_CHIP_ID_7800_:

	case ID_REV_CHIP_ID_7850_:

		phydev = phy_find_first(dev->mdiobus);

		if (!phydev) {

			netdev_err(dev->net, "no PHY found\n");

			return -ENODEV;

		}

		phydev->is_internal = true;

		dev->interface = PHY_INTERFACE_MODE_GMII;

		break;



	default:

		netdev_err(dev->net, "Unknown CHIP ID found\n");

		return -ENODEV;

	}

	ret = lan78xx_mac_prepare_for_phy(dev);

	if (ret < 0)

		goto free_phy;



	/* if phyirq is not set, use polling mode in phylib */

	if (dev->domain_data.phyirq > 0)
@@ -2662,6 +2736,14 @@ static int lan78xx_phy_init(struct lan78xx_net *dev) 
	dev->fc_autoneg = phydev->autoneg;



	return 0;



free_phy:

	if (phy_is_pseudo_fixed_link(phydev)) {

		fixed_phy_unregister(phydev);

		phy_device_free(phydev);

	}



	return ret;

}



static int lan78xx_set_rx_max_frame_length(struct lan78xx_net *dev, int size)