Re: [PATCH net-next v2] net: phy: micrel: Add support for lan9645x internal phy

[Jens Emil Schulz Ostergaard <jensemil.schulzostergaard@microchip.com>]

Hi,

On Fri, 2026-01-30 at 10:12 +0100, Jens Emil Schulz Østergaard wrote:
> LAN9645X is a family of switch chips with 5 internal copper phys. The
> internal PHY is based on parts of LAN8832. This is a low-power, single
> port triple-speed (10BASE-T/100BASE-TX/1000BASE-T) ethernet physical
> layer transceiver (PHY) that supports transmission and reception of data
> on standard CAT-5, as well as CAT-5e and CAT-6 Unshielded Twisted
> Pair (UTP) cables.
> 
> Add support for the internal PHY of the lan9645x chip family.
> 
> Reviewed-by: Steen Hegelund <Steen.Hegelund@microchip.com>
> Reviewed-by: Daniel Machon <daniel.machon@microchip.com>
> Signed-off-by: Jens Emil Schulz Østergaard <jensemil.schulzostergaard@microchip.com>
> ---
> Changes in v2:
> - Check write errors in lan9645x_config_intr.
> - Added more comments for the erratas which are not yet documented in
>   the datasheet.
> - Change workaround in lan9645x_suspend from ANEG restart and sleep to
>   asserting Software Soft Reset and poll for self-clear.
> - Return IRQ_NONE when IRQ is not handled in lan9645x_handle_interrupt.
> - Link to v1: https://lore.kernel.org/r/20260123-phy_micrel_add_support_for_lan9645x_internal_phy-v1-1-8484b1a5a7fd@microchip.com
> ---
>  drivers/net/phy/micrel.c   | 152 +++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/micrel_phy.h |   1 +
>  2 files changed, 153 insertions(+)
> 
> diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
> index 225d4adf28be..fe77ad899f10 100644
> --- a/drivers/net/phy/micrel.c
> +++ b/drivers/net/phy/micrel.c
> @@ -6502,6 +6502,142 @@ static void lan8842_get_phy_stats(struct phy_device *phydev,
>  	stats->tx_errors = priv->phy_stats.tx_errors;
>  }
>  
> +#define LAN9645X_CONTROL_REGISTER		0x1f
> +#define LAN9645X_CONTROL_REGISTER_SOFT_RESET	BIT(1)
> +
> +#define LAN9645X_DAC_ICAS_AMP_POWER_DOWN	0x47
> +#define LAN9645X_BTRX_QBIAS_POWER_DOWN		0x46
> +#define LAN9645X_TX_LOW_I_CH_CD_POWER_MGMT	0x45
> +#define LAN9645X_TX_LOW_I_CH_B_POWER_MGMT	0x44
> +#define LAN9645X_TX_LOW_I_CH_A_POWER_MGMT	0x43
> +
> +static const struct lanphy_reg_data force_dac_tx_errata[] = {
> +	/* Force channel A/B/C/D TX on */
> +	{ LAN8814_PAGE_POWER_REGS,
> +	  LAN9645X_DAC_ICAS_AMP_POWER_DOWN,
> +	  0 },
> +	/* Force channel A/B/C/D QBias on */
> +	{ LAN8814_PAGE_POWER_REGS,
> +	  LAN9645X_BTRX_QBIAS_POWER_DOWN,
> +	  0xaa },
> +	/* Tx low I on channel C/D overwrite */
> +	{ LAN8814_PAGE_POWER_REGS,
> +	  LAN9645X_TX_LOW_I_CH_CD_POWER_MGMT,
> +	  0xbfff },
> +	/* Channel B low I overwrite */
> +	{ LAN8814_PAGE_POWER_REGS,
> +	  LAN9645X_TX_LOW_I_CH_B_POWER_MGMT,
> +	  0xabbf },
> +	/* Channel A low I overwrite */
> +	{ LAN8814_PAGE_POWER_REGS,
> +	  LAN9645X_TX_LOW_I_CH_A_POWER_MGMT,
> +	  0xbd3f },
> +};
> +
> +static int lan9645x_config_init(struct phy_device *phydev)
> +{
> +	int ret;
> +
> +	/* Apply erratas from previous generations.  */
> +	ret = lan8842_erratas(phydev);
> +	if (ret < 0)
> +		return ret;
> +
> +	/* Apply errata for an issue where bringing a port down, can cause a few
> +	 * CRC errors for traffic flowing through adjacent ports.
> +	 */
> +	return lanphy_write_reg_data(phydev, force_dac_tx_errata,
> +				     ARRAY_SIZE(force_dac_tx_errata));
> +}
> +
> +static int lan9645x_suspend(struct phy_device *phydev)
> +{
> +	int ret, val;
> +
> +	/* Force link down before software power down (SPD), by doing software
> +	 * soft reset. This resets the PHY, but keeps all register configuration
> +	 * intact. The bit self clears.
> +	 *
> +	 * This is needed as a workaround for an issue where performing SPD on a
> +	 * port can bring adjacent ports down, when there is traffic flowing
> +	 * through the ports.
> +	 */
> +	ret = phy_modify(phydev, LAN9645X_CONTROL_REGISTER,
> +			 LAN9645X_CONTROL_REGISTER_SOFT_RESET, 1);
> +	if (ret)
> +		return ret;
> +

AI review pointed out an error here. I will fix in the next version.

> +	ret = phy_read_poll_timeout(phydev, LAN9645X_CONTROL_REGISTER, val,
> +				    !(val & LAN9645X_CONTROL_REGISTER_SOFT_RESET),
> +				    3000, 100000, true);
> +	if (ret)
> +		return ret;
> +
> +	return genphy_suspend(phydev);
> +}
> +
> +static int lan9645x_config_intr(struct phy_device *phydev)
> +{
> +	int err;
> +
> +	/* enable / disable interrupts */
> +	if (phydev->interrupts == PHY_INTERRUPT_ENABLED) {
> +		/* This is an internal PHY of lan9645x and is not possible to
> +		 * change the polarity of irq sources in the OIC (CPU_INTR)
> +		 * found in lan9645x. Therefore change the polarity of the
> +		 * interrupt in the PHY from being active low instead of active
> +		 * high.
> +		 */
> +		err = phy_write(phydev, LAN8804_CONTROL,
> +				LAN8804_CONTROL_INTR_POLARITY);
> +		if (err)
> +			return err;
> +
> +		/* By default interrupt buffer is open-drain in which case the
> +		 * interrupt can be active only low. Therefore change the
> +		 * interrupt buffer to be push-pull to be able to change
> +		 * interrupt polarity.
> +		 */
> +		err = phy_write(phydev, LAN8804_OUTPUT_CONTROL,
> +				LAN8804_OUTPUT_CONTROL_INTR_BUFFER);
> +		if (err)
> +			return err;
> +
> +		err = lan8814_ack_interrupt(phydev);
> +		if (err)
> +			return err;
> +
> +		err = phy_write(phydev, LAN8814_INTC,
> +				LAN8814_INT_LINK | LAN8814_INT_FLF);
> +	} else {
> +		err = phy_write(phydev, LAN8814_INTC, 0);
> +		if (err)
> +			return err;
> +
> +		err = lan8814_ack_interrupt(phydev);
> +	}
> +
> +	return err;
> +}
> +
> +static irqreturn_t lan9645x_handle_interrupt(struct phy_device *phydev)
> +{
> +	int status;
> +
> +	status = phy_read(phydev, LAN8814_INTS);
> +	if (status < 0) {
> +		phy_error(phydev);
> +		return IRQ_NONE;
> +	}
> +
> +	if (status & (LAN8814_INT_LINK | LAN8814_INT_FLF)) {
> +		phy_trigger_machine(phydev);
> +		return IRQ_HANDLED;
> +	}
> +
> +	return IRQ_NONE;
> +}
> +
>  static struct phy_driver ksphy_driver[] = {
>  {
>  	PHY_ID_MATCH_MODEL(PHY_ID_KS8737),
> @@ -6740,6 +6876,21 @@ static struct phy_driver ksphy_driver[] = {
>  	.set_tunable	= lan8842_set_tunable,
>  	.cable_test_start	= lan8814_cable_test_start,
>  	.cable_test_get_status	= ksz886x_cable_test_get_status,
> +}, {
> +	PHY_ID_MATCH_MODEL(PHY_ID_LAN9645X),
> +	.name		= "Microchip LAN9645X Gigabit PHY",
> +	.config_init	= lan9645x_config_init,
> +	.driver_data	= &ksz9021_type,
> +	.probe		= kszphy_probe,
> +	.soft_reset	= genphy_soft_reset,
> +	.suspend	= lan9645x_suspend,
> +	.resume		= genphy_resume,
> +	.config_intr	= lan9645x_config_intr,
> +	.handle_interrupt = lan9645x_handle_interrupt,
> +	.get_tunable	= lan8842_get_tunable,
> +	.set_tunable	= lan8842_set_tunable,
> +	.get_phy_stats	= lan8842_get_phy_stats,
> +	.update_stats	= lan8842_update_stats,
>  }, {
>  	PHY_ID_MATCH_MODEL(PHY_ID_KSZ9131),
>  	.name		= "Microchip KSZ9131 Gigabit PHY",
> @@ -6838,6 +6989,7 @@ static const struct mdio_device_id __maybe_unused micrel_tbl[] = {
>  	{ PHY_ID_MATCH_MODEL(PHY_ID_LAN8804) },
>  	{ PHY_ID_MATCH_MODEL(PHY_ID_LAN8841) },
>  	{ PHY_ID_MATCH_MODEL(PHY_ID_LAN8842) },
> +	{ PHY_ID_MATCH_MODEL(PHY_ID_LAN9645X) },
>  	{ }
>  };
>  
> diff --git a/include/linux/micrel_phy.h b/include/linux/micrel_phy.h
> index ca691641788b..9c6f9817383f 100644
> --- a/include/linux/micrel_phy.h
> +++ b/include/linux/micrel_phy.h
> @@ -33,6 +33,7 @@
>  #define PHY_ID_LAN8804		0x00221670
>  #define PHY_ID_LAN8841		0x00221650
>  #define PHY_ID_LAN8842		0x002216C0
> +#define PHY_ID_LAN9645X		0x002216D0
>  
>  #define PHY_ID_KSZ886X		0x00221430
>  #define PHY_ID_KSZ8863		0x00221435
> 
> ---
> base-commit: cbe8e6bef6a3b4b895b47ea56f5952f1936aacb6
> change-id: 20260114-phy_micrel_add_support_for_lan9645x_internal_phy-6ef9a782cb8b
> 
> Best regards,

Thanks,

Emil