Re: [PATCH net-next 1/2] net: phy: realtek: add PHY driver for RTL8127ATF

[Heiner Kallweit <hkallweit1@gmail.com>]

On 1/8/2026 11:56 PM, Daniel Golle wrote:
> On Thu, Jan 08, 2026 at 09:27:06PM +0100, Heiner Kallweit wrote:
>> RTL8127ATF supports a SFP+ port for fiber modules (10GBASE-SR/LR/ER/ZR and
>> DAC). The list of supported modes was provided by Realtek. According to the
>> r8127 vendor driver also 1G modules are supported, but this needs some more
>> complexity in the driver, and only 10G mode has been tested so far.
>> Therefore mainline support will be limited to 10G for now.
>> The SFP port signals are hidden in the chip IP and driven by firmware.
>> Therefore mainline SFP support can't be used here.
>> This PHY driver is used by the RTL8127ATF support in r8169.
>> RTL8127ATF reports the same PHY ID as the TP version. Therefore use a dummy
>> PHY ID.  This PHY driver is used by the RTL8127ATF support in r8169.
>>
>> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
>> ---
>>  MAINTAINERS                            |  1 +
>>  drivers/net/phy/realtek/realtek_main.c | 54 ++++++++++++++++++++++++++
>>  include/linux/realtek_phy.h            |  7 ++++
>>  3 files changed, 62 insertions(+)
>>  create mode 100644 include/linux/realtek_phy.h
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 765ad2daa21..6ede656b009 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -9416,6 +9416,7 @@ F:	include/linux/phy_link_topology.h
>>  F:	include/linux/phylib_stubs.h
>>  F:	include/linux/platform_data/mdio-bcm-unimac.h
>>  F:	include/linux/platform_data/mdio-gpio.h
>> +F:	include/linux/realtek_phy.h
>>  F:	include/trace/events/mdio.h
>>  F:	include/uapi/linux/mdio.h
>>  F:	include/uapi/linux/mii.h
>> diff --git a/drivers/net/phy/realtek/realtek_main.c b/drivers/net/phy/realtek/realtek_main.c
>> index eb5b540ada0..b57ef0ce15a 100644
>> --- a/drivers/net/phy/realtek/realtek_main.c
>> +++ b/drivers/net/phy/realtek/realtek_main.c
>> @@ -16,6 +16,7 @@
>>  #include <linux/module.h>
>>  #include <linux/delay.h>
>>  #include <linux/clk.h>
>> +#include <linux/realtek_phy.h>
>>  #include <linux/string_choices.h>
>>  
>>  #include "../phylib.h"
>> @@ -2100,6 +2101,45 @@ static irqreturn_t rtl8221b_handle_interrupt(struct phy_device *phydev)
>>  	return IRQ_HANDLED;
>>  }
>>  
>> +static int rtlgen_sfp_get_features(struct phy_device *phydev)
>> +{
>> +	linkmode_set_bit(ETHTOOL_LINK_MODE_10000baseT_Full_BIT,
>> +			 phydev->supported);
>> +
>> +	/* set default mode */
>> +	phydev->speed = SPEED_10000;
>> +	phydev->duplex = DUPLEX_FULL;
>> +
>> +	phydev->port = PORT_FIBRE;
>> +
>> +	return 0;
>> +}
>> +
>> +static int rtlgen_sfp_read_status(struct phy_device *phydev)
>> +{
>> +	int val, err;
>> +
>> +	err = genphy_update_link(phydev);
>> +	if (err)
>> +		return err;
>> +
>> +	if (!phydev->link)
>> +		return 0;
>> +
>> +	val = rtlgen_read_vend2(phydev, RTL_VND2_PHYSR);
> 
> This should be the same as
> phy_read(phydev, MII_RESV2); /* on page 0 */
> Please try.
> 

In case of an integrated PHY a phy_read() effectively is translated
into a rtlgen_read_vend2(). So technically there's no benefit.

I don't have hw with RTL8127ATF, but maybe Fabio can test.

> 
>> +	if (val < 0)
>> +		return val;
>> +
>> +	rtlgen_decode_physr(phydev, val);
>> +
>> +	return 0;
>> +}
>> +
>> +static int rtlgen_sfp_config_aneg(struct phy_device *phydev)
>> +{
>> +	return 0;
>> +}
>> +
>>  static struct phy_driver realtek_drvs[] = {
>>  	{
>>  		PHY_ID_MATCH_EXACT(0x00008201),
>> @@ -2361,6 +2401,20 @@ static struct phy_driver realtek_drvs[] = {
>>  		.write_page	= rtl821x_write_page,
>>  		.read_mmd	= rtl822x_read_mmd,
>>  		.write_mmd	= rtl822x_write_mmd,
>> +	}, {
>> +		PHY_ID_MATCH_EXACT(PHY_ID_RTL_DUMMY_SFP),
>> +		.name		= "Realtek SFP PHY Mode",
>> +		.flags		= PHY_IS_INTERNAL,
>> +		.probe		= rtl822x_probe,
>> +		.get_features	= rtlgen_sfp_get_features,
>> +		.config_aneg	= rtlgen_sfp_config_aneg,
>> +		.read_status	= rtlgen_sfp_read_status,
>> +		.suspend	= genphy_suspend,
>> +		.resume		= rtlgen_resume,
>> +		.read_page	= rtl821x_read_page,
>> +		.write_page	= rtl821x_write_page,
>> +		.read_mmd	= rtl822x_read_mmd,
>> +		.write_mmd	= rtl822x_write_mmd,
>>  	}, {
>>  		PHY_ID_MATCH_EXACT(0x001ccad0),
>>  		.name		= "RTL8224 2.5Gbps PHY",
>> diff --git a/include/linux/realtek_phy.h b/include/linux/realtek_phy.h
>> new file mode 100644
>> index 00000000000..d683bc1b065
>> --- /dev/null
>> +++ b/include/linux/realtek_phy.h
>> @@ -0,0 +1,7 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +#ifndef _REALTEK_PHY_H
>> +#define _REALTEK_PHY_H
>> +
>> +#define	PHY_ID_RTL_DUMMY_SFP	0x001ccbff
>> +
>> +#endif /* _REALTEK_PHY_H */
>> -- 
>> 2.52.0
>>
>>