Commit b87ee13e authored by Parthiban Veerasooran's avatar Parthiban Veerasooran Committed by Jakub Kicinski
Browse files

net: phy: phy-c45: add OATC14 10BASE-T1S PHY cable diagnostic support 

Add support for Open Alliance TC14 (OATC14) 10BASE-T1S PHYs cable
diagnostic feature.

This patch implements:
- genphy_c45_oatc14_cable_test_start() to initiate a cable test
- genphy_c45_oatc14_cable_test_get_status() to retrieve test results
- Helper function to map PHY cable test status to ethtool result codes
- Function declarations and exports for use by PHY drivers

This enables ethtool to report ok, open, short, and undetectable cable
conditions on OATC14 10Base-T1S PHYs.

Open Alliance TC14 10BASE-T1S Advanced Diagnostic PHY Features
Specification ref:
https://opensig.org/wp-content/uploads/2025/06/OPEN_Alliance_10BASE-T1S_Advanced_PHY_features_for-automotive_Ethernet_V2.1b.pdf



Signed-off-by: default avatarParthiban Veerasooran <parthiban.veerasooran@microchip.com>
Link: https://patch.msgid.link/20251105051213.50443-2-parthiban.veerasooran@microchip.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 14003958

drivers/net/phy/mdio-open-alliance.h

+36 −0
Original line number Diff line number Diff line
@@ -43,4 +43,40 @@ 
/* Version Identifiers */

#define OATC14_IDM		0x0a00



/*

 * Open Alliance TC14 (10BASE-T1S) - Advanced Diagnostic Features Registers

 *

 * Refer to the OPEN Alliance documentation:

 *   https://opensig.org/automotive-ethernet-specifications/

 *

 * Specification:

 *   "10BASE-T1S Advanced Diagnostic PHY Features"

 *   https://opensig.org/wp-content/uploads/2025/06/OPEN_Alliance_10BASE-T1S_Advanced_PHY_features_for-automotive_Ethernet_V2.1b.pdf

 */

/* Advanced Diagnostic Features Capability Register*/

#define MDIO_OATC14_ADFCAP		0xcc00

#define OATC14_ADFCAP_HDD_CAPABILITY	GENMASK(10, 8)



/* Harness Defect Detection Register */

#define MDIO_OATC14_HDD			0xcc01

#define OATC14_HDD_CONTROL		BIT(15)

#define OATC14_HDD_READY		BIT(14)

#define OATC14_HDD_START_CONTROL	BIT(13)

#define OATC14_HDD_VALID		BIT(2)

#define OATC14_HDD_SHORT_OPEN_STATUS	GENMASK(1, 0)



/* Bus Short/Open Status:

 * 0 0 - no fault; everything is ok. (Default)

 * 0 1 - detected as an open or missing termination(s)

 * 1 0 - detected as a short or extra termination(s)

 * 1 1 - fault but fault type not detectable. More details can be available by

 *       vender specific register if supported.

 */

enum oatc14_hdd_status {

	OATC14_HDD_STATUS_CABLE_OK = 0,

	OATC14_HDD_STATUS_OPEN,

	OATC14_HDD_STATUS_SHORT,

	OATC14_HDD_STATUS_NOT_DETECTABLE,

};



#endif /* __MDIO_OPEN_ALLIANCE__ */

drivers/net/phy/phy-c45.c

+122 −0
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 
#include <linux/mdio.h>

#include <linux/mii.h>

#include <linux/phy.h>

#include <linux/ethtool_netlink.h>



#include "mdio-open-alliance.h"

#include "phylib-internal.h"
@@ -1573,3 +1574,124 @@ int genphy_c45_ethtool_set_eee(struct phy_device *phydev, 
	return ret;

}

EXPORT_SYMBOL(genphy_c45_ethtool_set_eee);



/**

 * oatc14_cable_test_get_result_code - Convert hardware cable test status to

 *                                     ethtool result code.

 * @status: The hardware-reported cable test status

 *

 * This helper function maps the OATC14 HDD cable test status to the

 * corresponding ethtool cable test result code. It provides a translation

 * between the device-specific status values and the standardized ethtool

 * result codes.

 *

 * Return:

 * * ETHTOOL_A_CABLE_RESULT_CODE_OK          - Cable is OK

 * * ETHTOOL_A_CABLE_RESULT_CODE_OPEN        - Open circuit detected

 * * ETHTOOL_A_CABLE_RESULT_CODE_SAME_SHORT  - Short circuit detected

 * * ETHTOOL_A_CABLE_RESULT_CODE_UNSPEC      - Status not detectable or invalid

 */

static int oatc14_cable_test_get_result_code(enum oatc14_hdd_status status)

{

	switch (status) {

	case OATC14_HDD_STATUS_CABLE_OK:

		return ETHTOOL_A_CABLE_RESULT_CODE_OK;

	case OATC14_HDD_STATUS_OPEN:

		return ETHTOOL_A_CABLE_RESULT_CODE_OPEN;

	case OATC14_HDD_STATUS_SHORT:

		return ETHTOOL_A_CABLE_RESULT_CODE_SAME_SHORT;

	case OATC14_HDD_STATUS_NOT_DETECTABLE:

	default:

		return ETHTOOL_A_CABLE_RESULT_CODE_UNSPEC;

	}

}



/**

 * genphy_c45_oatc14_cable_test_get_status - Get status of OATC14 10Base-T1S

 *                                           PHY cable test.

 * @phydev:   pointer to the PHY device structure

 * @finished: pointer to a boolean set true if the test is complete

 *

 * Retrieves the current status of the OATC14 10Base-T1S PHY cable test.

 * This function reads the OATC14 HDD register to determine whether the test

 * results are valid and whether the test has finished.

 *

 * If the test is complete, the function reports the cable test result via

 * the ethtool cable test interface using ethnl_cable_test_result(), and then

 * clears the test control bit in the PHY register to reset the test state.

 *

 * Return: 0 on success, or a negative error code on failure (e.g. register

 *         read/write error).

 */

int genphy_c45_oatc14_cable_test_get_status(struct phy_device *phydev,

					    bool *finished)

{

	int ret;

	u8 sts;



	*finished = false;



	ret = phy_read_mmd(phydev, MDIO_MMD_VEND2, MDIO_OATC14_HDD);

	if (ret < 0)

		return ret;



	if (!(ret & OATC14_HDD_VALID))

		return 0;



	*finished = true;



	sts = FIELD_GET(OATC14_HDD_SHORT_OPEN_STATUS, ret);



	ret = ethnl_cable_test_result(phydev, ETHTOOL_A_CABLE_PAIR_A,

				      oatc14_cable_test_get_result_code(sts));

	if (ret)

		return ret;



	return phy_clear_bits_mmd(phydev, MDIO_MMD_VEND2,

				  MDIO_OATC14_HDD, OATC14_HDD_CONTROL);

}

EXPORT_SYMBOL(genphy_c45_oatc14_cable_test_get_status);



/**

 * genphy_c45_oatc14_cable_test_start - Start a cable test on an OATC14

 *                                      10Base-T1S PHY.

 * @phydev: Pointer to the PHY device structure

 *

 * This function initiates a cable diagnostic test on a Clause 45 OATC14

 * 10Base-T1S capable PHY device. It first reads the PHY’s advanced diagnostic

 * capability register to check if High Definition Diagnostics (HDD) mode is

 * supported. If the PHY does not report HDD capability, cable testing is not

 * supported and the function returns -EOPNOTSUPP.

 *

 * For PHYs that support HDD, the function sets the appropriate control bits in

 * the OATC14_HDD register to enable and start the cable diagnostic test.

 *

 * Return:

 * * 0 on success

 * * -EOPNOTSUPP if the PHY does not support HDD capability

 * * A negative error code on I/O or register access failures

 */

int genphy_c45_oatc14_cable_test_start(struct phy_device *phydev)

{

	int ret;



	ret = phy_read_mmd(phydev, MDIO_MMD_VEND2, MDIO_OATC14_ADFCAP);

	if (ret < 0)

		return ret;



	if (!(ret & OATC14_ADFCAP_HDD_CAPABILITY))

		return -EOPNOTSUPP;



	ret = phy_set_bits_mmd(phydev, MDIO_MMD_VEND2, MDIO_OATC14_HDD,

			       OATC14_HDD_CONTROL);

	if (ret)

		return ret;



	ret = phy_read_mmd(phydev, MDIO_MMD_VEND2, MDIO_OATC14_HDD);

	if (ret < 0)

		return ret;



	return phy_set_bits_mmd(phydev, MDIO_MMD_VEND2, MDIO_OATC14_HDD,

				OATC14_HDD_START_CONTROL);

}

EXPORT_SYMBOL(genphy_c45_oatc14_cable_test_start);

include/linux/phy.h

+3 −0
Original line number Diff line number Diff line
@@ -2251,6 +2251,9 @@ int genphy_c45_ethtool_get_eee(struct phy_device *phydev, 
int genphy_c45_ethtool_set_eee(struct phy_device *phydev,

			       struct ethtool_keee *data);

int genphy_c45_an_config_eee_aneg(struct phy_device *phydev);

int genphy_c45_oatc14_cable_test_start(struct phy_device *phydev);

int genphy_c45_oatc14_cable_test_get_status(struct phy_device *phydev,

					    bool *finished);



/* The gen10g_* functions are the old Clause 45 stub */

int gen10g_config_aneg(struct phy_device *phydev);