[PATCH net-next 0/2] net: phy: microchip_t1s: Add support for LAN867x Rev.D0 PHY

[PATCH net-next 0/2] net: phy: microchip_t1s: Add support for LAN867x Rev.D0 PHY

[Parthiban Veerasooran]

This patch series adds Open Alliance TC14 (OATC14) 10BASE-T1S cable
diagnostic feature support to the Linux kernel PHY subsystem and enable
this feature for Microchip LAN867x Rev.D0 PHYs. These patches provide
standardized cable test functionality for 10BASE-T1S Ethernet PHYs,
allowing users to perform cable diagnostics via ethtool.

Patch Summary:
1. add OATC14 10BASE-T1S PHY cable diagnostic support
	- Implements support for the OATC14 cable diagnostic feature in
	  Clause 45 PHYs.
	- Adds functions to start a cable test and retrieve its status,
	  mapping hardware results to ethtool codes.
	- Exports these functions for use by PHY drivers.
	- Open Alliance TC14 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
	
2. add cable diagnostic support for LAN867x Rev.D0
	- Integrates the generic OATC14 cable test functions into the
	  Microchip LAN867x Rev.D0 PHY driver.
	- Enables ethtool cable diagnostics for this PHY, improving
	  troubleshooting and maintenance.

Parthiban Veerasooran (2):
  net: phy: phy-c45: add OATC14 10BASE-T1S PHY cable diagnostic support
  net: phy: microchip_t1s:: add cable diagnostic support for LAN867x
    Rev.D0

 drivers/net/phy/mdio-open-alliance.h |  36 ++++++++
 drivers/net/phy/microchip_t1s.c      |   3 +
 drivers/net/phy/phy-c45.c            | 122 +++++++++++++++++++++++++++
 include/linux/phy.h                  |   3 +
 4 files changed, 164 insertions(+)


base-commit: 9e8a443401dfb15574f9cc962783500ca8c2eec2
-- 
2.34.1

[PATCH net-next 1/2] net: phy: phy-c45: add OATC14 10BASE-T1S PHY cable diagnostic support

[Parthiban Veerasooran]

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: Parthiban Veerasooran <parthiban.veerasooran@microchip.com>
---
 drivers/net/phy/mdio-open-alliance.h |  36 ++++++++
 drivers/net/phy/phy-c45.c            | 122 +++++++++++++++++++++++++++
 include/linux/phy.h                  |   3 +
 3 files changed, 161 insertions(+)

diff --git a/drivers/net/phy/mdio-open-alliance.h b/drivers/net/phy/mdio-open-alliance.h
index 931e14660d75..db302ff1f39a 100644
--- a/drivers/net/phy/mdio-open-alliance.h
+++ b/drivers/net/phy/mdio-open-alliance.h
@@ -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,
+	OATC14_HDD_STATUS_OPEN,
+	OATC14_HDD_STATUS_SHORT,
+	OATC14_HDD_STATUS_NOT_DETECTABLE,
+};
+
 #endif /* __MDIO_OPEN_ALLIANCE__ */
diff --git a/drivers/net/phy/phy-c45.c b/drivers/net/phy/phy-c45.c
index 61670be0f095..6030023bf840 100644
--- a/drivers/net/phy/phy-c45.c
+++ b/drivers/net/phy/phy-c45.c
@@ -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);
diff --git a/include/linux/phy.h b/include/linux/phy.h
index e3474f03cbc1..36457879c677 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -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);
-- 
2.34.1

[PATCH net-next 2/2] net: phy: microchip_t1s:: add cable diagnostic support for LAN867x Rev.D0

[Parthiban Veerasooran]

Enable Open Alliance TC14 (OATC14) 10Base-T1S cable diagnostic feature
for Microchip LAN867x Rev.D0 PHY by implementing `cable_test_start` and
`cable_test_get_status` using the generic C45 functions. This allows the
`ethtool` utility to perform cable diagnostic tests directly on the PHY,
improving network troubleshooting and maintenance.

Signed-off-by: Parthiban Veerasooran <parthiban.veerasooran@microchip.com>
---
 drivers/net/phy/microchip_t1s.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/phy/microchip_t1s.c b/drivers/net/phy/microchip_t1s.c
index bce5cf087b19..dd3de712c9d4 100644
--- a/drivers/net/phy/microchip_t1s.c
+++ b/drivers/net/phy/microchip_t1s.c
@@ -573,6 +573,9 @@ static struct phy_driver microchip_t1s_driver[] = {
 		.get_plca_cfg	    = genphy_c45_plca_get_cfg,
 		.set_plca_cfg	    = lan86xx_plca_set_cfg,
 		.get_plca_status    = genphy_c45_plca_get_status,
+		.cable_test_start   = genphy_c45_oatc14_cable_test_start,
+		.cable_test_get_status =
+					genphy_c45_oatc14_cable_test_get_status,
 	},
 	{
 		PHY_ID_MATCH_EXACT(PHY_ID_LAN865X_REVB),
-- 
2.34.1

Re: [PATCH net-next 1/2] net: phy: phy-c45: add OATC14 10BASE-T1S PHY cable diagnostic support

[Andrew Lunn]

> +/* 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,
> +	OATC14_HDD_STATUS_OPEN,
> +	OATC14_HDD_STATUS_SHORT,
> +	OATC14_HDD_STATUS_NOT_DETECTABLE,

You frequently see the first enum has an = 0 at the end. I don't know
what the C standard allows the compiler to do, in terms of assigning
values to these enums, but it won't work if it uses 42, 43, 44, 45.
etc.

Otherwise, this looks O.K.

	Andrew

Re: [PATCH net-next 2/2] net: phy: microchip_t1s:: add cable diagnostic support for LAN867x Rev.D0

[Andrew Lunn]

> +		.cable_test_start   = genphy_c45_oatc14_cable_test_start,
> +		.cable_test_get_status =
> +					genphy_c45_oatc14_cable_test_get_status,

netdev prefers lines at < 80, but up to 100 are accepted when they
make sense. Please keep this on one lines.

	Andre

Re: [PATCH net-next 1/2] net: phy: phy-c45: add OATC14 10BASE-T1S PHY cable diagnostic support

[Parthiban.Veerasooran]

Hi Andrew,

Thanks for reviewing the patches.

On 04/11/25 9:16 pm, Andrew Lunn wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> 
>> +/* 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,
>> +     OATC14_HDD_STATUS_OPEN,
>> +     OATC14_HDD_STATUS_SHORT,
>> +     OATC14_HDD_STATUS_NOT_DETECTABLE,
> 
> You frequently see the first enum has an = 0 at the end. I don't know
> what the C standard allows the compiler to do, in terms of assigning
> values to these enums, but it won't work if it uses 42, 43, 44, 45.
> etc.
> 
> Otherwise, this looks O.K.
Ok, I’ll update it in the next version. I mistakenly added the wrong 
cover letter subject line, so I’ve already sent v2 to correct that. I’ll 
include this update in v3.

Best regards,
Parthiban V
> 
>          Andrew

Re: [PATCH net-next 2/2] net: phy: microchip_t1s:: add cable diagnostic support for LAN867x Rev.D0

[Parthiban.Veerasooran]

On 04/11/25 9:18 pm, Andrew Lunn wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> 
>> +             .cable_test_start   = genphy_c45_oatc14_cable_test_start,
>> +             .cable_test_get_status =
>> +                                     genphy_c45_oatc14_cable_test_get_status,
> 
> netdev prefers lines at < 80, but up to 100 are accepted when they
> make sense. Please keep this on one lines.
Ok, thanks for the info. I will keep them in one line in the next 
version. I mistakenly added the wrong cover letter subject line, so I’ve 
already sent v2 to correct that. I’ll include this update in v3.

Best regards,
Parthiban V
> 
>          Andre