Commit 49011e0c authored by Oleksij Rempel's avatar Oleksij Rempel Committed by David S. Miller
Browse files

net: phy: micrel: ksz886x/ksz8081: add cabletest support 

This patch support for cable test for the ksz886x switches and the
ksz8081 PHY.

The patch was tested on a KSZ8873RLL switch with following results:

- port 1:
  - provides invalid values, thus return -ENOTSUPP
    (Errata: DS80000830A: "LinkMD does not work on Port 1",
     http://ww1.microchip.com/downloads/en/DeviceDoc/KSZ8873-Errata-DS80000830A.pdf

)

- port 2:
  - can detect distance
  - can detect open on each wire of pair A (wire 1 and 2)
  - can detect open only on one wire of pair B (only wire 3)
  - can detect short between wires of a pair (wires 1 + 2 or 3 + 6)
  - short between pairs is detected as open.
    For example short between wires 2 + 3 is detected as open.

Signed-off-by: default avatarOleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c916e8e1

drivers/net/dsa/microchip/ksz8795.c

+13 −0
Original line number Diff line number Diff line
@@ -970,6 +970,18 @@ static enum dsa_tag_protocol ksz8_get_tag_protocol(struct dsa_switch *ds, 
		DSA_TAG_PROTO_KSZ9893 : DSA_TAG_PROTO_KSZ8795;

}



static u32 ksz8_sw_get_phy_flags(struct dsa_switch *ds, int port)

{

	/* Silicon Errata Sheet (DS80000830A):

	 * Port 1 does not work with LinkMD Cable-Testing.

	 * Port 1 does not respond to received PAUSE control frames.

	 */

	if (!port)

		return MICREL_KSZ8_P1_ERRATA;



	return 0;

}



static void ksz8_get_strings(struct dsa_switch *ds, int port,

			     u32 stringset, uint8_t *buf)

{
@@ -1503,6 +1515,7 @@ static void ksz8_validate(struct dsa_switch *ds, int port, 


static const struct dsa_switch_ops ksz8_switch_ops = {

	.get_tag_protocol	= ksz8_get_tag_protocol,

	.get_phy_flags		= ksz8_sw_get_phy_flags,

	.setup			= ksz8_setup,

	.phy_read		= ksz_phy_read16,

	.phy_write		= ksz_phy_write16,

drivers/net/phy/micrel.c

+180 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 
 */



#include <linux/bitfield.h>

#include <linux/ethtool_netlink.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/phy.h>
@@ -53,6 +54,18 @@ 
#define KSZPHY_INTCS_STATUS			(KSZPHY_INTCS_LINK_DOWN_STATUS |\

						 KSZPHY_INTCS_LINK_UP_STATUS)



/* LinkMD Control/Status */

#define KSZ8081_LMD				0x1d

#define KSZ8081_LMD_ENABLE_TEST			BIT(15)

#define KSZ8081_LMD_STAT_NORMAL			0

#define KSZ8081_LMD_STAT_OPEN			1

#define KSZ8081_LMD_STAT_SHORT			2

#define KSZ8081_LMD_STAT_FAIL			3

#define KSZ8081_LMD_STAT_MASK			GENMASK(14, 13)

/* Short cable (<10 meter) has been detected by LinkMD */

#define KSZ8081_LMD_SHORT_INDICATOR		BIT(12)

#define KSZ8081_LMD_DELTA_TIME_MASK		GENMASK(8, 0)



/* PHY Control 1 */

#define MII_KSZPHY_CTRL_1			0x1e

#define KSZ8081_CTRL1_MDIX_STAT			BIT(4)
@@ -1363,6 +1376,167 @@ static int kszphy_probe(struct phy_device *phydev) 
	return 0;

}



static int ksz886x_cable_test_start(struct phy_device *phydev)

{

	if (phydev->dev_flags & MICREL_KSZ8_P1_ERRATA)

		return -EOPNOTSUPP;



	/* If autoneg is enabled, we won't be able to test cross pair

	 * short. In this case, the PHY will "detect" a link and

	 * confuse the internal state machine - disable auto neg here.

	 * If autoneg is disabled, we should set the speed to 10mbit.

	 */

	return phy_clear_bits(phydev, MII_BMCR, BMCR_ANENABLE | BMCR_SPEED100);

}



static int ksz886x_cable_test_result_trans(u16 status)

{

	switch (FIELD_GET(KSZ8081_LMD_STAT_MASK, status)) {

	case KSZ8081_LMD_STAT_NORMAL:

		return ETHTOOL_A_CABLE_RESULT_CODE_OK;

	case KSZ8081_LMD_STAT_SHORT:

		return ETHTOOL_A_CABLE_RESULT_CODE_SAME_SHORT;

	case KSZ8081_LMD_STAT_OPEN:

		return ETHTOOL_A_CABLE_RESULT_CODE_OPEN;

	case KSZ8081_LMD_STAT_FAIL:

		fallthrough;

	default:

		return ETHTOOL_A_CABLE_RESULT_CODE_UNSPEC;

	}

}



static bool ksz886x_cable_test_failed(u16 status)

{

	return FIELD_GET(KSZ8081_LMD_STAT_MASK, status) ==

		KSZ8081_LMD_STAT_FAIL;

}



static bool ksz886x_cable_test_fault_length_valid(u16 status)

{

	switch (FIELD_GET(KSZ8081_LMD_STAT_MASK, status)) {

	case KSZ8081_LMD_STAT_OPEN:

		fallthrough;

	case KSZ8081_LMD_STAT_SHORT:

		return true;

	}

	return false;

}



static int ksz886x_cable_test_fault_length(u16 status)

{

	int dt;



	/* According to the data sheet the distance to the fault is

	 * DELTA_TIME * 0.4 meters.

	 */

	dt = FIELD_GET(KSZ8081_LMD_DELTA_TIME_MASK, status);



	return (dt * 400) / 10;

}



static int ksz886x_cable_test_wait_for_completion(struct phy_device *phydev)

{

	int val, ret;



	ret = phy_read_poll_timeout(phydev, KSZ8081_LMD, val,

				    !(val & KSZ8081_LMD_ENABLE_TEST),

				    30000, 100000, true);



	return ret < 0 ? ret : 0;

}



static int ksz886x_cable_test_one_pair(struct phy_device *phydev, int pair)

{

	static const int ethtool_pair[] = {

		ETHTOOL_A_CABLE_PAIR_A,

		ETHTOOL_A_CABLE_PAIR_B,

	};

	int ret, val, mdix;



	/* There is no way to choice the pair, like we do one ksz9031.

	 * We can workaround this limitation by using the MDI-X functionality.

	 */

	if (pair == 0)

		mdix = ETH_TP_MDI;

	else

		mdix = ETH_TP_MDI_X;



	switch (phydev->phy_id & MICREL_PHY_ID_MASK) {

	case PHY_ID_KSZ8081:

		ret = ksz8081_config_mdix(phydev, mdix);

		break;

	case PHY_ID_KSZ886X:

		ret = ksz886x_config_mdix(phydev, mdix);

		break;

	default:

		ret = -ENODEV;

	}



	if (ret)

		return ret;



	/* Now we are ready to fire. This command will send a 100ns pulse

	 * to the pair.

	 */

	ret = phy_write(phydev, KSZ8081_LMD, KSZ8081_LMD_ENABLE_TEST);

	if (ret)

		return ret;



	ret = ksz886x_cable_test_wait_for_completion(phydev);

	if (ret)

		return ret;



	val = phy_read(phydev, KSZ8081_LMD);

	if (val < 0)

		return val;



	if (ksz886x_cable_test_failed(val))

		return -EAGAIN;



	ret = ethnl_cable_test_result(phydev, ethtool_pair[pair],

				      ksz886x_cable_test_result_trans(val));

	if (ret)

		return ret;



	if (!ksz886x_cable_test_fault_length_valid(val))

		return 0;



	return ethnl_cable_test_fault_length(phydev, ethtool_pair[pair],

					     ksz886x_cable_test_fault_length(val));

}



static int ksz886x_cable_test_get_status(struct phy_device *phydev,

					 bool *finished)

{

	unsigned long pair_mask = 0x3;

	int retries = 20;

	int pair, ret;



	*finished = false;



	/* Try harder if link partner is active */

	while (pair_mask && retries--) {

		for_each_set_bit(pair, &pair_mask, 4) {

			ret = ksz886x_cable_test_one_pair(phydev, pair);

			if (ret == -EAGAIN)

				continue;

			if (ret < 0)

				return ret;

			clear_bit(pair, &pair_mask);

		}

		/* If link partner is in autonegotiation mode it will send 2ms

		 * of FLPs with at least 6ms of silence.

		 * Add 2ms sleep to have better chances to hit this silence.

		 */

		if (pair_mask)

			msleep(2);

	}



	*finished = true;



	return ret;

}



static struct phy_driver ksphy_driver[] = {

{

	.phy_id		= PHY_ID_KS8737,
@@ -1469,6 +1643,7 @@ static struct phy_driver ksphy_driver[] = { 
	.phy_id		= PHY_ID_KSZ8081,

	.name		= "Micrel KSZ8081 or KSZ8091",

	.phy_id_mask	= MICREL_PHY_ID_MASK,

	.flags		= PHY_POLL_CABLE_TEST,

	/* PHY_BASIC_FEATURES */

	.driver_data	= &ksz8081_type,

	.probe		= kszphy_probe,
@@ -1483,6 +1658,8 @@ static struct phy_driver ksphy_driver[] = { 
	.get_stats	= kszphy_get_stats,

	.suspend	= kszphy_suspend,

	.resume		= kszphy_resume,

	.cable_test_start	= ksz886x_cable_test_start,

	.cable_test_get_status	= ksz886x_cable_test_get_status,

}, {

	.phy_id		= PHY_ID_KSZ8061,

	.name		= "Micrel KSZ8061",
@@ -1571,11 +1748,14 @@ static struct phy_driver ksphy_driver[] = { 
	.phy_id_mask	= MICREL_PHY_ID_MASK,

	.name		= "Micrel KSZ8851 Ethernet MAC or KSZ886X Switch",

	/* PHY_BASIC_FEATURES */

	.flags		= PHY_POLL_CABLE_TEST,

	.config_init	= kszphy_config_init,

	.config_aneg	= ksz886x_config_aneg,

	.read_status	= ksz886x_read_status,

	.suspend	= genphy_suspend,

	.resume		= genphy_resume,

	.cable_test_start	= ksz886x_cable_test_start,

	.cable_test_get_status	= ksz886x_cable_test_get_status,

}, {

	.name		= "Micrel KSZ87XX Switch",

	/* PHY_BASIC_FEATURES */

include/linux/micrel_phy.h

+1 −0
Original line number Diff line number Diff line
@@ -39,6 +39,7 @@ 
/* struct phy_device dev_flags definitions */

#define MICREL_PHY_50MHZ_CLK	0x00000001

#define MICREL_PHY_FXEN		0x00000002

#define MICREL_KSZ8_P1_ERRATA	0x00000003



#define MICREL_KSZ9021_EXTREG_CTRL	0xB

#define MICREL_KSZ9021_EXTREG_DATA_WRITE	0xC