Commit 58389c00 authored by Marek Vasut's avatar Marek Vasut Committed by Jakub Kicinski
Browse files

net: phy: micrel: ksz9031/ksz9131: add cabletest support 



Add cable test support for Micrel KSZ9x31 PHYs.

Tested on i.MX8M Mini with KSZ9131RNX in 100/Full mode with pairs shuffled
before magnetics:
(note: Cable test started/completed messages are omitted)

  mx8mm-ksz9131-a-d-connected$ ethtool --cable-test eth0
  Pair A code OK
  Pair B code Short within Pair
  Pair B, fault length: 0.80m
  Pair C code Short within Pair
  Pair C, fault length: 0.80m
  Pair D code OK

  mx8mm-ksz9131-a-b-connected$ ethtool --cable-test eth0
  Pair A code OK
  Pair B code OK
  Pair C code Short within Pair
  Pair C, fault length: 0.00m
  Pair D code Short within Pair
  Pair D, fault length: 0.00m

Tested on R8A77951 Salvator-XS with KSZ9031RNX and all four pairs connected:
(note: Cable test started/completed messages are omitted)

  r8a7795-ksz9031-all-connected$ ethtool --cable-test eth0
  Pair A code OK
  Pair B code OK
  Pair C code OK
  Pair D code OK

The CTRL1000 CTL1000_ENABLE_MASTER and CTL1000_AS_MASTER bits are not
restored by calling phy_init_hw(), they must be manually cached in
ksz9x31_cable_test_start() and restored at the end of
ksz9x31_cable_test_get_status().

Signed-off-by: default avatarMarek Vasut <marex@denx.de>
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Cc: Oleksij Rempel <linux@rempel-privat.de>
Cc: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
Tested-by: default avatarClaudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220407105534.85833-1-marex@denx.de


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 85b15c26

drivers/net/phy/micrel.c

+221 −0
Original line number Diff line number Diff line
@@ -70,6 +70,27 @@ 
#define KSZ8081_LMD_SHORT_INDICATOR		BIT(12)

#define KSZ8081_LMD_DELTA_TIME_MASK		GENMASK(8, 0)



#define KSZ9x31_LMD				0x12

#define KSZ9x31_LMD_VCT_EN			BIT(15)

#define KSZ9x31_LMD_VCT_DIS_TX			BIT(14)

#define KSZ9x31_LMD_VCT_PAIR(n)			(((n) & 0x3) << 12)

#define KSZ9x31_LMD_VCT_SEL_RESULT		0

#define KSZ9x31_LMD_VCT_SEL_THRES_HI		BIT(10)

#define KSZ9x31_LMD_VCT_SEL_THRES_LO		BIT(11)

#define KSZ9x31_LMD_VCT_SEL_MASK		GENMASK(11, 10)

#define KSZ9x31_LMD_VCT_ST_NORMAL		0

#define KSZ9x31_LMD_VCT_ST_OPEN			1

#define KSZ9x31_LMD_VCT_ST_SHORT		2

#define KSZ9x31_LMD_VCT_ST_FAIL			3

#define KSZ9x31_LMD_VCT_ST_MASK			GENMASK(9, 8)

#define KSZ9x31_LMD_VCT_DATA_REFLECTED_INVALID	BIT(7)

#define KSZ9x31_LMD_VCT_DATA_SIG_WAIT_TOO_LONG	BIT(6)

#define KSZ9x31_LMD_VCT_DATA_MASK100		BIT(5)

#define KSZ9x31_LMD_VCT_DATA_NLP_FLP		BIT(4)

#define KSZ9x31_LMD_VCT_DATA_LO_PULSE_MASK	GENMASK(3, 2)

#define KSZ9x31_LMD_VCT_DATA_HI_PULSE_MASK	GENMASK(1, 0)

#define KSZ9x31_LMD_VCT_DATA_MASK		GENMASK(7, 0)



/* Lan8814 general Interrupt control/status reg in GPHY specific block. */

#define LAN8814_INTC				0x18

#define LAN8814_INTS				0x1B
@@ -280,6 +301,7 @@ struct kszphy_priv { 
	struct kszphy_ptp_priv ptp_priv;

	const struct kszphy_type *type;

	int led_mode;

	u16 vct_ctrl1000;

	bool rmii_ref_clk_sel;

	bool rmii_ref_clk_sel_val;

	u64 stats[ARRAY_SIZE(kszphy_hw_stats)];
@@ -1326,6 +1348,199 @@ static int ksz9031_read_status(struct phy_device *phydev) 
	return 0;

}



static int ksz9x31_cable_test_start(struct phy_device *phydev)

{

	struct kszphy_priv *priv = phydev->priv;

	int ret;



	/* KSZ9131RNX, DS00002841B-page 38, 4.14 LinkMD (R) Cable Diagnostic

	 * Prior to running the cable diagnostics, Auto-negotiation should

	 * be disabled, full duplex set and the link speed set to 1000Mbps

	 * via the Basic Control Register.

	 */

	ret = phy_modify(phydev, MII_BMCR,

			 BMCR_SPEED1000 | BMCR_FULLDPLX |

			 BMCR_ANENABLE | BMCR_SPEED100,

			 BMCR_SPEED1000 | BMCR_FULLDPLX);

	if (ret)

		return ret;



	/* KSZ9131RNX, DS00002841B-page 38, 4.14 LinkMD (R) Cable Diagnostic

	 * The Master-Slave configuration should be set to Slave by writing

	 * a value of 0x1000 to the Auto-Negotiation Master Slave Control

	 * Register.

	 */

	ret = phy_read(phydev, MII_CTRL1000);

	if (ret < 0)

		return ret;



	/* Cache these bits, they need to be restored once LinkMD finishes. */

	priv->vct_ctrl1000 = ret & (CTL1000_ENABLE_MASTER | CTL1000_AS_MASTER);

	ret &= ~(CTL1000_ENABLE_MASTER | CTL1000_AS_MASTER);

	ret |= CTL1000_ENABLE_MASTER;



	return phy_write(phydev, MII_CTRL1000, ret);

}



static int ksz9x31_cable_test_result_trans(u16 status)

{

	switch (FIELD_GET(KSZ9x31_LMD_VCT_ST_MASK, status)) {

	case KSZ9x31_LMD_VCT_ST_NORMAL:

		return ETHTOOL_A_CABLE_RESULT_CODE_OK;

	case KSZ9x31_LMD_VCT_ST_OPEN:

		return ETHTOOL_A_CABLE_RESULT_CODE_OPEN;

	case KSZ9x31_LMD_VCT_ST_SHORT:

		return ETHTOOL_A_CABLE_RESULT_CODE_SAME_SHORT;

	case KSZ9x31_LMD_VCT_ST_FAIL:

		fallthrough;

	default:

		return ETHTOOL_A_CABLE_RESULT_CODE_UNSPEC;

	}

}



static bool ksz9x31_cable_test_failed(u16 status)

{

	int stat = FIELD_GET(KSZ9x31_LMD_VCT_ST_MASK, status);



	return stat == KSZ9x31_LMD_VCT_ST_FAIL;

}



static bool ksz9x31_cable_test_fault_length_valid(u16 status)

{

	switch (FIELD_GET(KSZ9x31_LMD_VCT_ST_MASK, status)) {

	case KSZ9x31_LMD_VCT_ST_OPEN:

		fallthrough;

	case KSZ9x31_LMD_VCT_ST_SHORT:

		return true;

	}

	return false;

}



static int ksz9x31_cable_test_fault_length(struct phy_device *phydev, u16 stat)

{

	int dt = FIELD_GET(KSZ9x31_LMD_VCT_DATA_MASK, stat);



	/* KSZ9131RNX, DS00002841B-page 38, 4.14 LinkMD (R) Cable Diagnostic

	 *

	 * distance to fault = (VCT_DATA - 22) * 4 / cable propagation velocity

	 */

	if ((phydev->phy_id & MICREL_PHY_ID_MASK) == PHY_ID_KSZ9131)

		dt = clamp(dt - 22, 0, 255);



	return (dt * 400) / 10;

}



static int ksz9x31_cable_test_wait_for_completion(struct phy_device *phydev)

{

	int val, ret;



	ret = phy_read_poll_timeout(phydev, KSZ9x31_LMD, val,

				    !(val & KSZ9x31_LMD_VCT_EN),

				    30000, 100000, true);



	return ret < 0 ? ret : 0;

}



static int ksz9x31_cable_test_get_pair(int pair)

{

	static const int ethtool_pair[] = {

		ETHTOOL_A_CABLE_PAIR_A,

		ETHTOOL_A_CABLE_PAIR_B,

		ETHTOOL_A_CABLE_PAIR_C,

		ETHTOOL_A_CABLE_PAIR_D,

	};



	return ethtool_pair[pair];

}



static int ksz9x31_cable_test_one_pair(struct phy_device *phydev, int pair)

{

	int ret, val;



	/* KSZ9131RNX, DS00002841B-page 38, 4.14 LinkMD (R) Cable Diagnostic

	 * To test each individual cable pair, set the cable pair in the Cable

	 * Diagnostics Test Pair (VCT_PAIR[1:0]) field of the LinkMD Cable

	 * Diagnostic Register, along with setting the Cable Diagnostics Test

	 * Enable (VCT_EN) bit. The Cable Diagnostics Test Enable (VCT_EN) bit

	 * will self clear when the test is concluded.

	 */

	ret = phy_write(phydev, KSZ9x31_LMD,

			KSZ9x31_LMD_VCT_EN | KSZ9x31_LMD_VCT_PAIR(pair));

	if (ret)

		return ret;



	ret = ksz9x31_cable_test_wait_for_completion(phydev);

	if (ret)

		return ret;



	val = phy_read(phydev, KSZ9x31_LMD);

	if (val < 0)

		return val;



	if (ksz9x31_cable_test_failed(val))

		return -EAGAIN;



	ret = ethnl_cable_test_result(phydev,

				      ksz9x31_cable_test_get_pair(pair),

				      ksz9x31_cable_test_result_trans(val));

	if (ret)

		return ret;



	if (!ksz9x31_cable_test_fault_length_valid(val))

		return 0;



	return ethnl_cable_test_fault_length(phydev,

					     ksz9x31_cable_test_get_pair(pair),

					     ksz9x31_cable_test_fault_length(phydev, val));

}



static int ksz9x31_cable_test_get_status(struct phy_device *phydev,

					 bool *finished)

{

	struct kszphy_priv *priv = phydev->priv;

	unsigned long pair_mask = 0xf;

	int retries = 20;

	int pair, ret, rv;



	*finished = false;



	/* Try harder if link partner is active */

	while (pair_mask && retries--) {

		for_each_set_bit(pair, &pair_mask, 4) {

			ret = ksz9x31_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)

			usleep_range(2000, 3000);

	}



	/* Report remaining unfinished pair result as unknown. */

	for_each_set_bit(pair, &pair_mask, 4) {

		ret = ethnl_cable_test_result(phydev,

					      ksz9x31_cable_test_get_pair(pair),

					      ETHTOOL_A_CABLE_RESULT_CODE_UNSPEC);

	}



	*finished = true;



	/* Restore cached bits from before LinkMD got started. */

	rv = phy_modify(phydev, MII_CTRL1000,

			CTL1000_ENABLE_MASTER | CTL1000_AS_MASTER,

			priv->vct_ctrl1000);

	if (rv)

		return rv;



	return ret;

}



static int ksz8873mll_config_aneg(struct phy_device *phydev)

{

	return 0;
@@ -2806,6 +3021,7 @@ static struct phy_driver ksphy_driver[] = { 
	.phy_id		= PHY_ID_KSZ9031,

	.phy_id_mask	= MICREL_PHY_ID_MASK,

	.name		= "Micrel KSZ9031 Gigabit PHY",

	.flags		= PHY_POLL_CABLE_TEST,

	.driver_data	= &ksz9021_type,

	.probe		= kszphy_probe,

	.get_features	= ksz9031_get_features,
@@ -2819,6 +3035,8 @@ static struct phy_driver ksphy_driver[] = { 
	.get_stats	= kszphy_get_stats,

	.suspend	= kszphy_suspend,

	.resume		= kszphy_resume,

	.cable_test_start	= ksz9x31_cable_test_start,

	.cable_test_get_status	= ksz9x31_cable_test_get_status,

}, {

	.phy_id		= PHY_ID_LAN8814,

	.phy_id_mask	= MICREL_PHY_ID_MASK,
@@ -2853,6 +3071,7 @@ static struct phy_driver ksphy_driver[] = { 
	.phy_id_mask	= MICREL_PHY_ID_MASK,

	.name		= "Microchip KSZ9131 Gigabit PHY",

	/* PHY_GBIT_FEATURES */

	.flags		= PHY_POLL_CABLE_TEST,

	.driver_data	= &ksz9021_type,

	.probe		= kszphy_probe,

	.config_init	= ksz9131_config_init,
@@ -2863,6 +3082,8 @@ static struct phy_driver ksphy_driver[] = { 
	.get_stats	= kszphy_get_stats,

	.suspend	= kszphy_suspend,

	.resume		= kszphy_resume,

	.cable_test_start	= ksz9x31_cable_test_start,

	.cable_test_get_status	= ksz9x31_cable_test_get_status,

}, {

	.phy_id		= PHY_ID_KSZ8873MLL,

	.phy_id_mask	= MICREL_PHY_ID_MASK,