Commit 36efaca9 authored by Tarun Alle's avatar Tarun Alle Committed by Jakub Kicinski
Browse files

net: phy: microchip_t1: SQI support for LAN887x 



Add support for measuring Signal Quality Index for LAN887x T1 PHY.
Signal Quality Index (SQI) is measure of Link Channel Quality from
0 to 7, with 7 as the best. By default, a link loss event shall
indicate an SQI of 0.

Signed-off-by: default avatarTarun Alle <Tarun.Alle@microchip.com>
Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20241007063943.3233-1-tarun.alle@microchip.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 3a04f871

drivers/net/phy/microchip_t1.c

+171 −0
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ 
#include <linux/delay.h>

#include <linux/mii.h>

#include <linux/phy.h>

#include <linux/sort.h>

#include <linux/ethtool.h>

#include <linux/ethtool_netlink.h>

#include <linux/bitfield.h>
@@ -238,6 +239,35 @@ 
#define LAN887X_MX_CHIP_TOP_ALL_MSK	(LAN887X_INT_MSK_T1_PHY_INT_MSK |\

					 LAN887X_MX_CHIP_TOP_LINK_MSK)



#define LAN887X_COEFF_PWR_DN_CONFIG_100		0x0404

#define LAN887X_COEFF_PWR_DN_CONFIG_100_V	0x16d6

#define LAN887X_SQI_CONFIG_100			0x042e

#define LAN887X_SQI_CONFIG_100_V		0x9572

#define LAN887X_SQI_MSE_100			0x483



#define LAN887X_POKE_PEEK_100			0x040d

#define LAN887X_POKE_PEEK_100_EN		BIT(0)



#define LAN887X_COEFF_MOD_CONFIG		0x080d

#define LAN887X_COEFF_MOD_CONFIG_DCQ_COEFF_EN	BIT(8)



#define LAN887X_DCQ_SQI_STATUS			0x08b2



/* SQI raw samples count */

#define SQI_SAMPLES 200



/* Samples percentage considered for SQI calculation */

#define SQI_INLINERS_PERCENT 60



/* Samples count considered for SQI calculation */

#define SQI_INLIERS_NUM (SQI_SAMPLES * SQI_INLINERS_PERCENT / 100)



/* Start offset of samples */

#define SQI_INLIERS_START ((SQI_SAMPLES - SQI_INLIERS_NUM) / 2)



/* End offset of samples */

#define SQI_INLIERS_END (SQI_INLIERS_START + SQI_INLIERS_NUM)



#define DRIVER_AUTHOR	"Nisar Sayed <nisar.sayed@microchip.com>"

#define DRIVER_DESC	"Microchip LAN87XX/LAN937x/LAN887x T1 PHY driver"
@@ -1889,6 +1919,145 @@ static int lan887x_cable_test_get_status(struct phy_device *phydev, 
	return lan887x_cable_test_report(phydev);

}



/* Compare block to sort in ascending order */

static int sqi_compare(const void *a, const void *b)

{

	return  *(u16 *)a - *(u16 *)b;

}



static int lan887x_get_sqi_100M(struct phy_device *phydev)

{

	u16 rawtable[SQI_SAMPLES];

	u32 sqiavg = 0;

	u8 sqinum = 0;

	int rc, i;



	/* Configuration of SQI 100M */

	rc = phy_write_mmd(phydev, MDIO_MMD_VEND1,

			   LAN887X_COEFF_PWR_DN_CONFIG_100,

			   LAN887X_COEFF_PWR_DN_CONFIG_100_V);

	if (rc < 0)

		return rc;



	rc = phy_write_mmd(phydev, MDIO_MMD_VEND1, LAN887X_SQI_CONFIG_100,

			   LAN887X_SQI_CONFIG_100_V);

	if (rc < 0)

		return rc;



	rc = phy_read_mmd(phydev, MDIO_MMD_VEND1, LAN887X_SQI_CONFIG_100);

	if (rc != LAN887X_SQI_CONFIG_100_V)

		return -EINVAL;



	rc = phy_modify_mmd(phydev, MDIO_MMD_VEND1, LAN887X_POKE_PEEK_100,

			    LAN887X_POKE_PEEK_100_EN,

			    LAN887X_POKE_PEEK_100_EN);

	if (rc < 0)

		return rc;



	/* Required before reading register

	 * otherwise it will return high value

	 */

	msleep(50);



	/* Link check before raw readings */

	rc = genphy_c45_read_link(phydev);

	if (rc < 0)

		return rc;



	if (!phydev->link)

		return -ENETDOWN;



	/* Get 200 SQI raw readings */

	for (i = 0; i < SQI_SAMPLES; i++) {

		rc = phy_write_mmd(phydev, MDIO_MMD_VEND1,

				   LAN887X_POKE_PEEK_100,

				   LAN887X_POKE_PEEK_100_EN);

		if (rc < 0)

			return rc;



		rc = phy_read_mmd(phydev, MDIO_MMD_VEND1,

				  LAN887X_SQI_MSE_100);

		if (rc < 0)

			return rc;



		rawtable[i] = (u16)rc;

	}



	/* Link check after raw readings */

	rc = genphy_c45_read_link(phydev);

	if (rc < 0)

		return rc;



	if (!phydev->link)

		return -ENETDOWN;



	/* Sort SQI raw readings in ascending order */

	sort(rawtable, SQI_SAMPLES, sizeof(u16), sqi_compare, NULL);



	/* Keep inliers and discard outliers */

	for (i = SQI_INLIERS_START; i < SQI_INLIERS_END; i++)

		sqiavg += rawtable[i];



	/* Handle invalid samples */

	if (sqiavg != 0) {

		/* Get SQI average */

		sqiavg /= SQI_INLIERS_NUM;



		if (sqiavg < 75)

			sqinum = 7;

		else if (sqiavg < 94)

			sqinum = 6;

		else if (sqiavg < 119)

			sqinum = 5;

		else if (sqiavg < 150)

			sqinum = 4;

		else if (sqiavg < 189)

			sqinum = 3;

		else if (sqiavg < 237)

			sqinum = 2;

		else if (sqiavg < 299)

			sqinum = 1;

		else

			sqinum = 0;

	}



	return sqinum;

}



static int lan887x_get_sqi(struct phy_device *phydev)

{

	int rc, val;



	if (phydev->speed != SPEED_1000 &&

	    phydev->speed != SPEED_100)

		return -ENETDOWN;



	if (phydev->speed == SPEED_100)

		return lan887x_get_sqi_100M(phydev);



	/* Writing DCQ_COEFF_EN to trigger a SQI read */

	rc = phy_set_bits_mmd(phydev, MDIO_MMD_VEND1,

			      LAN887X_COEFF_MOD_CONFIG,

			      LAN887X_COEFF_MOD_CONFIG_DCQ_COEFF_EN);

	if (rc < 0)

		return rc;



	/* Wait for DCQ done */

	rc = phy_read_mmd_poll_timeout(phydev, MDIO_MMD_VEND1,

				       LAN887X_COEFF_MOD_CONFIG, val, ((val &

				       LAN887X_COEFF_MOD_CONFIG_DCQ_COEFF_EN) !=

				       LAN887X_COEFF_MOD_CONFIG_DCQ_COEFF_EN),

				       10, 200, true);

	if (rc < 0)

		return rc;



	rc = phy_read_mmd(phydev, MDIO_MMD_VEND1, LAN887X_DCQ_SQI_STATUS);

	if (rc < 0)

		return rc;



	return FIELD_GET(T1_DCQ_SQI_MSK, rc);

}



static struct phy_driver microchip_t1_phy_driver[] = {

	{

		PHY_ID_MATCH_MODEL(PHY_ID_LAN87XX),
@@ -1942,6 +2111,8 @@ static struct phy_driver microchip_t1_phy_driver[] = { 
		.cable_test_get_status = lan887x_cable_test_get_status,

		.config_intr    = lan887x_config_intr,

		.handle_interrupt = lan887x_handle_interrupt,

		.get_sqi	= lan887x_get_sqi,

		.get_sqi_max	= lan87xx_get_sqi_max,

	}

};