[PATCH net-next v5] net: phy: microchip_t1: SQI support for LAN887x
From: Tarun Alle
Date: Thu Oct 03 2024 - 12:26:51 EST
From: Tarun Alle <Tarun.Alle@xxxxxxxxxxxxx>
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: Tarun Alle <Tarun.Alle@xxxxxxxxxxxxx>
---
v4 -> v5
- Renamed and organised the macros of SQI samples.
v3 -> v4
- Added check to handle invalid samples.
- Added macro for ARRAY_SIZE(rawtable).
v2 -> v3
- Replaced hard-coded values with ARRAY_SIZE(rawtable).
v1 -> v2
- Replaced hard-coded 200 with ARRAY_SIZE(rawtable).
- Replaced return value -EINVAL with -ENETDOWN.
- Changed link checks.
---
drivers/net/phy/microchip_t1.c | 172 +++++++++++++++++++++++++++++++++
1 file changed, 172 insertions(+)
diff --git a/drivers/net/phy/microchip_t1.c b/drivers/net/phy/microchip_t1.c
index a5ef8fe50704..69e01692db65 100644
--- a/drivers/net/phy/microchip_t1.c
+++ b/drivers/net/phy/microchip_t1.c
@@ -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>
@@ -226,6 +227,35 @@
#define MICROCHIP_CABLE_MAX_TIME_DIFF \
(MICROCHIP_CABLE_MIN_TIME_DIFF + MICROCHIP_CABLE_TIME_MARGIN)
+#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@xxxxxxxxxxxxx>"
#define DRIVER_DESC "Microchip LAN87XX/LAN937x/LAN887x T1 PHY driver"
@@ -1830,6 +1860,146 @@ 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),
@@ -1881,6 +2051,8 @@ static struct phy_driver microchip_t1_phy_driver[] = {
.read_status = genphy_c45_read_status,
.cable_test_start = lan887x_cable_test_start,
.cable_test_get_status = lan887x_cable_test_get_status,
+ .get_sqi = lan887x_get_sqi,
+ .get_sqi_max = lan87xx_get_sqi_max,
}
};
--
2.34.1