[PATCH net-next v3 1/2] net: stmmac: enable 2.5Gbps link speed

Michael Sit Wei Hong
2021-03-25T08:44:16Z

From: Voon Weifeng <weifeng.voon@intel.com>

The MAC support 2.5G mode when the PCS is in 1000BASE-T mode. The
2.5G mode of operation is functionally same as 1000BASE-T mode,
except that the clock rate is 2.5 times the original rate.
In this mode, the serdes/PHY operates at a serial baud rate of
3.125 Gbps and the PCS data path and GMII interface of the MAC
operate at 312.5 MHz instead of 125 MHz.

The MAC running in 10M/100M/1G mode or 2.5G mode depends on
the link speed mode in the serdes.

Signed-off-by: Voon Weifeng <weifeng.voon@intel.com>
Signed-off-by: Michael Sit Wei Hong <michael.wei.hong.sit@intel.com>
---
.../net/ethernet/stmicro/stmmac/dwmac-intel.c | 44 ++++++++++++++++++-
.../net/ethernet/stmicro/stmmac/dwmac-intel.h | 13 ++++++
.../net/ethernet/stmicro/stmmac/dwmac4_core.c | 1 +
.../net/ethernet/stmicro/stmmac/stmmac_main.c | 35 ++++++++++++++-
include/linux/stmmac.h | 2 +
5 files changed, 92 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c
index 8e4dbfdca237..750e7b7c554e 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c
@@ -96,6 +96,22 @@ static int intel_serdes_powerup(struct net_device *ndev, void *priv_data)

serdes_phy_addr = intel_priv->mdio_adhoc_addr;

+ /* Set the serdes rate and the PCLK rate */
+ data = mdiobus_read(priv->mii, serdes_phy_addr,
+ SERDES_GCR0);
+
+ data &= ~SERDES_RATE_MASK;
+ data &= ~SERDES_PCLK_MASK;
+
+ if (priv->plat->speed_2500_en)
+ data |= SERDES_RATE_PCIE_GEN2 << SERDES_RATE_PCIE_SHIFT |
+ SERDES_PCLK_37p5MHZ << SERDES_PCLK_SHIFT;
+ else
+ data |= SERDES_RATE_PCIE_GEN1 << SERDES_RATE_PCIE_SHIFT |
+ SERDES_PCLK_70MHZ << SERDES_PCLK_SHIFT;
+
+ mdiobus_write(priv->mii, serdes_phy_addr, SERDES_GCR0, data);
+
/* assert clk_req */
data = mdiobus_read(priv->mii, serdes_phy_addr, SERDES_GCR0);
data |= SERDES_PLL_CLK;
@@ -214,6 +230,28 @@ static void intel_serdes_powerdown(struct net_device *ndev, void *intel_data)
}
}

+static bool intel_speed_mode_2500(struct net_device *ndev, void *intel_data)
+{
+ struct intel_priv_data *intel_priv = intel_data;
+ struct stmmac_priv *priv = netdev_priv(ndev);
+ int serdes_phy_addr = 0;
+ u32 data = 0;
+
+ serdes_phy_addr = intel_priv->mdio_adhoc_addr;
+
+ /* Determine the link speed mode: 2.5Gbps/1Gbps */
+ data = mdiobus_read(priv->mii, serdes_phy_addr,
+ SERDES_GCR);
+
+ if (((data & SERDES_LINK_MODE_MASK) >> SERDES_LINK_MODE_SHIFT) ==
+ SERDES_LINK_MODE_2G5) {
+ dev_info(priv->device, "Link Speed Mode: 2.5Gbps\n");
+ return true;
+ } else {
+ return false;
+ }
+}
+
/* Program PTP Clock Frequency for different variant of
* Intel mGBE that has slightly different GPO mapping
*/
@@ -405,7 +443,7 @@ static int ehl_sgmii_data(struct pci_dev *pdev,
{
plat->bus_id = 1;
plat->phy_interface = PHY_INTERFACE_MODE_SGMII;
-
+ plat->speed_mode_2500 = intel_speed_mode_2500;
plat->serdes_powerup = intel_serdes_powerup;
plat->serdes_powerdown = intel_serdes_powerdown;

@@ -456,6 +494,7 @@ static int ehl_pse0_sgmii1g_data(struct pci_dev *pdev,
struct plat_stmmacenet_data *plat)
{
plat->phy_interface = PHY_INTERFACE_MODE_SGMII;
+ plat->speed_mode_2500 = intel_speed_mode_2500;
plat->serdes_powerup = intel_serdes_powerup;
plat->serdes_powerdown = intel_serdes_powerdown;
return ehl_pse0_common_data(pdev, plat);
@@ -492,6 +531,7 @@ static int ehl_pse1_sgmii1g_data(struct pci_dev *pdev,
struct plat_stmmacenet_data *plat)
{
plat->phy_interface = PHY_INTERFACE_MODE_SGMII;
+ plat->speed_mode_2500 = intel_speed_mode_2500;
plat->serdes_powerup = intel_serdes_powerup;
plat->serdes_powerdown = intel_serdes_powerdown;
return ehl_pse1_common_data(pdev, plat);
@@ -516,6 +556,7 @@ static int tgl_sgmii_phy0_data(struct pci_dev *pdev,
{
plat->bus_id = 1;
plat->phy_interface = PHY_INTERFACE_MODE_SGMII;
+ plat->speed_mode_2500 = intel_speed_mode_2500;
plat->serdes_powerup = intel_serdes_powerup;
plat->serdes_powerdown = intel_serdes_powerdown;
return tgl_common_data(pdev, plat);
@@ -530,6 +571,7 @@ static int tgl_sgmii_phy1_data(struct pci_dev *pdev,
{
plat->bus_id = 2;
plat->phy_interface = PHY_INTERFACE_MODE_SGMII;
+ plat->speed_mode_2500 = intel_speed_mode_2500;
plat->serdes_powerup = intel_serdes_powerup;
plat->serdes_powerdown = intel_serdes_powerdown;
return tgl_common_data(pdev, plat);
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.h b/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.h
index e723096c0b15..021a5c178d97 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.h
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.h
@@ -9,6 +9,7 @@
#define POLL_DELAY_US 8

/* SERDES Register */
+#define SERDES_GCR 0x0 /* Global Conguration */
#define SERDES_GSR0 0x5 /* Global Status Reg0 */
#define SERDES_GCR0 0xb /* Global Configuration Reg0 */

@@ -16,8 +17,20 @@
#define SERDES_PLL_CLK BIT(0) /* PLL clk valid signal */
#define SERDES_RST BIT(2) /* Serdes Reset */
#define SERDES_PWR_ST_MASK GENMASK(6, 4) /* Serdes Power state*/
+#define SERDES_RATE_MASK GENMASK(9, 8)
+#define SERDES_PCLK_MASK GENMASK(14, 12) /* PCLK rate to PHY */
+#define SERDES_LINK_MODE_MASK GENMASK(2, 1)
+#define SERDES_LINK_MODE_SHIFT 1
#define SERDES_PWR_ST_SHIFT 4
#define SERDES_PWR_ST_P0 0x0
#define SERDES_PWR_ST_P3 0x3
+#define SERDES_LINK_MODE_2G5 0x3
+#define SERSED_LINK_MODE_1G 0x2
+#define SERDES_PCLK_37p5MHZ 0x0
+#define SERDES_PCLK_70MHZ 0x1
+#define SERDES_RATE_PCIE_GEN1 0x0
+#define SERDES_RATE_PCIE_GEN2 0x1
+#define SERDES_RATE_PCIE_SHIFT 8
+#define SERDES_PCLK_SHIFT 12

#endif /* __DWMAC_INTEL_H__ */
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
index 29f765a246a0..cbfc4de7e9a3 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
@@ -1349,6 +1349,7 @@ int dwmac4_setup(struct stmmac_priv *priv)
mac->link.speed10 = GMAC_CONFIG_PS;
mac->link.speed100 = GMAC_CONFIG_FES | GMAC_CONFIG_PS;
mac->link.speed1000 = 0;
+ mac->link.speed2500 = GMAC_CONFIG_FES;
mac->link.speed_mask = GMAC_CONFIG_FES | GMAC_CONFIG_PS;
mac->mii.addr = GMAC_MDIO_ADDR;
mac->mii.data = GMAC_MDIO_DATA;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index c89f0421bfdb..df582ad7892a 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -877,6 +877,25 @@ static void stmmac_validate(struct phylink_config *config,
phylink_set(mac_supported, Asym_Pause);
phylink_set_port_modes(mac_supported);

+ if (priv->plat->has_gmac ||
+ priv->plat->has_gmac4 ||
+ priv->plat->has_xgmac) {
+ phylink_set(mac_supported, 1000baseT_Half);
+ phylink_set(mac_supported, 1000baseT_Full);
+ phylink_set(mac_supported, 1000baseKX_Full);
+ }
+
+ /* 2.5G mode only support 2500baseT full duplex only */
+ if (priv->plat->has_gmac4 && priv->plat->speed_2500_en) {
+ phylink_set(mac_supported, 2500baseT_Full);
+ phylink_set(mask, 10baseT_Half);
+ phylink_set(mask, 10baseT_Full);
+ phylink_set(mask, 100baseT_Half);
+ phylink_set(mask, 100baseT_Full);
+ phylink_set(mask, 1000baseT_Half);
+ phylink_set(mask, 1000baseT_Full);
+ }
+
/* Cut down 1G if asked to */
if ((max_speed > 0) && (max_speed < 1000)) {
phylink_set(mask, 1000baseT_Full);
@@ -1166,8 +1185,14 @@ static int stmmac_phy_setup(struct stmmac_priv *priv)
priv->phylink_config.dev = &priv->dev->dev;
priv->phylink_config.type = PHYLINK_NETDEV;
priv->phylink_config.pcs_poll = true;
- priv->phylink_config.ovr_an_inband =
- priv->plat->mdio_bus_data->xpcs_an_inband;
+ /* For 2.5G, we do not use SGMII in-band AN */
+ if (priv->plat->speed_2500_en) {
+ priv->phylink_config.ovr_an_inband = false;
+ } else {
+ priv->phylink_config.ovr_an_inband =
+ priv->plat->mdio_bus_data->xpcs_an_inband;
+ }
+

if (!fwnode)
fwnode = dev_fwnode(priv->device);
@@ -5284,6 +5309,12 @@ int stmmac_dvr_probe(struct device *device,
}
}

+ if (priv->plat->speed_mode_2500) {
+ priv->plat->speed_2500_en = priv->plat->speed_mode_2500(ndev,
+ priv->plat->bsp_priv);
+ priv->hw->xpcs_args.speed_2500_en = priv->plat->speed_2500_en;
+ }
+
ret = stmmac_phy_setup(priv);
if (ret) {
netdev_err(ndev, "failed to setup phy (%d)\n", ret);
diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
index bf73982f92b3..d68805a57eb4 100644
--- a/include/linux/stmmac.h
+++ b/include/linux/stmmac.h
@@ -182,6 +182,7 @@ struct plat_stmmacenet_data {
void (*fix_mac_speed)(void *priv, unsigned int speed);
int (*serdes_powerup)(struct net_device *ndev, void *priv);
void (*serdes_powerdown)(struct net_device *ndev, void *priv);
+ bool (*speed_mode_2500)(struct net_device *ndev, void *priv);
void (*ptp_clk_freq_config)(void *priv);
int (*init)(struct platform_device *pdev, void *priv);
void (*exit)(struct platform_device *pdev, void *priv);
@@ -205,6 +206,7 @@ struct plat_stmmacenet_data {
int has_xgmac;
bool vlan_fail_q_en;
u8 vlan_fail_q;
+ bool speed_2500_en;
unsigned int eee_usecs_rate;
struct pci_dev *pdev;
bool has_safety_feat;
--
2.17.1