diff --git a/MAINTAINERS b/MAINTAINERS
index 9479f77afb8e0abf625c9c3fdf1316daed87019c..9688a27deef19581756a8cc672ab2bae7707299a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -878,6 +878,13 @@ L: netdev@vger.kernel.org
S: Maintained
F: drivers/net/ethernet/altera/
+ALTERA TSE PCS
+M: Maxime Chevallier <maxime.chevallier@bootlin.com>
+L: netdev@vger.kernel.org
+S: Supported
+F: drivers/net/pcs/pcs-altera-tse.c
+F: include/linux/pcs-altera-tse.h
+
ALTERA UART/JTAG UART SERIAL DRIVERS
M: Tobias Klauser <tklauser@distanz.ch>
L: linux-serial@vger.kernel.org
diff --git a/drivers/net/pcs/Kconfig b/drivers/net/pcs/Kconfig
index 6289b7c765f13be49f4903ad3811b8d094f4725d..6e7e6c346a3ec551c91cf889b2902b7ef922d5a5 100644
--- a/drivers/net/pcs/Kconfig
+++ b/drivers/net/pcs/Kconfig
@@ -26,4 +26,10 @@ config PCS_RZN1_MIIC
on RZ/N1 SoCs. This PCS converts MII to RMII/RGMII or can be set in
pass-through mode for MII.
+config PCS_ALTERA_TSE
+ tristate
+ help
+ This module provides helper functions for the Altera Triple Speed
+ Ethernet SGMII PCS, that can be found on the Intel Socfpga family.
+
endmenu
diff --git a/drivers/net/pcs/Makefile b/drivers/net/pcs/Makefile
index 0ff5388fcdeaf8f61457fc1dbc2eee90eba34c13..4c780d8f2e98453943329cf4277c4370759caacc 100644
--- a/drivers/net/pcs/Makefile
+++ b/drivers/net/pcs/Makefile
@@ -6,3 +6,4 @@ pcs_xpcs-$(CONFIG_PCS_XPCS) := pcs-xpcs.o pcs-xpcs-nxp.o
obj-$(CONFIG_PCS_XPCS) += pcs_xpcs.o
obj-$(CONFIG_PCS_LYNX) += pcs-lynx.o
obj-$(CONFIG_PCS_RZN1_MIIC) += pcs-rzn1-miic.o
+obj-$(CONFIG_PCS_ALTERA_TSE) += pcs-altera-tse.o
diff --git a/drivers/net/pcs/pcs-altera-tse.c b/drivers/net/pcs/pcs-altera-tse.c
new file mode 100644
index 0000000000000000000000000000000000000000..97a7cabff962a4db891c148a20ed77e5589a7775
--- /dev/null
+++ b/drivers/net/pcs/pcs-altera-tse.c
@@ -0,0 +1,175 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2022 Bootlin
+ *
+ * Maxime Chevallier <maxime.chevallier@bootlin.com>
+ */
+
+#include <linux/netdevice.h>
+#include <linux/phy.h>
+#include <linux/phylink.h>
+#include <linux/pcs-altera-tse.h>
+
+/* SGMII PCS register addresses
+ */
+#define SGMII_PCS_SCRATCH 0x10
+#define SGMII_PCS_REV 0x11
+#define SGMII_PCS_LINK_TIMER_0 0x12
+#define SGMII_PCS_LINK_TIMER_REG(x) (0x12 + (x))
+#define SGMII_PCS_LINK_TIMER_1 0x13
+#define SGMII_PCS_IF_MODE 0x14
+#define PCS_IF_MODE_SGMII_ENA BIT(0)
+#define PCS_IF_MODE_USE_SGMII_AN BIT(1)
+#define PCS_IF_MODE_SGMI_SPEED_MASK GENMASK(3, 2)
+#define PCS_IF_MODE_SGMI_SPEED_10 (0 << 2)
+#define PCS_IF_MODE_SGMI_SPEED_100 (1 << 2)
+#define PCS_IF_MODE_SGMI_SPEED_1000 (2 << 2)
+#define PCS_IF_MODE_SGMI_HALF_DUPLEX BIT(4)
+#define PCS_IF_MODE_SGMI_PHY_AN BIT(5)
+#define SGMII_PCS_DIS_READ_TO 0x15
+#define SGMII_PCS_READ_TO 0x16
+#define SGMII_PCS_SW_RESET_TIMEOUT 100 /* usecs */
+
+struct altera_tse_pcs {
+ struct phylink_pcs pcs;
+ void __iomem *base;
+ int reg_width;
+};
+
+static struct altera_tse_pcs *phylink_pcs_to_tse_pcs(struct phylink_pcs *pcs)
+{
+ return container_of(pcs, struct altera_tse_pcs, pcs);
+}
+
+static u16 tse_pcs_read(struct altera_tse_pcs *tse_pcs, int regnum)
+{
+ if (tse_pcs->reg_width == 4)
+ return readl(tse_pcs->base + regnum * 4);
+ else
+ return readw(tse_pcs->base + regnum * 2);
+}
+
+static void tse_pcs_write(struct altera_tse_pcs *tse_pcs, int regnum,
+ u16 value)
+{
+ if (tse_pcs->reg_width == 4)
+ writel(value, tse_pcs->base + regnum * 4);
+ else
+ writew(value, tse_pcs->base + regnum * 2);
+}
+
+static int tse_pcs_reset(struct altera_tse_pcs *tse_pcs)
+{
+ int i = 0;
+ u16 bmcr;
+
+ /* Reset PCS block */
+ bmcr = tse_pcs_read(tse_pcs, MII_BMCR);
+ bmcr |= BMCR_RESET;
+ tse_pcs_write(tse_pcs, MII_BMCR, bmcr);
+
+ for (i = 0; i < SGMII_PCS_SW_RESET_TIMEOUT; i++) {
+ if (!(tse_pcs_read(tse_pcs, MII_BMCR) & BMCR_RESET))
+ return 0;
+ udelay(1);
+ }
+
+ return -ETIMEDOUT;
+}
+
+static int alt_tse_pcs_validate(struct phylink_pcs *pcs,
+ unsigned long *supported,
+ const struct phylink_link_state *state)
+{
+ if (state->interface == PHY_INTERFACE_MODE_SGMII ||
+ state->interface == PHY_INTERFACE_MODE_1000BASEX)
+ return 1;
+
+ return -EINVAL;
+}
+
+static int alt_tse_pcs_config(struct phylink_pcs *pcs, unsigned int mode,
+ phy_interface_t interface,
+ const unsigned long *advertising,
+ bool permit_pause_to_mac)
+{
+ struct altera_tse_pcs *tse_pcs = phylink_pcs_to_tse_pcs(pcs);
+ u32 ctrl, if_mode;
+
+ ctrl = tse_pcs_read(tse_pcs, MII_BMCR);
+ if_mode = tse_pcs_read(tse_pcs, SGMII_PCS_IF_MODE);
+
+ /* Set link timer to 1.6ms, as per the MegaCore Function User Guide */
+ tse_pcs_write(tse_pcs, SGMII_PCS_LINK_TIMER_0, 0x0D40);
+ tse_pcs_write(tse_pcs, SGMII_PCS_LINK_TIMER_1, 0x03);
+
+ if (interface == PHY_INTERFACE_MODE_SGMII) {
+ if_mode |= PCS_IF_MODE_USE_SGMII_AN | PCS_IF_MODE_SGMII_ENA;
+ } else if (interface == PHY_INTERFACE_MODE_1000BASEX) {
+ if_mode &= ~(PCS_IF_MODE_USE_SGMII_AN | PCS_IF_MODE_SGMII_ENA);
+ if_mode |= PCS_IF_MODE_SGMI_SPEED_1000;
+ }
+
+ ctrl |= (BMCR_SPEED1000 | BMCR_FULLDPLX | BMCR_ANENABLE);
+
+ tse_pcs_write(tse_pcs, MII_BMCR, ctrl);
+ tse_pcs_write(tse_pcs, SGMII_PCS_IF_MODE, if_mode);
+
+ return tse_pcs_reset(tse_pcs);
+}
+
+static void alt_tse_pcs_get_state(struct phylink_pcs *pcs,
+ struct phylink_link_state *state)
+{
+ struct altera_tse_pcs *tse_pcs = phylink_pcs_to_tse_pcs(pcs);
+ u16 bmsr, lpa;
+
+ bmsr = tse_pcs_read(tse_pcs, MII_BMSR);
+ lpa = tse_pcs_read(tse_pcs, MII_LPA);
+
+ phylink_mii_c22_pcs_decode_state(state, bmsr, lpa);
+}
+
+static void alt_tse_pcs_an_restart(struct phylink_pcs *pcs)
+{
+ struct altera_tse_pcs *tse_pcs = phylink_pcs_to_tse_pcs(pcs);
+ u16 bmcr;
+
+ bmcr = tse_pcs_read(tse_pcs, MII_BMCR);
+ bmcr |= BMCR_ANRESTART;
+ tse_pcs_write(tse_pcs, MII_BMCR, bmcr);
+
+ /* This PCS seems to require a soft reset to re-sync the AN logic */
+ tse_pcs_reset(tse_pcs);
+}
+
+static const struct phylink_pcs_ops alt_tse_pcs_ops = {
+ .pcs_validate = alt_tse_pcs_validate,
+ .pcs_get_state = alt_tse_pcs_get_state,
+ .pcs_config = alt_tse_pcs_config,
+ .pcs_an_restart = alt_tse_pcs_an_restart,
+};
+
+struct phylink_pcs *alt_tse_pcs_create(struct net_device *ndev,
+ void __iomem *pcs_base, int reg_width)
+{
+ struct altera_tse_pcs *tse_pcs;
+
+ if (reg_width != 4 && reg_width != 2)
+ return ERR_PTR(-EINVAL);
+
+ tse_pcs = devm_kzalloc(&ndev->dev, sizeof(*tse_pcs), GFP_KERNEL);
+ if (!tse_pcs)
+ return ERR_PTR(-ENOMEM);
+
+ tse_pcs->pcs.ops = &alt_tse_pcs_ops;
+ tse_pcs->base = pcs_base;
+ tse_pcs->reg_width = reg_width;
+
+ return &tse_pcs->pcs;
+}
+EXPORT_SYMBOL_GPL(alt_tse_pcs_create);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Altera TSE PCS driver");
+MODULE_AUTHOR("Maxime Chevallier <maxime.chevallier@bootlin.com>");
diff --git a/include/linux/pcs-altera-tse.h b/include/linux/pcs-altera-tse.h
new file mode 100644
index 0000000000000000000000000000000000000000..92ab9f08e8359b194641936a239e798b498d238b
--- /dev/null
+++ b/include/linux/pcs-altera-tse.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2022 Bootlin
+ *
+ * Maxime Chevallier <maxime.chevallier@bootlin.com>
+ */
+
+#ifndef __LINUX_PCS_ALTERA_TSE_H
+#define __LINUX_PCS_ALTERA_TSE_H
+
+struct phylink_pcs;
+struct net_device;
+
+struct phylink_pcs *alt_tse_pcs_create(struct net_device *ndev,
+ void __iomem *pcs_base, int reg_width);
+
+#endif /* __LINUX_PCS_ALTERA_TSE_H */