11 files changed, 566 insertions, 1 deletions

diff --git a/drivers/net/ethernet/intel/ice/Makefile b/drivers/net/ethernet/intel/ice/Makefile
index 389fff70d22e..44b8464b7663 100644
--- a/drivers/net/ethernet/intel/ice/Makefile
+++ b/drivers/net/ethernet/intel/ice/Makefile
@@ -40,6 +40,7 @@ ice-$(CONFIG_PCI_IOV) +=	\
 	ice_vf_vsi_vlan_ops.o	\
 	ice_virtchnl_pf.o
 ice-$(CONFIG_PTP_1588_CLOCK) += ice_ptp.o ice_ptp_hw.o
+ice-$(CONFIG_TTY) += ice_gnss.o
 ice-$(CONFIG_DCB) += ice_dcb.o ice_dcb_nl.o ice_dcb_lib.o
 ice-$(CONFIG_RFS_ACCEL) += ice_arfs.o
 ice-$(CONFIG_XDP_SOCKETS) += ice_xsk.o
diff --git a/drivers/net/ethernet/intel/ice/ice.h b/drivers/net/ethernet/intel/ice/ice.h
index 737740c5e801..1ca1273a7cd3 100644
--- a/drivers/net/ethernet/intel/ice/ice.h
+++ b/drivers/net/ethernet/intel/ice/ice.h
@@ -73,6 +73,7 @@
 #include "ice_eswitch.h"
 #include "ice_lag.h"
 #include "ice_vsi_vlan_ops.h"
+#include "ice_gnss.h"
 
 #define ICE_BAR0		0
 #define ICE_REQ_DESC_MULTIPLE	32
@@ -184,6 +185,7 @@
 enum ice_feature {
 	ICE_F_DSCP,
 	ICE_F_SMA_CTRL,
+	ICE_F_GNSS,
 	ICE_F_MAX
 };
 
@@ -486,6 +488,7 @@ enum ice_pf_flags {
 	ICE_FLAG_VF_VLAN_PRUNING,
 	ICE_FLAG_LINK_LENIENT_MODE_ENA,
 	ICE_FLAG_PLUG_AUX_DEV,
+	ICE_FLAG_GNSS,			/* GNSS successfully initialized */
 	ICE_PF_FLAGS_NBITS		/* must be last */
 };
 
@@ -549,6 +552,9 @@ struct ice_pf {
 	struct mutex tc_mutex;		/* lock to protect TC changes */
 	u32 msg_enable;
 	struct ice_ptp ptp;
+	struct tty_driver *ice_gnss_tty_driver;
+	struct tty_port gnss_tty_port;
+	struct gnss_serial *gnss_serial;
 	u16 num_rdma_msix;		/* Total MSIX vectors for RDMA driver */
 	u16 rdma_base_vector;
 
diff --git a/drivers/net/ethernet/intel/ice/ice_adminq_cmd.h b/drivers/net/ethernet/intel/ice/ice_adminq_cmd.h
index fd8ee5b7f596..b25e27c4d887 100644
--- a/drivers/net/ethernet/intel/ice/ice_adminq_cmd.h
+++ b/drivers/net/ethernet/intel/ice/ice_adminq_cmd.h
@@ -1401,6 +1401,24 @@ struct ice_aqc_get_link_topo {
 	u8 rsvd[9];
 };
 
+/* Read I2C (direct, 0x06E2) */
+struct ice_aqc_i2c {
+	struct ice_aqc_link_topo_addr topo_addr;
+	__le16 i2c_addr;
+	u8 i2c_params;
+#define ICE_AQC_I2C_DATA_SIZE_M		GENMASK(3, 0)
+#define ICE_AQC_I2C_USE_REPEATED_START	BIT(7)
+
+	u8 rsvd;
+	__le16 i2c_bus_addr;
+	u8 rsvd2[4];
+};
+
+/* Read I2C Response (direct, 0x06E2) */
+struct ice_aqc_read_i2c_resp {
+	u8 i2c_data[16];
+};
+
 /* Set Port Identification LED (direct, 0x06E9) */
 struct ice_aqc_set_port_id_led {
 	u8 lport_num;
@@ -2112,6 +2130,8 @@ struct ice_aq_desc {
 		struct ice_aqc_get_link_status get_link_status;
 		struct ice_aqc_event_lan_overflow lan_overflow;
 		struct ice_aqc_get_link_topo get_link_topo;
+		struct ice_aqc_i2c read_i2c;
+		struct ice_aqc_read_i2c_resp read_i2c_resp;
 	} params;
 };
 
@@ -2226,6 +2246,7 @@ enum ice_adminq_opc {
 	ice_aqc_opc_set_event_mask			= 0x0613,
 	ice_aqc_opc_set_mac_lb				= 0x0620,
 	ice_aqc_opc_get_link_topo			= 0x06E0,
+	ice_aqc_opc_read_i2c				= 0x06E2,
 	ice_aqc_opc_set_port_id_led			= 0x06E9,
 	ice_aqc_opc_set_gpio				= 0x06EC,
 	ice_aqc_opc_get_gpio				= 0x06ED,
diff --git a/drivers/net/ethernet/intel/ice/ice_common.c b/drivers/net/ethernet/intel/ice/ice_common.c
index 0e4434e3c290..9619bdb9e49a 100644
--- a/drivers/net/ethernet/intel/ice/ice_common.c
+++ b/drivers/net/ethernet/intel/ice/ice_common.c
@@ -4798,6 +4798,59 @@ ice_sched_query_elem(struct ice_hw *hw, u32 node_teid,
 }
 
 /**
+ * ice_aq_read_i2c
+ * @hw: pointer to the hw struct
+ * @topo_addr: topology address for a device to communicate with
+ * @bus_addr: 7-bit I2C bus address
+ * @addr: I2C memory address (I2C offset) with up to 16 bits
+ * @params: I2C parameters: bit [7] - Repeated start,
+ *			    bits [6:5] data offset size,
+ *			    bit [4] - I2C address type,
+ *			    bits [3:0] - data size to read (0-16 bytes)
+ * @data: pointer to data (0 to 16 bytes) to be read from the I2C device
+ * @cd: pointer to command details structure or NULL
+ *
+ * Read I2C (0x06E2)
+ */
+int
+ice_aq_read_i2c(struct ice_hw *hw, struct ice_aqc_link_topo_addr topo_addr,
+		u16 bus_addr, __le16 addr, u8 params, u8 *data,
+		struct ice_sq_cd *cd)
+{
+	struct ice_aq_desc desc = { 0 };
+	struct ice_aqc_i2c *cmd;
+	u8 data_size;
+	int status;
+
+	ice_fill_dflt_direct_cmd_desc(&desc, ice_aqc_opc_read_i2c);
+	cmd = &desc.params.read_i2c;
+
+	if (!data)
+		return -EINVAL;
+
+	data_size = FIELD_GET(ICE_AQC_I2C_DATA_SIZE_M, params);
+
+	cmd->i2c_bus_addr = cpu_to_le16(bus_addr);
+	cmd->topo_addr = topo_addr;
+	cmd->i2c_params = params;
+	cmd->i2c_addr = addr;
+
+	status = ice_aq_send_cmd(hw, &desc, NULL, 0, cd);
+	if (!status) {
+		struct ice_aqc_read_i2c_resp *resp;
+		u8 i;
+
+		resp = &desc.params.read_i2c_resp;
+		for (i = 0; i < data_size; i++) {
+			*data = resp->i2c_data[i];
+			data++;
+		}
+	}
+
+	return status;
+}
+
+/**
  * ice_aq_set_driver_param - Set driver parameter to share via firmware
  * @hw: pointer to the HW struct
  * @idx: parameter index to set
diff --git a/drivers/net/ethernet/intel/ice/ice_common.h b/drivers/net/ethernet/intel/ice/ice_common.h
index d28749edd92f..1efe6b2c32f0 100644
--- a/drivers/net/ethernet/intel/ice/ice_common.h
+++ b/drivers/net/ethernet/intel/ice/ice_common.h
@@ -4,6 +4,8 @@
 #ifndef _ICE_COMMON_H_
 #define _ICE_COMMON_H_
 
+#include <linux/bitfield.h>
+
 #include "ice.h"
 #include "ice_type.h"
 #include "ice_nvm.h"
@@ -208,5 +210,9 @@ ice_aq_set_lldp_mib(struct ice_hw *hw, u8 mib_type, void *buf, u16 buf_size,
 bool ice_fw_supports_lldp_fltr_ctrl(struct ice_hw *hw);
 int
 ice_lldp_fltr_add_remove(struct ice_hw *hw, u16 vsi_num, bool add);
+int
+ice_aq_read_i2c(struct ice_hw *hw, struct ice_aqc_link_topo_addr topo_addr,
+		u16 bus_addr, __le16 addr, u8 params, u8 *data,
+		struct ice_sq_cd *cd);
 bool ice_fw_supports_report_dflt_cfg(struct ice_hw *hw);
 #endif /* _ICE_COMMON_H_ */
diff --git a/drivers/net/ethernet/intel/ice/ice_gnss.c b/drivers/net/ethernet/intel/ice/ice_gnss.c
new file mode 100644
index 000000000000..755e1580f368
--- /dev/null
+++ b/drivers/net/ethernet/intel/ice/ice_gnss.c
@@ -0,0 +1,376 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2018-2021, Intel Corporation. */
+
+#include "ice.h"
+#include "ice_lib.h"
+#include <linux/tty_driver.h>
+
+/**
+ * ice_gnss_read - Read data from internal GNSS module
+ * @work: GNSS read work structure
+ *
+ * Read the data from internal GNSS receiver, number of bytes read will be
+ * returned in *read_data parameter.
+ */
+static void ice_gnss_read(struct kthread_work *work)
+{
+	struct gnss_serial *gnss = container_of(work, struct gnss_serial,
+						read_work.work);
+	struct ice_aqc_link_topo_addr link_topo;
+	u8 i2c_params, bytes_read;
+	struct tty_port *port;
+	struct ice_pf *pf;
+	struct ice_hw *hw;
+	__be16 data_len_b;
+	char *buf = NULL;
+	u16 i, data_len;
+	int err = 0;
+
+	pf = gnss->back;
+	if (!pf || !gnss->tty || !gnss->tty->port) {
+		err = -EFAULT;
+		goto exit;
+	}
+
+	hw = &pf->hw;
+	port = gnss->tty->port;
+
+	buf = (char *)get_zeroed_page(GFP_KERNEL);
+	if (!buf) {
+		err = -ENOMEM;
+		goto exit;
+	}
+
+	memset(&link_topo, 0, sizeof(struct ice_aqc_link_topo_addr));
+	link_topo.topo_params.index = ICE_E810T_GNSS_I2C_BUS;
+	link_topo.topo_params.node_type_ctx |=
+		FIELD_PREP(ICE_AQC_LINK_TOPO_NODE_CTX_M,
+			   ICE_AQC_LINK_TOPO_NODE_CTX_OVERRIDE);
+
+	i2c_params = ICE_GNSS_UBX_DATA_LEN_WIDTH |
+		     ICE_AQC_I2C_USE_REPEATED_START;
+
+	/* Read data length in a loop, when it's not 0 the data is ready */
+	for (i = 0; i < ICE_MAX_UBX_READ_TRIES; i++) {
+		err = ice_aq_read_i2c(hw, link_topo, ICE_GNSS_UBX_I2C_BUS_ADDR,
+				      cpu_to_le16(ICE_GNSS_UBX_DATA_LEN_H),
+				      i2c_params, (u8 *)&data_len_b, NULL);
+		if (err)
+			goto exit_buf;
+
+		data_len = be16_to_cpu(data_len_b);
+		if (data_len != 0 && data_len != U16_MAX)
+			break;
+
+		mdelay(10);
+	}
+
+	data_len = min(data_len, (u16)PAGE_SIZE);
+	data_len = tty_buffer_request_room(port, data_len);
+	if (!data_len) {
+		err = -ENOMEM;
+		goto exit_buf;
+	}
+
+	/* Read received data */
+	for (i = 0; i < data_len; i += bytes_read) {
+		u16 bytes_left = data_len - i;
+
+		bytes_read = bytes_left < ICE_MAX_I2C_DATA_SIZE ? bytes_left :
+					  ICE_MAX_I2C_DATA_SIZE;
+
+		err = ice_aq_read_i2c(hw, link_topo, ICE_GNSS_UBX_I2C_BUS_ADDR,
+				      cpu_to_le16(ICE_GNSS_UBX_EMPTY_DATA),
+				      bytes_read, &buf[i], NULL);
+		if (err)
+			goto exit_buf;
+	}
+
+	/* Send the data to the tty layer for users to read. This doesn't
+	 * actually push the data through unless tty->low_latency is set.
+	 */
+	tty_insert_flip_string(port, buf, i);
+	tty_flip_buffer_push(port);
+
+exit_buf:
+	free_page((unsigned long)buf);
+	kthread_queue_delayed_work(gnss->kworker, &gnss->read_work,
+				   ICE_GNSS_TIMER_DELAY_TIME);
+exit:
+	if (err)
+		dev_dbg(ice_pf_to_dev(pf), "GNSS failed to read err=%d\n", err);
+}
+
+/**
+ * ice_gnss_struct_init - Initialize GNSS structure for the TTY
+ * @pf: Board private structure
+ */
+static struct gnss_serial *ice_gnss_struct_init(struct ice_pf *pf)
+{
+	struct device *dev = ice_pf_to_dev(pf);
+	struct kthread_worker *kworker;
+	struct gnss_serial *gnss;
+
+	gnss = kzalloc(sizeof(*gnss), GFP_KERNEL);
+	if (!gnss)
+		return NULL;
+
+	mutex_init(&gnss->gnss_mutex);
+	gnss->open_count = 0;
+	gnss->back = pf;
+	pf->gnss_serial = gnss;
+
+	kthread_init_delayed_work(&gnss->read_work, ice_gnss_read);
+	/* Allocate a kworker for handling work required for the GNSS TTY
+	 * writes.
+	 */
+	kworker = kthread_create_worker(0, "ice-gnss-%s", dev_name(dev));
+	if (!kworker) {
+		kfree(gnss);
+		return NULL;
+	}
+
+	gnss->kworker = kworker;
+
+	return gnss;
+}
+
+/**
+ * ice_gnss_tty_open - Initialize GNSS structures on TTY device open
+ * @tty: pointer to the tty_struct
+ * @filp: pointer to the file
+ *
+ * This routine is mandatory. If this routine is not filled in, the attempted
+ * open will fail with ENODEV.
+ */
+static int ice_gnss_tty_open(struct tty_struct *tty, struct file *filp)
+{
+	struct gnss_serial *gnss;
+	struct ice_pf *pf;
+
+	pf = (struct ice_pf *)tty->driver->driver_state;
+	if (!pf)
+		return -EFAULT;
+
+	/* Clear the pointer in case something fails */
+	tty->driver_data = NULL;
+
+	/* Get the serial object associated with this tty pointer */
+	gnss = pf->gnss_serial;
+	if (!gnss) {
+		/* Initialize GNSS struct on the first device open */
+		gnss = ice_gnss_struct_init(pf);
+		if (!gnss)
+			return -ENOMEM;
+	}
+
+	mutex_lock(&gnss->gnss_mutex);
+
+	/* Save our structure within the tty structure */
+	tty->driver_data = gnss;
+	gnss->tty = tty;
+	gnss->open_count++;
+	kthread_queue_delayed_work(gnss->kworker, &gnss->read_work, 0);
+
+	mutex_unlock(&gnss->gnss_mutex);
+
+	return 0;
+}
+
+/**
+ * ice_gnss_tty_close - Cleanup GNSS structures on tty device close
+ * @tty: pointer to the tty_struct
+ * @filp: pointer to the file
+ */
+static void ice_gnss_tty_close(struct tty_struct *tty, struct file *filp)
+{
+	struct gnss_serial *gnss = tty->driver_data;
+	struct ice_pf *pf;
+
+	if (!gnss)
+		return;
+
+	pf = (struct ice_pf *)tty->driver->driver_state;
+	if (!pf)
+		return;
+
+	mutex_lock(&gnss->gnss_mutex);
+
+	if (!gnss->open_count) {
+		/* Port was never opened */
+		dev_err(ice_pf_to_dev(pf), "GNSS port not opened\n");
+		goto exit;
+	}
+
+	gnss->open_count--;
+	if (gnss->open_count <= 0) {
+		/* Port is in shutdown state */
+		kthread_cancel_delayed_work_sync(&gnss->read_work);
+	}
+exit:
+	mutex_unlock(&gnss->gnss_mutex);
+}
+
+/**
+ * ice_gnss_tty_write - Dummy TTY write function to avoid kernel panic
+ * @tty: pointer to the tty_struct
+ * @buf: pointer to the user data
+ * @cnt: the number of characters that was able to be sent to the hardware (or
+ *       queued to be sent at a later time)
+ */
+static int
+ice_gnss_tty_write(struct tty_struct *tty, const unsigned char *buf, int cnt)
+{
+	return 0;
+}
+
+/**
+ * ice_gnss_tty_write_room - Dummy TTY write_room function to avoid kernel panic
+ * @tty: pointer to the tty_struct
+ */
+static unsigned int ice_gnss_tty_write_room(struct tty_struct *tty)
+{
+	return 0;
+}
+
+static const struct tty_operations tty_gps_ops = {
+	.open =		ice_gnss_tty_open,
+	.close =	ice_gnss_tty_close,
+	.write =	ice_gnss_tty_write,
+	.write_room =	ice_gnss_tty_write_room,
+};
+
+/**
+ * ice_gnss_create_tty_driver - Create a TTY driver for GNSS
+ * @pf: Board private structure
+ */
+static struct tty_driver *ice_gnss_create_tty_driver(struct ice_pf *pf)
+{
+	struct device *dev = ice_pf_to_dev(pf);
+	const int ICE_TTYDRV_NAME_MAX = 14;
+	struct tty_driver *tty_driver;
+	char *ttydrv_name;
+	int err;
+
+	tty_driver = tty_alloc_driver(1, TTY_DRIVER_REAL_RAW);
+	if (!tty_driver) {
+		dev_err(ice_pf_to_dev(pf), "Failed to allocate memory for GNSS TTY\n");
+		return NULL;
+	}
+
+	ttydrv_name = kzalloc(ICE_TTYDRV_NAME_MAX, GFP_KERNEL);
+	if (!ttydrv_name) {
+		tty_driver_kref_put(tty_driver);
+		return NULL;
+	}
+
+	snprintf(ttydrv_name, ICE_TTYDRV_NAME_MAX, "ttyGNSS_%02x%02x_",
+		 (u8)pf->pdev->bus->number, (u8)PCI_SLOT(pf->pdev->devfn));
+
+	/* Initialize the tty driver*/
+	tty_driver->owner = THIS_MODULE;
+	tty_driver->driver_name = dev_driver_string(dev);
+	tty_driver->name = (const char *)ttydrv_name;
+	tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
+	tty_driver->subtype = SERIAL_TYPE_NORMAL;
+	tty_driver->init_termios = tty_std_termios;
+	tty_driver->init_termios.c_iflag &= ~INLCR;
+	tty_driver->init_termios.c_iflag |= IGNCR;
+	tty_driver->init_termios.c_oflag &= ~OPOST;
+	tty_driver->init_termios.c_lflag &= ~ICANON;
+	tty_driver->init_termios.c_cflag &= ~(CSIZE | CBAUD | CBAUDEX);
+	/* baud rate 9600 */
+	tty_termios_encode_baud_rate(&tty_driver->init_termios, 9600, 9600);
+	tty_driver->driver_state = pf;
+	tty_set_operations(tty_driver, &tty_gps_ops);
+
+	pf->gnss_serial = NULL;
+
+	tty_port_init(&pf->gnss_tty_port);
+	tty_port_link_device(&pf->gnss_tty_port, tty_driver, 0);
+
+	err = tty_register_driver(tty_driver);
+	if (err) {
+		dev_err(ice_pf_to_dev(pf), "Failed to register TTY driver err=%d\n",
+			err);
+
+		tty_port_destroy(&pf->gnss_tty_port);
+		kfree(ttydrv_name);
+		tty_driver_kref_put(pf->ice_gnss_tty_driver);
+
+		return NULL;
+	}
+
+	return tty_driver;
+}
+
+/**
+ * ice_gnss_init - Initialize GNSS TTY support
+ * @pf: Board private structure
+ */
+void ice_gnss_init(struct ice_pf *pf)
+{
+	struct tty_driver *tty_driver;
+
+	tty_driver = ice_gnss_create_tty_driver(pf);
+	if (!tty_driver)
+		return;
+
+	pf->ice_gnss_tty_driver = tty_driver;
+
+	set_bit(ICE_FLAG_GNSS, pf->flags);
+	dev_info(ice_pf_to_dev(pf), "GNSS TTY init successful\n");
+}
+
+/**
+ * ice_gnss_exit - Disable GNSS TTY support
+ * @pf: Board private structure
+ */
+void ice_gnss_exit(struct ice_pf *pf)
+{
+	if (!test_bit(ICE_FLAG_GNSS, pf->flags) || !pf->ice_gnss_tty_driver)
+		return;
+
+	tty_port_destroy(&pf->gnss_tty_port);
+
+	if (pf->gnss_serial) {
+		struct gnss_serial *gnss = pf->gnss_serial;
+
+		kthread_cancel_delayed_work_sync(&gnss->read_work);
+		kfree(gnss);
+		pf->gnss_serial = NULL;
+	}
+
+	tty_unregister_driver(pf->ice_gnss_tty_driver);
+	kfree(pf->ice_gnss_tty_driver->name);
+	tty_driver_kref_put(pf->ice_gnss_tty_driver);
+	pf->ice_gnss_tty_driver = NULL;
+}
+
+/**
+ * ice_gnss_is_gps_present - Check if GPS HW is present
+ * @hw: pointer to HW struct
+ */
+bool ice_gnss_is_gps_present(struct ice_hw *hw)
+{
+	if (!hw->func_caps.ts_func_info.src_tmr_owned)
+		return false;
+
+#if IS_ENABLED(CONFIG_PTP_1588_CLOCK)
+	if (ice_is_e810t(hw)) {
+		int err;
+		u8 data;
+
+		err = ice_read_pca9575_reg_e810t(hw, ICE_PCA9575_P0_IN, &data);
+		if (err || !!(data & ICE_E810T_P0_GNSS_PRSNT_N))
+			return false;
+	} else {
+		return false;
+	}
+#else
+	if (!ice_is_e810t(hw))
+		return false;
+#endif /* IS_ENABLED(CONFIG_PTP_1588_CLOCK) */
+
+	return true;
+}
diff --git a/drivers/net/ethernet/intel/ice/ice_gnss.h b/drivers/net/ethernet/intel/ice/ice_gnss.h
new file mode 100644
index 000000000000..9211adb2372c
--- /dev/null
+++ b/drivers/net/ethernet/intel/ice/ice_gnss.h
@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2018-2021, Intel Corporation. */
+
+#ifndef _ICE_GNSS_H_
+#define _ICE_GNSS_H_
+
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+
+#define ICE_E810T_GNSS_I2C_BUS		0x2
+#define ICE_GNSS_UBX_I2C_BUS_ADDR	0x42
+/* Data length register is big endian */
+#define ICE_GNSS_UBX_DATA_LEN_H		0xFD
+#define ICE_GNSS_UBX_DATA_LEN_WIDTH	2
+#define ICE_GNSS_UBX_EMPTY_DATA		0xFF
+#define ICE_GNSS_TIMER_DELAY_TIME	(HZ / 10) /* 0.1 second per message */
+#define ICE_MAX_I2C_DATA_SIZE		FIELD_MAX(ICE_AQC_I2C_DATA_SIZE_M)
+#define ICE_MAX_UBX_READ_TRIES		255
+
+/**
+ * struct gnss_serial - data used to initialize GNSS TTY port
+ * @back: back pointer to PF
+ * @tty: pointer to the tty for this device
+ * @open_count: number of times this port has been opened
+ * @gnss_mutex: gnss_mutex used to protect GNSS serial operations
+ * @kworker: kwork thread for handling periodic work
+ * @read_work: read_work function for handling GNSS reads
+ */
+struct gnss_serial {
+	struct ice_pf *back;
+	struct tty_struct *tty;
+	int open_count;
+	struct mutex gnss_mutex; /* protects GNSS serial structure */
+	struct kthread_worker *kworker;
+	struct kthread_delayed_work read_work;
+};
+
+#if IS_ENABLED(CONFIG_TTY)
+void ice_gnss_init(struct ice_pf *pf);
+void ice_gnss_exit(struct ice_pf *pf);
+bool ice_gnss_is_gps_present(struct ice_hw *hw);
+#else
+static inline void ice_gnss_init(struct ice_pf *pf) { }
+static inline void ice_gnss_exit(struct ice_pf *pf) { }
+static inline bool ice_gnss_is_gps_present(struct ice_hw *hw)
+{
+	return false;
+}
+#endif /* IS_ENABLED(CONFIG_TTY) */
+#endif /* _ICE_GNSS_H_ */
diff --git a/drivers/net/ethernet/intel/ice/ice_lib.c b/drivers/net/ethernet/intel/ice/ice_lib.c
index 2d15bb73a074..662493d1002b 100644
--- a/drivers/net/ethernet/intel/ice/ice_lib.c
+++ b/drivers/net/ethernet/intel/ice/ice_lib.c
@@ -4094,8 +4094,11 @@ void ice_init_feature_support(struct ice_pf *pf)
 	case ICE_DEV_ID_E810C_QSFP:
 	case ICE_DEV_ID_E810C_SFP:
 		ice_set_feature_support(pf, ICE_F_DSCP);
-		if (ice_is_e810t(&pf->hw))
+		if (ice_is_e810t(&pf->hw)) {
 			ice_set_feature_support(pf, ICE_F_SMA_CTRL);
+			if (ice_gnss_is_gps_present(&pf->hw))
+				ice_set_feature_support(pf, ICE_F_GNSS);
+		}
 		break;
 	default:
 		break;
diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index 74ce56580016..95dfd04e8c3a 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -568,6 +568,9 @@ skip:
 	if (test_bit(ICE_FLAG_PTP_SUPPORTED, pf->flags))
 		ice_ptp_prepare_for_reset(pf);
 
+	if (ice_is_feature_supported(pf, ICE_F_GNSS))
+		ice_gnss_exit(pf);
+
 	if (hw->port_info)
 		ice_sched_clear_port(hw->port_info);
 
@@ -4702,6 +4705,9 @@ ice_probe(struct pci_dev *pdev, const struct pci_device_id __always_unused *ent)
 	if (test_bit(ICE_FLAG_PTP_SUPPORTED, pf->flags))
 		ice_ptp_init(pf);
 
+	if (ice_is_feature_supported(pf, ICE_F_GNSS))
+		ice_gnss_init(pf);
+
 	/* Note: Flow director init failure is non-fatal to load */
 	if (ice_init_fdir(pf))
 		dev_err(dev, "could not initialize flow director\n");
@@ -4877,6 +4883,8 @@ static void ice_remove(struct pci_dev *pdev)
 	ice_deinit_lag(pf);
 	if (test_bit(ICE_FLAG_PTP_SUPPORTED, pf->flags))
 		ice_ptp_release(pf);
+	if (ice_is_feature_supported(pf, ICE_F_GNSS))
+		ice_gnss_exit(pf);
 	if (!ice_is_safe_mode(pf))
 		ice_remove_arfs(pf);
 	ice_setup_mc_magic_wake(pf);
@@ -6920,6 +6928,9 @@ static void ice_rebuild(struct ice_pf *pf, enum ice_reset_req reset_type)
 	if (test_bit(ICE_FLAG_PTP_SUPPORTED, pf->flags))
 		ice_ptp_reset(pf);
 
+	if (ice_is_feature_supported(pf, ICE_F_GNSS))
+		ice_gnss_init(pf);
+
 	/* rebuild PF VSI */
 	err = ice_vsi_rebuild_by_type(pf, ICE_VSI_PF);
 	if (err) {
diff --git a/drivers/net/ethernet/intel/ice/ice_ptp_hw.c b/drivers/net/ethernet/intel/ice/ice_ptp_hw.c
index ec8450f034e6..6dff97d53d81 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp_hw.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp_hw.c
@@ -3251,6 +3251,37 @@ int ice_write_sma_ctrl_e810t(struct ice_hw *hw, u8 data)
 }
 
 /**
+ * ice_read_pca9575_reg_e810t
+ * @hw: pointer to the hw struct
+ * @offset: GPIO controller register offset
+ * @data: pointer to data to be read from the GPIO controller
+ *
+ * Read the register from the GPIO controller
+ */
+int ice_read_pca9575_reg_e810t(struct ice_hw *hw, u8 offset, u8 *data)
+{
+	struct ice_aqc_link_topo_addr link_topo;
+	__le16 addr;
+	u16 handle;
+	int err;
+
+	memset(&link_topo, 0, sizeof(link_topo));
+
+	err = ice_get_pca9575_handle(hw, &handle);
+	if (err)
+		return err;
+
+	link_topo.handle = cpu_to_le16(handle);
+	link_topo.topo_params.node_type_ctx =
+		FIELD_PREP(ICE_AQC_LINK_TOPO_NODE_CTX_M,
+			   ICE_AQC_LINK_TOPO_NODE_CTX_PROVIDED);
+
+	addr = cpu_to_le16((u16)offset);
+
+	return ice_aq_read_i2c(hw, link_topo, 0, addr, 1, data, NULL);
+}
+
+/**
  * ice_is_pca9575_present
  * @hw: pointer to the hw struct
  *
diff --git a/drivers/net/ethernet/intel/ice/ice_ptp_hw.h b/drivers/net/ethernet/intel/ice/ice_ptp_hw.h
index 519e75462e67..1246e4ee4b5d 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp_hw.h
+++ b/drivers/net/ethernet/intel/ice/ice_ptp_hw.h
@@ -191,6 +191,7 @@ int ice_phy_exit_bypass_e822(struct ice_hw *hw, u8 port);
 int ice_ptp_init_phy_e810(struct ice_hw *hw);
 int ice_read_sma_ctrl_e810t(struct ice_hw *hw, u8 *data);
 int ice_write_sma_ctrl_e810t(struct ice_hw *hw, u8 data);
+int ice_read_pca9575_reg_e810t(struct ice_hw *hw, u8 offset, u8 *data);
 bool ice_is_pca9575_present(struct ice_hw *hw);
 
 #define PFTSYN_SEM_BYTES	4
@@ -443,4 +444,10 @@ bool ice_is_pca9575_present(struct ice_hw *hw);
 #define ICE_SMA_MAX_BIT_E810T	7
 #define ICE_PCA9575_P1_OFFSET	8
 
+/* E810T PCA9575 IO controller registers */
+#define ICE_PCA9575_P0_IN	0x0
+
+/* E810T PCA9575 IO controller pin control */
+#define ICE_E810T_P0_GNSS_PRSNT_N	BIT(4)
+
 #endif /* _ICE_PTP_HW_H_ */