1 files changed, 376 insertions, 0 deletions
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;
+}