1 files changed, 320 insertions, 0 deletions

diff --git a/drivers/tty/serdev/serdev-ttyport.c b/drivers/tty/serdev/serdev-ttyport.c
new file mode 100644
index 0000000..fa16729
--- /dev/null
+++ b/drivers/tty/serdev/serdev-ttyport.c
@@ -0,0 +1,320 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2016-2017 Linaro Ltd., Rob Herring <robh@kernel.org>
+ */
+#include <linux/kernel.h>
+#include <linux/serdev.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/poll.h>
+
+#define SERPORT_ACTIVE		1
+
+struct serport {
+	struct tty_port *port;
+	struct tty_struct *tty;
+	struct tty_driver *tty_drv;
+	int tty_idx;
+	unsigned long flags;
+};
+
+/*
+ * Callback functions from the tty port.
+ */
+
+static int ttyport_receive_buf(struct tty_port *port, const unsigned char *cp,
+				const unsigned char *fp, size_t count)
+{
+	struct serdev_controller *ctrl = port->client_data;
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	int ret;
+
+	if (!test_bit(SERPORT_ACTIVE, &serport->flags))
+		return 0;
+
+	ret = serdev_controller_receive_buf(ctrl, cp, count);
+
+	dev_WARN_ONCE(&ctrl->dev, ret < 0 || ret > count,
+				"receive_buf returns %d (count = %zu)\n",
+				ret, count);
+	if (ret < 0)
+		return 0;
+	else if (ret > count)
+		return count;
+
+	return ret;
+}
+
+static void ttyport_write_wakeup(struct tty_port *port)
+{
+	struct serdev_controller *ctrl = port->client_data;
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	struct tty_struct *tty;
+
+	tty = tty_port_tty_get(port);
+	if (!tty)
+		return;
+
+	if (test_and_clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags) &&
+	    test_bit(SERPORT_ACTIVE, &serport->flags))
+		serdev_controller_write_wakeup(ctrl);
+
+	/* Wake up any tty_wait_until_sent() */
+	wake_up_interruptible(&tty->write_wait);
+
+	tty_kref_put(tty);
+}
+
+static const struct tty_port_client_operations client_ops = {
+	.receive_buf = ttyport_receive_buf,
+	.write_wakeup = ttyport_write_wakeup,
+};
+
+/*
+ * Callback functions from the serdev core.
+ */
+
+static int ttyport_write_buf(struct serdev_controller *ctrl, const unsigned char *data, size_t len)
+{
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	struct tty_struct *tty = serport->tty;
+
+	if (!test_bit(SERPORT_ACTIVE, &serport->flags))
+		return 0;
+
+	set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
+	return tty->ops->write(serport->tty, data, len);
+}
+
+static void ttyport_write_flush(struct serdev_controller *ctrl)
+{
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	struct tty_struct *tty = serport->tty;
+
+	tty_driver_flush_buffer(tty);
+}
+
+static int ttyport_write_room(struct serdev_controller *ctrl)
+{
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	struct tty_struct *tty = serport->tty;
+
+	return tty_write_room(tty);
+}
+
+static int ttyport_open(struct serdev_controller *ctrl)
+{
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	struct tty_struct *tty;
+	struct ktermios ktermios;
+	int ret;
+
+	tty = tty_init_dev(serport->tty_drv, serport->tty_idx);
+	if (IS_ERR(tty))
+		return PTR_ERR(tty);
+	serport->tty = tty;
+
+	if (!tty->ops->open || !tty->ops->close) {
+		ret = -ENODEV;
+		goto err_unlock;
+	}
+
+	ret = tty->ops->open(serport->tty, NULL);
+	if (ret)
+		goto err_close;
+
+	tty_unlock(serport->tty);
+
+	/* Bring the UART into a known 8 bits no parity hw fc state */
+	ktermios = tty->termios;
+	ktermios.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP |
+			      INLCR | IGNCR | ICRNL | IXON);
+	ktermios.c_oflag &= ~OPOST;
+	ktermios.c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
+	ktermios.c_cflag &= ~(CSIZE | PARENB);
+	ktermios.c_cflag |= CS8;
+	ktermios.c_cflag |= CRTSCTS;
+	/* Hangups are not supported so make sure to ignore carrier detect. */
+	ktermios.c_cflag |= CLOCAL;
+	tty_set_termios(tty, &ktermios);
+
+	set_bit(SERPORT_ACTIVE, &serport->flags);
+
+	return 0;
+
+err_close:
+	tty->ops->close(tty, NULL);
+err_unlock:
+	tty_unlock(tty);
+	tty_release_struct(tty, serport->tty_idx);
+
+	return ret;
+}
+
+static void ttyport_close(struct serdev_controller *ctrl)
+{
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	struct tty_struct *tty = serport->tty;
+
+	clear_bit(SERPORT_ACTIVE, &serport->flags);
+
+	tty_lock(tty);
+	if (tty->ops->close)
+		tty->ops->close(tty, NULL);
+	tty_unlock(tty);
+
+	tty_release_struct(tty, serport->tty_idx);
+}
+
+static unsigned int ttyport_set_baudrate(struct serdev_controller *ctrl, unsigned int speed)
+{
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	struct tty_struct *tty = serport->tty;
+	struct ktermios ktermios = tty->termios;
+
+	ktermios.c_cflag &= ~CBAUD;
+	tty_termios_encode_baud_rate(&ktermios, speed, speed);
+
+	/* tty_set_termios() return not checked as it is always 0 */
+	tty_set_termios(tty, &ktermios);
+	return ktermios.c_ospeed;
+}
+
+static void ttyport_set_flow_control(struct serdev_controller *ctrl, bool enable)
+{
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	struct tty_struct *tty = serport->tty;
+	struct ktermios ktermios = tty->termios;
+
+	if (enable)
+		ktermios.c_cflag |= CRTSCTS;
+	else
+		ktermios.c_cflag &= ~CRTSCTS;
+
+	tty_set_termios(tty, &ktermios);
+}
+
+static int ttyport_set_parity(struct serdev_controller *ctrl,
+			      enum serdev_parity parity)
+{
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	struct tty_struct *tty = serport->tty;
+	struct ktermios ktermios = tty->termios;
+
+	ktermios.c_cflag &= ~(PARENB | PARODD | CMSPAR);
+	if (parity != SERDEV_PARITY_NONE) {
+		ktermios.c_cflag |= PARENB;
+		if (parity == SERDEV_PARITY_ODD)
+			ktermios.c_cflag |= PARODD;
+	}
+
+	tty_set_termios(tty, &ktermios);
+
+	if ((tty->termios.c_cflag & (PARENB | PARODD | CMSPAR)) !=
+	    (ktermios.c_cflag & (PARENB | PARODD | CMSPAR)))
+		return -EINVAL;
+
+	return 0;
+}
+
+static void ttyport_wait_until_sent(struct serdev_controller *ctrl, long timeout)
+{
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	struct tty_struct *tty = serport->tty;
+
+	tty_wait_until_sent(tty, timeout);
+}
+
+static int ttyport_get_tiocm(struct serdev_controller *ctrl)
+{
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	struct tty_struct *tty = serport->tty;
+
+	if (!tty->ops->tiocmget)
+		return -ENOTSUPP;
+
+	return tty->driver->ops->tiocmget(tty);
+}
+
+static int ttyport_set_tiocm(struct serdev_controller *ctrl, unsigned int set, unsigned int clear)
+{
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	struct tty_struct *tty = serport->tty;
+
+	if (!tty->ops->tiocmset)
+		return -ENOTSUPP;
+
+	return tty->driver->ops->tiocmset(tty, set, clear);
+}
+
+static const struct serdev_controller_ops ctrl_ops = {
+	.write_buf = ttyport_write_buf,
+	.write_flush = ttyport_write_flush,
+	.write_room = ttyport_write_room,
+	.open = ttyport_open,
+	.close = ttyport_close,
+	.set_flow_control = ttyport_set_flow_control,
+	.set_parity = ttyport_set_parity,
+	.set_baudrate = ttyport_set_baudrate,
+	.wait_until_sent = ttyport_wait_until_sent,
+	.get_tiocm = ttyport_get_tiocm,
+	.set_tiocm = ttyport_set_tiocm,
+};
+
+struct device *serdev_tty_port_register(struct tty_port *port,
+					struct device *parent,
+					struct tty_driver *drv, int idx)
+{
+	const struct tty_port_client_operations *old_ops;
+	struct serdev_controller *ctrl;
+	struct serport *serport;
+	int ret;
+
+	if (!port || !drv || !parent)
+		return ERR_PTR(-ENODEV);
+
+	ctrl = serdev_controller_alloc(parent, sizeof(struct serport));
+	if (!ctrl)
+		return ERR_PTR(-ENOMEM);
+	serport = serdev_controller_get_drvdata(ctrl);
+
+	serport->port = port;
+	serport->tty_idx = idx;
+	serport->tty_drv = drv;
+
+	ctrl->ops = &ctrl_ops;
+
+	old_ops = port->client_ops;
+	port->client_ops = &client_ops;
+	port->client_data = ctrl;
+
+	ret = serdev_controller_add(ctrl);
+	if (ret)
+		goto err_reset_data;
+
+	dev_info(&ctrl->dev, "tty port %s%d registered\n", drv->name, idx);
+	return &ctrl->dev;
+
+err_reset_data:
+	port->client_data = NULL;
+	port->client_ops = old_ops;
+	serdev_controller_put(ctrl);
+
+	return ERR_PTR(ret);
+}
+
+int serdev_tty_port_unregister(struct tty_port *port)
+{
+	struct serdev_controller *ctrl = port->client_data;
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+
+	if (!serport)
+		return -ENODEV;
+
+	serdev_controller_remove(ctrl);
+	port->client_ops = NULL;
+	port->client_data = NULL;
+	serdev_controller_put(ctrl);
+
+	return 0;
+}