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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/tty/serdev/serdev-ttyport.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/tty/serdev/serdev-ttyport.c')
-rw-r--r-- | drivers/tty/serdev/serdev-ttyport.c | 330 |
1 files changed, 330 insertions, 0 deletions
diff --git a/drivers/tty/serdev/serdev-ttyport.c b/drivers/tty/serdev/serdev-ttyport.c new file mode 100644 index 0000000000..e3856814ce --- /dev/null +++ b/drivers/tty/serdev/serdev-ttyport.c @@ -0,0 +1,330 @@ +// 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 size_t ttyport_receive_buf(struct tty_port *port, const u8 *cp, + const u8 *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 -EOPNOTSUPP; + + return tty->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 -EOPNOTSUPP; + + return tty->ops->tiocmset(tty, set, clear); +} + +static int ttyport_break_ctl(struct serdev_controller *ctrl, unsigned int break_state) +{ + struct serport *serport = serdev_controller_get_drvdata(ctrl); + struct tty_struct *tty = serport->tty; + + if (!tty->ops->break_ctl) + return -EOPNOTSUPP; + + return tty->ops->break_ctl(tty, break_state); +} + +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, + .break_ctl = ttyport_break_ctl, +}; + +struct device *serdev_tty_port_register(struct tty_port *port, + struct device *parent, + struct tty_driver *drv, int idx) +{ + 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; + + 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 = &tty_port_default_client_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_data = NULL; + port->client_ops = &tty_port_default_client_ops; + serdev_controller_put(ctrl); + + return 0; +} |