diff options
Diffstat (limited to 'drivers/tty/serial/serial_core.c')
| -rw-r--r-- | drivers/tty/serial/serial_core.c | 1013 |
1 files changed, 633 insertions, 380 deletions
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 76e506ee335c..179ee199df34 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -14,14 +14,17 @@ #include <linux/sched/signal.h> #include <linux/init.h> #include <linux/console.h> +#include <linux/gpio/consumer.h> #include <linux/of.h> #include <linux/proc_fs.h> #include <linux/seq_file.h> #include <linux/device.h> #include <linux/serial.h> /* for serial_state and serial_icounter_struct */ #include <linux/serial_core.h> +#include <linux/sysrq.h> #include <linux/delay.h> #include <linux/mutex.h> +#include <linux/math64.h> #include <linux/security.h> #include <linux/irq.h> @@ -40,8 +43,13 @@ static struct lock_class_key port_lock_key; #define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8) +/* + * Max time with active RTS before/after data is sent. + */ +#define RS485_MAX_RTS_DELAY 100 /* msecs */ + static void uart_change_speed(struct tty_struct *tty, struct uart_state *state, - struct ktermios *old_termios); + const struct ktermios *old_termios); static void uart_wait_until_sent(struct tty_struct *tty, int timeout); static void uart_change_pm(struct uart_state *state, enum uart_pm_state pm_state); @@ -89,9 +97,16 @@ static inline struct uart_port *uart_port_check(struct uart_state *state) return state->uart_port; } -/* - * This routine is used by the interrupt handler to schedule processing in - * the software interrupt portion of the driver. +/** + * uart_write_wakeup - schedule write processing + * @port: port to be processed + * + * This routine is used by the interrupt handler to schedule processing in the + * software interrupt portion of the driver. A driver is expected to call this + * function when the number of characters in the transmit buffer have dropped + * below a threshold. + * + * Locking: @port->lock should be held */ void uart_write_wakeup(struct uart_port *port) { @@ -103,6 +118,7 @@ void uart_write_wakeup(struct uart_port *port) BUG_ON(!state); tty_port_tty_wakeup(&state->port); } +EXPORT_SYMBOL(uart_write_wakeup); static void uart_stop(struct tty_struct *tty) { @@ -145,7 +161,7 @@ uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear) spin_lock_irqsave(&port->lock, flags); old = port->mctrl; port->mctrl = (old & ~clear) | set; - if (old != port->mctrl) + if (old != port->mctrl && !(port->rs485.flags & SER_RS485_ENABLED)) port->ops->set_mctrl(port, port->mctrl); spin_unlock_irqrestore(&port->lock, flags); } @@ -155,23 +171,10 @@ uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear) static void uart_port_dtr_rts(struct uart_port *uport, int raise) { - int rs485_on = uport->rs485_config && - (uport->rs485.flags & SER_RS485_ENABLED); - int RTS_after_send = !!(uport->rs485.flags & SER_RS485_RTS_AFTER_SEND); - - if (raise) { - if (rs485_on && !RTS_after_send) { - uart_set_mctrl(uport, TIOCM_DTR); - uart_clear_mctrl(uport, TIOCM_RTS); - } else { - uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS); - } - } else { - unsigned int clear = TIOCM_DTR; - - clear |= (!rs485_on || !RTS_after_send) ? TIOCM_RTS : 0; - uart_clear_mctrl(uport, clear); - } + if (raise) + uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS); + else + uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS); } /* @@ -182,8 +185,8 @@ static int uart_port_startup(struct tty_struct *tty, struct uart_state *state, int init_hw) { struct uart_port *uport = uart_port_check(state); + unsigned long flags; unsigned long page; - unsigned long flags = 0; int retval = 0; if (uport->type == PORT_UNKNOWN) @@ -220,7 +223,11 @@ static int uart_port_startup(struct tty_struct *tty, struct uart_state *state, if (retval == 0) { if (uart_console(uport) && uport->cons->cflag) { tty->termios.c_cflag = uport->cons->cflag; + tty->termios.c_ispeed = uport->cons->ispeed; + tty->termios.c_ospeed = uport->cons->ospeed; uport->cons->cflag = 0; + uport->cons->ispeed = 0; + uport->cons->ospeed = 0; } /* * Initialise the hardware port settings. @@ -273,7 +280,7 @@ static void uart_shutdown(struct tty_struct *tty, struct uart_state *state) { struct uart_port *uport = uart_port_check(state); struct tty_port *port = &state->port; - unsigned long flags = 0; + unsigned long flags; char *xmit_buf = NULL; /* @@ -288,8 +295,11 @@ static void uart_shutdown(struct tty_struct *tty, struct uart_state *state) /* * Turn off DTR and RTS early. */ - if (uport && uart_console(uport) && tty) + if (uport && uart_console(uport) && tty) { uport->cons->cflag = tty->termios.c_cflag; + uport->cons->ispeed = tty->termios.c_ispeed; + uport->cons->ospeed = tty->termios.c_ospeed; + } if (!tty || C_HUPCL(tty)) uart_port_dtr_rts(uport, 0); @@ -315,82 +325,57 @@ static void uart_shutdown(struct tty_struct *tty, struct uart_state *state) state->xmit.buf = NULL; uart_port_unlock(uport, flags); - if (xmit_buf) - free_page((unsigned long)xmit_buf); + free_page((unsigned long)xmit_buf); } /** - * uart_update_timeout - update per-port FIFO timeout. - * @port: uart_port structure describing the port - * @cflag: termios cflag value - * @baud: speed of the port + * uart_update_timeout - update per-port frame timing information + * @port: uart_port structure describing the port + * @cflag: termios cflag value + * @baud: speed of the port + * + * Set the @port frame timing information from which the FIFO timeout value is + * derived. The @cflag value should reflect the actual hardware settings as + * number of bits, parity, stop bits and baud rate is taken into account here. * - * Set the port FIFO timeout value. The @cflag value should - * reflect the actual hardware settings. + * Locking: caller is expected to take @port->lock */ void uart_update_timeout(struct uart_port *port, unsigned int cflag, unsigned int baud) { - unsigned int bits; - - /* byte size and parity */ - switch (cflag & CSIZE) { - case CS5: - bits = 7; - break; - case CS6: - bits = 8; - break; - case CS7: - bits = 9; - break; - default: - bits = 10; - break; /* CS8 */ - } - - if (cflag & CSTOPB) - bits++; - if (cflag & PARENB) - bits++; + unsigned int size = tty_get_frame_size(cflag); + u64 frame_time; - /* - * The total number of bits to be transmitted in the fifo. - */ - bits = bits * port->fifosize; - - /* - * Figure the timeout to send the above number of bits. - * Add .02 seconds of slop - */ - port->timeout = (HZ * bits) / baud + HZ/50; + frame_time = (u64)size * NSEC_PER_SEC; + port->frame_time = DIV64_U64_ROUND_UP(frame_time, baud); } - EXPORT_SYMBOL(uart_update_timeout); /** - * uart_get_baud_rate - return baud rate for a particular port - * @port: uart_port structure describing the port in question. - * @termios: desired termios settings. - * @old: old termios (or NULL) - * @min: minimum acceptable baud rate - * @max: maximum acceptable baud rate + * uart_get_baud_rate - return baud rate for a particular port + * @port: uart_port structure describing the port in question. + * @termios: desired termios settings + * @old: old termios (or %NULL) + * @min: minimum acceptable baud rate + * @max: maximum acceptable baud rate * - * Decode the termios structure into a numeric baud rate, - * taking account of the magic 38400 baud rate (with spd_* - * flags), and mapping the %B0 rate to 9600 baud. + * Decode the termios structure into a numeric baud rate, taking account of the + * magic 38400 baud rate (with spd_* flags), and mapping the %B0 rate to 9600 + * baud. * - * If the new baud rate is invalid, try the old termios setting. - * If it's still invalid, we try 9600 baud. + * If the new baud rate is invalid, try the @old termios setting. If it's still + * invalid, we try 9600 baud. * - * Update the @termios structure to reflect the baud rate - * we're actually going to be using. Don't do this for the case - * where B0 is requested ("hang up"). + * The @termios structure is updated to reflect the baud rate we're actually + * going to be using. Don't do this for the case where B0 is requested ("hang + * up"). + * + * Locking: caller dependent */ unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios, - struct ktermios *old, unsigned int min, unsigned int max) + const struct ktermios *old, unsigned int min, unsigned int max) { unsigned int try; unsigned int baud; @@ -468,15 +453,20 @@ uart_get_baud_rate(struct uart_port *port, struct ktermios *termios, WARN_ON(1); return 0; } - EXPORT_SYMBOL(uart_get_baud_rate); /** - * uart_get_divisor - return uart clock divisor - * @port: uart_port structure describing the port. - * @baud: desired baud rate + * uart_get_divisor - return uart clock divisor + * @port: uart_port structure describing the port + * @baud: desired baud rate * - * Calculate the uart clock divisor for the port. + * Calculate the divisor (baud_base / baud) for the specified @baud, + * appropriately rounded. + * + * If 38400 baud and custom divisor is selected, return the custom divisor + * instead. + * + * Locking: caller dependent */ unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud) @@ -493,12 +483,11 @@ uart_get_divisor(struct uart_port *port, unsigned int baud) return quot; } - EXPORT_SYMBOL(uart_get_divisor); /* Caller holds port mutex */ static void uart_change_speed(struct tty_struct *tty, struct uart_state *state, - struct ktermios *old_termios) + const struct ktermios *old_termios) { struct uart_port *uport = uart_port_check(state); struct ktermios *termios; @@ -614,12 +603,12 @@ static int uart_write(struct tty_struct *tty, return ret; } -static int uart_write_room(struct tty_struct *tty) +static unsigned int uart_write_room(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; struct uart_port *port; unsigned long flags; - int ret; + unsigned int ret; port = uart_port_lock(state, flags); ret = uart_circ_chars_free(&state->xmit); @@ -627,12 +616,12 @@ static int uart_write_room(struct tty_struct *tty) return ret; } -static int uart_chars_in_buffer(struct tty_struct *tty) +static unsigned int uart_chars_in_buffer(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; struct uart_port *port; unsigned long flags; - int ret; + unsigned int ret; port = uart_port_lock(state, flags); ret = uart_circ_chars_pending(&state->xmit); @@ -668,6 +657,20 @@ static void uart_flush_buffer(struct tty_struct *tty) } /* + * This function performs low-level write of high-priority XON/XOFF + * character and accounting for it. + * + * Requires uart_port to implement .serial_out(). + */ +void uart_xchar_out(struct uart_port *uport, int offset) +{ + serial_port_out(uport, offset, uport->x_char); + uport->icount.tx++; + uport->x_char = 0; +} +EXPORT_SYMBOL_GPL(uart_xchar_out); + +/* * This function is used to send a high-priority XON/XOFF character to * the device */ @@ -757,8 +760,6 @@ static int uart_get_info(struct tty_port *port, struct serial_struct *retinfo) struct uart_port *uport; int ret = -ENODEV; - memset(retinfo, 0, sizeof(*retinfo)); - /* * Ensure the state we copy is consistent and no hardware changes * occur as we go @@ -863,9 +864,11 @@ static int uart_set_info(struct tty_struct *tty, struct tty_port *port, goto check_and_exit; } - retval = security_locked_down(LOCKDOWN_TIOCSSERIAL); - if (retval && (change_irq || change_port)) - goto exit; + if (change_irq || change_port) { + retval = security_locked_down(LOCKDOWN_TIOCSSERIAL); + if (retval) + goto exit; + } /* * Ask the low level driver to verify the settings. @@ -973,7 +976,6 @@ static int uart_set_info(struct tty_struct *tty, struct tty_port *port, port->closing_wait = closing_wait; if (new_info->xmit_fifo_size) uport->fifosize = new_info->xmit_fifo_size; - port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0; check_and_exit: retval = 0; @@ -1027,10 +1029,10 @@ static int uart_set_info_user(struct tty_struct *tty, struct serial_struct *ss) } /** - * uart_get_lsr_info - get line status register info - * @tty: tty associated with the UART - * @state: UART being queried - * @value: returned modem value + * uart_get_lsr_info - get line status register info + * @tty: tty associated with the UART + * @state: UART being queried + * @value: returned modem value */ static int uart_get_lsr_info(struct tty_struct *tty, struct uart_state *state, unsigned int __user *value) @@ -1119,7 +1121,7 @@ out: return ret; } -static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state) +static int uart_do_autoconfig(struct tty_struct *tty, struct uart_state *state) { struct tty_port *port = &state->port; struct uart_port *uport; @@ -1280,6 +1282,125 @@ static int uart_get_icount(struct tty_struct *tty, return 0; } +#define SER_RS485_LEGACY_FLAGS (SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | \ + SER_RS485_RTS_AFTER_SEND | SER_RS485_RX_DURING_TX | \ + SER_RS485_TERMINATE_BUS) + +static int uart_check_rs485_flags(struct uart_port *port, struct serial_rs485 *rs485) +{ + u32 flags = rs485->flags; + + /* Don't return -EINVAL for unsupported legacy flags */ + flags &= ~SER_RS485_LEGACY_FLAGS; + + /* + * For any bit outside of the legacy ones that is not supported by + * the driver, return -EINVAL. + */ + if (flags & ~port->rs485_supported.flags) + return -EINVAL; + + /* Asking for address w/o addressing mode? */ + if (!(rs485->flags & SER_RS485_ADDRB) && + (rs485->flags & (SER_RS485_ADDR_RECV|SER_RS485_ADDR_DEST))) + return -EINVAL; + + /* Address given but not enabled? */ + if (!(rs485->flags & SER_RS485_ADDR_RECV) && rs485->addr_recv) + return -EINVAL; + if (!(rs485->flags & SER_RS485_ADDR_DEST) && rs485->addr_dest) + return -EINVAL; + + return 0; +} + +static void uart_sanitize_serial_rs485_delays(struct uart_port *port, + struct serial_rs485 *rs485) +{ + if (!port->rs485_supported.delay_rts_before_send) { + if (rs485->delay_rts_before_send) { + dev_warn_ratelimited(port->dev, + "%s (%d): RTS delay before sending not supported\n", + port->name, port->line); + } + rs485->delay_rts_before_send = 0; + } else if (rs485->delay_rts_before_send > RS485_MAX_RTS_DELAY) { + rs485->delay_rts_before_send = RS485_MAX_RTS_DELAY; + dev_warn_ratelimited(port->dev, + "%s (%d): RTS delay before sending clamped to %u ms\n", + port->name, port->line, rs485->delay_rts_before_send); + } + + if (!port->rs485_supported.delay_rts_after_send) { + if (rs485->delay_rts_after_send) { + dev_warn_ratelimited(port->dev, + "%s (%d): RTS delay after sending not supported\n", + port->name, port->line); + } + rs485->delay_rts_after_send = 0; + } else if (rs485->delay_rts_after_send > RS485_MAX_RTS_DELAY) { + rs485->delay_rts_after_send = RS485_MAX_RTS_DELAY; + dev_warn_ratelimited(port->dev, + "%s (%d): RTS delay after sending clamped to %u ms\n", + port->name, port->line, rs485->delay_rts_after_send); + } +} + +static void uart_sanitize_serial_rs485(struct uart_port *port, struct serial_rs485 *rs485) +{ + u32 supported_flags = port->rs485_supported.flags; + + if (!(rs485->flags & SER_RS485_ENABLED)) { + memset(rs485, 0, sizeof(*rs485)); + return; + } + + /* Pick sane settings if the user hasn't */ + if ((supported_flags & (SER_RS485_RTS_ON_SEND|SER_RS485_RTS_AFTER_SEND)) && + !(rs485->flags & SER_RS485_RTS_ON_SEND) == + !(rs485->flags & SER_RS485_RTS_AFTER_SEND)) { + dev_warn_ratelimited(port->dev, + "%s (%d): invalid RTS setting, using RTS_ON_SEND instead\n", + port->name, port->line); + rs485->flags |= SER_RS485_RTS_ON_SEND; + rs485->flags &= ~SER_RS485_RTS_AFTER_SEND; + supported_flags |= SER_RS485_RTS_ON_SEND|SER_RS485_RTS_AFTER_SEND; + } + + rs485->flags &= supported_flags; + + uart_sanitize_serial_rs485_delays(port, rs485); + + /* Return clean padding area to userspace */ + memset(rs485->padding0, 0, sizeof(rs485->padding0)); + memset(rs485->padding1, 0, sizeof(rs485->padding1)); +} + +static void uart_set_rs485_termination(struct uart_port *port, + const struct serial_rs485 *rs485) +{ + if (!(rs485->flags & SER_RS485_ENABLED)) + return; + + gpiod_set_value_cansleep(port->rs485_term_gpio, + !!(rs485->flags & SER_RS485_TERMINATE_BUS)); +} + +static int uart_rs485_config(struct uart_port *port) +{ + struct serial_rs485 *rs485 = &port->rs485; + int ret; + + uart_sanitize_serial_rs485(port, rs485); + uart_set_rs485_termination(port, rs485); + + ret = port->rs485_config(port, NULL, rs485); + if (ret) + memset(rs485, 0, sizeof(*rs485)); + + return ret; +} + static int uart_get_rs485_config(struct uart_port *port, struct serial_rs485 __user *rs485) { @@ -1296,7 +1417,7 @@ static int uart_get_rs485_config(struct uart_port *port, return 0; } -static int uart_set_rs485_config(struct uart_port *port, +static int uart_set_rs485_config(struct tty_struct *tty, struct uart_port *port, struct serial_rs485 __user *rs485_user) { struct serial_rs485 rs485; @@ -1304,13 +1425,26 @@ static int uart_set_rs485_config(struct uart_port *port, unsigned long flags; if (!port->rs485_config) - return -ENOIOCTLCMD; + return -ENOTTY; if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user))) return -EFAULT; + ret = uart_check_rs485_flags(port, &rs485); + if (ret) + return ret; + uart_sanitize_serial_rs485(port, &rs485); + uart_set_rs485_termination(port, &rs485); + spin_lock_irqsave(&port->lock, flags); - ret = port->rs485_config(port, &rs485); + ret = port->rs485_config(port, &tty->termios, &rs485); + if (!ret) { + port->rs485 = rs485; + + /* Reset RTS and other mctrl lines when disabling RS485 */ + if (!(rs485.flags & SER_RS485_ENABLED)) + port->ops->set_mctrl(port, port->mctrl); + } spin_unlock_irqrestore(&port->lock, flags); if (ret) return ret; @@ -1328,7 +1462,7 @@ static int uart_get_iso7816_config(struct uart_port *port, struct serial_iso7816 aux; if (!port->iso7816_config) - return -ENOIOCTLCMD; + return -ENOTTY; spin_lock_irqsave(&port->lock, flags); aux = port->iso7816; @@ -1348,7 +1482,7 @@ static int uart_set_iso7816_config(struct uart_port *port, unsigned long flags; if (!port->iso7816_config) - return -ENOIOCTLCMD; + return -ENOTTY; if (copy_from_user(&iso7816, iso7816_user, sizeof(*iso7816_user))) return -EFAULT; @@ -1417,6 +1551,10 @@ uart_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg) if (ret != -ENOIOCTLCMD) goto out; + /* rs485_config requires more locking than others */ + if (cmd == TIOCGRS485) + down_write(&tty->termios_rwsem); + mutex_lock(&port->mutex); uport = uart_port_check(state); @@ -1440,7 +1578,7 @@ uart_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg) break; case TIOCSRS485: - ret = uart_set_rs485_config(uport, uarg); + ret = uart_set_rs485_config(tty, uport, uarg); break; case TIOCSISO7816: @@ -1457,6 +1595,8 @@ uart_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg) } out_up: mutex_unlock(&port->mutex); + if (cmd == TIOCGRS485) + up_write(&tty->termios_rwsem); out: return ret; } @@ -1465,6 +1605,10 @@ static void uart_set_ldisc(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; struct uart_port *uport; + struct tty_port *port = &state->port; + + if (!tty_port_initialized(port)) + return; mutex_lock(&state->port.mutex); uport = uart_port_check(state); @@ -1474,7 +1618,7 @@ static void uart_set_ldisc(struct tty_struct *tty) } static void uart_set_termios(struct tty_struct *tty, - struct ktermios *old_termios) + const struct ktermios *old_termios) { struct uart_state *state = tty->driver_data; struct uart_port *uport; @@ -1522,6 +1666,7 @@ static void uart_set_termios(struct tty_struct *tty, /* Handle transition away from B0 status */ else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) { unsigned int mask = TIOCM_DTR; + if (!(cflag & CRTSCTS) || !tty_throttled(tty)) mask |= TIOCM_RTS; uart_set_mctrl(uport, mask); @@ -1560,6 +1705,7 @@ static void uart_tty_port_shutdown(struct tty_port *port) { struct uart_state *state = container_of(port, struct uart_state, port); struct uart_port *uport = uart_port_check(state); + char *buf; /* * At this point, we stop accepting input. To do this, we @@ -1581,15 +1727,24 @@ static void uart_tty_port_shutdown(struct tty_port *port) */ tty_port_set_suspended(port, 0); - uart_change_pm(state, UART_PM_STATE_OFF); + /* + * Free the transmit buffer. + */ + spin_lock_irq(&uport->lock); + buf = state->xmit.buf; + state->xmit.buf = NULL; + spin_unlock_irq(&uport->lock); + free_page((unsigned long)buf); + + uart_change_pm(state, UART_PM_STATE_OFF); } static void uart_wait_until_sent(struct tty_struct *tty, int timeout) { struct uart_state *state = tty->driver_data; struct uart_port *port; - unsigned long char_time, expire; + unsigned long char_time, expire, fifo_timeout; port = uart_port_ref(state); if (!port) @@ -1608,24 +1763,25 @@ static void uart_wait_until_sent(struct tty_struct *tty, int timeout) * Note: we have to use pretty tight timings here to satisfy * the NIST-PCTS. */ - char_time = (port->timeout - HZ/50) / port->fifosize; - char_time = char_time / 5; - if (char_time == 0) - char_time = 1; + char_time = max(nsecs_to_jiffies(port->frame_time / 5), 1UL); + if (timeout && timeout < char_time) char_time = timeout; - /* - * If the transmitter hasn't cleared in twice the approximate - * amount of time to send the entire FIFO, it probably won't - * ever clear. This assumes the UART isn't doing flow - * control, which is currently the case. Hence, if it ever - * takes longer than port->timeout, this is probably due to a - * UART bug of some kind. So, we clamp the timeout parameter at - * 2*port->timeout. - */ - if (timeout == 0 || timeout > 2 * port->timeout) - timeout = 2 * port->timeout; + if (!uart_cts_enabled(port)) { + /* + * If the transmitter hasn't cleared in twice the approximate + * amount of time to send the entire FIFO, it probably won't + * ever clear. This assumes the UART isn't doing flow + * control, which is currently the case. Hence, if it ever + * takes longer than FIFO timeout, this is probably due to a + * UART bug of some kind. So, we clamp the timeout parameter at + * 2 * FIFO timeout. + */ + fifo_timeout = uart_fifo_timeout(port); + if (timeout == 0 || timeout > 2 * fifo_timeout) + timeout = 2 * fifo_timeout; + } expire = jiffies + timeout; @@ -1641,7 +1797,7 @@ static void uart_wait_until_sent(struct tty_struct *tty, int timeout) msleep_interruptible(jiffies_to_msecs(char_time)); if (signal_pending(current)) break; - if (time_after(jiffies, expire)) + if (timeout && time_after(jiffies, expire)) break; } uart_port_deref(port); @@ -1696,17 +1852,13 @@ static void uart_port_shutdown(struct tty_port *port) */ wake_up_interruptible(&port->delta_msr_wait); - /* - * Free the IRQ and disable the port. - */ - if (uport) + if (uport) { + /* Free the IRQ and disable the port. */ uport->ops->shutdown(uport); - /* - * Ensure that the IRQ handler isn't running on another CPU. - */ - if (uport) + /* Ensure that the IRQ handler isn't running on another CPU. */ synchronize_irq(uport->irq); + } } static int uart_carrier_raised(struct tty_port *port) @@ -1788,8 +1940,6 @@ static int uart_port_activate(struct tty_port *port, struct tty_struct *tty) if (!uport || uport->flags & UPF_DEAD) return -ENXIO; - port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0; - /* * Start up the serial port. */ @@ -1908,17 +2058,23 @@ static int uart_proc_show(struct seq_file *m, void *v) } #endif +static void uart_port_spin_lock_init(struct uart_port *port) +{ + spin_lock_init(&port->lock); + lockdep_set_class(&port->lock, &port_lock_key); +} + #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL) /** - * uart_console_write - write a console message to a serial port - * @port: the port to write the message - * @s: array of characters - * @count: number of characters in string to write - * @putchar: function to write character to port + * uart_console_write - write a console message to a serial port + * @port: the port to write the message + * @s: array of characters + * @count: number of characters in string to write + * @putchar: function to write character to port */ void uart_console_write(struct uart_port *port, const char *s, unsigned int count, - void (*putchar)(struct uart_port *, int)) + void (*putchar)(struct uart_port *, unsigned char)) { unsigned int i; @@ -1930,10 +2086,15 @@ void uart_console_write(struct uart_port *port, const char *s, } EXPORT_SYMBOL_GPL(uart_console_write); -/* - * Check whether an invalid uart number has been specified, and - * if so, search for the first available port that does have - * console support. +/** + * uart_get_console - get uart port for console + * @ports: ports to search in + * @nr: number of @ports + * @co: console to search for + * Returns: uart_port for the console @co + * + * Check whether an invalid uart number has been specified (as @co->index), and + * if so, search for the first available port that does have console support. */ struct uart_port * __init uart_get_console(struct uart_port *ports, int nr, struct console *co) @@ -1953,24 +2114,23 @@ uart_get_console(struct uart_port *ports, int nr, struct console *co) } /** - * uart_parse_earlycon - Parse earlycon options - * @p: ptr to 2nd field (ie., just beyond '<name>,') - * @iotype: ptr for decoded iotype (out) - * @addr: ptr for decoded mapbase/iobase (out) - * @options: ptr for <options> field; NULL if not present (out) - * - * Decodes earlycon kernel command line parameters of the form - * earlycon=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options> - * console=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options> + * uart_parse_earlycon - Parse earlycon options + * @p: ptr to 2nd field (ie., just beyond '<name>,') + * @iotype: ptr for decoded iotype (out) + * @addr: ptr for decoded mapbase/iobase (out) + * @options: ptr for <options> field; %NULL if not present (out) * - * The optional form + * Decodes earlycon kernel command line parameters of the form: + * * earlycon=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options> + * * console=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options> * - * earlycon=<name>,0x<addr>,<options> - * console=<name>,0x<addr>,<options> + * The optional form: + * * earlycon=<name>,0x<addr>,<options> + * * console=<name>,0x<addr>,<options> * - * is also accepted; the returned @iotype will be UPIO_MEM. + * is also accepted; the returned @iotype will be %UPIO_MEM. * - * Returns 0 on success or -EINVAL on failure + * Returns: 0 on success or -%EINVAL on failure */ int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr, char **options) @@ -2015,16 +2175,16 @@ int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr, EXPORT_SYMBOL_GPL(uart_parse_earlycon); /** - * uart_parse_options - Parse serial port baud/parity/bits/flow control. - * @options: pointer to option string - * @baud: pointer to an 'int' variable for the baud rate. - * @parity: pointer to an 'int' variable for the parity. - * @bits: pointer to an 'int' variable for the number of data bits. - * @flow: pointer to an 'int' variable for the flow control character. + * uart_parse_options - Parse serial port baud/parity/bits/flow control. + * @options: pointer to option string + * @baud: pointer to an 'int' variable for the baud rate. + * @parity: pointer to an 'int' variable for the parity. + * @bits: pointer to an 'int' variable for the number of data bits. + * @flow: pointer to an 'int' variable for the flow control character. * - * uart_parse_options decodes a string containing the serial console - * options. The format of the string is <baud><parity><bits><flow>, - * eg: 115200n8r + * uart_parse_options() decodes a string containing the serial console + * options. The format of the string is <baud><parity><bits><flow>, + * eg: 115200n8r */ void uart_parse_options(const char *options, int *baud, int *parity, @@ -2045,13 +2205,13 @@ uart_parse_options(const char *options, int *baud, int *parity, EXPORT_SYMBOL_GPL(uart_parse_options); /** - * uart_set_options - setup the serial console parameters - * @port: pointer to the serial ports uart_port structure - * @co: console pointer - * @baud: baud rate - * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even) - * @bits: number of data bits - * @flow: flow control character - 'r' (rts) + * uart_set_options - setup the serial console parameters + * @port: pointer to the serial ports uart_port structure + * @co: console pointer + * @baud: baud rate + * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even) + * @bits: number of data bits + * @flow: flow control character - 'r' (rts) */ int uart_set_options(struct uart_port *port, struct console *co, @@ -2061,15 +2221,14 @@ uart_set_options(struct uart_port *port, struct console *co, static struct ktermios dummy; /* - * Ensure that the serial console lock is initialised - * early. - * If this port is a console, then the spinlock is already - * initialised. + * Ensure that the serial-console lock is initialised early. + * + * Note that the console-enabled check is needed because of kgdboc, + * which can end up calling uart_set_options() for an already enabled + * console via tty_find_polling_driver() and uart_poll_init(). */ - if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) { - spin_lock_init(&port->lock); - lockdep_set_class(&port->lock, &port_lock_key); - } + if (!uart_console_enabled(port) && !port->console_reinit) + uart_port_spin_lock_init(port); memset(&termios, 0, sizeof(struct ktermios)); @@ -2084,7 +2243,7 @@ uart_set_options(struct uart_port *port, struct console *co, switch (parity) { case 'o': case 'O': termios.c_cflag |= PARODD; - /*fall through*/ + fallthrough; case 'e': case 'E': termios.c_cflag |= PARENB; break; @@ -2104,8 +2263,11 @@ uart_set_options(struct uart_port *port, struct console *co, * Allow the setting of the UART parameters with a NULL console * too: */ - if (co) + if (co) { co->cflag = termios.c_cflag; + co->ispeed = termios.c_ispeed; + co->ospeed = termios.c_ospeed; + } return 0; } @@ -2165,22 +2327,35 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport) } put_device(tty_dev); - /* Nothing to do if the console is not suspending */ - if (!console_suspend_enabled && uart_console(uport)) + /* + * Nothing to do if the console is not suspending + * except stop_rx to prevent any asynchronous data + * over RX line. However ensure that we will be + * able to Re-start_rx later. + */ + if (!console_suspend_enabled && uart_console(uport)) { + if (uport->ops->start_rx) + uport->ops->stop_rx(uport); goto unlock; + } uport->suspended = 1; if (tty_port_initialized(port)) { const struct uart_ops *ops = uport->ops; int tries; + unsigned int mctrl; tty_port_set_suspended(port, 1); tty_port_set_initialized(port, 0); spin_lock_irq(&uport->lock); ops->stop_tx(uport); - ops->set_mctrl(uport, 0); + if (!(uport->rs485.flags & SER_RS485_ENABLED)) + ops->set_mctrl(uport, 0); + /* save mctrl so it can be restored on resume */ + mctrl = uport->mctrl; + uport->mctrl = 0; ops->stop_rx(uport); spin_unlock_irq(&uport->lock); @@ -2194,6 +2369,7 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport) uport->name); ops->shutdown(uport); + uport->mctrl = mctrl; } /* @@ -2208,6 +2384,7 @@ unlock: return 0; } +EXPORT_SYMBOL(uart_suspend_port); int uart_resume_port(struct uart_driver *drv, struct uart_port *uport) { @@ -2239,6 +2416,8 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport) */ memset(&termios, 0, sizeof(struct ktermios)); termios.c_cflag = uport->cons->cflag; + termios.c_ispeed = uport->cons->ispeed; + termios.c_ospeed = uport->cons->ospeed; /* * If that's unset, use the tty termios setting. @@ -2249,6 +2428,8 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport) if (console_suspend_enabled) uart_change_pm(state, UART_PM_STATE_ON); uport->ops->set_termios(uport, &termios, NULL); + if (!console_suspend_enabled && uport->ops->start_rx) + uport->ops->start_rx(uport); if (console_suspend_enabled) console_start(uport->cons); } @@ -2259,17 +2440,22 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport) uart_change_pm(state, UART_PM_STATE_ON); spin_lock_irq(&uport->lock); - ops->set_mctrl(uport, 0); + if (!(uport->rs485.flags & SER_RS485_ENABLED)) + ops->set_mctrl(uport, 0); spin_unlock_irq(&uport->lock); if (console_suspend_enabled || !uart_console(uport)) { /* Protected by port mutex for now */ struct tty_struct *tty = port->tty; + ret = ops->startup(uport); if (ret == 0) { if (tty) uart_change_speed(tty, state, NULL); spin_lock_irq(&uport->lock); - ops->set_mctrl(uport, uport->mctrl); + if (!(uport->rs485.flags & SER_RS485_ENABLED)) + ops->set_mctrl(uport, uport->mctrl); + else + uart_rs485_config(uport); ops->start_tx(uport); spin_unlock_irq(&uport->lock); tty_port_set_initialized(port, 1); @@ -2290,6 +2476,7 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport) return 0; } +EXPORT_SYMBOL(uart_resume_port); static inline void uart_report_port(struct uart_driver *drv, struct uart_port *port) @@ -2314,7 +2501,7 @@ uart_report_port(struct uart_driver *drv, struct uart_port *port) "MMIO 0x%llx", (unsigned long long)port->mapbase); break; default: - strlcpy(address, "*unknown*", sizeof(address)); + strscpy(address, "*unknown*", sizeof(address)); break; } @@ -2323,6 +2510,14 @@ uart_report_port(struct uart_driver *drv, struct uart_port *port) port->dev ? ": " : "", port->name, address, port->irq, port->uartclk / 16, uart_type(port)); + + /* The magic multiplier feature is a bit obscure, so report it too. */ + if (port->flags & UPF_MAGIC_MULTIPLIER) + pr_info("%s%s%s extra baud rates supported: %d, %d", + port->dev ? dev_name(port->dev) : "", + port->dev ? ": " : "", + port->name, + port->uartclk / 8, port->uartclk / 4); } static void @@ -2366,7 +2561,11 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state, * We probably don't need a spinlock around this, but */ spin_lock_irqsave(&port->lock, flags); - port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR); + port->mctrl &= TIOCM_DTR; + if (!(port->rs485.flags & SER_RS485_ENABLED)) + port->ops->set_mctrl(port, port->mctrl); + else + uart_rs485_config(port); spin_unlock_irqrestore(&port->lock, flags); /* @@ -2504,17 +2703,19 @@ static const struct tty_port_operations uart_port_ops = { }; /** - * uart_register_driver - register a driver with the uart core layer - * @drv: low level driver structure + * uart_register_driver - register a driver with the uart core layer + * @drv: low level driver structure + * + * Register a uart driver with the core driver. We in turn register with the + * tty layer, and initialise the core driver per-port state. * - * Register a uart driver with the core driver. We in turn register - * with the tty layer, and initialise the core driver per-port state. + * We have a proc file in /proc/tty/driver which is named after the normal + * driver. * - * We have a proc file in /proc/tty/driver which is named after the - * normal driver. + * @drv->port should be %NULL, and the per-port structures should be registered + * using uart_add_one_port() after this call has succeeded. * - * drv->port should be NULL, and the per-port structures should be - * registered using uart_add_one_port after this call has succeeded. + * Locking: none, Interrupts: enabled */ int uart_register_driver(struct uart_driver *drv) { @@ -2531,9 +2732,12 @@ int uart_register_driver(struct uart_driver *drv) if (!drv->state) goto out; - normal = alloc_tty_driver(drv->nr); - if (!normal) + normal = tty_alloc_driver(drv->nr, TTY_DRIVER_REAL_RAW | + TTY_DRIVER_DYNAMIC_DEV); + if (IS_ERR(normal)) { + retval = PTR_ERR(normal); goto out_kfree; + } drv->tty_driver = normal; @@ -2546,7 +2750,6 @@ int uart_register_driver(struct uart_driver *drv) normal->init_termios = tty_std_termios; normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL; normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600; - normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV; normal->driver_state = drv; tty_set_operations(normal, &uart_ops); @@ -2567,21 +2770,23 @@ int uart_register_driver(struct uart_driver *drv) for (i = 0; i < drv->nr; i++) tty_port_destroy(&drv->state[i].port); - put_tty_driver(normal); + tty_driver_kref_put(normal); out_kfree: kfree(drv->state); out: return retval; } +EXPORT_SYMBOL(uart_register_driver); /** - * uart_unregister_driver - remove a driver from the uart core layer - * @drv: low level driver structure + * uart_unregister_driver - remove a driver from the uart core layer + * @drv: low level driver structure * - * Remove all references to a driver from the core driver. The low - * level driver must have removed all its ports via the - * uart_remove_one_port() if it registered them with uart_add_one_port(). - * (ie, drv->port == NULL) + * Remove all references to a driver from the core driver. The low level + * driver must have removed all its ports via the uart_remove_one_port() if it + * registered them with uart_add_one_port(). (I.e. @drv->port is %NULL.) + * + * Locking: none, Interrupts: enabled */ void uart_unregister_driver(struct uart_driver *drv) { @@ -2589,13 +2794,14 @@ void uart_unregister_driver(struct uart_driver *drv) unsigned int i; tty_unregister_driver(p); - put_tty_driver(p); + tty_driver_kref_put(p); for (i = 0; i < drv->nr; i++) tty_port_destroy(&drv->state[i].port); kfree(drv->state); drv->state = NULL; drv->tty_driver = NULL; } +EXPORT_SYMBOL(uart_unregister_driver); struct tty_driver *uart_console_device(struct console *co, int *index) { @@ -2605,36 +2811,37 @@ struct tty_driver *uart_console_device(struct console *co, int *index) } EXPORT_SYMBOL_GPL(uart_console_device); -static ssize_t uart_get_attr_uartclk(struct device *dev, +static ssize_t uartclk_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); - return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16); + return sprintf(buf, "%d\n", tmp.baud_base * 16); } -static ssize_t uart_get_attr_type(struct device *dev, +static ssize_t type_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); - return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type); + return sprintf(buf, "%d\n", tmp.type); } -static ssize_t uart_get_attr_line(struct device *dev, + +static ssize_t line_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); - return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line); + return sprintf(buf, "%d\n", tmp.line); } -static ssize_t uart_get_attr_port(struct device *dev, +static ssize_t port_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; @@ -2645,145 +2852,198 @@ static ssize_t uart_get_attr_port(struct device *dev, ioaddr = tmp.port; if (HIGH_BITS_OFFSET) ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET; - return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr); + return sprintf(buf, "0x%lX\n", ioaddr); } -static ssize_t uart_get_attr_irq(struct device *dev, +static ssize_t irq_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); - return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq); + return sprintf(buf, "%d\n", tmp.irq); } -static ssize_t uart_get_attr_flags(struct device *dev, +static ssize_t flags_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); - return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags); + return sprintf(buf, "0x%X\n", tmp.flags); } -static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev, +static ssize_t xmit_fifo_size_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); - return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size); + return sprintf(buf, "%d\n", tmp.xmit_fifo_size); } - -static ssize_t uart_get_attr_close_delay(struct device *dev, +static ssize_t close_delay_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); - return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay); + return sprintf(buf, "%d\n", tmp.close_delay); } - -static ssize_t uart_get_attr_closing_wait(struct device *dev, +static ssize_t closing_wait_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); - return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait); + return sprintf(buf, "%d\n", tmp.closing_wait); } -static ssize_t uart_get_attr_custom_divisor(struct device *dev, +static ssize_t custom_divisor_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); - return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor); + return sprintf(buf, "%d\n", tmp.custom_divisor); } -static ssize_t uart_get_attr_io_type(struct device *dev, +static ssize_t io_type_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); - return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type); + return sprintf(buf, "%d\n", tmp.io_type); } -static ssize_t uart_get_attr_iomem_base(struct device *dev, +static ssize_t iomem_base_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); - return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base); + return sprintf(buf, "0x%lX\n", (unsigned long)tmp.iomem_base); } -static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev, +static ssize_t iomem_reg_shift_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); - return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift); -} - -static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL); -static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL); -static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL); -static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL); -static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL); -static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL); -static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL); -static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL); -static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL); -static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL); -static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL); -static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL); -static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL); + return sprintf(buf, "%d\n", tmp.iomem_reg_shift); +} + +static ssize_t console_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct tty_port *port = dev_get_drvdata(dev); + struct uart_state *state = container_of(port, struct uart_state, port); + struct uart_port *uport; + bool console = false; + + mutex_lock(&port->mutex); + uport = uart_port_check(state); + if (uport) + console = uart_console_enabled(uport); + mutex_unlock(&port->mutex); + + return sprintf(buf, "%c\n", console ? 'Y' : 'N'); +} + +static ssize_t console_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + struct tty_port *port = dev_get_drvdata(dev); + struct uart_state *state = container_of(port, struct uart_state, port); + struct uart_port *uport; + bool oldconsole, newconsole; + int ret; + + ret = kstrtobool(buf, &newconsole); + if (ret) + return ret; + + mutex_lock(&port->mutex); + uport = uart_port_check(state); + if (uport) { + oldconsole = uart_console_enabled(uport); + if (oldconsole && !newconsole) { + ret = unregister_console(uport->cons); + } else if (!oldconsole && newconsole) { + if (uart_console(uport)) { + uport->console_reinit = 1; + register_console(uport->cons); + } else { + ret = -ENOENT; + } + } + } else { + ret = -ENXIO; + } + mutex_unlock(&port->mutex); + + return ret < 0 ? ret : count; +} + +static DEVICE_ATTR_RO(uartclk); +static DEVICE_ATTR_RO(type); +static DEVICE_ATTR_RO(line); +static DEVICE_ATTR_RO(port); +static DEVICE_ATTR_RO(irq); +static DEVICE_ATTR_RO(flags); +static DEVICE_ATTR_RO(xmit_fifo_size); +static DEVICE_ATTR_RO(close_delay); +static DEVICE_ATTR_RO(closing_wait); +static DEVICE_ATTR_RO(custom_divisor); +static DEVICE_ATTR_RO(io_type); +static DEVICE_ATTR_RO(iomem_base); +static DEVICE_ATTR_RO(iomem_reg_shift); +static DEVICE_ATTR_RW(console); static struct attribute *tty_dev_attrs[] = { + &dev_attr_uartclk.attr, &dev_attr_type.attr, &dev_attr_line.attr, &dev_attr_port.attr, &dev_attr_irq.attr, &dev_attr_flags.attr, &dev_attr_xmit_fifo_size.attr, - &dev_attr_uartclk.attr, &dev_attr_close_delay.attr, &dev_attr_closing_wait.attr, &dev_attr_custom_divisor.attr, &dev_attr_io_type.attr, &dev_attr_iomem_base.attr, &dev_attr_iomem_reg_shift.attr, - NULL, - }; + &dev_attr_console.attr, + NULL +}; static const struct attribute_group tty_dev_attr_group = { .attrs = tty_dev_attrs, - }; +}; /** - * uart_add_one_port - attach a driver-defined port structure - * @drv: pointer to the uart low level driver structure for this port - * @uport: uart port structure to use for this port. + * uart_add_one_port - attach a driver-defined port structure + * @drv: pointer to the uart low level driver structure for this port + * @uport: uart port structure to use for this port. + * + * Context: task context, might sleep * - * This allows the driver to register its own uart_port structure - * with the core driver. The main purpose is to allow the low - * level uart drivers to expand uart_port, rather than having yet - * more levels of structures. + * This allows the driver @drv to register its own uart_port structure with the + * core driver. The main purpose is to allow the low level uart drivers to + * expand uart_port, rather than having yet more levels of structures. */ int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport) { @@ -2793,8 +3053,6 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport) struct device *tty_dev; int num_groups; - BUG_ON(in_interrupt()); - if (uport->line >= drv->nr) return -EINVAL; @@ -2825,13 +3083,12 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport) } /* - * If this port is a console, then the spinlock is already + * If this port is in use as a console then the spinlock is already * initialised. */ - if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) { - spin_lock_init(&uport->lock); - lockdep_set_class(&uport->lock, &port_lock_key); - } + if (!uart_console_enabled(uport)) + uart_port_spin_lock_init(uport); + if (uport->cons && uport->dev) of_console_check(uport->dev->of_node, uport->cons->name, uport->line); @@ -2878,15 +3135,17 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport) return ret; } +EXPORT_SYMBOL(uart_add_one_port); /** - * uart_remove_one_port - detach a driver defined port structure - * @drv: pointer to the uart low level driver structure for this port - * @uport: uart port structure for this port + * uart_remove_one_port - detach a driver defined port structure + * @drv: pointer to the uart low level driver structure for this port + * @uport: uart port structure for this port + * + * Context: task context, might sleep * - * This unhooks (and hangs up) the specified port structure from the - * core driver. No further calls will be made to the low-level code - * for this port. + * This unhooks (and hangs up) the specified port structure from the core + * driver. No further calls will be made to the low-level code for this port. */ int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport) { @@ -2896,8 +3155,6 @@ int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport) struct tty_struct *tty; int ret = 0; - BUG_ON(in_interrupt()); - mutex_lock(&port_mutex); /* @@ -2958,39 +3215,47 @@ out: return ret; } +EXPORT_SYMBOL(uart_remove_one_port); -/* - * Are the two ports equivalent? +/** + * uart_match_port - are the two ports equivalent? + * @port1: first port + * @port2: second port + * + * This utility function can be used to determine whether two uart_port + * structures describe the same port. */ -int uart_match_port(struct uart_port *port1, struct uart_port *port2) +bool uart_match_port(const struct uart_port *port1, + const struct uart_port *port2) { if (port1->iotype != port2->iotype) - return 0; + return false; switch (port1->iotype) { case UPIO_PORT: - return (port1->iobase == port2->iobase); + return port1->iobase == port2->iobase; case UPIO_HUB6: - return (port1->iobase == port2->iobase) && - (port1->hub6 == port2->hub6); + return port1->iobase == port2->iobase && + port1->hub6 == port2->hub6; case UPIO_MEM: case UPIO_MEM16: case UPIO_MEM32: case UPIO_MEM32BE: case UPIO_AU: case UPIO_TSI: - return (port1->mapbase == port2->mapbase); + return port1->mapbase == port2->mapbase; } - return 0; + + return false; } EXPORT_SYMBOL(uart_match_port); /** - * uart_handle_dcd_change - handle a change of carrier detect state - * @uport: uart_port structure for the open port - * @status: new carrier detect status, nonzero if active + * uart_handle_dcd_change - handle a change of carrier detect state + * @uport: uart_port structure for the open port + * @status: new carrier detect status, nonzero if active * - * Caller must hold uport->lock + * Caller must hold uport->lock. */ void uart_handle_dcd_change(struct uart_port *uport, unsigned int status) { @@ -3021,11 +3286,11 @@ void uart_handle_dcd_change(struct uart_port *uport, unsigned int status) EXPORT_SYMBOL_GPL(uart_handle_dcd_change); /** - * uart_handle_cts_change - handle a change of clear-to-send state - * @uport: uart_port structure for the open port - * @status: new clear to send status, nonzero if active + * uart_handle_cts_change - handle a change of clear-to-send state + * @uport: uart_port structure for the open port + * @status: new clear to send status, nonzero if active * - * Caller must hold uport->lock + * Caller must hold uport->lock. */ void uart_handle_cts_change(struct uart_port *uport, unsigned int status) { @@ -3082,107 +3347,67 @@ void uart_insert_char(struct uart_port *port, unsigned int status, } EXPORT_SYMBOL_GPL(uart_insert_char); -int uart_handle_sysrq_char(struct uart_port *port, unsigned int ch) -{ - if (!IS_ENABLED(CONFIG_MAGIC_SYSRQ_SERIAL)) - return 0; - - if (!port->has_sysrq || !port->sysrq) - return 0; +#ifdef CONFIG_MAGIC_SYSRQ_SERIAL +static const char sysrq_toggle_seq[] = CONFIG_MAGIC_SYSRQ_SERIAL_SEQUENCE; - if (ch && time_before(jiffies, port->sysrq)) { - handle_sysrq(ch); - port->sysrq = 0; - return 1; - } - port->sysrq = 0; +static void uart_sysrq_on(struct work_struct *w) +{ + int sysrq_toggle_seq_len = strlen(sysrq_toggle_seq); - return 0; + sysrq_toggle_support(1); + pr_info("SysRq is enabled by magic sequence '%*pE' on serial\n", + sysrq_toggle_seq_len, sysrq_toggle_seq); } -EXPORT_SYMBOL_GPL(uart_handle_sysrq_char); +static DECLARE_WORK(sysrq_enable_work, uart_sysrq_on); -int uart_prepare_sysrq_char(struct uart_port *port, unsigned int ch) +/** + * uart_try_toggle_sysrq - Enables SysRq from serial line + * @port: uart_port structure where char(s) after BREAK met + * @ch: new character in the sequence after received BREAK + * + * Enables magic SysRq when the required sequence is met on port + * (see CONFIG_MAGIC_SYSRQ_SERIAL_SEQUENCE). + * + * Returns: %false if @ch is out of enabling sequence and should be + * handled some other way, %true if @ch was consumed. + */ +bool uart_try_toggle_sysrq(struct uart_port *port, unsigned int ch) { - if (!IS_ENABLED(CONFIG_MAGIC_SYSRQ_SERIAL)) - return 0; + int sysrq_toggle_seq_len = strlen(sysrq_toggle_seq); - if (!port->has_sysrq || !port->sysrq) - return 0; + if (!sysrq_toggle_seq_len) + return false; - if (ch && time_before(jiffies, port->sysrq)) { - port->sysrq_ch = ch; - port->sysrq = 0; - return 1; + BUILD_BUG_ON(ARRAY_SIZE(sysrq_toggle_seq) >= U8_MAX); + if (sysrq_toggle_seq[port->sysrq_seq] != ch) { + port->sysrq_seq = 0; + return false; } - port->sysrq = 0; - - return 0; -} -EXPORT_SYMBOL_GPL(uart_prepare_sysrq_char); - -void uart_unlock_and_check_sysrq(struct uart_port *port, unsigned long irqflags) -{ - int sysrq_ch; - if (!port->has_sysrq) { - spin_unlock_irqrestore(&port->lock, irqflags); - return; + if (++port->sysrq_seq < sysrq_toggle_seq_len) { + port->sysrq = jiffies + SYSRQ_TIMEOUT; + return true; } - sysrq_ch = port->sysrq_ch; - port->sysrq_ch = 0; - - spin_unlock_irqrestore(&port->lock, irqflags); - - if (sysrq_ch) - handle_sysrq(sysrq_ch); -} -EXPORT_SYMBOL_GPL(uart_unlock_and_check_sysrq); - -/* - * We do the SysRQ and SAK checking like this... - */ -int uart_handle_break(struct uart_port *port) -{ - struct uart_state *state = port->state; + schedule_work(&sysrq_enable_work); - if (port->handle_break) - port->handle_break(port); - - if (port->has_sysrq) { - if (port->cons && port->cons->index == port->line) { - if (!port->sysrq) { - port->sysrq = jiffies + HZ*5; - return 1; - } - port->sysrq = 0; - } - } - - if (port->flags & UPF_SAK) - do_SAK(state->port.tty); - return 0; + port->sysrq = 0; + return true; } -EXPORT_SYMBOL_GPL(uart_handle_break); - -EXPORT_SYMBOL(uart_write_wakeup); -EXPORT_SYMBOL(uart_register_driver); -EXPORT_SYMBOL(uart_unregister_driver); -EXPORT_SYMBOL(uart_suspend_port); -EXPORT_SYMBOL(uart_resume_port); -EXPORT_SYMBOL(uart_add_one_port); -EXPORT_SYMBOL(uart_remove_one_port); +EXPORT_SYMBOL_GPL(uart_try_toggle_sysrq); +#endif /** * uart_get_rs485_mode() - retrieve rs485 properties for given uart - * @dev: uart device - * @rs485conf: output parameter + * @port: uart device's target port * * This function implements the device tree binding described in * Documentation/devicetree/bindings/serial/rs485.txt. */ -void uart_get_rs485_mode(struct device *dev, struct serial_rs485 *rs485conf) +int uart_get_rs485_mode(struct uart_port *port) { + struct serial_rs485 *rs485conf = &port->rs485; + struct device *dev = port->dev; u32 rs485_delay[2]; int ret; @@ -3196,11 +3421,14 @@ void uart_get_rs485_mode(struct device *dev, struct serial_rs485 *rs485conf) rs485conf->delay_rts_after_send = 0; } + uart_sanitize_serial_rs485_delays(port, rs485conf); + /* * Clear full-duplex and enabled flags, set RTS polarity to active high * to get to a defined state with the following properties: */ rs485conf->flags &= ~(SER_RS485_RX_DURING_TX | SER_RS485_ENABLED | + SER_RS485_TERMINATE_BUS | SER_RS485_RTS_AFTER_SEND); rs485conf->flags |= SER_RS485_RTS_ON_SEND; @@ -3214,8 +3442,33 @@ void uart_get_rs485_mode(struct device *dev, struct serial_rs485 *rs485conf) rs485conf->flags &= ~SER_RS485_RTS_ON_SEND; rs485conf->flags |= SER_RS485_RTS_AFTER_SEND; } + + /* + * Disabling termination by default is the safe choice: Else if many + * bus participants enable it, no communication is possible at all. + * Works fine for short cables and users may enable for longer cables. + */ + port->rs485_term_gpio = devm_gpiod_get_optional(dev, "rs485-term", + GPIOD_OUT_LOW); + if (IS_ERR(port->rs485_term_gpio)) { + ret = PTR_ERR(port->rs485_term_gpio); + port->rs485_term_gpio = NULL; + return dev_err_probe(dev, ret, "Cannot get rs485-term-gpios\n"); + } + if (port->rs485_term_gpio) + port->rs485_supported.flags |= SER_RS485_TERMINATE_BUS; + + return 0; } EXPORT_SYMBOL_GPL(uart_get_rs485_mode); +/* Compile-time assertions for serial_rs485 layout */ +static_assert(offsetof(struct serial_rs485, padding) == + (offsetof(struct serial_rs485, delay_rts_after_send) + sizeof(__u32))); +static_assert(offsetof(struct serial_rs485, padding1) == + offsetof(struct serial_rs485, padding[1])); +static_assert((offsetof(struct serial_rs485, padding[4]) + sizeof(__u32)) == + sizeof(struct serial_rs485)); + MODULE_DESCRIPTION("Serial driver core"); MODULE_LICENSE("GPL"); |