Merge tag 'v5.19-rc3' into tty-next

[linux-2.6-microblaze.git] / drivers / tty / serial / 8250 / 8250_port.c

diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 8f32fe9..3e3d784 100644 (file)
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -647,6 +647,14 @@ void serial8250_em485_destroy(struct uart_8250_port *p)
 }
 EXPORT_SYMBOL_GPL(serial8250_em485_destroy);
 
+struct serial_rs485 serial8250_em485_supported = {
+       .flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND |
+                SER_RS485_TERMINATE_BUS | SER_RS485_RX_DURING_TX,
+       .delay_rts_before_send = 1,
+       .delay_rts_after_send = 1,
+};
+EXPORT_SYMBOL_GPL(serial8250_em485_supported);
+
 /**
  * serial8250_em485_config() - generic ->rs485_config() callback
  * @port: uart port
@@ -667,13 +675,6 @@ int serial8250_em485_config(struct uart_port *port, struct serial_rs485 *rs485)
                rs485->flags &= ~SER_RS485_RTS_AFTER_SEND;
        }
 
-       /* clamp the delays to [0, 100ms] */
-       rs485->delay_rts_before_send = min(rs485->delay_rts_before_send, 100U);
-       rs485->delay_rts_after_send  = min(rs485->delay_rts_after_send, 100U);
-
-       memset(rs485->padding, 0, sizeof(rs485->padding));
-       port->rs485 = *rs485;
-
        gpiod_set_value(port->rs485_term_gpio,
                        rs485->flags & SER_RS485_TERMINATE_BUS);
 
@@ -681,15 +682,8 @@ int serial8250_em485_config(struct uart_port *port, struct serial_rs485 *rs485)
         * Both serial8250_em485_init() and serial8250_em485_destroy()
         * are idempotent.
         */
-       if (rs485->flags & SER_RS485_ENABLED) {
-               int ret = serial8250_em485_init(up);
-
-               if (ret) {
-                       rs485->flags &= ~SER_RS485_ENABLED;
-                       port->rs485.flags &= ~SER_RS485_ENABLED;
-               }
-               return ret;
-       }
+       if (rs485->flags & SER_RS485_ENABLED)
+               return serial8250_em485_init(up);
 
        serial8250_em485_destroy(up);
        return 0;
@@ -1503,18 +1497,12 @@ static void __stop_tx_rs485(struct uart_8250_port *p, u64 stop_delay)
        }
 }
 
-static inline void __do_stop_tx(struct uart_8250_port *p)
-{
-       if (serial8250_clear_THRI(p))
-               serial8250_rpm_put_tx(p);
-}
-
 static inline void __stop_tx(struct uart_8250_port *p)
 {
        struct uart_8250_em485 *em485 = p->em485;
 
        if (em485) {
-               unsigned char lsr = serial_in(p, UART_LSR);
+               unsigned char lsr = serial_lsr_in(p);
                u64 stop_delay = 0;
 
                p->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
@@ -1544,7 +1532,9 @@ static inline void __stop_tx(struct uart_8250_port *p)
 
                __stop_tx_rs485(p, stop_delay);
        }
-       __do_stop_tx(p);
+
+       if (serial8250_clear_THRI(p))
+               serial8250_rpm_put_tx(p);
 }
 
 static void serial8250_stop_tx(struct uart_port *port)
@@ -1573,10 +1563,8 @@ static inline void __start_tx(struct uart_port *port)
 
        if (serial8250_set_THRI(up)) {
                if (up->bugs & UART_BUG_TXEN) {
-                       unsigned char lsr;
+                       unsigned char lsr = serial_lsr_in(up);
 
-                       lsr = serial_in(up, UART_LSR);
-                       up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
                        if (lsr & UART_LSR_THRE)
                                serial8250_tx_chars(up);
                }
@@ -1616,7 +1604,8 @@ void serial8250_em485_start_tx(struct uart_8250_port *up)
 }
 EXPORT_SYMBOL_GPL(serial8250_em485_start_tx);
 
-static inline void start_tx_rs485(struct uart_port *port)
+/* Returns false, if start_tx_timer was setup to defer TX start */
+static bool start_tx_rs485(struct uart_port *port)
 {
        struct uart_8250_port *up = up_to_u8250p(port);
        struct uart_8250_em485 *em485 = up->em485;
@@ -1644,11 +1633,11 @@ static inline void start_tx_rs485(struct uart_port *port)
                        em485->active_timer = &em485->start_tx_timer;
                        start_hrtimer_ms(&em485->start_tx_timer,
                                         up->port.rs485.delay_rts_before_send);
-                       return;
+                       return false;
                }
        }
 
-       __start_tx(port);
+       return true;
 }
 
 static enum hrtimer_restart serial8250_em485_handle_start_tx(struct hrtimer *t)
@@ -1678,14 +1667,12 @@ static void serial8250_start_tx(struct uart_port *port)
 
        serial8250_rpm_get_tx(up);
 
-       if (em485 &&
-           em485->active_timer == &em485->start_tx_timer)
-               return;
-
-       if (em485)
-               start_tx_rs485(port);
-       else
-               __start_tx(port);
+       if (em485) {
+               if ((em485->active_timer == &em485->start_tx_timer) ||
+                   !start_tx_rs485(port))
+                       return;
+       }
+       __start_tx(port);
 }
 
 static void serial8250_throttle(struct uart_port *port)
@@ -1792,9 +1779,11 @@ void serial8250_read_char(struct uart_8250_port *up, unsigned char lsr)
 EXPORT_SYMBOL_GPL(serial8250_read_char);
 
 /*
- * serial8250_rx_chars: processes according to the passed in LSR
- * value, and returns the remaining LSR bits not handled
- * by this Rx routine.
+ * serial8250_rx_chars - Read characters. The first LSR value must be passed in.
+ *
+ * Returns LSR bits. The caller should rely only on non-Rx related LSR bits
+ * (such as THRE) because the LSR value might come from an already consumed
+ * character.
  */
 unsigned char serial8250_rx_chars(struct uart_8250_port *up, unsigned char lsr)
 {
@@ -1926,7 +1915,7 @@ int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
 
        spin_lock_irqsave(&port->lock, flags);
 
-       status = serial_port_in(port, UART_LSR);
+       status = serial_lsr_in(up);
 
        /*
         * If port is stopped and there are no error conditions in the
@@ -2007,8 +1996,7 @@ static unsigned int serial8250_tx_empty(struct uart_port *port)
        serial8250_rpm_get(up);
 
        spin_lock_irqsave(&port->lock, flags);
-       lsr = serial_port_in(port, UART_LSR);
-       up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
+       lsr = serial_lsr_in(up);
        spin_unlock_irqrestore(&port->lock, flags);
 
        serial8250_rpm_put(up);
@@ -2084,9 +2072,7 @@ static void wait_for_lsr(struct uart_8250_port *up, int bits)
 
        /* Wait up to 10ms for the character(s) to be sent. */
        for (;;) {
-               status = serial_in(up, UART_LSR);
-
-               up->lsr_saved_flags |= status & LSR_SAVE_FLAGS;
+               status = serial_lsr_in(up);
 
                if ((status & bits) == bits)
                        break;
@@ -3201,7 +3187,7 @@ static void serial8250_config_port(struct uart_port *port, int flags)
                autoconfig(up);
 
        if (port->rs485.flags & SER_RS485_ENABLED)
-               port->rs485_config(port, &port->rs485);
+               uart_rs485_config(port);
 
        /* if access method is AU, it is a 16550 with a quirk */
        if (port->type == PORT_16550A && port->iotype == UPIO_AU)