[PATCH] serial: serial_txx9 driver update

Update the serial_txx9 driver.

 * More strict check in verify_port.  Cleanup.
 * Do not insert a char caused previous overrun.
 * Fix some spin_locks.
 * Do not call uart_add_one_port for absent ports.

Also, this patch removes a BROKEN tag from Kconfig.  This driver has been
marked as BROKEN by removal of uart_register_port, but it has been solved
already on Sep 2005.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/serial/Kconfig

@@ -866,7 +866,7 @@ config SERIAL_M32R_PLDSIO
 
 config SERIAL_TXX9
 	bool "TMPTX39XX/49XX SIO support"
-	depends HAS_TXX9_SERIAL && BROKEN
+	depends HAS_TXX9_SERIAL
 	select SERIAL_CORE
 	default y
 

drivers/serial/serial_txx9.c

@@ -33,6 +33,10 @@
  *	1.02	Cleanup. (import 8250.c changes)
  *	1.03	Fix low-latency mode. (import 8250.c changes)
  *	1.04	Remove usage of deprecated functions, cleanup.
+ *	1.05	More strict check in verify_port.  Cleanup.
+ *	1.06	Do not insert a char caused previous overrun.
+ *		Fix some spin_locks.
+ *		Do not call uart_add_one_port for absent ports.
  */
 #include <linux/config.h>
 
@@ -57,7 +61,7 @@
 #include <asm/io.h>
 #include <asm/irq.h>
 
-static char *serial_version = "1.04";
+static char *serial_version = "1.06";
 static char *serial_name = "TX39/49 Serial driver";
 
 #define PASS_LIMIT	256
@@ -94,6 +98,8 @@ static char *serial_name = "TX39/49 Serial driver";
 #define UART_NR  4
 #endif
 
+#define HIGH_BITS_OFFSET	((sizeof(long)-sizeof(int))*8)
+
 struct uart_txx9_port {
 	struct uart_port	port;
 
@@ -210,7 +216,7 @@ static inline unsigned int sio_in(struct uart_txx9_port *up, int offset)
 {
 	switch (up->port.iotype) {
 	default:
-		return *(volatile u32 *)(up->port.membase + offset);
+		return __raw_readl(up->port.membase + offset);
 	case UPIO_PORT:
 		return inl(up->port.iobase + offset);
 	}
@@ -221,7 +227,7 @@ sio_out(struct uart_txx9_port *up, int offset, int value)
 {
 	switch (up->port.iotype) {
 	default:
-		*(volatile u32 *)(up->port.membase + offset) = value;
+		__raw_writel(value, up->port.membase + offset);
 		break;
 	case UPIO_PORT:
 		outl(value, up->port.iobase + offset);
@@ -259,34 +265,19 @@ sio_quot_set(struct uart_txx9_port *up, int quot)
 static void serial_txx9_stop_tx(struct uart_port *port)
 {
 	struct uart_txx9_port *up = (struct uart_txx9_port *)port;
-	unsigned long flags;
-
-	spin_lock_irqsave(&up->port.lock, flags);
 	sio_mask(up, TXX9_SIDICR, TXX9_SIDICR_TIE);
-	spin_unlock_irqrestore(&up->port.lock, flags);
 }
 
 static void serial_txx9_start_tx(struct uart_port *port)
 {
 	struct uart_txx9_port *up = (struct uart_txx9_port *)port;
-	unsigned long flags;
-
-	spin_lock_irqsave(&up->port.lock, flags);
 	sio_set(up, TXX9_SIDICR, TXX9_SIDICR_TIE);
-	spin_unlock_irqrestore(&up->port.lock, flags);
 }
 
 static void serial_txx9_stop_rx(struct uart_port *port)
 {
 	struct uart_txx9_port *up = (struct uart_txx9_port *)port;
-	unsigned long flags;
-
-	spin_lock_irqsave(&up->port.lock, flags);
 	up->port.read_status_mask &= ~TXX9_SIDISR_RDIS;
-#if 0
-	sio_mask(up, TXX9_SIDICR, TXX9_SIDICR_RIE);
-#endif
-	spin_unlock_irqrestore(&up->port.lock, flags);
 }
 
 static void serial_txx9_enable_ms(struct uart_port *port)
@@ -302,12 +293,16 @@ receive_chars(struct uart_txx9_port *up, unsigned int *status, struct pt_regs *r
 	unsigned int disr = *status;
 	int max_count = 256;
 	char flag;
+	unsigned int next_ignore_status_mask;
 
 	do {
 		ch = sio_in(up, TXX9_SIRFIFO);
 		flag = TTY_NORMAL;
 		up->port.icount.rx++;
 
+		/* mask out RFDN_MASK bit added by previous overrun */
+		next_ignore_status_mask =
+			up->port.ignore_status_mask & ~TXX9_SIDISR_RFDN_MASK;
 		if (unlikely(disr & (TXX9_SIDISR_UBRK | TXX9_SIDISR_UPER |
 				     TXX9_SIDISR_UFER | TXX9_SIDISR_UOER))) {
 			/*
@@ -328,8 +323,17 @@ receive_chars(struct uart_txx9_port *up, unsigned int *status, struct pt_regs *r
 				up->port.icount.parity++;
 			else if (disr & TXX9_SIDISR_UFER)
 				up->port.icount.frame++;
-			if (disr & TXX9_SIDISR_UOER)
+			if (disr & TXX9_SIDISR_UOER) {
 				up->port.icount.overrun++;
+				/*
+				 * The receiver read buffer still hold
+				 * a char which caused overrun.
+				 * Ignore next char by adding RFDN_MASK
+				 * to ignore_status_mask temporarily.
+				 */
+				next_ignore_status_mask |=
+					TXX9_SIDISR_RFDN_MASK;
+			}
 
 			/*
 			 * Mask off conditions which should be ingored.
@@ -349,6 +353,7 @@ receive_chars(struct uart_txx9_port *up, unsigned int *status, struct pt_regs *r
 		uart_insert_char(&up->port, disr, TXX9_SIDISR_UOER, ch, flag);
 
 	ignore_char:
+		up->port.ignore_status_mask = next_ignore_status_mask;
 		disr = sio_in(up, TXX9_SIDISR);
 	} while (!(disr & TXX9_SIDISR_UVALID) && (max_count-- > 0));
 	spin_unlock(&up->port.lock);
@@ -450,14 +455,11 @@ static unsigned int serial_txx9_get_mctrl(struct uart_port *port)
 static void serial_txx9_set_mctrl(struct uart_port *port, unsigned int mctrl)
 {
 	struct uart_txx9_port *up = (struct uart_txx9_port *)port;
-	unsigned long flags;
 
-	spin_lock_irqsave(&up->port.lock, flags);
 	if (mctrl & TIOCM_RTS)
 		sio_mask(up, TXX9_SIFLCR, TXX9_SIFLCR_RTSSC);
 	else
 		sio_set(up, TXX9_SIFLCR, TXX9_SIFLCR_RTSSC);
-	spin_unlock_irqrestore(&up->port.lock, flags);
 }
 
 static void serial_txx9_break_ctl(struct uart_port *port, int break_state)
@@ -784,8 +786,14 @@ static void serial_txx9_config_port(struct uart_port *port, int uflags)
 static int
 serial_txx9_verify_port(struct uart_port *port, struct serial_struct *ser)
 {
-	if (ser->irq < 0 ||
-	    ser->baud_base < 9600 || ser->type != PORT_TXX9)
+	unsigned long new_port = ser->port;
+	if (HIGH_BITS_OFFSET)
+		new_port += (unsigned long)ser->port_high << HIGH_BITS_OFFSET;
+	if (ser->type != port->type ||
+	    ser->irq != port->irq ||
+	    ser->io_type != port->iotype ||
+	    new_port != port->iobase ||
+	    (unsigned long)ser->iomem_base != port->mapbase)
 		return -EINVAL;
 	return 0;
 }
@@ -827,7 +835,8 @@ static void __init serial_txx9_register_ports(struct uart_driver *drv)
 
 		up->port.line = i;
 		up->port.ops = &serial_txx9_pops;
-		uart_add_one_port(drv, &up->port);
+		if (up->port.iobase || up->port.mapbase)
+			uart_add_one_port(drv, &up->port);
 	}
 }
 
@@ -926,11 +935,6 @@ static int serial_txx9_console_setup(struct console *co, char *options)
 	if (!port->ops)
 		return -ENODEV;
 
-	/*
-	 * Temporary fix.
-	 */
-	spin_lock_init(&port->lock);
-
 	/*
 	 *	Disable UART interrupts, set DTR and RTS high
 	 *	and set speed.
@@ -1041,11 +1045,10 @@ static int __devinit serial_txx9_register_port(struct uart_port *port)
 	mutex_lock(&serial_txx9_mutex);
 	for (i = 0; i < UART_NR; i++) {
 		uart = &serial_txx9_ports[i];
-		if (uart->port.type == PORT_UNKNOWN)
+		if (!(uart->port.iobase || uart->port.mapbase))
 			break;
 	}
 	if (i < UART_NR) {
-		uart_remove_one_port(&serial_txx9_reg, &uart->port);
 		uart->port.iobase = port->iobase;
 		uart->port.membase = port->membase;
 		uart->port.irq      = port->irq;
@@ -1080,9 +1083,8 @@ static void __devexit serial_txx9_unregister_port(int line)
 	uart->port.type = PORT_UNKNOWN;
 	uart->port.iobase = 0;
 	uart->port.mapbase = 0;
-	uart->port.membase = 0;
+	uart->port.membase = NULL;
 	uart->port.dev = NULL;
-	uart_add_one_port(&serial_txx9_reg, &uart->port);
 	mutex_unlock(&serial_txx9_mutex);
 }
 
@@ -1198,8 +1200,11 @@ static void __exit serial_txx9_exit(void)
 #ifdef ENABLE_SERIAL_TXX9_PCI
 	pci_unregister_driver(&serial_txx9_pci_driver);
 #endif
-	for (i = 0; i < UART_NR; i++)
-		uart_remove_one_port(&serial_txx9_reg, &serial_txx9_ports[i].port);
+	for (i = 0; i < UART_NR; i++) {
+		struct uart_txx9_port *up = &serial_txx9_ports[i];
+		if (up->port.iobase || up->port.mapbase)
+			uart_remove_one_port(&serial_txx9_reg, &up->port);
+	}
 
 	uart_unregister_driver(&serial_txx9_reg);
 }