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Diffstat (limited to 'drivers/serial/8250.c')
-rw-r--r--drivers/serial/8250.c125
1 files changed, 77 insertions, 48 deletions
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index 30e8beb7143..7e8fc7c1d4c 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -77,23 +77,9 @@ static unsigned int share_irqs = SERIAL8250_SHARE_IRQS;
*/
#define is_real_interrupt(irq) ((irq) != 0)
-/*
- * This converts from our new CONFIG_ symbols to the symbols
- * that asm/serial.h expects. You _NEED_ to comment out the
- * linux/config.h include contained inside asm/serial.h for
- * this to work.
- */
-#undef CONFIG_SERIAL_MANY_PORTS
-#undef CONFIG_SERIAL_DETECT_IRQ
-#undef CONFIG_SERIAL_MULTIPORT
-#undef CONFIG_HUB6
-
#ifdef CONFIG_SERIAL_8250_DETECT_IRQ
#define CONFIG_SERIAL_DETECT_IRQ 1
#endif
-#ifdef CONFIG_SERIAL_8250_MULTIPORT
-#define CONFIG_SERIAL_MULTIPORT 1
-#endif
#ifdef CONFIG_SERIAL_8250_MANY_PORTS
#define CONFIG_SERIAL_MANY_PORTS 1
#endif
@@ -119,7 +105,7 @@ static struct old_serial_port old_serial_port[] = {
SERIAL_PORT_DFNS /* defined in asm/serial.h */
};
-#define UART_NR (ARRAY_SIZE(old_serial_port) + CONFIG_SERIAL_8250_NR_UARTS)
+#define UART_NR CONFIG_SERIAL_8250_NR_UARTS
#ifdef CONFIG_SERIAL_8250_RSA
@@ -132,9 +118,9 @@ struct uart_8250_port {
struct uart_port port;
struct timer_list timer; /* "no irq" timer */
struct list_head list; /* ports on this IRQ */
- unsigned int capabilities; /* port capabilities */
+ unsigned short capabilities; /* port capabilities */
+ unsigned short bugs; /* port bugs */
unsigned int tx_loadsz; /* transmit fifo load size */
- unsigned short rev;
unsigned char acr;
unsigned char ier;
unsigned char lcr;
@@ -560,7 +546,14 @@ static void autoconfig_has_efr(struct uart_8250_port *up)
if (id1 == 0x16 && id2 == 0xC9 &&
(id3 == 0x50 || id3 == 0x52 || id3 == 0x54)) {
up->port.type = PORT_16C950;
- up->rev = rev | (id3 << 8);
+
+ /*
+ * Enable work around for the Oxford Semiconductor 952 rev B
+ * chip which causes it to seriously miscalculate baud rates
+ * when DLL is 0.
+ */
+ if (id3 == 0x52 && rev == 0x01)
+ up->bugs |= UART_BUG_QUOT;
return;
}
@@ -577,8 +570,6 @@ static void autoconfig_has_efr(struct uart_8250_port *up)
id2 = id1 >> 8;
if (id2 == 0x10 || id2 == 0x12 || id2 == 0x14) {
- if (id2 == 0x10)
- up->rev = id1 & 255;
up->port.type = PORT_16850;
return;
}
@@ -809,6 +800,7 @@ static void autoconfig(struct uart_8250_port *up, unsigned int probeflags)
// save_flags(flags); cli();
up->capabilities = 0;
+ up->bugs = 0;
if (!(up->port.flags & UPF_BUGGY_UART)) {
/*
@@ -1001,26 +993,31 @@ static void autoconfig_irq(struct uart_8250_port *up)
up->port.irq = (irq > 0) ? irq : 0;
}
+static inline void __stop_tx(struct uart_8250_port *p)
+{
+ if (p->ier & UART_IER_THRI) {
+ p->ier &= ~UART_IER_THRI;
+ serial_out(p, UART_IER, p->ier);
+ }
+}
+
static void serial8250_stop_tx(struct uart_port *port, unsigned int tty_stop)
{
struct uart_8250_port *up = (struct uart_8250_port *)port;
- if (up->ier & UART_IER_THRI) {
- up->ier &= ~UART_IER_THRI;
- serial_out(up, UART_IER, up->ier);
- }
+ __stop_tx(up);
/*
- * We only do this from uart_stop - if we run out of
- * characters to send, we don't want to prevent the
- * FIFO from emptying.
+ * We really want to stop the transmitter from sending.
*/
- if (up->port.type == PORT_16C950 && tty_stop) {
+ if (up->port.type == PORT_16C950) {
up->acr |= UART_ACR_TXDIS;
serial_icr_write(up, UART_ACR, up->acr);
}
}
+static void transmit_chars(struct uart_8250_port *up);
+
static void serial8250_start_tx(struct uart_port *port, unsigned int tty_start)
{
struct uart_8250_port *up = (struct uart_8250_port *)port;
@@ -1028,11 +1025,20 @@ static void serial8250_start_tx(struct uart_port *port, unsigned int tty_start)
if (!(up->ier & UART_IER_THRI)) {
up->ier |= UART_IER_THRI;
serial_out(up, UART_IER, up->ier);
+
+ if (up->bugs & UART_BUG_TXEN) {
+ unsigned char lsr, iir;
+ lsr = serial_in(up, UART_LSR);
+ iir = serial_in(up, UART_IIR);
+ if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT)
+ transmit_chars(up);
+ }
}
+
/*
- * We only do this from uart_start
+ * Re-enable the transmitter if we disabled it.
*/
- if (tty_start && up->port.type == PORT_16C950) {
+ if (up->port.type == PORT_16C950 && up->acr & UART_ACR_TXDIS) {
up->acr &= ~UART_ACR_TXDIS;
serial_icr_write(up, UART_ACR, up->acr);
}
@@ -1153,7 +1159,7 @@ static _INLINE_ void transmit_chars(struct uart_8250_port *up)
return;
}
if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
- serial8250_stop_tx(&up->port, 0);
+ __stop_tx(up);
return;
}
@@ -1172,7 +1178,7 @@ static _INLINE_ void transmit_chars(struct uart_8250_port *up)
DEBUG_INTR("THRE...");
if (uart_circ_empty(xmit))
- serial8250_stop_tx(&up->port, 0);
+ __stop_tx(up);
}
static _INLINE_ void check_modem_status(struct uart_8250_port *up)
@@ -1374,13 +1380,10 @@ static unsigned int serial8250_tx_empty(struct uart_port *port)
static unsigned int serial8250_get_mctrl(struct uart_port *port)
{
struct uart_8250_port *up = (struct uart_8250_port *)port;
- unsigned long flags;
unsigned char status;
unsigned int ret;
- spin_lock_irqsave(&up->port.lock, flags);
status = serial_in(up, UART_MSR);
- spin_unlock_irqrestore(&up->port.lock, flags);
ret = 0;
if (status & UART_MSR_DCD)
@@ -1433,6 +1436,7 @@ static int serial8250_startup(struct uart_port *port)
{
struct uart_8250_port *up = (struct uart_8250_port *)port;
unsigned long flags;
+ unsigned char lsr, iir;
int retval;
up->capabilities = uart_config[up->port.type].flags;
@@ -1536,6 +1540,26 @@ static int serial8250_startup(struct uart_port *port)
up->port.mctrl |= TIOCM_OUT2;
serial8250_set_mctrl(&up->port, up->port.mctrl);
+
+ /*
+ * Do a quick test to see if we receive an
+ * interrupt when we enable the TX irq.
+ */
+ serial_outp(up, UART_IER, UART_IER_THRI);
+ lsr = serial_in(up, UART_LSR);
+ iir = serial_in(up, UART_IIR);
+ serial_outp(up, UART_IER, 0);
+
+ if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT) {
+ if (!(up->bugs & UART_BUG_TXEN)) {
+ up->bugs |= UART_BUG_TXEN;
+ pr_debug("ttyS%d - enabling bad tx status workarounds\n",
+ port->line);
+ }
+ } else {
+ up->bugs &= ~UART_BUG_TXEN;
+ }
+
spin_unlock_irqrestore(&up->port.lock, flags);
/*
@@ -1645,22 +1669,22 @@ serial8250_set_termios(struct uart_port *port, struct termios *termios,
switch (termios->c_cflag & CSIZE) {
case CS5:
- cval = 0x00;
+ cval = UART_LCR_WLEN5;
break;
case CS6:
- cval = 0x01;
+ cval = UART_LCR_WLEN6;
break;
case CS7:
- cval = 0x02;
+ cval = UART_LCR_WLEN7;
break;
default:
case CS8:
- cval = 0x03;
+ cval = UART_LCR_WLEN8;
break;
}
if (termios->c_cflag & CSTOPB)
- cval |= 0x04;
+ cval |= UART_LCR_STOP;
if (termios->c_cflag & PARENB)
cval |= UART_LCR_PARITY;
if (!(termios->c_cflag & PARODD))
@@ -1677,12 +1701,9 @@ serial8250_set_termios(struct uart_port *port, struct termios *termios,
quot = serial8250_get_divisor(port, baud);
/*
- * Work around a bug in the Oxford Semiconductor 952 rev B
- * chip which causes it to seriously miscalculate baud rates
- * when DLL is 0.
+ * Oxford Semi 952 rev B workaround
*/
- if ((quot & 0xff) == 0 && up->port.type == PORT_16C950 &&
- up->rev == 0x5201)
+ if (up->bugs & UART_BUG_QUOT && (quot & 0xff) == 0)
quot ++;
if (up->capabilities & UART_CAP_FIFO && up->port.fifosize > 1) {
@@ -2040,7 +2061,8 @@ static void __init serial8250_isa_init_ports(void)
up->port.ops = &serial8250_pops;
}
- for (i = 0, up = serial8250_ports; i < ARRAY_SIZE(old_serial_port);
+ for (i = 0, up = serial8250_ports;
+ i < ARRAY_SIZE(old_serial_port) && i < UART_NR;
i++, up++) {
up->port.iobase = old_serial_port[i].port;
up->port.irq = irq_canonicalize(old_serial_port[i].irq);
@@ -2289,10 +2311,11 @@ static int __devinit serial8250_probe(struct device *dev)
{
struct plat_serial8250_port *p = dev->platform_data;
struct uart_port port;
+ int ret, i;
memset(&port, 0, sizeof(struct uart_port));
- for (; p && p->flags != 0; p++) {
+ for (i = 0; p && p->flags != 0; p++, i++) {
port.iobase = p->iobase;
port.membase = p->membase;
port.irq = p->irq;
@@ -2301,10 +2324,16 @@ static int __devinit serial8250_probe(struct device *dev)
port.iotype = p->iotype;
port.flags = p->flags;
port.mapbase = p->mapbase;
+ port.hub6 = p->hub6;
port.dev = dev;
if (share_irqs)
port.flags |= UPF_SHARE_IRQ;
- serial8250_register_port(&port);
+ ret = serial8250_register_port(&port);
+ if (ret < 0) {
+ dev_err(dev, "unable to register port at index %d "
+ "(IO%lx MEM%lx IRQ%d): %d\n", i,
+ p->iobase, p->mapbase, p->irq, ret);
+ }
}
return 0;
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-26 01:14:00 +0000