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Diffstat (limited to 'drivers/serial/8250.c')
-rw-r--r--drivers/serial/8250.c152
1 files changed, 73 insertions, 79 deletions
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index d2bcd1f87cd..179c1f065e6 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -31,7 +31,6 @@
#include <linux/init.h>
#include <linux/console.h>
#include <linux/sysrq.h>
-#include <linux/mca.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/tty.h>
@@ -41,6 +40,7 @@
#include <linux/serial.h>
#include <linux/serial_8250.h>
#include <linux/nmi.h>
+#include <linux/mutex.h>
#include <asm/io.h>
#include <asm/irq.h>
@@ -54,6 +54,8 @@
*/
static unsigned int share_irqs = SERIAL8250_SHARE_IRQS;
+static unsigned int nr_uarts = CONFIG_SERIAL_8250_RUNTIME_UARTS;
+
/*
* Debugging.
*/
@@ -296,7 +298,7 @@ static inline int map_8250_out_reg(struct uart_8250_port *up, int offset)
#endif
-static _INLINE_ unsigned int serial_in(struct uart_8250_port *up, int offset)
+static unsigned int serial_in(struct uart_8250_port *up, int offset)
{
offset = map_8250_in_reg(up, offset) << up->port.regshift;
@@ -321,7 +323,7 @@ static _INLINE_ unsigned int serial_in(struct uart_8250_port *up, int offset)
}
}
-static _INLINE_ void
+static void
serial_out(struct uart_8250_port *up, int offset, int value)
{
offset = map_8250_out_reg(up, offset) << up->port.regshift;
@@ -1131,7 +1133,7 @@ static void serial8250_enable_ms(struct uart_port *port)
serial_out(up, UART_IER, up->ier);
}
-static _INLINE_ void
+static void
receive_chars(struct uart_8250_port *up, int *status, struct pt_regs *regs)
{
struct tty_struct *tty = up->port.info->tty;
@@ -1140,19 +1142,6 @@ receive_chars(struct uart_8250_port *up, int *status, struct pt_regs *regs)
char flag;
do {
- /* The following is not allowed by the tty layer and
- unsafe. It should be fixed ASAP */
- if (unlikely(tty->flip.count >= TTY_FLIPBUF_SIZE)) {
- if (tty->low_latency) {
- spin_unlock(&up->port.lock);
- tty_flip_buffer_push(tty);
- spin_lock(&up->port.lock);
- }
- /*
- * If this failed then we will throw away the
- * bytes but must do so to clear interrupts
- */
- }
ch = serial_inp(up, UART_RX);
flag = TTY_NORMAL;
up->port.icount.rx++;
@@ -1217,7 +1206,7 @@ receive_chars(struct uart_8250_port *up, int *status, struct pt_regs *regs)
*status = lsr;
}
-static _INLINE_ void transmit_chars(struct uart_8250_port *up)
+static void transmit_chars(struct uart_8250_port *up)
{
struct circ_buf *xmit = &up->port.info->xmit;
int count;
@@ -1255,25 +1244,24 @@ static _INLINE_ void transmit_chars(struct uart_8250_port *up)
__stop_tx(up);
}
-static _INLINE_ void check_modem_status(struct uart_8250_port *up)
+static unsigned int check_modem_status(struct uart_8250_port *up)
{
- int status;
+ unsigned int status = serial_in(up, UART_MSR);
- status = serial_in(up, UART_MSR);
+ if (status & UART_MSR_ANY_DELTA && up->ier & UART_IER_MSI) {
+ if (status & UART_MSR_TERI)
+ up->port.icount.rng++;
+ if (status & UART_MSR_DDSR)
+ up->port.icount.dsr++;
+ if (status & UART_MSR_DDCD)
+ uart_handle_dcd_change(&up->port, status & UART_MSR_DCD);
+ if (status & UART_MSR_DCTS)
+ uart_handle_cts_change(&up->port, status & UART_MSR_CTS);
- if ((status & UART_MSR_ANY_DELTA) == 0)
- return;
-
- if (status & UART_MSR_TERI)
- up->port.icount.rng++;
- if (status & UART_MSR_DDSR)
- up->port.icount.dsr++;
- if (status & UART_MSR_DDCD)
- uart_handle_dcd_change(&up->port, status & UART_MSR_DCD);
- if (status & UART_MSR_DCTS)
- uart_handle_cts_change(&up->port, status & UART_MSR_CTS);
+ wake_up_interruptible(&up->port.info->delta_msr_wait);
+ }
- wake_up_interruptible(&up->port.info->delta_msr_wait);
+ return status;
}
/*
@@ -1282,7 +1270,11 @@ static _INLINE_ void check_modem_status(struct uart_8250_port *up)
static inline void
serial8250_handle_port(struct uart_8250_port *up, struct pt_regs *regs)
{
- unsigned int status = serial_inp(up, UART_LSR);
+ unsigned int status;
+
+ spin_lock(&up->port.lock);
+
+ status = serial_inp(up, UART_LSR);
DEBUG_INTR("status = %x...", status);
@@ -1291,6 +1283,8 @@ serial8250_handle_port(struct uart_8250_port *up, struct pt_regs *regs)
check_modem_status(up);
if (status & UART_LSR_THRE)
transmit_chars(up);
+
+ spin_unlock(&up->port.lock);
}
/*
@@ -1326,9 +1320,7 @@ static irqreturn_t serial8250_interrupt(int irq, void *dev_id, struct pt_regs *r
iir = serial_in(up, UART_IIR);
if (!(iir & UART_IIR_NO_INT)) {
- spin_lock(&up->port.lock);
serial8250_handle_port(up, regs);
- spin_unlock(&up->port.lock);
handled = 1;
@@ -1427,11 +1419,8 @@ static void serial8250_timeout(unsigned long data)
unsigned int iir;
iir = serial_in(up, UART_IIR);
- if (!(iir & UART_IIR_NO_INT)) {
- spin_lock(&up->port.lock);
+ if (!(iir & UART_IIR_NO_INT))
serial8250_handle_port(up, NULL);
- spin_unlock(&up->port.lock);
- }
timeout = up->port.timeout;
timeout = timeout > 6 ? (timeout / 2 - 2) : 1;
@@ -1454,10 +1443,10 @@ 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 char status;
+ unsigned int status;
unsigned int ret;
- status = serial_in(up, UART_MSR);
+ status = check_modem_status(up);
ret = 0;
if (status & UART_MSR_DCD)
@@ -2037,12 +2026,6 @@ static void serial8250_config_port(struct uart_port *port, int flags)
int ret;
/*
- * Don't probe for MCA ports on non-MCA machines.
- */
- if (up->port.flags & UPF_BOOT_ONLYMCA && !MCA_bus)
- return;
-
- /*
* Find the region that we can probe for. This in turn
* tells us whether we can probe for the type of port.
*/
@@ -2118,7 +2101,7 @@ static void __init serial8250_isa_init_ports(void)
return;
first = 0;
- for (i = 0; i < UART_NR; i++) {
+ for (i = 0; i < nr_uarts; i++) {
struct uart_8250_port *up = &serial8250_ports[i];
up->port.line = i;
@@ -2137,7 +2120,7 @@ static void __init serial8250_isa_init_ports(void)
}
for (i = 0, up = serial8250_ports;
- i < ARRAY_SIZE(old_serial_port) && i < UART_NR;
+ i < ARRAY_SIZE(old_serial_port) && i < nr_uarts;
i++, up++) {
up->port.iobase = old_serial_port[i].port;
up->port.irq = irq_canonicalize(old_serial_port[i].irq);
@@ -2159,7 +2142,7 @@ serial8250_register_ports(struct uart_driver *drv, struct device *dev)
serial8250_isa_init_ports();
- for (i = 0; i < UART_NR; i++) {
+ for (i = 0; i < nr_uarts; i++) {
struct uart_8250_port *up = &serial8250_ports[i];
up->port.dev = dev;
@@ -2174,7 +2157,7 @@ serial8250_register_ports(struct uart_driver *drv, struct device *dev)
/*
* Wait for transmitter & holding register to empty
*/
-static inline void wait_for_xmitr(struct uart_8250_port *up)
+static inline void wait_for_xmitr(struct uart_8250_port *up, int bits)
{
unsigned int status, tmout = 10000;
@@ -2188,7 +2171,7 @@ static inline void wait_for_xmitr(struct uart_8250_port *up)
if (--tmout == 0)
break;
udelay(1);
- } while ((status & BOTH_EMPTY) != BOTH_EMPTY);
+ } while ((status & bits) != bits);
/* Wait up to 1s for flow control if necessary */
if (up->port.flags & UPF_CONS_FLOW) {
@@ -2228,7 +2211,7 @@ serial8250_console_write(struct console *co, const char *s, unsigned int count)
* Now, do each character
*/
for (i = 0; i < count; i++, s++) {
- wait_for_xmitr(up);
+ wait_for_xmitr(up, UART_LSR_THRE);
/*
* Send the character out.
@@ -2236,7 +2219,7 @@ serial8250_console_write(struct console *co, const char *s, unsigned int count)
*/
serial_out(up, UART_TX, *s);
if (*s == 10) {
- wait_for_xmitr(up);
+ wait_for_xmitr(up, UART_LSR_THRE);
serial_out(up, UART_TX, 13);
}
}
@@ -2245,8 +2228,8 @@ serial8250_console_write(struct console *co, const char *s, unsigned int count)
* Finally, wait for transmitter to become empty
* and restore the IER
*/
- wait_for_xmitr(up);
- serial_out(up, UART_IER, ier);
+ wait_for_xmitr(up, BOTH_EMPTY);
+ serial_out(up, UART_IER, ier | UART_IER_THRI);
}
static int serial8250_console_setup(struct console *co, char *options)
@@ -2262,7 +2245,7 @@ static int serial8250_console_setup(struct console *co, char *options)
* if so, search for the first available port that does have
* console support.
*/
- if (co->index >= UART_NR)
+ if (co->index >= nr_uarts)
co->index = 0;
port = &serial8250_ports[co->index].port;
if (!port->iobase && !port->membase)
@@ -2298,11 +2281,9 @@ static int __init find_port(struct uart_port *p)
int line;
struct uart_port *port;
- for (line = 0; line < UART_NR; line++) {
+ for (line = 0; line < nr_uarts; line++) {
port = &serial8250_ports[line].port;
- if (p->iotype == port->iotype &&
- p->iobase == port->iobase &&
- p->membase == port->membase)
+ if (uart_match_port(p, port))
return line;
}
return -ENODEV;
@@ -2422,7 +2403,7 @@ static int __devexit serial8250_remove(struct platform_device *dev)
{
int i;
- for (i = 0; i < UART_NR; i++) {
+ for (i = 0; i < nr_uarts; i++) {
struct uart_8250_port *up = &serial8250_ports[i];
if (up->port.dev == &dev->dev)
@@ -2466,6 +2447,7 @@ static struct platform_driver serial8250_isa_driver = {
.resume = serial8250_resume,
.driver = {
.name = "serial8250",
+ .owner = THIS_MODULE,
},
};
@@ -2480,7 +2462,7 @@ static struct platform_device *serial8250_isa_devs;
* 16x50 serial ports to be configured at run-time, to support PCMCIA
* modems and PCI multiport cards.
*/
-static DECLARE_MUTEX(serial_sem);
+static DEFINE_MUTEX(serial_mutex);
static struct uart_8250_port *serial8250_find_match_or_unused(struct uart_port *port)
{
@@ -2489,7 +2471,7 @@ static struct uart_8250_port *serial8250_find_match_or_unused(struct uart_port *
/*
* First, find a port entry which matches.
*/
- for (i = 0; i < UART_NR; i++)
+ for (i = 0; i < nr_uarts; i++)
if (uart_match_port(&serial8250_ports[i].port, port))
return &serial8250_ports[i];
@@ -2498,7 +2480,7 @@ static struct uart_8250_port *serial8250_find_match_or_unused(struct uart_port *
* free entry. We look for one which hasn't been previously
* used (indicated by zero iobase).
*/
- for (i = 0; i < UART_NR; i++)
+ for (i = 0; i < nr_uarts; i++)
if (serial8250_ports[i].port.type == PORT_UNKNOWN &&
serial8250_ports[i].port.iobase == 0)
return &serial8250_ports[i];
@@ -2507,7 +2489,7 @@ static struct uart_8250_port *serial8250_find_match_or_unused(struct uart_port *
* That also failed. Last resort is to find any entry which
* doesn't have a real port associated with it.
*/
- for (i = 0; i < UART_NR; i++)
+ for (i = 0; i < nr_uarts; i++)
if (serial8250_ports[i].port.type == PORT_UNKNOWN)
return &serial8250_ports[i];
@@ -2535,7 +2517,7 @@ int serial8250_register_port(struct uart_port *port)
if (port->uartclk == 0)
return -EINVAL;
- down(&serial_sem);
+ mutex_lock(&serial_mutex);
uart = serial8250_find_match_or_unused(port);
if (uart) {
@@ -2557,7 +2539,7 @@ int serial8250_register_port(struct uart_port *port)
if (ret == 0)
ret = uart->port.line;
}
- up(&serial_sem);
+ mutex_unlock(&serial_mutex);
return ret;
}
@@ -2574,7 +2556,7 @@ void serial8250_unregister_port(int line)
{
struct uart_8250_port *uart = &serial8250_ports[line];
- down(&serial_sem);
+ mutex_lock(&serial_mutex);
uart_remove_one_port(&serial8250_reg, &uart->port);
if (serial8250_isa_devs) {
uart->port.flags &= ~UPF_BOOT_AUTOCONF;
@@ -2584,7 +2566,7 @@ void serial8250_unregister_port(int line)
} else {
uart->port.dev = NULL;
}
- up(&serial_sem);
+ mutex_unlock(&serial_mutex);
}
EXPORT_SYMBOL(serial8250_unregister_port);
@@ -2592,8 +2574,11 @@ static int __init serial8250_init(void)
{
int ret, i;
+ if (nr_uarts > UART_NR)
+ nr_uarts = UART_NR;
+
printk(KERN_INFO "Serial: 8250/16550 driver $Revision: 1.90 $ "
- "%d ports, IRQ sharing %sabled\n", (int) UART_NR,
+ "%d ports, IRQ sharing %sabled\n", nr_uarts,
share_irqs ? "en" : "dis");
for (i = 0; i < NR_IRQS; i++)
@@ -2603,21 +2588,27 @@ static int __init serial8250_init(void)
if (ret)
goto out;
- serial8250_isa_devs = platform_device_register_simple("serial8250",
- PLAT8250_DEV_LEGACY, NULL, 0);
- if (IS_ERR(serial8250_isa_devs)) {
- ret = PTR_ERR(serial8250_isa_devs);
- goto unreg;
+ serial8250_isa_devs = platform_device_alloc("serial8250",
+ PLAT8250_DEV_LEGACY);
+ if (!serial8250_isa_devs) {
+ ret = -ENOMEM;
+ goto unreg_uart_drv;
}
+ ret = platform_device_add(serial8250_isa_devs);
+ if (ret)
+ goto put_dev;
+
serial8250_register_ports(&serial8250_reg, &serial8250_isa_devs->dev);
ret = platform_driver_register(&serial8250_isa_driver);
if (ret == 0)
goto out;
- platform_device_unregister(serial8250_isa_devs);
- unreg:
+ platform_device_del(serial8250_isa_devs);
+ put_dev:
+ platform_device_put(serial8250_isa_devs);
+ unreg_uart_drv:
uart_unregister_driver(&serial8250_reg);
out:
return ret;
@@ -2653,6 +2644,9 @@ module_param(share_irqs, uint, 0644);
MODULE_PARM_DESC(share_irqs, "Share IRQs with other non-8250/16x50 devices"
" (unsafe)");
+module_param(nr_uarts, uint, 0644);
+MODULE_PARM_DESC(nr_uarts, "Maximum number of UARTs supported. (1-" __MODULE_STRING(CONFIG_SERIAL_8250_NR_UARTS) ")");
+
#ifdef CONFIG_SERIAL_8250_RSA
module_param_array(probe_rsa, ulong, &probe_rsa_count, 0444);
MODULE_PARM_DESC(probe_rsa, "Probe I/O ports for RSA");