Differential D16402 Diff 45752 sys/dev/uart/uart_dev_ns8250.c

Changeset View

Standalone View

sys/dev/uart/uart_dev_ns8250.c

Show All 32 Lines
__FBSDID("$FreeBSD$");		__FBSDID("$FreeBSD$");

#include <sys/param.h>		#include <sys/param.h>
#include <sys/systm.h>		#include <sys/systm.h>
#include <sys/bus.h>		#include <sys/bus.h>
#include <sys/conf.h>		#include <sys/conf.h>
#include <sys/kernel.h>		#include <sys/kernel.h>
#include <sys/sysctl.h>		#include <sys/sysctl.h>
		#include <sys/tty.h>
#include <machine/bus.h>		#include <machine/bus.h>

#ifdef FDT		#ifdef FDT
#include <dev/fdt/fdt_common.h>		#include <dev/fdt/fdt_common.h>
#include <dev/ofw/ofw_bus.h>		#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>		#include <dev/ofw/ofw_bus_subr.h>
#endif		#endif

▲ Show 20 Lines • Show All 90 Lines • ▼ Show 20 Lines	ns8250_divisor(int rclk, int baudrate)

/* enforce maximum error tolerance: */		/* enforce maximum error tolerance: */
if (error < -UART_DEV_TOLERANCE_PCT \|\| error > UART_DEV_TOLERANCE_PCT)		if (error < -UART_DEV_TOLERANCE_PCT \|\| error > UART_DEV_TOLERANCE_PCT)
return (0);		return (0);

return (divisor);		return (divisor);
}		}

		/*
		* As above, but takes a fractional baudrate.
		* This one currently does NOT enforce a maximum deviation.
		*/
static int		static int
		ns8250_fdivisor(int rclk, int baudrate_n, int baudrate_d)
		{
		int divisor;
		int divisor_n, divisor_d;

		if (baudrate_n == 0 \|\| baudrate_d == 0)
		return (0);

		divisor_n = rclk * baudrate_d;
		divisor_d = baudrate_n;

		divisor = (divisor_n / (divisor_d << 3) + 1) >> 1;
		if (divisor <= 0 \|\| divisor > 65535)
		return (0);

		/* TODO: Enforce max 3% error in actual baudrate */

		return (divisor);
		}

		static int
ns8250_drain(struct uart_bas *bas, int what)		ns8250_drain(struct uart_bas *bas, int what)
{		{
int delay, limit;		int delay, limit;

delay = ns8250_delay(bas);		delay = ns8250_delay(bas);

if (what & UART_DRAIN_TRANSMITTER) {		if (what & UART_DRAIN_TRANSMITTER) {
/*		/*
▲ Show 20 Lines • Show All 449 Lines • ▼ Show 20 Lines
}		}

int		int
ns8250_bus_ioctl(struct uart_softc *sc, int request, intptr_t data)		ns8250_bus_ioctl(struct uart_softc *sc, int request, intptr_t data)
{		{
struct uart_bas *bas;		struct uart_bas *bas;
int baudrate, divisor, error;		int baudrate, divisor, error;
uint8_t efr, lcr;		uint8_t efr, lcr;
		struct baud_fraction *bf;

bas = &sc->sc_bas;		bas = &sc->sc_bas;
error = 0;		error = 0;
uart_lock(sc->sc_hwmtx);		uart_lock(sc->sc_hwmtx);
switch (request) {		switch (request) {
case UART_IOCTL_BREAK:		case UART_IOCTL_BREAK:
lcr = uart_getreg(bas, REG_LCR);		lcr = uart_getreg(bas, REG_LCR);
if (data)		if (data)
▲ Show 20 Lines • Show All 43 Lines • ▼ Show 20 Lines	case UART_IOCTL_BAUD:
uart_setreg(bas, REG_LCR, lcr);		uart_setreg(bas, REG_LCR, lcr);
uart_barrier(bas);		uart_barrier(bas);
baudrate = (divisor > 0) ? bas->rclk / divisor / 16 : 0;		baudrate = (divisor > 0) ? bas->rclk / divisor / 16 : 0;
if (baudrate > 0)		if (baudrate > 0)
(int)data = baudrate;		(int)data = baudrate;
else		else
error = ENXIO;		error = ENXIO;
break;		break;
		case UART_IOCTL_SET_FBAUD: {
		/* Set baudrate. */
		bf = (struct baud_fraction *)data;

		divisor = ns8250_fdivisor(bas->rclk, bf->bf_numerator, bf->bf_denominator);
		if (divisor <= 0 \|\| divisor > 65535) {
		error = EINVAL;
		break;
		}
		lcr = uart_getreg(bas, REG_LCR);
		uart_setreg(bas, REG_LCR, lcr \| LCR_DLAB);
		uart_barrier(bas);
		uart_setreg(bas, REG_DLL, divisor & 0xff);
		uart_setreg(bas, REG_DLH, (divisor >> 8) & 0xff);
		uart_barrier(bas);
		uart_setreg(bas, REG_LCR, lcr);
		uart_barrier(bas);
		sc->sc_u.u_tty.tp->t_termios.c_ispeed = ((bas->rclk / (divisor << 3)) + 1) >> 1;
		sc->sc_u.u_tty.tp->t_termios.c_ospeed = sc->sc_u.u_tty.tp->t_termios.c_ispeed;
		break;
		case UART_IOCTL_GET_FBAUD: {
		bf = (struct baud_fraction *)data;

		lcr = uart_getreg(bas, REG_LCR);
		uart_setreg(bas, REG_LCR, lcr \| LCR_DLAB);
		uart_barrier(bas);
		divisor = uart_getreg(bas, REG_DLL) \|
		(uart_getreg(bas, REG_DLH) << 8);
		uart_barrier(bas);
		uart_setreg(bas, REG_LCR, lcr);
		uart_barrier(bas);
		if (divisor <= 0)
		error = ENXIO;
		else {
		bf->bf_numerator = bas->rclk;
		bf->bf_denominator = divisor << 4;
		}
		break;
		}
		}
default:		default:
error = EINVAL;		error = EINVAL;
break;		break;
}		}
uart_unlock(sc->sc_hwmtx);		uart_unlock(sc->sc_hwmtx);
return (error);		return (error);
}		}

▲ Show 20 Lines • Show All 381 Lines • Show Last 20 Lines