| Current Path : /usr/src/sys/arm/at91/ |
FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
| Current File : //usr/src/sys/arm/at91/uart_dev_at91usart.c |
/*-
* Copyright (c) 2005 M. Warner Losh
* Copyright (c) 2005 Olivier Houchard
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: release/9.1.0/sys/arm/at91/uart_dev_at91usart.c 237093 2012-06-14 20:02:53Z marius $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/cons.h>
#include <sys/tty.h>
#include <machine/bus.h>
#include <dev/uart/uart.h>
#include <dev/uart/uart_cpu.h>
#include <dev/uart/uart_bus.h>
#include <arm/at91/at91_usartreg.h>
#include <arm/at91/at91_pdcreg.h>
#include <arm/at91/at91var.h>
#include "uart_if.h"
#define DEFAULT_RCLK at91_master_clock
#define USART_BUFFER_SIZE 128
/*
* High-level UART interface.
*/
struct at91_usart_rx {
bus_addr_t pa;
uint8_t *buffer;
bus_dmamap_t map;
};
struct at91_usart_softc {
struct uart_softc base;
bus_dma_tag_t tx_tag;
bus_dmamap_t tx_map;
uint32_t flags;
#define HAS_TIMEOUT 1
bus_dma_tag_t rx_tag;
struct at91_usart_rx ping_pong[2];
struct at91_usart_rx *ping;
struct at91_usart_rx *pong;
};
#define RD4(bas, reg) \
bus_space_read_4((bas)->bst, (bas)->bsh, uart_regofs(bas, reg))
#define WR4(bas, reg, value) \
bus_space_write_4((bas)->bst, (bas)->bsh, uart_regofs(bas, reg), value)
#define SIGCHG(c, i, s, d) \
do { \
if (c) { \
i |= (i & s) ? s : s | d; \
} else { \
i = (i & s) ? (i & ~s) | d : i; \
} \
} while (0);
#define BAUD2DIVISOR(b) \
((((DEFAULT_RCLK * 10) / ((b) * 16)) + 5) / 10)
/*
* Low-level UART interface.
*/
static int at91_usart_probe(struct uart_bas *bas);
static void at91_usart_init(struct uart_bas *bas, int, int, int, int);
static void at91_usart_term(struct uart_bas *bas);
static void at91_usart_putc(struct uart_bas *bas, int);
static int at91_usart_rxready(struct uart_bas *bas);
static int at91_usart_getc(struct uart_bas *bas, struct mtx *hwmtx);
extern SLIST_HEAD(uart_devinfo_list, uart_devinfo) uart_sysdevs;
static int
at91_usart_param(struct uart_bas *bas, int baudrate, int databits,
int stopbits, int parity)
{
uint32_t mr;
/*
* Assume 3-wire RS-232 configuration.
* XXX Not sure how uart will present the other modes to us, so
* XXX they are unimplemented. maybe ioctl?
*/
mr = USART_MR_MODE_NORMAL;
mr |= USART_MR_USCLKS_MCK; /* Assume MCK */
/*
* Or in the databits requested
*/
if (databits < 9)
mr &= ~USART_MR_MODE9;
switch (databits) {
case 5:
mr |= USART_MR_CHRL_5BITS;
break;
case 6:
mr |= USART_MR_CHRL_6BITS;
break;
case 7:
mr |= USART_MR_CHRL_7BITS;
break;
case 8:
mr |= USART_MR_CHRL_8BITS;
break;
case 9:
mr |= USART_MR_CHRL_8BITS | USART_MR_MODE9;
break;
default:
return (EINVAL);
}
/*
* Or in the parity
*/
switch (parity) {
case UART_PARITY_NONE:
mr |= USART_MR_PAR_NONE;
break;
case UART_PARITY_ODD:
mr |= USART_MR_PAR_ODD;
break;
case UART_PARITY_EVEN:
mr |= USART_MR_PAR_EVEN;
break;
case UART_PARITY_MARK:
mr |= USART_MR_PAR_MARK;
break;
case UART_PARITY_SPACE:
mr |= USART_MR_PAR_SPACE;
break;
default:
return (EINVAL);
}
/*
* Or in the stop bits. Note: The hardware supports 1.5 stop
* bits in async mode, but there's no way to specify that
* AFAICT. Instead, rely on the convention documented at
* http://www.lammertbies.nl/comm/info/RS-232_specs.html which
* states that 1.5 stop bits are used for 5 bit bytes and
* 2 stop bits only for longer bytes.
*/
if (stopbits == 1)
mr |= USART_MR_NBSTOP_1;
else if (databits > 5)
mr |= USART_MR_NBSTOP_2;
else
mr |= USART_MR_NBSTOP_1_5;
/*
* We want normal plumbing mode too, none of this fancy
* loopback or echo mode.
*/
mr |= USART_MR_CHMODE_NORMAL;
mr &= ~USART_MR_MSBF; /* lsb first */
mr &= ~USART_MR_CKLO_SCK; /* Don't drive SCK */
WR4(bas, USART_MR, mr);
/*
* Set the baud rate (only if we know our master clock rate)
*/
if (DEFAULT_RCLK != 0)
WR4(bas, USART_BRGR, BAUD2DIVISOR(baudrate));
/* XXX Need to take possible synchronous mode into account */
return (0);
}
static struct uart_ops at91_usart_ops = {
.probe = at91_usart_probe,
.init = at91_usart_init,
.term = at91_usart_term,
.putc = at91_usart_putc,
.rxready = at91_usart_rxready,
.getc = at91_usart_getc,
};
static int
at91_usart_probe(struct uart_bas *bas)
{
/* We know that this is always here */
return (0);
}
/*
* Initialize this device for use as a console.
*/
static void
at91_usart_init(struct uart_bas *bas, int baudrate, int databits, int stopbits,
int parity)
{
at91_usart_param(bas, baudrate, databits, stopbits, parity);
/* Reset the rx and tx buffers and turn on rx and tx */
WR4(bas, USART_CR, USART_CR_RSTSTA | USART_CR_RSTRX | USART_CR_RSTTX);
WR4(bas, USART_CR, USART_CR_RXEN | USART_CR_TXEN);
WR4(bas, USART_IDR, 0xffffffff);
}
/*
* Free resources now that we're no longer the console. This appears to
* be never called, and I'm unsure quite what to do if I am called.
*/
static void
at91_usart_term(struct uart_bas *bas)
{
/* XXX */
}
/*
* Put a character of console output (so we do it here polling rather than
* interrutp driven).
*/
static void
at91_usart_putc(struct uart_bas *bas, int c)
{
while (!(RD4(bas, USART_CSR) & USART_CSR_TXRDY))
continue;
WR4(bas, USART_THR, c);
}
/*
* Check for a character available.
*/
static int
at91_usart_rxready(struct uart_bas *bas)
{
return ((RD4(bas, USART_CSR) & USART_CSR_RXRDY) != 0 ? 1 : 0);
}
/*
* Block waiting for a character.
*/
static int
at91_usart_getc(struct uart_bas *bas, struct mtx *hwmtx)
{
int c;
uart_lock(hwmtx);
while (!(RD4(bas, USART_CSR) & USART_CSR_RXRDY)) {
uart_unlock(hwmtx);
DELAY(4);
uart_lock(hwmtx);
}
c = RD4(bas, USART_RHR) & 0xff;
uart_unlock(hwmtx);
return (c);
}
static int at91_usart_bus_probe(struct uart_softc *sc);
static int at91_usart_bus_attach(struct uart_softc *sc);
static int at91_usart_bus_flush(struct uart_softc *, int);
static int at91_usart_bus_getsig(struct uart_softc *);
static int at91_usart_bus_ioctl(struct uart_softc *, int, intptr_t);
static int at91_usart_bus_ipend(struct uart_softc *);
static int at91_usart_bus_param(struct uart_softc *, int, int, int, int);
static int at91_usart_bus_receive(struct uart_softc *);
static int at91_usart_bus_setsig(struct uart_softc *, int);
static int at91_usart_bus_transmit(struct uart_softc *);
static kobj_method_t at91_usart_methods[] = {
KOBJMETHOD(uart_probe, at91_usart_bus_probe),
KOBJMETHOD(uart_attach, at91_usart_bus_attach),
KOBJMETHOD(uart_flush, at91_usart_bus_flush),
KOBJMETHOD(uart_getsig, at91_usart_bus_getsig),
KOBJMETHOD(uart_ioctl, at91_usart_bus_ioctl),
KOBJMETHOD(uart_ipend, at91_usart_bus_ipend),
KOBJMETHOD(uart_param, at91_usart_bus_param),
KOBJMETHOD(uart_receive, at91_usart_bus_receive),
KOBJMETHOD(uart_setsig, at91_usart_bus_setsig),
KOBJMETHOD(uart_transmit, at91_usart_bus_transmit),
KOBJMETHOD_END
};
int
at91_usart_bus_probe(struct uart_softc *sc)
{
sc->sc_txfifosz = USART_BUFFER_SIZE;
sc->sc_rxfifosz = USART_BUFFER_SIZE;
sc->sc_hwiflow = 0;
return (0);
}
static void
at91_getaddr(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
{
if (error != 0)
return;
*(bus_addr_t *)arg = segs[0].ds_addr;
}
static int
at91_usart_bus_attach(struct uart_softc *sc)
{
int err;
int i;
uint32_t cr;
struct at91_usart_softc *atsc;
atsc = (struct at91_usart_softc *)sc;
/*
* See if we have a TIMEOUT bit. We disable all interrupts as
* a side effect. Boot loaders may have enabled them. Since
* a TIMEOUT interrupt can't happen without other setup, the
* apparent race here can't actually happen.
*/
WR4(&sc->sc_bas, USART_IDR, 0xffffffff);
WR4(&sc->sc_bas, USART_IER, USART_CSR_TIMEOUT);
if (RD4(&sc->sc_bas, USART_IMR) & USART_CSR_TIMEOUT)
atsc->flags |= HAS_TIMEOUT;
WR4(&sc->sc_bas, USART_IDR, 0xffffffff);
/*
* Allocate transmit DMA tag and map. We allow a transmit buffer
* to be any size, but it must map to a single contiguous physical
* extent.
*/
err = bus_dma_tag_create(bus_get_dma_tag(sc->sc_dev), 1, 0,
BUS_SPACE_MAXADDR_32BIT, BUS_SPACE_MAXADDR, NULL, NULL,
BUS_SPACE_MAXSIZE_32BIT, 1, BUS_SPACE_MAXSIZE_32BIT, 0, NULL,
NULL, &atsc->tx_tag);
if (err != 0)
goto errout;
err = bus_dmamap_create(atsc->tx_tag, 0, &atsc->tx_map);
if (err != 0)
goto errout;
if (atsc->flags & HAS_TIMEOUT) {
/*
* Allocate receive DMA tags, maps, and buffers.
* The receive buffers should be aligned to arm_dcache_align,
* otherwise partial cache line flushes on every receive
* interrupt are pretty much guaranteed.
*/
err = bus_dma_tag_create(bus_get_dma_tag(sc->sc_dev),
arm_dcache_align, 0, BUS_SPACE_MAXADDR_32BIT,
BUS_SPACE_MAXADDR, NULL, NULL, sc->sc_rxfifosz, 1,
sc->sc_rxfifosz, BUS_DMA_ALLOCNOW, NULL, NULL,
&atsc->rx_tag);
if (err != 0)
goto errout;
for (i = 0; i < 2; i++) {
err = bus_dmamem_alloc(atsc->rx_tag,
(void **)&atsc->ping_pong[i].buffer,
BUS_DMA_NOWAIT, &atsc->ping_pong[i].map);
if (err != 0)
goto errout;
err = bus_dmamap_load(atsc->rx_tag,
atsc->ping_pong[i].map,
atsc->ping_pong[i].buffer, sc->sc_rxfifosz,
at91_getaddr, &atsc->ping_pong[i].pa, 0);
if (err != 0)
goto errout;
bus_dmamap_sync(atsc->rx_tag, atsc->ping_pong[i].map,
BUS_DMASYNC_PREREAD);
}
atsc->ping = &atsc->ping_pong[0];
atsc->pong = &atsc->ping_pong[1];
}
/* Turn on rx and tx */
cr = USART_CR_RSTSTA | USART_CR_RSTRX | USART_CR_RSTTX;
WR4(&sc->sc_bas, USART_CR, cr);
WR4(&sc->sc_bas, USART_CR, USART_CR_RXEN | USART_CR_TXEN);
/*
* Setup the PDC to receive data. We use the ping-pong buffers
* so that we can more easily bounce between the two and so that
* we get an interrupt 1/2 way through the software 'fifo' we have
* to avoid overruns.
*/
if (atsc->flags & HAS_TIMEOUT) {
WR4(&sc->sc_bas, PDC_RPR, atsc->ping->pa);
WR4(&sc->sc_bas, PDC_RCR, sc->sc_rxfifosz);
WR4(&sc->sc_bas, PDC_RNPR, atsc->pong->pa);
WR4(&sc->sc_bas, PDC_RNCR, sc->sc_rxfifosz);
WR4(&sc->sc_bas, PDC_PTCR, PDC_PTCR_RXTEN);
/*
* Set the receive timeout to be 1.5 character times
* assuming 8N1.
*/
WR4(&sc->sc_bas, USART_RTOR, 15);
WR4(&sc->sc_bas, USART_CR, USART_CR_STTTO);
WR4(&sc->sc_bas, USART_IER, USART_CSR_TIMEOUT |
USART_CSR_RXBUFF | USART_CSR_ENDRX);
} else {
WR4(&sc->sc_bas, USART_IER, USART_CSR_RXRDY);
}
WR4(&sc->sc_bas, USART_IER, USART_CSR_RXBRK);
errout:
return (err);
}
static int
at91_usart_bus_transmit(struct uart_softc *sc)
{
bus_addr_t addr;
struct at91_usart_softc *atsc;
int err;
err = 0;
atsc = (struct at91_usart_softc *)sc;
uart_lock(sc->sc_hwmtx);
if (bus_dmamap_load(atsc->tx_tag, atsc->tx_map, sc->sc_txbuf,
sc->sc_txdatasz, at91_getaddr, &addr, 0) != 0) {
err = EAGAIN;
goto errout;
}
bus_dmamap_sync(atsc->tx_tag, atsc->tx_map, BUS_DMASYNC_PREWRITE);
sc->sc_txbusy = 1;
/*
* Setup the PDC to transfer the data and interrupt us when it
* is done. We've already requested the interrupt.
*/
WR4(&sc->sc_bas, PDC_TPR, addr);
WR4(&sc->sc_bas, PDC_TCR, sc->sc_txdatasz);
WR4(&sc->sc_bas, PDC_PTCR, PDC_PTCR_TXTEN);
WR4(&sc->sc_bas, USART_IER, USART_CSR_ENDTX);
errout:
uart_unlock(sc->sc_hwmtx);
return (err);
}
static int
at91_usart_bus_setsig(struct uart_softc *sc, int sig)
{
uint32_t new, old, cr;
struct uart_bas *bas;
do {
old = sc->sc_hwsig;
new = old;
if (sig & SER_DDTR)
SIGCHG(sig & SER_DTR, new, SER_DTR, SER_DDTR);
if (sig & SER_DRTS)
SIGCHG(sig & SER_RTS, new, SER_RTS, SER_DRTS);
} while (!atomic_cmpset_32(&sc->sc_hwsig, old, new));
bas = &sc->sc_bas;
uart_lock(sc->sc_hwmtx);
cr = 0;
if (new & SER_DTR)
cr |= USART_CR_DTREN;
else
cr |= USART_CR_DTRDIS;
if (new & SER_RTS)
cr |= USART_CR_RTSEN;
else
cr |= USART_CR_RTSDIS;
WR4(bas, USART_CR, cr);
uart_unlock(sc->sc_hwmtx);
return (0);
}
static int
at91_usart_bus_receive(struct uart_softc *sc)
{
return (0);
}
static int
at91_usart_bus_param(struct uart_softc *sc, int baudrate, int databits,
int stopbits, int parity)
{
return (at91_usart_param(&sc->sc_bas, baudrate, databits, stopbits,
parity));
}
static __inline void
at91_rx_put(struct uart_softc *sc, int key)
{
#if defined(KDB)
if (sc->sc_sysdev != NULL && sc->sc_sysdev->type == UART_DEV_CONSOLE)
kdb_alt_break(key, &sc->sc_altbrk);
#endif
uart_rx_put(sc, key);
}
static int
at91_usart_bus_ipend(struct uart_softc *sc)
{
struct at91_usart_softc *atsc;
struct at91_usart_rx *p;
int i, ipend, len;
uint32_t csr;
ipend = 0;
atsc = (struct at91_usart_softc *)sc;
uart_lock(sc->sc_hwmtx);
csr = RD4(&sc->sc_bas, USART_CSR);
if (csr & USART_CSR_ENDTX) {
bus_dmamap_sync(atsc->tx_tag, atsc->tx_map,
BUS_DMASYNC_POSTWRITE);
bus_dmamap_unload(atsc->tx_tag, atsc->tx_map);
}
if (csr & (USART_CSR_TXRDY | USART_CSR_ENDTX)) {
if (sc->sc_txbusy)
ipend |= SER_INT_TXIDLE;
WR4(&sc->sc_bas, USART_IDR, csr & (USART_CSR_TXRDY |
USART_CSR_ENDTX));
}
/*
* Due to the contraints of the DMA engine present in the
* atmel chip, I can't just say I have a rx interrupt pending
* and do all the work elsewhere. I need to look at the CSR
* bits right now and do things based on them to avoid races.
*/
if (atsc->flags & HAS_TIMEOUT) {
if (csr & USART_CSR_RXBUFF) {
/*
* We have a buffer overflow. Copy all data from both
* ping and pong. Insert overflow character. Reset
* ping and pong and re-enable the PDC to receive
* characters again.
*/
bus_dmamap_sync(atsc->rx_tag, atsc->ping->map,
BUS_DMASYNC_POSTREAD);
bus_dmamap_sync(atsc->rx_tag, atsc->pong->map,
BUS_DMASYNC_POSTREAD);
for (i = 0; i < sc->sc_rxfifosz; i++)
at91_rx_put(sc, atsc->ping->buffer[i]);
for (i = 0; i < sc->sc_rxfifosz; i++)
at91_rx_put(sc, atsc->pong->buffer[i]);
uart_rx_put(sc, UART_STAT_OVERRUN);
bus_dmamap_sync(atsc->rx_tag, atsc->ping->map,
BUS_DMASYNC_PREREAD);
bus_dmamap_sync(atsc->rx_tag, atsc->pong->map,
BUS_DMASYNC_PREREAD);
WR4(&sc->sc_bas, PDC_RPR, atsc->ping->pa);
WR4(&sc->sc_bas, PDC_RCR, sc->sc_rxfifosz);
WR4(&sc->sc_bas, PDC_RNPR, atsc->pong->pa);
WR4(&sc->sc_bas, PDC_RNCR, sc->sc_rxfifosz);
WR4(&sc->sc_bas, PDC_PTCR, PDC_PTCR_RXTEN);
ipend |= SER_INT_RXREADY;
} else if (csr & USART_CSR_ENDRX) {
/*
* Shuffle data from ping of ping pong buffer, but
* leave current pong in place, as it has become the
* new ping. We need to copy data and setup the old
* ping as the new pong when we're done.
*/
bus_dmamap_sync(atsc->rx_tag, atsc->ping->map,
BUS_DMASYNC_POSTREAD);
for (i = 0; i < sc->sc_rxfifosz; i++)
at91_rx_put(sc, atsc->ping->buffer[i]);
p = atsc->ping;
atsc->ping = atsc->pong;
atsc->pong = p;
bus_dmamap_sync(atsc->rx_tag, atsc->pong->map,
BUS_DMASYNC_PREREAD);
WR4(&sc->sc_bas, PDC_RNPR, atsc->pong->pa);
WR4(&sc->sc_bas, PDC_RNCR, sc->sc_rxfifosz);
ipend |= SER_INT_RXREADY;
} else if (csr & USART_CSR_TIMEOUT) {
/*
* We have one partial buffer. We need to stop the
* PDC, get the number of characters left and from
* that compute number of valid characters. We then
* need to reset ping and pong and reenable the PDC.
* Not sure if there's a race here at fast baud rates
* we need to worry about.
*/
WR4(&sc->sc_bas, PDC_PTCR, PDC_PTCR_RXTDIS);
bus_dmamap_sync(atsc->rx_tag, atsc->ping->map,
BUS_DMASYNC_POSTREAD);
len = sc->sc_rxfifosz - RD4(&sc->sc_bas, PDC_RCR);
for (i = 0; i < len; i++)
at91_rx_put(sc, atsc->ping->buffer[i]);
bus_dmamap_sync(atsc->rx_tag, atsc->ping->map,
BUS_DMASYNC_PREREAD);
WR4(&sc->sc_bas, PDC_RPR, atsc->ping->pa);
WR4(&sc->sc_bas, PDC_RCR, sc->sc_rxfifosz);
WR4(&sc->sc_bas, USART_CR, USART_CR_STTTO);
WR4(&sc->sc_bas, PDC_PTCR, PDC_PTCR_RXTEN);
ipend |= SER_INT_RXREADY;
}
} else if (csr & USART_CSR_RXRDY) {
/*
* We have another charater in a device that doesn't support
* timeouts, so we do it one character at a time.
*/
at91_rx_put(sc, RD4(&sc->sc_bas, USART_RHR) & 0xff);
ipend |= SER_INT_RXREADY;
}
if (csr & USART_CSR_RXBRK) {
ipend |= SER_INT_BREAK;
WR4(&sc->sc_bas, USART_CR, USART_CR_RSTSTA);
}
uart_unlock(sc->sc_hwmtx);
return (ipend);
}
static int
at91_usart_bus_flush(struct uart_softc *sc, int what)
{
return (0);
}
static int
at91_usart_bus_getsig(struct uart_softc *sc)
{
uint32_t csr, new, sig;
uart_lock(sc->sc_hwmtx);
csr = RD4(&sc->sc_bas, USART_CSR);
sig = 0;
if (csr & USART_CSR_CTS)
sig |= SER_CTS;
if (csr & USART_CSR_DCD)
sig |= SER_DCD;
if (csr & USART_CSR_DSR)
sig |= SER_DSR;
if (csr & USART_CSR_RI)
sig |= SER_RI;
new = sig & ~SER_MASK_DELTA;
sc->sc_hwsig = new;
uart_unlock(sc->sc_hwmtx);
return (sig);
}
static int
at91_usart_bus_ioctl(struct uart_softc *sc, int request, intptr_t data)
{
switch (request) {
case UART_IOCTL_BREAK:
case UART_IOCTL_IFLOW:
case UART_IOCTL_OFLOW:
break;
case UART_IOCTL_BAUD:
/* only if we know our master clock rate */
if (DEFAULT_RCLK != 0)
WR4(&sc->sc_bas, USART_BRGR,
BAUD2DIVISOR(*(int *)data));
return (0);
}
return (EINVAL);
}
struct uart_class at91_usart_class = {
"at91_usart",
at91_usart_methods,
sizeof(struct at91_usart_softc),
.uc_ops = &at91_usart_ops,
.uc_range = 8
};