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freebsd-dev/sys/arm/at91/uart_dev_at91usart.c
Olivier Houchard d5d776c16b Resurrect Skyeye support : 
Add a new option, SKYEYE_WORKAROUNDS, which as the name suggests adds
workarounds for things skyeye doesn't simulate. Specifically :
- Use USART0 instead of DBGU as the console, make it not use DMA, and           manually provoke an interrupt when we're done in the transmit function.
- Skyeye maintains an internal counter for clock, but apparently there's
no way to access it, so hack the timecounter code to return a value which
is increased at every clock interrupts. This is gross, but I didn't find a
better way to implement timecounters without hacking Skyeye to get the
counter value.
- Force the write-back of PTEs once we're done writing them, even if they
are supposed to be write-through. I don't know why I have to do that.
2006-05-13 23:41:16 +00:00

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/*-
* 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 THE AUTHOR ``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 THE AUTHOR 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("$FreeBSD$");
#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/at91rm92reg.h>
#include <arm/at91/at91_usartreg.h>
#include <arm/at91/at91_pdcreg.h>
#include "uart_if.h"
/*
* High-level UART interface.
*/
struct at91_usart_softc {
struct uart_softc base;
bus_dma_tag_t dmatag; /* bus dma tag for mbufs */
bus_dmamap_t tx_map;
bus_dmamap_t rx_map;
};
#define DEFAULT_RCLK AT91C_MASTER_CLOCK
#define USART_BUFFER_SIZE 128
#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);
/*
* 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_poll(struct uart_bas *bas);
static int at91_usart_getc(struct uart_bas *bas, struct mtx *mtx);
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-write 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.
*/
if (stopbits > 1)
mr |= USART_MR_NBSTOP_2;
else
mr |= USART_MR_NBSTOP_2;
/* else if (stopbits == 1.5)
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 */
/* XXX Need to take possible synchronous mode into account */
return (0);
}
struct uart_ops at91_usart_ops = {
.probe = at91_usart_probe,
.init = at91_usart_init,
.term = at91_usart_term,
.putc = at91_usart_putc,
.poll = at91_usart_poll,
.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 (I think as the console)
*/
static void
at91_usart_init(struct uart_bas *bas, int baudrate, int databits, int stopbits,
int parity)
{
int cr;
at91_usart_param(bas, baudrate, databits, stopbits, parity);
/* Turn on rx and tx */
cr = USART_CR_RSTSTA | USART_CR_RSTRX | USART_CR_RSTTX;
WR4(bas, USART_CR, cr);
WR4(bas, USART_CR, USART_CR_RXEN | USART_CR_TXEN);
WR4(bas, USART_IER, USART_CSR_TIMEOUT |
USART_CSR_TXRDY | USART_CSR_RXRDY |
USART_CSR_RXBRK | USART_CSR_ENDRX | USART_CSR_ENDTX);
/* Set the receive timeout to be 1.5 character times. */
WR4(bas, USART_RTOR, 12);
}
/*
* 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));
WR4(bas, USART_THR, c);
}
/*
* Poll for a character available
*/
static int
at91_usart_poll(struct uart_bas *bas)
{
if (!(RD4(bas, USART_CSR) & USART_CSR_RXRDY))
return (-1);
return (RD4(bas, USART_RHR) & 0xff);
}
/*
* Block waiting for a character.
*/
static int
at91_usart_getc(struct uart_bas *bas, struct mtx *mtx)
{
int c;
while (!(RD4(bas, USART_CSR) & USART_CSR_RXRDY))
;
c = RD4(bas, USART_RHR);
c &= 0xff;
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),
{ 0, 0 }
};
int
at91_usart_bus_probe(struct uart_softc *sc)
{
return (0);
}
static int
at91_usart_bus_attach(struct uart_softc *sc)
{
int err;
struct at91_usart_softc *atsc;
atsc = (struct at91_usart_softc *)sc;
sc->sc_txfifosz = USART_BUFFER_SIZE;
sc->sc_rxfifosz = USART_BUFFER_SIZE;
sc->sc_hwiflow = 0;
/*
* Allocate DMA tags and maps
*/
err = bus_dma_tag_create(NULL, 1, 0, BUS_SPACE_MAXADDR_32BIT,
BUS_SPACE_MAXADDR, NULL, NULL, USART_BUFFER_SIZE, 1,
USART_BUFFER_SIZE, BUS_DMA_ALLOCNOW, NULL, NULL, &atsc->dmatag);
if (err != 0)
goto errout;
err = bus_dmamap_create(atsc->dmatag, 0, &atsc->tx_map);
if (err != 0)
goto errout;
err = bus_dmamap_create(atsc->dmatag, 0, &atsc->rx_map);
if (err != 0)
goto errout;
errout:;
// XXX bad
return (err);
}
#ifndef SKYEYE_WORKAROUNDS
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;
}
#endif
static int
at91_usart_bus_transmit(struct uart_softc *sc)
{
#ifndef SKYEYE_WORKAROUNDS
bus_addr_t addr;
#endif
struct at91_usart_softc *atsc;
atsc = (struct at91_usart_softc *)sc;
#ifndef SKYEYE_WORKAROUNDS
if (bus_dmamap_load(atsc->dmatag, atsc->tx_map, sc->sc_txbuf,
sc->sc_txdatasz, at91_getaddr, &addr, 0) != 0)
return (EAGAIN);
bus_dmamap_sync(atsc->dmatag, atsc->tx_map, BUS_DMASYNC_PREWRITE);
#endif
uart_lock(sc->sc_hwmtx);
sc->sc_txbusy = 1;
#ifndef SKYEYE_WORKAROUNDS
/*
* 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);
uart_unlock(sc->sc_hwmtx);
#else
for (int i = 0; i < sc->sc_txdatasz; i++)
at91_usart_putc(&sc->sc_bas, sc->sc_txbuf[i]);
/*
* XXX: Gross hack : Skyeye doesn't raise an interrupt once the
* transfer is done, so simulate it.
*/
WR4(&sc->sc_bas, USART_IER, USART_CSR_TXRDY);
#endif
return (0);
}
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 = RD4(bas, USART_CR);
cr &= ~(USART_CR_DTREN | USART_CR_DTRDIS | USART_CR_RTSEN |
USART_CR_RTSDIS);
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)
{
uart_lock(sc->sc_hwmtx);
uart_rx_put(sc, at91_usart_getc(&sc->sc_bas, NULL));
uart_unlock(sc->sc_hwmtx);
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 int
at91_usart_bus_ipend(struct uart_softc *sc)
{
int csr = RD4(&sc->sc_bas, USART_CSR);
int ipend = 0;
struct at91_usart_softc *atsc;
atsc = (struct at91_usart_softc *)sc;
if (csr & USART_CSR_ENDTX) {
bus_dmamap_sync(atsc->dmatag, atsc->tx_map,
BUS_DMASYNC_POSTWRITE);
bus_dmamap_unload(atsc->dmatag, atsc->tx_map);
}
uart_lock(sc->sc_hwmtx);
if (csr & USART_CSR_TXRDY && sc->sc_txbusy)
ipend |= SER_INT_TXIDLE;
if (csr & USART_CSR_ENDTX && sc->sc_txbusy)
ipend |= SER_INT_TXIDLE;
if (csr & (USART_CSR_RXRDY /* | USART_CSR_ENDRX | USART_CSR_TIMEOUT */))
ipend |= SER_INT_RXREADY;
if (csr & USART_CSR_RXBRK) {
unsigned int cr = USART_CR_RSTSTA;
ipend |= SER_INT_BREAK;
WR4(&sc->sc_bas, USART_CR, cr);
}
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 new, sig;
uint8_t csr;
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)
{
return (EINVAL);
}
struct uart_class at91_usart_class = {
"at91_usart class",
at91_usart_methods,
sizeof(struct at91_usart_softc),
.uc_range = 8,
.uc_rclk = DEFAULT_RCLK
};
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