/*-
 * 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: src/sys/arm/at91/uart_dev_at91usart.c,v 1.6 2006/05/13 23:41:16 cognet Exp $");

#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
};
