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freebsd-dev/sys/dev/uart/uart_dev_imx.c

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/*-
* Copyright (c) 2012 The FreeBSD Foundation
* All rights reserved.
*
* This software was developed by Oleksandr Rybalko under sponsorship
* from the FreeBSD Foundation.
*
* 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 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 THE 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("$FreeBSD$");
#include "opt_ddb.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/kdb.h>
#include <machine/bus.h>
#include <machine/fdt.h>
#include <dev/uart/uart.h>
#include <dev/uart/uart_cpu.h>
#include <dev/uart/uart_bus.h>
#include <dev/uart/uart_dev_imx.h>
#include "uart_if.h"
#include <arm/freescale/imx/imx_ccmvar.h>
/*
* Low-level UART interface.
*/
static int imx_uart_probe(struct uart_bas *bas);
static void imx_uart_init(struct uart_bas *bas, int, int, int, int);
static void imx_uart_term(struct uart_bas *bas);
static void imx_uart_putc(struct uart_bas *bas, int);
static int imx_uart_rxready(struct uart_bas *bas);
static int imx_uart_getc(struct uart_bas *bas, struct mtx *);
static struct uart_ops uart_imx_uart_ops = {
.probe = imx_uart_probe,
.init = imx_uart_init,
.term = imx_uart_term,
.putc = imx_uart_putc,
.rxready = imx_uart_rxready,
.getc = imx_uart_getc,
};
#if 0 /* Handy when debugging. */
static void
dumpregs(struct uart_bas *bas, const char * msg)
{
if (!bootverbose)
return;
printf("%s bsh 0x%08lx UCR1 0x%08x UCR2 0x%08x "
"UCR3 0x%08x UCR4 0x%08x USR1 0x%08x USR2 0x%08x\n",
msg, bas->bsh,
GETREG(bas, REG(UCR1)), GETREG(bas, REG(UCR2)),
GETREG(bas, REG(UCR3)), GETREG(bas, REG(UCR4)),
GETREG(bas, REG(USR1)), GETREG(bas, REG(USR2)));
}
#endif
static int
imx_uart_probe(struct uart_bas *bas)
{
return (0);
}
static void
imx_uart_init(struct uart_bas *bas, int baudrate, int databits,
int stopbits, int parity)
{
uint32_t baseclk, reg;
/* Enable the device and the RX/TX channels. */
SET(bas, REG(UCR1), FLD(UCR1, UARTEN));
SET(bas, REG(UCR2), FLD(UCR2, RXEN) | FLD(UCR2, TXEN));
if (databits == 7)
DIS(bas, UCR2, WS);
else
ENA(bas, UCR2, WS);
if (stopbits == 2)
ENA(bas, UCR2, STPB);
else
DIS(bas, UCR2, STPB);
switch (parity) {
case UART_PARITY_ODD:
DIS(bas, UCR2, PROE);
ENA(bas, UCR2, PREN);
break;
case UART_PARITY_EVEN:
ENA(bas, UCR2, PROE);
ENA(bas, UCR2, PREN);
break;
case UART_PARITY_MARK:
case UART_PARITY_SPACE:
/* FALLTHROUGH: Hardware doesn't support mark/space. */
case UART_PARITY_NONE:
default:
DIS(bas, UCR2, PREN);
break;
}
/*
* The hardware has an extremely flexible baud clock: it allows setting
* both the numerator and denominator of the divider, as well as a
* separate pre-divider. We simplify the problem of coming up with a
* workable pair of numbers by assuming a pre-divider and numerator of
* one because our base clock is so fast we can reach virtually any
* reasonable speed with a simple divisor. The numerator value actually
* includes the 16x over-sampling (so a value of 16 means divide by 1);
* the register value is the numerator-1, so we have a hard-coded 15.
* Note that a quirk of the hardware requires that both UBIR and UBMR be
* set back to back in order for the change to take effect.
*/
if (baudrate > 0) {
baseclk = imx_ccm_uart_hz();
reg = GETREG(bas, REG(UFCR));
reg = (reg & ~IMXUART_UFCR_RFDIV_MASK) | IMXUART_UFCR_RFDIV_DIV1;
SETREG(bas, REG(UFCR), reg);
SETREG(bas, REG(UBIR), 15);
SETREG(bas, REG(UBMR), (baseclk / baudrate) - 1);
}
}
static void
imx_uart_term(struct uart_bas *bas)
{
}
static void
imx_uart_putc(struct uart_bas *bas, int c)
{
while (!(IS(bas, USR2, TXFE)))
;
SETREG(bas, REG(UTXD), c);
}
static int
imx_uart_rxready(struct uart_bas *bas)
{
return ((IS(bas, USR2, RDR)) ? 1 : 0);
}
static int
imx_uart_getc(struct uart_bas *bas, struct mtx *hwmtx)
{
int c;
uart_lock(hwmtx);
while (!(IS(bas, USR2, RDR)))
;
c = GETREG(bas, REG(URXD));
uart_unlock(hwmtx);
#if defined(KDB)
if (c & FLD(URXD, BRK)) {
if (kdb_break())
return (0);
}
#endif
return (c & 0xff);
}
/*
* High-level UART interface.
*/
struct imx_uart_softc {
struct uart_softc base;
};
static int imx_uart_bus_attach(struct uart_softc *);
static int imx_uart_bus_detach(struct uart_softc *);
static int imx_uart_bus_flush(struct uart_softc *, int);
static int imx_uart_bus_getsig(struct uart_softc *);
static int imx_uart_bus_ioctl(struct uart_softc *, int, intptr_t);
static int imx_uart_bus_ipend(struct uart_softc *);
static int imx_uart_bus_param(struct uart_softc *, int, int, int, int);
static int imx_uart_bus_probe(struct uart_softc *);
static int imx_uart_bus_receive(struct uart_softc *);
static int imx_uart_bus_setsig(struct uart_softc *, int);
static int imx_uart_bus_transmit(struct uart_softc *);
static void imx_uart_bus_grab(struct uart_softc *);
static void imx_uart_bus_ungrab(struct uart_softc *);
static kobj_method_t imx_uart_methods[] = {
KOBJMETHOD(uart_attach, imx_uart_bus_attach),
KOBJMETHOD(uart_detach, imx_uart_bus_detach),
KOBJMETHOD(uart_flush, imx_uart_bus_flush),
KOBJMETHOD(uart_getsig, imx_uart_bus_getsig),
KOBJMETHOD(uart_ioctl, imx_uart_bus_ioctl),
KOBJMETHOD(uart_ipend, imx_uart_bus_ipend),
KOBJMETHOD(uart_param, imx_uart_bus_param),
KOBJMETHOD(uart_probe, imx_uart_bus_probe),
KOBJMETHOD(uart_receive, imx_uart_bus_receive),
KOBJMETHOD(uart_setsig, imx_uart_bus_setsig),
KOBJMETHOD(uart_transmit, imx_uart_bus_transmit),
KOBJMETHOD(uart_grab, imx_uart_bus_grab),
KOBJMETHOD(uart_ungrab, imx_uart_bus_ungrab),
{ 0, 0 }
};
struct uart_class uart_imx_class = {
"imx",
imx_uart_methods,
sizeof(struct imx_uart_softc),
.uc_ops = &uart_imx_uart_ops,
.uc_range = 0x100,
.uc_rclk = 24000000 /* TODO: get value from CCM */
};
#define SIGCHG(c, i, s, d) \
if (c) { \
i |= (i & s) ? s : s | d; \
} else { \
i = (i & s) ? (i & ~s) | d : i; \
}
static int
imx_uart_bus_attach(struct uart_softc *sc)
{
struct uart_bas *bas;
struct uart_devinfo *di;
bas = &sc->sc_bas;
if (sc->sc_sysdev != NULL) {
di = sc->sc_sysdev;
imx_uart_init(bas, di->baudrate, di->databits, di->stopbits,
di->parity);
} else {
imx_uart_init(bas, 115200, 8, 1, 0);
}
(void)imx_uart_bus_getsig(sc);
ENA(bas, UCR4, DREN);
DIS(bas, UCR1, RRDYEN);
DIS(bas, UCR1, IDEN);
DIS(bas, UCR3, RXDSEN);
DIS(bas, UCR2, ATEN);
DIS(bas, UCR1, TXMPTYEN);
DIS(bas, UCR1, TRDYEN);
DIS(bas, UCR4, TCEN);
DIS(bas, UCR4, OREN);
ENA(bas, UCR4, BKEN);
DIS(bas, UCR4, WKEN);
DIS(bas, UCR1, ADEN);
DIS(bas, UCR3, ACIEN);
DIS(bas, UCR2, ESCI);
DIS(bas, UCR4, ENIRI);
DIS(bas, UCR3, AIRINTEN);
DIS(bas, UCR3, AWAKEN);
DIS(bas, UCR3, FRAERREN);
DIS(bas, UCR3, PARERREN);
DIS(bas, UCR1, RTSDEN);
DIS(bas, UCR2, RTSEN);
DIS(bas, UCR3, DTREN);
DIS(bas, UCR3, RI);
DIS(bas, UCR3, DCD);
DIS(bas, UCR3, DTRDEN);
ENA(bas, UCR2, IRTS);
ENA(bas, UCR3, RXDMUXSEL);
/* ACK all interrupts */
SETREG(bas, REG(USR1), 0xffff);
SETREG(bas, REG(USR2), 0xffff);
return (0);
}
static int
imx_uart_bus_detach(struct uart_softc *sc)
{
SETREG(&sc->sc_bas, REG(UCR4), 0);
return (0);
}
static int
imx_uart_bus_flush(struct uart_softc *sc, int what)
{
/* TODO */
return (0);
}
static int
imx_uart_bus_getsig(struct uart_softc *sc)
{
uint32_t new, old, sig;
uint8_t bes;
do {
old = sc->sc_hwsig;
sig = old;
uart_lock(sc->sc_hwmtx);
bes = GETREG(&sc->sc_bas, REG(USR2));
uart_unlock(sc->sc_hwmtx);
/* XXX: chip can show delta */
SIGCHG(bes & FLD(USR2, DCDIN), sig, SER_DCD, SER_DDCD);
new = sig & ~SER_MASK_DELTA;
} while (!atomic_cmpset_32(&sc->sc_hwsig, old, new));
return (sig);
}
static int
imx_uart_bus_ioctl(struct uart_softc *sc, int request, intptr_t data)
{
struct uart_bas *bas;
int error;
bas = &sc->sc_bas;
error = 0;
uart_lock(sc->sc_hwmtx);
switch (request) {
case UART_IOCTL_BREAK:
/* TODO */
break;
case UART_IOCTL_BAUD:
/* TODO */
*(int*)data = 115200;
break;
default:
error = EINVAL;
break;
}
uart_unlock(sc->sc_hwmtx);
return (error);
}
static int
imx_uart_bus_ipend(struct uart_softc *sc)
{
struct uart_bas *bas;
int ipend;
uint32_t usr1, usr2;
uint32_t ucr1, ucr4;
bas = &sc->sc_bas;
ipend = 0;
uart_lock(sc->sc_hwmtx);
/* Read pending interrupts */
usr1 = GETREG(bas, REG(USR1));
usr2 = GETREG(bas, REG(USR2));
/* ACK interrupts */
SETREG(bas, REG(USR1), usr1);
SETREG(bas, REG(USR2), usr2);
ucr1 = GETREG(bas, REG(UCR1));
ucr4 = GETREG(bas, REG(UCR4));
if ((usr2 & FLD(USR2, TXFE)) && (ucr1 & FLD(UCR1, TXMPTYEN))) {
DIS(bas, UCR1, TXMPTYEN);
/* Continue TXing */
ipend |= SER_INT_TXIDLE;
}
if ((usr2 & FLD(USR2, RDR)) && (ucr4 & FLD(UCR4, DREN))) {
DIS(bas, UCR4, DREN);
/* Wow, new char on input */
ipend |= SER_INT_RXREADY;
}
if ((usr2 & FLD(USR2, BRCD)) && (ucr4 & FLD(UCR4, BKEN)))
ipend |= SER_INT_BREAK;
uart_unlock(sc->sc_hwmtx);
return (ipend);
}
static int
imx_uart_bus_param(struct uart_softc *sc, int baudrate, int databits,
int stopbits, int parity)
{
uart_lock(sc->sc_hwmtx);
imx_uart_init(&sc->sc_bas, baudrate, databits, stopbits, parity);
uart_unlock(sc->sc_hwmtx);
return (0);
}
static int
imx_uart_bus_probe(struct uart_softc *sc)
{
int error;
error = imx_uart_probe(&sc->sc_bas);
if (error)
return (error);
sc->sc_rxfifosz = 1;
sc->sc_txfifosz = 1;
device_set_desc(sc->sc_dev, "Freescale i.MX UART");
return (0);
}
static int
imx_uart_bus_receive(struct uart_softc *sc)
{
struct uart_bas *bas;
int xc, out;
bas = &sc->sc_bas;
uart_lock(sc->sc_hwmtx);
/* Read while we have anything in FIFO */
while (IS(bas, USR2, RDR)) {
if (uart_rx_full(sc)) {
/* No space left in input buffer */
sc->sc_rxbuf[sc->sc_rxput] = UART_STAT_OVERRUN;
break;
}
out = 0;
xc = GETREG(bas, REG(URXD));
/* We have valid char */
if (xc & FLD(URXD, CHARRDY))
out = xc & 0x000000ff;
if (xc & FLD(URXD, FRMERR))
out |= UART_STAT_FRAMERR;
if (xc & FLD(URXD, PRERR))
out |= UART_STAT_PARERR;
if (xc & FLD(URXD, OVRRUN))
out |= UART_STAT_OVERRUN;
if (xc & FLD(URXD, BRK))
out |= UART_STAT_BREAK;
uart_rx_put(sc, out);
}
/* Reenable Data Ready interrupt */
ENA(bas, UCR4, DREN);
uart_unlock(sc->sc_hwmtx);
return (0);
}
static int
imx_uart_bus_setsig(struct uart_softc *sc, int sig)
{
return (0);
}
static int
imx_uart_bus_transmit(struct uart_softc *sc)
{
struct uart_bas *bas = &sc->sc_bas;
int i;
bas = &sc->sc_bas;
uart_lock(sc->sc_hwmtx);
/* Fill TX FIFO */
for (i = 0; i < sc->sc_txdatasz; i++) {
SETREG(bas, REG(UTXD), sc->sc_txbuf[i] & 0xff);
}
sc->sc_txbusy = 1;
/* Call me when ready */
ENA(bas, UCR1, TXMPTYEN);
uart_unlock(sc->sc_hwmtx);
return (0);
}
static void
imx_uart_bus_grab(struct uart_softc *sc)
{
struct uart_bas *bas = &sc->sc_bas;
bas = &sc->sc_bas;
uart_lock(sc->sc_hwmtx);
DIS(bas, UCR4, DREN);
uart_unlock(sc->sc_hwmtx);
}
static void
imx_uart_bus_ungrab(struct uart_softc *sc)
{
struct uart_bas *bas = &sc->sc_bas;
bas = &sc->sc_bas;
uart_lock(sc->sc_hwmtx);
ENA(bas, UCR4, DREN);
uart_unlock(sc->sc_hwmtx);
}
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