freebsd-dev/sys/mips/mediatek/uart_dev_mtk.c
Stanislav Galabov dc0996af4e Initial import of Ralink/Mediatek MIPS SoC support #4
UART drivers.

- uart_dev_mtk.[ch] are the old-style Mediatek/Ralink-specific UART driver
  as also found in sys/mips/rt305x/uart_dev_rt305x.c, with minor improvements
  and FDT attachment enabled for the appropriate SoCs.
- uart_dev_mtk_ns8250.c is the new-style ns16550a-compatible UART driver
  found in newer Mediatek SoCs. It uses the uart_dev_ns8250.c driver
  indirectly and is basically just a wrapper around it and only overrides its
  probe method.
  The reason I am not using the uart_dev_ns8250.c driver directly is because
  I have some code that does UART clock detection before initializing the
  UART, so that we don't need to hard-code the UART clock frequency in the
  dts files for each board.

Approved by:	adrian (mentor)
Sponsored by:	Smartcom - Bulgaria AD
Differential Revision:	https://reviews.freebsd.org/D5840
2016-04-07 11:16:32 +00:00

553 lines
13 KiB
C

/* $NetBSD: uart.c,v 1.2 2007/03/23 20:05:47 dogcow Exp $ */
/*-
* Copyright (c) 2013, Alexander A. Mityaev <sansan@adm.ua>
* Copyright (c) 2010 Aleksandr Rybalko.
* Copyright (c) 2007 Ruslan Ermilov and Vsevolod Lobko.
* Copyright (c) 2007 Oleksandr Tymoshenko.
* 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 AUTHORS ``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 AUTHORS
* 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 <sys/reboot.h>
#include <sys/sysctl.h>
#include <sys/kernel.h>
#include <machine/bus.h>
#include <machine/fdt.h>
#include <dev/uart/uart.h>
#include <dev/uart/uart_cpu.h>
#include <dev/uart/uart_cpu_fdt.h>
#include <dev/uart/uart_bus.h>
#include <mips/mediatek/uart_dev_mtk.h>
#include <mips/mediatek/mtk_soc.h>
#include <mips/mediatek/mtk_sysctl.h>
#include "uart_if.h"
/* Set some reference clock value. Real value will be taken from FDT */
#define DEFAULT_RCLK (120 * 1000 * 1000)
/*
* Low-level UART interface.
*/
static int mtk_uart_probe(struct uart_bas *bas);
static void mtk_uart_init(struct uart_bas *bas, int, int, int, int);
static void mtk_uart_term(struct uart_bas *bas);
static void mtk_uart_putc(struct uart_bas *bas, int);
static int mtk_uart_rxready(struct uart_bas *bas);
static int mtk_uart_getc(struct uart_bas *bas, struct mtx *);
static struct uart_ops uart_mtk_ops = {
.probe = mtk_uart_probe,
.init = mtk_uart_init,
.term = mtk_uart_term,
.putc = mtk_uart_putc,
.rxready = mtk_uart_rxready,
.getc = mtk_uart_getc,
};
static int uart_output = 1;
TUNABLE_INT("kern.uart_output", &uart_output);
SYSCTL_INT(_kern, OID_AUTO, uart_output, CTLFLAG_RW,
&uart_output, 0, "UART output enabled.");
static int
mtk_uart_probe(struct uart_bas *bas)
{
return (0);
}
static void
mtk_uart_init(struct uart_bas *bas, int baudrate, int databits,
int stopbits, int parity)
{
/* CLKDIV = 384000000/ 3/ 16/ br */
/* for 384MHz CLKDIV = 8000000 / baudrate; */
switch (databits) {
case 5:
databits = UART_LCR_5B;
break;
case 6:
databits = UART_LCR_6B;
break;
case 7:
databits = UART_LCR_7B;
break;
case 8:
databits = UART_LCR_8B;
break;
default:
/* Unsupported */
return;
}
switch (parity) {
case UART_PARITY_EVEN: parity = (UART_LCR_PEN|UART_LCR_EVEN); break;
case UART_PARITY_ODD: parity = (UART_LCR_PEN); break;
case UART_PARITY_NONE: parity = 0; break;
/* Unsupported */
default: return;
}
if (bas->rclk && baudrate) {
uart_setreg(bas, UART_CDDL_REG, bas->rclk/16/baudrate);
uart_barrier(bas);
}
uart_setreg(bas, UART_LCR_REG, databits |
(stopbits==1?0:UART_LCR_STB_15) |
parity);
uart_barrier(bas);
}
static void
mtk_uart_term(struct uart_bas *bas)
{
uart_setreg(bas, UART_MCR_REG, 0);
uart_barrier(bas);
}
static void
mtk_uart_putc(struct uart_bas *bas, int c)
{
char chr;
if (!uart_output) return;
chr = c;
while (!(uart_getreg(bas, UART_LSR_REG) & UART_LSR_THRE));
uart_setreg(bas, UART_TX_REG, c);
uart_barrier(bas);
while (!(uart_getreg(bas, UART_LSR_REG) & UART_LSR_THRE));
}
static int
mtk_uart_rxready(struct uart_bas *bas)
{
if (uart_getreg(bas, UART_LSR_REG) & UART_LSR_DR)
return (1);
return (0);
}
static int
mtk_uart_getc(struct uart_bas *bas, struct mtx *hwmtx)
{
int c;
uart_lock(hwmtx);
while (!(uart_getreg(bas, UART_LSR_REG) & UART_LSR_DR)) {
uart_unlock(hwmtx);
DELAY(10);
uart_lock(hwmtx);
}
c = uart_getreg(bas, UART_RX_REG);
uart_unlock(hwmtx);
return (c);
}
/*
* High-level UART interface.
*/
struct uart_mtk_softc {
struct uart_softc base;
uint8_t ier_mask;
uint8_t ier;
};
static int mtk_uart_bus_attach(struct uart_softc *);
static int mtk_uart_bus_detach(struct uart_softc *);
static int mtk_uart_bus_flush(struct uart_softc *, int);
static int mtk_uart_bus_getsig(struct uart_softc *);
static int mtk_uart_bus_ioctl(struct uart_softc *, int, intptr_t);
static int mtk_uart_bus_ipend(struct uart_softc *);
static int mtk_uart_bus_param(struct uart_softc *, int, int, int, int);
static int mtk_uart_bus_probe(struct uart_softc *);
static int mtk_uart_bus_receive(struct uart_softc *);
static int mtk_uart_bus_setsig(struct uart_softc *, int);
static int mtk_uart_bus_transmit(struct uart_softc *);
static void mtk_uart_bus_grab(struct uart_softc *);
static void mtk_uart_bus_ungrab(struct uart_softc *);
static kobj_method_t uart_mtk_methods[] = {
KOBJMETHOD(uart_attach, mtk_uart_bus_attach),
KOBJMETHOD(uart_detach, mtk_uart_bus_detach),
KOBJMETHOD(uart_flush, mtk_uart_bus_flush),
KOBJMETHOD(uart_getsig, mtk_uart_bus_getsig),
KOBJMETHOD(uart_ioctl, mtk_uart_bus_ioctl),
KOBJMETHOD(uart_ipend, mtk_uart_bus_ipend),
KOBJMETHOD(uart_param, mtk_uart_bus_param),
KOBJMETHOD(uart_probe, mtk_uart_bus_probe),
KOBJMETHOD(uart_receive, mtk_uart_bus_receive),
KOBJMETHOD(uart_setsig, mtk_uart_bus_setsig),
KOBJMETHOD(uart_transmit, mtk_uart_bus_transmit),
KOBJMETHOD(uart_grab, mtk_uart_bus_grab),
KOBJMETHOD(uart_ungrab, mtk_uart_bus_ungrab),
{ 0, 0 }
};
struct uart_class uart_mtk_class = {
"uart_mtk",
uart_mtk_methods,
sizeof(struct uart_mtk_softc),
.uc_ops = &uart_mtk_ops,
.uc_range = 1, /* use hinted range */
.uc_rclk = 0
};
static struct ofw_compat_data compat_data[] = {
{ "ralink,rt2880-uart", (uintptr_t)&uart_mtk_class },
{ "ralink,rt3050-uart", (uintptr_t)&uart_mtk_class },
{ "ralink,rt3352-uart", (uintptr_t)&uart_mtk_class },
{ "ralink,rt3883-uart", (uintptr_t)&uart_mtk_class },
{ "ralink,rt5350-uart", (uintptr_t)&uart_mtk_class },
{ "ralink,mt7620a-uart", (uintptr_t)&uart_mtk_class },
{ NULL, (uintptr_t)NULL },
};
UART_FDT_CLASS_AND_DEVICE(compat_data);
#define SIGCHG(c, i, s, d) \
if (c) { \
i |= (i & s) ? s : s | d; \
} else { \
i = (i & s) ? (i & ~s) | d : i; \
}
/*
* Disable TX interrupt. uart should be locked
*/
static __inline void
mtk_uart_disable_txintr(struct uart_softc *sc)
{
struct uart_bas *bas = &sc->sc_bas;
uint8_t cr;
cr = uart_getreg(bas, UART_IER_REG);
cr &= ~UART_IER_ETBEI;
uart_setreg(bas, UART_IER_REG, cr);
uart_barrier(bas);
}
/*
* Enable TX interrupt. uart should be locked
*/
static __inline void
mtk_uart_enable_txintr(struct uart_softc *sc)
{
struct uart_bas *bas = &sc->sc_bas;
uint8_t cr;
cr = uart_getreg(bas, UART_IER_REG);
cr |= UART_IER_ETBEI;
uart_setreg(bas, UART_IER_REG, cr);
uart_barrier(bas);
}
static int
mtk_uart_bus_attach(struct uart_softc *sc)
{
struct uart_bas *bas;
struct uart_devinfo *di;
struct uart_mtk_softc *usc = (struct uart_mtk_softc *)sc;
bas = &sc->sc_bas;
if (!bas->rclk) {
bas->rclk = mtk_soc_get_uartclk();
}
if (sc->sc_sysdev != NULL) {
di = sc->sc_sysdev;
mtk_uart_init(bas, di->baudrate, di->databits, di->stopbits,
di->parity);
} else {
mtk_uart_init(bas, 57600, 8, 1, 0);
}
sc->sc_rxfifosz = 16;
sc->sc_txfifosz = 16;
(void)mtk_uart_bus_getsig(sc);
/* Enable FIFO */
uart_setreg(bas, UART_FCR_REG,
uart_getreg(bas, UART_FCR_REG) |
UART_FCR_FIFOEN | UART_FCR_TXTGR_1 | UART_FCR_RXTGR_1);
uart_barrier(bas);
/* Enable interrupts */
usc->ier_mask = 0xf0;
uart_setreg(bas, UART_IER_REG,
UART_IER_EDSSI | UART_IER_ELSI | UART_IER_ERBFI);
uart_barrier(bas);
return (0);
}
static int
mtk_uart_bus_detach(struct uart_softc *sc)
{
return (0);
}
static int
mtk_uart_bus_flush(struct uart_softc *sc, int what)
{
struct uart_bas *bas = &sc->sc_bas;
uint32_t fcr = uart_getreg(bas, UART_FCR_REG);
if (what & UART_FLUSH_TRANSMITTER) {
uart_setreg(bas, UART_FCR_REG, fcr|UART_FCR_TXRST);
uart_barrier(bas);
}
if (what & UART_FLUSH_RECEIVER) {
uart_setreg(bas, UART_FCR_REG, fcr|UART_FCR_RXRST);
uart_barrier(bas);
}
uart_setreg(bas, UART_FCR_REG, fcr);
uart_barrier(bas);
return (0);
}
static int
mtk_uart_bus_getsig(struct uart_softc *sc)
{
uint32_t new, old, sig;
uint8_t bes;
return(0);
do {
old = sc->sc_hwsig;
sig = old;
uart_lock(sc->sc_hwmtx);
bes = uart_getreg(&sc->sc_bas, UART_MSR_REG);
uart_unlock(sc->sc_hwmtx);
/* XXX: chip can show delta */
SIGCHG(bes & UART_MSR_CTS, sig, SER_CTS, SER_DCTS);
SIGCHG(bes & UART_MSR_DCD, sig, SER_DCD, SER_DDCD);
SIGCHG(bes & UART_MSR_DSR, sig, SER_DSR, SER_DDSR);
new = sig & ~SER_MASK_DELTA;
} while (!atomic_cmpset_32(&sc->sc_hwsig, old, new));
return (sig);
}
static int
mtk_uart_bus_ioctl(struct uart_softc *sc, int request, intptr_t data)
{
struct uart_bas *bas;
int baudrate, divisor, error;
bas = &sc->sc_bas;
error = 0;
uart_lock(sc->sc_hwmtx);
switch (request) {
case UART_IOCTL_BREAK:
/* TODO: Send BREAK */
break;
case UART_IOCTL_BAUD:
divisor = uart_getreg(bas, UART_CDDL_REG);
baudrate = bas->rclk / (divisor * 16);
*(int*)data = baudrate;
break;
default:
error = EINVAL;
break;
}
uart_unlock(sc->sc_hwmtx);
return (error);
}
static int
mtk_uart_bus_ipend(struct uart_softc *sc)
{
struct uart_bas *bas;
int ipend;
uint8_t iir, lsr, msr;
// breakpoint();
bas = &sc->sc_bas;
ipend = 0;
uart_lock(sc->sc_hwmtx);
iir = uart_getreg(&sc->sc_bas, UART_IIR_REG);
lsr = uart_getreg(&sc->sc_bas, UART_LSR_REG);
uart_setreg(&sc->sc_bas, UART_LSR_REG, lsr);
msr = uart_getreg(&sc->sc_bas, UART_MSR_REG);
uart_setreg(&sc->sc_bas, UART_MSR_REG, msr);
if (iir & UART_IIR_INTP) {
uart_unlock(sc->sc_hwmtx);
return (0);
}
switch ((iir >> 1) & 0x07) {
case UART_IIR_ID_THRE:
ipend |= SER_INT_TXIDLE;
break;
case UART_IIR_ID_DR2:
mtk_uart_bus_flush(sc, UART_FLUSH_RECEIVER);
/* passthrough */
case UART_IIR_ID_DR:
ipend |= SER_INT_RXREADY;
break;
case UART_IIR_ID_MST:
case UART_IIR_ID_LINESTATUS:
ipend |= SER_INT_SIGCHG;
if (lsr & UART_LSR_BI)
ipend |= SER_INT_BREAK;
if (lsr & UART_LSR_OE)
ipend |= SER_INT_OVERRUN;
break;
default:
/* XXX: maybe return error here */
break;
}
uart_unlock(sc->sc_hwmtx);
return (ipend);
}
static int
mtk_uart_bus_param(struct uart_softc *sc, int baudrate, int databits,
int stopbits, int parity)
{
uart_lock(sc->sc_hwmtx);
mtk_uart_init(&sc->sc_bas, baudrate, databits, stopbits, parity);
uart_unlock(sc->sc_hwmtx);
return (0);
}
static int
mtk_uart_bus_probe(struct uart_softc *sc)
{
int error;
error = mtk_uart_probe(&sc->sc_bas);
if (error)
return (error);
device_set_desc(sc->sc_dev, "MTK UART Controller");
return (0);
}
static int
mtk_uart_bus_receive(struct uart_softc *sc)
{
struct uart_bas *bas;
int xc;
uint8_t lsr;
bas = &sc->sc_bas;
uart_lock(sc->sc_hwmtx);
lsr = uart_getreg(bas, UART_LSR_REG);
while ((lsr & UART_LSR_DR)) {
if (uart_rx_full(sc)) {
sc->sc_rxbuf[sc->sc_rxput] = UART_STAT_OVERRUN;
break;
}
xc = 0;
xc = uart_getreg(bas, UART_RX_REG);
if (lsr & UART_LSR_FE)
xc |= UART_STAT_FRAMERR;
if (lsr & UART_LSR_PE)
xc |= UART_STAT_PARERR;
if (lsr & UART_LSR_OE)
xc |= UART_STAT_OVERRUN;
uart_barrier(bas);
uart_rx_put(sc, xc);
lsr = uart_getreg(bas, UART_LSR_REG);
}
uart_unlock(sc->sc_hwmtx);
return (0);
}
static int
mtk_uart_bus_setsig(struct uart_softc *sc, int sig)
{
/* TODO: implement (?) */
return (sig);
}
static int
mtk_uart_bus_transmit(struct uart_softc *sc)
{
struct uart_bas *bas = &sc->sc_bas;
int i;
if (!uart_output) return (0);
bas = &sc->sc_bas;
uart_lock(sc->sc_hwmtx);
while ((uart_getreg(bas, UART_LSR_REG) & UART_LSR_THRE) == 0);
mtk_uart_enable_txintr(sc);
for (i = 0; i < sc->sc_txdatasz; i++) {
uart_setreg(bas, UART_TX_REG, sc->sc_txbuf[i]);
uart_barrier(bas);
}
sc->sc_txbusy = 1;
uart_unlock(sc->sc_hwmtx);
return (0);
}
void
mtk_uart_bus_grab(struct uart_softc *sc)
{
struct uart_bas *bas = &sc->sc_bas;
struct uart_mtk_softc *usc = (struct uart_mtk_softc *)sc;
uart_lock(sc->sc_hwmtx);
usc->ier = uart_getreg(bas, UART_IER_REG);
uart_setreg(bas, UART_IER_REG, usc->ier & usc->ier_mask);
uart_barrier(bas);
uart_unlock(sc->sc_hwmtx);
}
void
mtk_uart_bus_ungrab(struct uart_softc *sc)
{
struct uart_mtk_softc *usc = (struct uart_mtk_softc *)sc;
struct uart_bas *bas = &sc->sc_bas;
uart_lock(sc->sc_hwmtx);
uart_setreg(bas, UART_IER_REG, usc->ier);
uart_barrier(bas);
uart_unlock(sc->sc_hwmtx);
}