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/*-
* Copyright (c) 2016 Michal Meloun <mmel@FreeBSD.org>
* 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 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>
/*
* UART driver for Tegra SoCs.
*/
#include "opt_platform.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/sysctl.h>
#include <machine/bus.h>
#include <dev/extres/clk/clk.h>
#include <dev/extres/hwreset/hwreset.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.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 <dev/uart/uart_dev_ns8250.h>
#include <dev/ic/ns16550.h>
#include "uart_if.h"
/*
* High-level UART interface.
*/
struct tegra_softc {
struct ns8250_softc ns8250_base;
clk_t clk;
hwreset_t reset;
};
/*
* UART class interface.
*/
static int
tegra_uart_attach(struct uart_softc *sc)
{
int rv;
struct ns8250_softc *ns8250 = (struct ns8250_softc*)sc;
struct uart_bas *bas = &sc->sc_bas;
rv = ns8250_bus_attach(sc);
if (rv != 0)
return (rv);
ns8250->ier_rxbits = 0x1d;
ns8250->ier_mask = 0xc0;
ns8250->ier = uart_getreg(bas, REG_IER) & ns8250->ier_mask;
ns8250->ier |= ns8250->ier_rxbits;
uart_setreg(bas, REG_IER, ns8250->ier);
uart_barrier(bas);
return (0);
}
static void
tegra_uart_grab(struct uart_softc *sc)
{
struct uart_bas *bas = &sc->sc_bas;
struct ns8250_softc *ns8250 = (struct ns8250_softc*)sc;
u_char ier;
/*
* turn off all interrupts to enter polling mode. Leave the
* saved mask alone. We'll restore whatever it was in ungrab.
* All pending interrupt signals are reset when IER is set to 0.
*/
uart_lock(sc->sc_hwmtx);
ier = uart_getreg(bas, REG_IER);
uart_setreg(bas, REG_IER, ier & ns8250->ier_mask);
while ((uart_getreg(bas, REG_LSR) & LSR_TEMT) == 0)
;
uart_setreg(bas, REG_FCR, 0);
uart_barrier(bas);
uart_unlock(sc->sc_hwmtx);
}
static void
tegra_uart_ungrab(struct uart_softc *sc)
{
struct ns8250_softc *ns8250 = (struct ns8250_softc*)sc;
struct uart_bas *bas = &sc->sc_bas;
/*
* Restore previous interrupt mask
*/
uart_lock(sc->sc_hwmtx);
uart_setreg(bas, REG_FCR, ns8250->fcr);
uart_setreg(bas, REG_IER, ns8250->ier);
uart_barrier(bas);
uart_unlock(sc->sc_hwmtx);
}
static kobj_method_t tegra_methods[] = {
KOBJMETHOD(uart_probe, ns8250_bus_probe),
KOBJMETHOD(uart_attach, tegra_uart_attach),
KOBJMETHOD(uart_detach, ns8250_bus_detach),
KOBJMETHOD(uart_flush, ns8250_bus_flush),
KOBJMETHOD(uart_getsig, ns8250_bus_getsig),
KOBJMETHOD(uart_ioctl, ns8250_bus_ioctl),
KOBJMETHOD(uart_ipend, ns8250_bus_ipend),
KOBJMETHOD(uart_param, ns8250_bus_param),
KOBJMETHOD(uart_receive, ns8250_bus_receive),
KOBJMETHOD(uart_setsig, ns8250_bus_setsig),
KOBJMETHOD(uart_transmit, ns8250_bus_transmit),
KOBJMETHOD(uart_txbusy, ns8250_bus_txbusy),
KOBJMETHOD(uart_grab, tegra_uart_grab),
KOBJMETHOD(uart_ungrab, tegra_uart_ungrab),
KOBJMETHOD_END
};
static struct uart_class tegra_uart_class = {
"tegra class",
tegra_methods,
sizeof(struct tegra_softc),
.uc_ops = &uart_ns8250_ops,
.uc_range = 8,
.uc_rclk = 0,
};
/* Compatible devices. */
static struct ofw_compat_data compat_data[] = {
{"nvidia,tegra124-uart", (uintptr_t)&tegra_uart_class},
{"nvidia,tegra210-uart", (uintptr_t)&tegra_uart_class},
{NULL, (uintptr_t)NULL},
};
UART_FDT_CLASS(compat_data);
/*
* UART Driver interface.
*/
static int
uart_fdt_get_shift1(phandle_t node)
{
pcell_t shift;
if ((OF_getencprop(node, "reg-shift", &shift, sizeof(shift))) <= 0)
shift = 2;
return ((int)shift);
}
static int
tegra_uart_probe(device_t dev)
{
struct tegra_softc *sc;
phandle_t node;
uint64_t freq;
int shift;
int rv;
const struct ofw_compat_data *cd;
sc = device_get_softc(dev);
if (!ofw_bus_status_okay(dev))
return (ENXIO);
cd = ofw_bus_search_compatible(dev, compat_data);
if (cd->ocd_data == 0)
return (ENXIO);
sc->ns8250_base.base.sc_class = (struct uart_class *)cd->ocd_data;
rv = hwreset_get_by_ofw_name(dev, 0, "serial", &sc->reset);
if (rv != 0) {
device_printf(dev, "Cannot get 'serial' reset\n");
return (ENXIO);
}
rv = hwreset_deassert(sc->reset);
if (rv != 0) {
device_printf(dev, "Cannot unreset 'serial' reset\n");
return (ENXIO);
}
node = ofw_bus_get_node(dev);
shift = uart_fdt_get_shift1(node);
rv = clk_get_by_ofw_index(dev, 0, 0, &sc->clk);
if (rv != 0) {
device_printf(dev, "Cannot get UART clock: %d\n", rv);
return (ENXIO);
}
rv = clk_enable(sc->clk);
if (rv != 0) {
device_printf(dev, "Cannot enable UART clock: %d\n", rv);
return (ENXIO);
}
rv = clk_get_freq(sc->clk, &freq);
if (rv != 0) {
device_printf(dev, "Cannot enable UART clock: %d\n", rv);
return (ENXIO);
}
return (uart_bus_probe(dev, shift, 0, (int)freq, 0, 0, 0));
}
static int
tegra_uart_detach(device_t dev)
{
struct tegra_softc *sc;
sc = device_get_softc(dev);
if (sc->clk != NULL) {
clk_release(sc->clk);
}
return (uart_bus_detach(dev));
}
static device_method_t tegra_uart_bus_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, tegra_uart_probe),
DEVMETHOD(device_attach, uart_bus_attach),
DEVMETHOD(device_detach, tegra_uart_detach),
DEVMETHOD_END
};
static driver_t tegra_uart_driver = {
uart_driver_name,
tegra_uart_bus_methods,
sizeof(struct tegra_softc),
};
DRIVER_MODULE(tegra_uart, simplebus, tegra_uart_driver, uart_devclass,
0, 0);
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