freebsd-dev/sys/dev/uart/uart_bus_fdt.c
Andrew Turner 405ada37fb Add support for the uart classes to set their default register shift value.
This is needed with the pl011 driver. Before this change it would default
to a shift of 0, however the hardware places the registers at 4-byte
addresses meaning the value should be 2.

This patch fixes this for the pl011 when configured using the fdt. The
other drivers have a default value of 0 to keep this a no-op.

MFC after:	1 week
2015-04-11 17:16:23 +00:00

135 lines
3.7 KiB
C

/*-
* Copyright (c) 2009-2010 The FreeBSD Foundation
* All rights reserved.
*
* This software was developed by Semihalf 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_platform.h"
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <machine/bus.h>
#include <dev/fdt/fdt_common.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <dev/uart/uart.h>
#include <dev/uart/uart_bus.h>
#include <dev/uart/uart_cpu.h>
#include <dev/uart/uart_cpu_fdt.h>
static int uart_fdt_probe(device_t);
static device_method_t uart_fdt_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, uart_fdt_probe),
DEVMETHOD(device_attach, uart_bus_attach),
DEVMETHOD(device_detach, uart_bus_detach),
{ 0, 0 }
};
static driver_t uart_fdt_driver = {
uart_driver_name,
uart_fdt_methods,
sizeof(struct uart_softc),
};
int
uart_fdt_get_clock(phandle_t node, pcell_t *cell)
{
/* clock-frequency is a FreeBSD-only extention. */
if ((OF_getencprop(node, "clock-frequency", cell,
sizeof(*cell))) <= 0) {
/* Try to retrieve parent 'bus-frequency' */
/* XXX this should go to simple-bus fixup or so */
if ((OF_getencprop(OF_parent(node), "bus-frequency", cell,
sizeof(*cell))) <= 0)
*cell = 0;
}
return (0);
}
int
uart_fdt_get_shift(phandle_t node, pcell_t *cell)
{
if ((OF_getencprop(node, "reg-shift", cell, sizeof(*cell))) <= 0)
return (-1);
return (0);
}
static uintptr_t
uart_fdt_find_device(device_t dev)
{
struct ofw_compat_data **cd;
const struct ofw_compat_data *ocd;
SET_FOREACH(cd, uart_fdt_class_and_device_set) {
ocd = ofw_bus_search_compatible(dev, *cd);
if (ocd->ocd_data != 0)
return (ocd->ocd_data);
}
return (0);
}
static int
uart_fdt_probe(device_t dev)
{
struct uart_softc *sc;
phandle_t node;
pcell_t clock, shift;
int err;
sc = device_get_softc(dev);
if (!ofw_bus_status_okay(dev))
return (ENXIO);
sc->sc_class = (struct uart_class *)uart_fdt_find_device(dev);
if (sc->sc_class == NULL)
return (ENXIO);
node = ofw_bus_get_node(dev);
if ((err = uart_fdt_get_clock(node, &clock)) != 0)
return (err);
if (uart_fdt_get_shift(node, &shift) != 0)
shift = uart_getregshift(sc->sc_class);
return (uart_bus_probe(dev, (int)shift, (int)clock, 0, 0));
}
DRIVER_MODULE(uart, simplebus, uart_fdt_driver, uart_devclass, 0, 0);
DRIVER_MODULE(uart, ofwbus, uart_fdt_driver, uart_devclass, 0, 0);