freebsd-skq/sys/dev/uart/uart_bus_fdt.c
andrew 99c1acd018 We will be switching to a new arm64 uart cpu driver that handles both FDT
and ACPI. As such pull out what will be the common parts of the FDT cpu
detection to a new function that can be shared between them.

Reviewed by:	manu
Obtained from:	ABT Systems Ltd
MFC after:	1 month
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D7262
2016-07-20 17:19:47 +00:00

259 lines
6.5 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/systm.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 extension. */
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
phandle_chosen_propdev(phandle_t chosen, const char *name, phandle_t *node)
{
char buf[64];
if (OF_getprop(chosen, name, buf, sizeof(buf)) <= 0)
return (ENXIO);
if ((*node = OF_finddevice(buf)) == -1)
return (ENXIO);
return (0);
}
static const struct ofw_compat_data *
uart_fdt_find_compatible(phandle_t node, const struct ofw_compat_data *cd)
{
const struct ofw_compat_data *ocd;
for (ocd = cd; ocd->ocd_str != NULL; ocd++) {
if (fdt_is_compatible(node, ocd->ocd_str))
return (ocd);
}
return (NULL);
}
static uintptr_t
uart_fdt_find_by_node(phandle_t node, int class_list)
{
struct ofw_compat_data **cd;
const struct ofw_compat_data *ocd;
if (class_list) {
SET_FOREACH(cd, uart_fdt_class_set) {
ocd = uart_fdt_find_compatible(node, *cd);
if ((ocd != NULL) && (ocd->ocd_data != 0))
return (ocd->ocd_data);
}
} else {
SET_FOREACH(cd, uart_fdt_class_and_device_set) {
ocd = uart_fdt_find_compatible(node, *cd);
if ((ocd != NULL) && (ocd->ocd_data != 0))
return (ocd->ocd_data);
}
}
return (0);
}
int
uart_cpu_fdt_probe(struct uart_class **classp, bus_space_tag_t *bst,
bus_space_handle_t *bsh, int *baud, u_int *rclk, u_int *shiftp)
{
const char *propnames[] = {"stdout-path", "linux,stdout-path", "stdout",
"stdin-path", "stdin", NULL};
const char **name;
struct uart_class *class;
phandle_t node, chosen;
pcell_t br, clk, shift;
char *cp;
int err;
/* Has the user forced a specific device node? */
cp = kern_getenv("hw.fdt.console");
if (cp == NULL) {
/*
* Retrieve /chosen/std{in,out}.
*/
node = -1;
if ((chosen = OF_finddevice("/chosen")) != -1) {
for (name = propnames; *name != NULL; name++) {
if (phandle_chosen_propdev(chosen, *name,
&node) == 0)
break;
}
}
if (chosen == -1 || *name == NULL)
node = OF_finddevice("serial0"); /* Last ditch */
} else {
node = OF_finddevice(cp);
}
if (node == -1)
return (ENXIO);
/*
* Check old style of UART definition first. Unfortunately, the common
* FDT processing is not possible if we have clock, power domains and
* pinmux stuff.
*/
class = (struct uart_class *)uart_fdt_find_by_node(node, 0);
if (class != NULL) {
if ((err = uart_fdt_get_clock(node, &clk)) != 0)
return (err);
} else {
/* Check class only linker set */
class =
(struct uart_class *)uart_fdt_find_by_node(node, 1);
if (class == NULL)
return (ENXIO);
clk = 0;
}
/*
* Retrieve serial attributes.
*/
if (uart_fdt_get_shift(node, &shift) != 0)
shift = uart_getregshift(class);
if (OF_getencprop(node, "current-speed", &br, sizeof(br)) <= 0)
br = 0;
err = OF_decode_addr(node, 0, bst, bsh, NULL);
if (err != 0)
return (err);
*classp = class;
*baud = br;
*rclk = clk;
*shiftp = shift;
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);