NetBSD/sys/dev/fdt/fdt_clock.c

269 lines
6.9 KiB
C

/* $NetBSD: fdt_clock.c,v 1.10 2019/11/09 23:28:26 jmcneill Exp $ */
/*-
* Copyright (c) 2015 Jared D. McNeill <jmcneill@invisible.ca>
* 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 ``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 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>
__KERNEL_RCSID(0, "$NetBSD: fdt_clock.c,v 1.10 2019/11/09 23:28:26 jmcneill Exp $");
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/kmem.h>
#include <sys/queue.h>
#include <libfdt.h>
#include <dev/fdt/fdtvar.h>
#include <dev/clk/clk_backend.h>
struct fdtbus_clock_controller {
device_t cc_dev;
int cc_phandle;
const struct fdtbus_clock_controller_func *cc_funcs;
LIST_ENTRY(fdtbus_clock_controller) cc_next;
};
static LIST_HEAD(, fdtbus_clock_controller) fdtbus_clock_controllers =
LIST_HEAD_INITIALIZER(fdtbus_clock_controller);
int
fdtbus_register_clock_controller(device_t dev, int phandle,
const struct fdtbus_clock_controller_func *funcs)
{
struct fdtbus_clock_controller *cc;
cc = kmem_alloc(sizeof(*cc), KM_SLEEP);
cc->cc_dev = dev;
cc->cc_phandle = phandle;
cc->cc_funcs = funcs;
LIST_INSERT_HEAD(&fdtbus_clock_controllers, cc, cc_next);
fdtbus_clock_assign(phandle);
return 0;
}
static struct fdtbus_clock_controller *
fdtbus_get_clock_controller(int phandle)
{
struct fdtbus_clock_controller *cc;
LIST_FOREACH(cc, &fdtbus_clock_controllers, cc_next) {
if (cc->cc_phandle == phandle)
return cc;
}
return NULL;
}
static struct clk *
fdtbus_clock_get_index_prop(int phandle, u_int index, const char *prop)
{
struct fdtbus_clock_controller *cc;
struct clk *clk = NULL;
const u_int *p;
u_int n, clock_cells;
int len, resid;
p = fdtbus_get_prop(phandle, prop, &len);
if (p == NULL)
return NULL;
for (n = 0, resid = len; resid > 0; n++) {
const int cc_phandle =
fdtbus_get_phandle_from_native(be32toh(p[0]));
if (of_getprop_uint32(cc_phandle, "#clock-cells", &clock_cells))
break;
if (n == index) {
cc = fdtbus_get_clock_controller(cc_phandle);
if (cc == NULL)
break;
clk = cc->cc_funcs->decode(cc->cc_dev, cc_phandle,
clock_cells > 0 ? &p[1] : NULL, clock_cells * 4);
break;
}
resid -= (clock_cells + 1) * 4;
p += clock_cells + 1;
}
return clk;
}
struct clk *
fdtbus_clock_get_index(int phandle, u_int index)
{
return fdtbus_clock_get_index_prop(phandle, index, "clocks");
}
static struct clk *
fdtbus_clock_get_prop(int phandle, const char *clkname, const char *prop)
{
u_int index;
int err;
err = fdtbus_get_index(phandle, prop, clkname, &index);
if (err != 0)
return NULL;
return fdtbus_clock_get_index(phandle, index);
}
u_int
fdtbus_clock_count(int phandle, const char *prop)
{
u_int n, clock_cells;
int len, resid;
const u_int *p = fdtbus_get_prop(phandle, prop, &len);
if (p == NULL)
return 0;
for (n = 0, resid = len; resid > 0; n++) {
const int cc_phandle =
fdtbus_get_phandle_from_native(be32toh(p[0]));
if (of_getprop_uint32(cc_phandle, "#clock-cells", &clock_cells))
break;
resid -= (clock_cells + 1) * 4;
p += clock_cells + 1;
}
return n;
}
struct clk *
fdtbus_clock_get(int phandle, const char *clkname)
{
return fdtbus_clock_get_prop(phandle, clkname, "clock-names");
}
int
fdtbus_clock_enable(int phandle, const char *clkname, bool required)
{
struct clk *clk;
clk = fdtbus_clock_get(phandle, clkname);
if (clk == NULL)
return required ? ENOENT : 0;
return clk_enable(clk);
}
int
fdtbus_clock_enable_index(int phandle, u_int index, bool required)
{
struct clk *clk;
clk = fdtbus_clock_get_index(phandle, index);
if (clk == NULL)
return required ? ENOENT : 0;
return clk_enable(clk);
}
/*
* Search the DT for a clock by "clock-output-names" property.
*
* This should only be used by clk backends. Not for use by ordinary
* clock consumers!
*/
struct clk *
fdtbus_clock_byname(const char *clkname)
{
struct fdtbus_clock_controller *cc;
u_int index, clock_cells;
int err;
LIST_FOREACH(cc, &fdtbus_clock_controllers, cc_next) {
err = fdtbus_get_index(cc->cc_phandle, "clock-output-names", clkname, &index);
if (err != 0)
continue;
if (of_getprop_uint32(cc->cc_phandle, "#clock-cells", &clock_cells))
continue;
const u_int index_raw = htobe32(index);
return cc->cc_funcs->decode(cc->cc_dev,
cc->cc_phandle,
clock_cells > 0 ? &index_raw : NULL,
clock_cells > 0 ? 4 : 0);
}
return NULL;
}
/*
* Apply assigned clock parents and rates.
*
* This is automatically called by fdtbus_register_clock_controller, so clock
* drivers likely don't need to call this directly.
*/
void
fdtbus_clock_assign(int phandle)
{
u_int index, rates_len;
struct clk *clk, *clk_parent;
int error;
const u_int *rates = fdtbus_get_prop(phandle, "assigned-clock-rates", &rates_len);
if (rates == NULL)
rates_len = 0;
const u_int nclocks = fdtbus_clock_count(phandle, "assigned-clocks");
const u_int nparents = fdtbus_clock_count(phandle, "assigned-clock-parents");
const u_int nrates = rates_len / sizeof(*rates);
for (index = 0; index < nclocks; index++) {
clk = fdtbus_clock_get_index_prop(phandle, index, "assigned-clocks");
if (clk == NULL) {
aprint_debug("clk: assigned clock (%u) not found, skipping...\n", index);
continue;
}
if (index < nparents) {
clk_parent = fdtbus_clock_get_index_prop(phandle, index, "assigned-clock-parents");
if (clk_parent != NULL) {
error = clk_set_parent(clk, clk_parent);
if (error != 0) {
aprint_error("clk: failed to set %s parent to %s, error %d\n",
clk->name, clk_parent->name, error);
}
} else {
aprint_debug("clk: failed to set %s parent (not found)\n", clk->name);
}
}
if (index < nrates) {
const u_int rate = be32toh(rates[index]);
if (rate != 0) {
error = clk_set_rate(clk, rate);
if (error != 0)
aprint_error("clk: failed to set %s rate to %u Hz, error %d\n",
clk->name, rate, error);
}
}
}
}