xref: /freebsd/sys/dev/qcom_clk/qcom_clk_fdiv.c (revision e34a491b35626b4209ef0a195e85a03a1089c572)

/*-
 * Copyright (c) 2021 Adrian Chadd <adrian@FreeBSD.org>.
 *
 * 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 <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/rman.h>
#include <machine/bus.h>

#include <dev/extres/clk/clk.h>
#include <dev/extres/clk/clk_div.h>
#include <dev/extres/clk/clk_fixed.h>
#include <dev/extres/clk/clk_mux.h>

#include "qcom_clk_fdiv.h"

#include "clkdev_if.h"

/*
 * This is a fixed divisor node.  It represents some divisor
 * that is setup by the boot environment and we don't have
 * any need for the driver to go and fiddle with.
 *
 * It likely should just live in the extres/clk code.
 */

struct qcom_clk_fdiv_sc {
	struct clknode	*clknode;
	uint32_t divisor;
};

static int
qcom_clk_fdiv_recalc(struct clknode *clk, uint64_t *freq)
{
	struct qcom_clk_fdiv_sc *sc;

	sc = clknode_get_softc(clk);

	if (freq == NULL || *freq == 0) {
		printf("%s: called; NULL or 0 frequency\n", __func__);
		return (ENXIO);
	}

	*freq = *freq / sc->divisor;
	return (0);
}

static int
qcom_clk_fdiv_init(struct clknode *clk, device_t dev)
{
	/*
	 * There's only a single parent here for an fixed divisor,
	 * so just set it to 0; the caller doesn't need to supply it.
	 */
	clknode_init_parent_idx(clk, 0);

	return(0);
}

static clknode_method_t qcom_clk_fdiv_methods[] = {
	/* Device interface */
	CLKNODEMETHOD(clknode_init,		qcom_clk_fdiv_init),
	CLKNODEMETHOD(clknode_recalc_freq,	qcom_clk_fdiv_recalc),
	CLKNODEMETHOD_END
};

DEFINE_CLASS_1(qcom_clk_fepll, qcom_clk_fdiv_class, qcom_clk_fdiv_methods,
   sizeof(struct qcom_clk_fdiv_sc), clknode_class);

int
qcom_clk_fdiv_register(struct clkdom *clkdom, struct qcom_clk_fdiv_def *clkdef)
{
	struct clknode *clk;
	struct qcom_clk_fdiv_sc *sc;

	clk = clknode_create(clkdom, &qcom_clk_fdiv_class, &clkdef->clkdef);
	if (clk == NULL)
		return (1);

	sc = clknode_get_softc(clk);
	sc->clknode = clk;

	sc->divisor = clkdef->divisor;

	clknode_register(clkdom, clk);

	return (0);
}