clk_fixed.c revision 294660 
1/*-
2 * Copyright 2016 Michal Meloun <mmel@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: head/sys/dev/extres/clk/clk_fixed.c 294660 2016-01-24 11:00:38Z mmel $");
29
30
31#include <sys/param.h>
32#include <sys/conf.h>
33#include <sys/bus.h>
34#include <sys/kernel.h>
35#include <sys/kobj.h>
36#include <sys/malloc.h>
37#include <sys/mutex.h>
38#include <sys/rman.h>
39#include <sys/systm.h>
40
41#include <machine/bus.h>
42
43#include <dev/extres/clk/clk_fixed.h>
44
45#define	DEVICE_LOCK(_sc)      mtx_lock((_sc)->mtx)
46#define	DEVICE_UNLOCK(_sc)    mtx_unlock((_sc)->mtx)
47
48static int clknode_fixed_init(struct clknode *clk, device_t dev);
49static int clknode_fixed_recalc(struct clknode *clk, uint64_t *freq);
50struct clknode_fixed_sc {
51	struct mtx	*mtx;
52	int		fixed_flags;
53	uint64_t	freq;
54	uint32_t	mult;
55	uint32_t	div;
56};
57
58static clknode_method_t clknode_fixed_methods[] = {
59	/* Device interface */
60	CLKNODEMETHOD(clknode_init,	   clknode_fixed_init),
61	CLKNODEMETHOD(clknode_recalc_freq, clknode_fixed_recalc),
62	CLKNODEMETHOD_END
63};
64DEFINE_CLASS_1(clknode_fixed, clknode_fixed_class, clknode_fixed_methods,
65   sizeof(struct clknode_fixed_sc), clknode_class);
66
67static int
68clknode_fixed_init(struct clknode *clk, device_t dev)
69{
70	struct clknode_fixed_sc *sc;
71
72	sc = clknode_get_softc(clk);
73	if (sc->freq == 0)
74		clknode_init_parent_idx(clk, 0);
75	return(0);
76}
77static int
78clknode_fixed_recalc(struct clknode *clk, uint64_t *freq)
79{
80	struct clknode_fixed_sc *sc;
81
82	sc = clknode_get_softc(clk);
83	if (sc->freq != 0)
84		*freq = sc->freq;
85	else if ((sc->mult != 0) && (sc->div != 0))
86		*freq = (*freq / sc->div) * sc->mult;
87	else
88		*freq = 0;
89	return (0);
90}
91
92int
93clknode_fixed_register(struct clkdom *clkdom, struct clk_fixed_def *clkdef,
94    struct mtx *dev_mtx)
95{
96	struct clknode *clk;
97	struct clknode_fixed_sc *sc;
98
99	if ((clkdef->freq == 0) && (clkdef->clkdef.parent_cnt == 0))
100		panic("fixed clk: Frequency is not defined for clock source");
101	clk = clknode_create(clkdom, &clknode_fixed_class, &clkdef->clkdef);
102	if (clk == NULL)
103		return (1);
104
105	sc = clknode_get_softc(clk);
106	sc->mtx = dev_mtx;
107	sc->fixed_flags = clkdef->fixed_flags;
108	sc->freq = clkdef->freq;
109	sc->mult = clkdef->mult;
110	sc->div = clkdef->div;
111
112	clknode_register(clkdom, clk);
113	return (0);
114}
115