xref: /freebsd/sys/dev/qcom_clk/qcom_clk_fdiv.c (revision 685dc743dc3b5645e34836464128e1c0558b404b)
1 /*-
2  * Copyright (c) 2021 Adrian Chadd <adrian@FreeBSD.org>.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  */
25 
26 #include <sys/cdefs.h>
27 #include <sys/param.h>
28 #include <sys/systm.h>
29 #include <sys/bus.h>
30 #include <sys/lock.h>
31 #include <sys/mutex.h>
32 #include <sys/rman.h>
33 #include <machine/bus.h>
34 
35 #include <dev/extres/clk/clk.h>
36 #include <dev/extres/clk/clk_div.h>
37 #include <dev/extres/clk/clk_fixed.h>
38 #include <dev/extres/clk/clk_mux.h>
39 
40 #include "qcom_clk_fdiv.h"
41 
42 #include "clkdev_if.h"
43 
44 /*
45  * This is a fixed divisor node.  It represents some divisor
46  * that is setup by the boot environment and we don't have
47  * any need for the driver to go and fiddle with.
48  *
49  * It likely should just live in the extres/clk code.
50  */
51 
52 struct qcom_clk_fdiv_sc {
53 	struct clknode	*clknode;
54 	uint32_t divisor;
55 };
56 
57 static int
58 qcom_clk_fdiv_recalc(struct clknode *clk, uint64_t *freq)
59 {
60 	struct qcom_clk_fdiv_sc *sc;
61 
62 	sc = clknode_get_softc(clk);
63 
64 	if (freq == NULL || *freq == 0) {
65 		printf("%s: called; NULL or 0 frequency\n", __func__);
66 		return (ENXIO);
67 	}
68 
69 	*freq = *freq / sc->divisor;
70 	return (0);
71 }
72 
73 static int
74 qcom_clk_fdiv_init(struct clknode *clk, device_t dev)
75 {
76 	/*
77 	 * There's only a single parent here for an fixed divisor,
78 	 * so just set it to 0; the caller doesn't need to supply it.
79 	 */
80 	clknode_init_parent_idx(clk, 0);
81 
82 	return(0);
83 }
84 
85 static clknode_method_t qcom_clk_fdiv_methods[] = {
86 	/* Device interface */
87 	CLKNODEMETHOD(clknode_init,		qcom_clk_fdiv_init),
88 	CLKNODEMETHOD(clknode_recalc_freq,	qcom_clk_fdiv_recalc),
89 	CLKNODEMETHOD_END
90 };
91 
92 DEFINE_CLASS_1(qcom_clk_fepll, qcom_clk_fdiv_class, qcom_clk_fdiv_methods,
93    sizeof(struct qcom_clk_fdiv_sc), clknode_class);
94 
95 int
96 qcom_clk_fdiv_register(struct clkdom *clkdom, struct qcom_clk_fdiv_def *clkdef)
97 {
98 	struct clknode *clk;
99 	struct qcom_clk_fdiv_sc *sc;
100 
101 	clk = clknode_create(clkdom, &qcom_clk_fdiv_class, &clkdef->clkdef);
102 	if (clk == NULL)
103 		return (1);
104 
105 	sc = clknode_get_softc(clk);
106 	sc->clknode = clk;
107 
108 	sc->divisor = clkdef->divisor;
109 
110 	clknode_register(clkdom, clk);
111 
112 	return (0);
113 }
114