xref: /freebsd/sys/dev/qcom_clk/qcom_clk_fdiv.c (revision 38c63bdc46252d4d8cd313dff4183ec4546d26d9)
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/param.h>
27 #include <sys/systm.h>
28 #include <sys/bus.h>
29 #include <sys/lock.h>
30 #include <sys/mutex.h>
31 #include <sys/rman.h>
32 #include <machine/bus.h>
33 
34 #include <dev/extres/clk/clk.h>
35 #include <dev/extres/clk/clk_div.h>
36 #include <dev/extres/clk/clk_fixed.h>
37 #include <dev/extres/clk/clk_mux.h>
38 
39 #include "qcom_clk_fdiv.h"
40 
41 #include "clkdev_if.h"
42 
43 /*
44  * This is a fixed divisor node.  It represents some divisor
45  * that is setup by the boot environment and we don't have
46  * any need for the driver to go and fiddle with.
47  *
48  * It likely should just live in the extres/clk code.
49  */
50 
51 struct qcom_clk_fdiv_sc {
52 	struct clknode	*clknode;
53 	uint32_t divisor;
54 };
55 
56 static int
57 qcom_clk_fdiv_recalc(struct clknode *clk, uint64_t *freq)
58 {
59 	struct qcom_clk_fdiv_sc *sc;
60 
61 	sc = clknode_get_softc(clk);
62 
63 	if (freq == NULL || *freq == 0) {
64 		printf("%s: called; NULL or 0 frequency\n", __func__);
65 		return (ENXIO);
66 	}
67 
68 	*freq = *freq / sc->divisor;
69 	return (0);
70 }
71 
72 static int
73 qcom_clk_fdiv_init(struct clknode *clk, device_t dev)
74 {
75 	/*
76 	 * There's only a single parent here for an fixed divisor,
77 	 * so just set it to 0; the caller doesn't need to supply it.
78 	 */
79 	clknode_init_parent_idx(clk, 0);
80 
81 	return(0);
82 }
83 
84 static clknode_method_t qcom_clk_fdiv_methods[] = {
85 	/* Device interface */
86 	CLKNODEMETHOD(clknode_init,		qcom_clk_fdiv_init),
87 	CLKNODEMETHOD(clknode_recalc_freq,	qcom_clk_fdiv_recalc),
88 	CLKNODEMETHOD_END
89 };
90 
91 DEFINE_CLASS_1(qcom_clk_fepll, qcom_clk_fdiv_class, qcom_clk_fdiv_methods,
92    sizeof(struct qcom_clk_fdiv_sc), clknode_class);
93 
94 int
95 qcom_clk_fdiv_register(struct clkdom *clkdom, struct qcom_clk_fdiv_def *clkdef)
96 {
97 	struct clknode *clk;
98 	struct qcom_clk_fdiv_sc *sc;
99 
100 	clk = clknode_create(clkdom, &qcom_clk_fdiv_class, &clkdef->clkdef);
101 	if (clk == NULL)
102 		return (1);
103 
104 	sc = clknode_get_softc(clk);
105 	sc->clknode = clk;
106 
107 	sc->divisor = clkdef->divisor;
108 
109 	clknode_register(clkdom, clk);
110 
111 	return (0);
112 }
113