xref: /freebsd/sys/arm/mv/clk/a37x0_tbg_pll.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2021 Semihalf.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include <sys/param.h>
32 #include <sys/bus.h>
33 #include <sys/rman.h>
34 #include <machine/bus.h>
35 
36 #include <dev/extres/clk/clk.h>
37 
38 #include <dev/ofw/ofw_bus.h>
39 #include <dev/ofw/ofw_bus_subr.h>
40 
41 #include "clkdev_if.h"
42 
43 #include "a37x0_tbg_pll.h"
44 
45 #define RD4(_clk, offset, val)			\
46 	CLKDEV_READ_4(clknode_get_device(_clk), offset, val)
47 
48 struct a37x0_tbg_pll_softc {
49 	struct a37x0_tbg_pll_reg_def		vcodiv;
50 	struct a37x0_tbg_pll_reg_def		refdiv;
51 	struct a37x0_tbg_pll_reg_def		fbdiv;
52 	struct a37x0_tbg_pll_reg_def		tbg_bypass;
53 };
54 
55 static int
56 a37x0_tbg_pll_recalc_freq(struct clknode *clk, uint64_t *freq)
57 {
58 	struct a37x0_tbg_pll_softc *sc;
59 	uint32_t vcodiv, fbdiv, refdiv;
60 	unsigned int val;
61 
62 	sc = clknode_get_softc(clk);
63 
64 	RD4(clk, sc->tbg_bypass.offset, &val);
65 	if ((val >> sc->tbg_bypass.shift) & sc->tbg_bypass.mask)
66 		return 0;
67 
68 	RD4(clk, sc->vcodiv.offset, &val);
69 	vcodiv = 1 << ((val >> sc->vcodiv.shift) & sc->vcodiv.mask);
70 
71 	RD4(clk, sc->refdiv.offset, &val);
72 	refdiv = (val >> sc->refdiv.shift) & sc->refdiv.mask;
73 
74 	RD4(clk, sc->fbdiv.offset, &val);
75 	fbdiv = (val >> sc->fbdiv.shift) & sc->fbdiv.mask;
76 
77 	if (refdiv == 0)
78 		refdiv = 1;
79 
80 	*freq = *freq * (fbdiv / refdiv) * 4;
81 	*freq /= vcodiv;
82 
83 	return (0);
84 }
85 
86 static int
87 a37x0_tbg_pll_init(struct clknode *clk, device_t dev)
88 {
89 
90 	clknode_init_parent_idx(clk, 0);
91 
92 	return (0);
93 }
94 
95 static clknode_method_t a37x0_tbg_pll_clknode_methods[] = {
96 	CLKNODEMETHOD(clknode_recalc_freq,	a37x0_tbg_pll_recalc_freq),
97 	CLKNODEMETHOD(clknode_init,		a37x0_tbg_pll_init),
98 
99 	CLKNODEMETHOD_END
100 };
101 
102 DEFINE_CLASS_1(a37x0_tbg_pll__clknode, a37x0_tbg_pll_clknode_class,
103     a37x0_tbg_pll_clknode_methods, sizeof(struct a37x0_tbg_pll_softc),
104     clknode_class);
105 
106 int
107 a37x0_tbg_pll_clk_register(struct clkdom *clkdom,
108     const struct a37x0_tbg_pll_clk_def *clkdef)
109 {
110 	struct a37x0_tbg_pll_softc *sc;
111 	struct clknode *clk;
112 
113 	clk = clknode_create(clkdom, &a37x0_tbg_pll_clknode_class,
114 	    &clkdef->clkdef);
115 
116 	if (clk == NULL)
117 		return (1);
118 
119 	sc = clknode_get_softc(clk);
120 
121 	sc->vcodiv = clkdef->vcodiv;
122 	sc->refdiv = clkdef->refdiv;
123 	sc->fbdiv = clkdef->fbdiv;
124 	sc->tbg_bypass = clkdef->tbg_bypass;
125 
126 	if (clknode_register(clkdom, clk) == NULL)
127 		return (1);
128 
129 	return (0);
130 }
131