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/clk/clk.h>
35 #include <dev/clk/clk_div.h>
36 #include <dev/clk/clk_fixed.h>
37 #include <dev/clk/clk_mux.h>
38
39 #include "qcom_clk_ro_div.h"
40
41 #include "clkdev_if.h"
42
43 #if 0
44 #define DPRINTF(dev, msg...) device_printf(dev, "cpufreq_dt: " msg);
45 #else
46 #define DPRINTF(dev, msg...)
47 #endif
48
49 /*
50 * This is a read-only divisor table node.
51 * It represents some divisor that is setup by the boot environment
52 * and we don't have any need for the driver to go and fiddle with.
53 *
54 * It likely should just live in the extres/clk code.
55 */
56
57 struct qcom_clk_ro_div_sc {
58 struct clknode *clknode;
59 uint32_t offset;
60 uint32_t shift;
61 uint32_t width;
62 struct qcom_clk_ro_div_tbl *div_tbl;
63 };
64
65 static int
qcom_clk_ro_div_recalc(struct clknode * clk,uint64_t * freq)66 qcom_clk_ro_div_recalc(struct clknode *clk, uint64_t *freq)
67 {
68 struct qcom_clk_ro_div_sc *sc;
69 uint32_t reg, idx, div = 1;
70 int i;
71
72 sc = clknode_get_softc(clk);
73
74 if (freq == NULL || *freq == 0) {
75 printf("%s: called; NULL or 0 frequency\n", __func__);
76 return (ENXIO);
77 }
78
79 CLKDEV_DEVICE_LOCK(clknode_get_device(sc->clknode));
80 CLKDEV_READ_4(clknode_get_device(sc->clknode), sc->offset, ®);
81 CLKDEV_DEVICE_UNLOCK(clknode_get_device(sc->clknode));
82
83 idx = (reg >> sc->shift) & ((1U << sc->width) - 1);
84
85 for (i = 0; (sc->div_tbl[i].div != 0); i++) {
86 if (idx == sc->div_tbl[i].val) {
87 div = sc->div_tbl[i].div;
88 break;
89 }
90 }
91
92 DPRINTF(clknode_get_device(sc->clknode),
93 "%s: freq=%llu, idx=%u, div=%u, out_freq=%llu\n",
94 __func__,
95 *freq,
96 idx,
97 div,
98 *freq / div);
99
100 *freq = *freq / div;
101 return (0);
102 }
103
104 static int
qcom_clk_ro_div_init(struct clknode * clk,device_t dev)105 qcom_clk_ro_div_init(struct clknode *clk, device_t dev)
106 {
107
108 /*
109 * There's only a single parent here for this divisor,
110 * so just set it to 0; the caller doesn't need to supply it.
111 */
112 clknode_init_parent_idx(clk, 0);
113
114 return (0);
115 }
116
117 static clknode_method_t qcom_clk_ro_div_methods[] = {
118 /* Device interface */
119 CLKNODEMETHOD(clknode_init, qcom_clk_ro_div_init),
120 CLKNODEMETHOD(clknode_recalc_freq, qcom_clk_ro_div_recalc),
121 CLKNODEMETHOD_END
122 };
123
124 DEFINE_CLASS_1(qcom_clk_fepll, qcom_clk_ro_div_class,
125 qcom_clk_ro_div_methods, sizeof(struct qcom_clk_ro_div_sc),
126 clknode_class);
127
128 int
qcom_clk_ro_div_register(struct clkdom * clkdom,struct qcom_clk_ro_div_def * clkdef)129 qcom_clk_ro_div_register(struct clkdom *clkdom,
130 struct qcom_clk_ro_div_def *clkdef)
131 {
132 struct clknode *clk;
133 struct qcom_clk_ro_div_sc *sc;
134
135 clk = clknode_create(clkdom, &qcom_clk_ro_div_class,
136 &clkdef->clkdef);
137 if (clk == NULL)
138 return (1);
139
140 sc = clknode_get_softc(clk);
141 sc->clknode = clk;
142 sc->offset = clkdef->offset;
143 sc->shift = clkdef->shift;
144 sc->width = clkdef->width;
145 sc->div_tbl = clkdef->div_tbl;
146
147 clknode_register(clkdom, clk);
148
149 return (0);
150 }
151