1 /* $NetBSD: fixedfactorclock.c,v 1.4 2021/01/27 03:10:21 thorpej Exp $ */
2
3 /*-
4 * Copyright (c) 2017 Jared McNeill <jmcneill@invisible.ca>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 __KERNEL_RCSID(0, "$NetBSD: fixedfactorclock.c,v 1.4 2021/01/27 03:10:21 thorpej Exp $");
31
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/device.h>
35 #include <sys/kmem.h>
36 #include <sys/bus.h>
37
38 #include <dev/clk/clk_backend.h>
39
40 #include <dev/fdt/fdtvar.h>
41
42 static int fixedfactorclock_match(device_t, cfdata_t, void *);
43 static void fixedfactorclock_attach(device_t, device_t, void *);
44
45 static struct clk *fixedfactorclock_decode(device_t, int, const void *, size_t);
46
47 static const struct fdtbus_clock_controller_func fixedfactorclock_fdt_funcs = {
48 .decode = fixedfactorclock_decode
49 };
50
51 static struct clk *fixedfactorclock_get(void *, const char *);
52 static void fixedfactorclock_put(void *, struct clk *);
53 static u_int fixedfactorclock_get_rate(void *, struct clk *);
54
55 static const struct clk_funcs fixedfactorclock_clk_funcs = {
56 .get = fixedfactorclock_get,
57 .put = fixedfactorclock_put,
58 .get_rate = fixedfactorclock_get_rate,
59 };
60
61 struct fixedfactorclock_clk {
62 struct clk base;
63
64 u_int div;
65 u_int mult;
66 };
67
68 struct fixedfactorclock_softc {
69 device_t sc_dev;
70 int sc_phandle;
71
72 struct clk_domain sc_clkdom;
73 struct fixedfactorclock_clk sc_clk;
74 };
75
76 CFATTACH_DECL_NEW(ffclock, sizeof(struct fixedfactorclock_softc),
77 fixedfactorclock_match, fixedfactorclock_attach, NULL, NULL);
78
79 static const struct device_compatible_entry compat_data[] = {
80 { .compat = "fixed-factor-clock" },
81 DEVICE_COMPAT_EOL
82 };
83
84 static int
fixedfactorclock_match(device_t parent,cfdata_t cf,void * aux)85 fixedfactorclock_match(device_t parent, cfdata_t cf, void *aux)
86 {
87 const struct fdt_attach_args *faa = aux;
88
89 return of_compatible_match(faa->faa_phandle, compat_data);
90 }
91
92 static void
fixedfactorclock_attach(device_t parent,device_t self,void * aux)93 fixedfactorclock_attach(device_t parent, device_t self, void *aux)
94 {
95 struct fixedfactorclock_softc * const sc = device_private(self);
96 const struct fdt_attach_args *faa = aux;
97 const int phandle = faa->faa_phandle;
98 const char *name;
99
100 sc->sc_dev = self;
101 sc->sc_phandle = phandle;
102 sc->sc_clkdom.name = device_xname(self);
103 sc->sc_clkdom.funcs = &fixedfactorclock_clk_funcs;
104 sc->sc_clkdom.priv = sc;
105
106 of_getprop_uint32(phandle, "clock-div", &sc->sc_clk.div);
107 of_getprop_uint32(phandle, "clock-mult", &sc->sc_clk.mult);
108
109 if (sc->sc_clk.div == 0 || sc->sc_clk.mult == 0) {
110 aprint_error(": invalid properties\n");
111 return;
112 }
113
114 name = fdtbus_get_string(phandle, "clock-output-names");
115 if (name == NULL)
116 name = faa->faa_name;
117
118 sc->sc_clk.base.domain = &sc->sc_clkdom;
119 sc->sc_clk.base.name = name;
120 clk_attach(&sc->sc_clk.base);
121
122 aprint_naive("\n");
123 aprint_normal(": x%u /%u fixed-factor clock\n",
124 sc->sc_clk.mult, sc->sc_clk.div);
125
126 fdtbus_register_clock_controller(self, phandle,
127 &fixedfactorclock_fdt_funcs);
128 }
129
130 static struct clk *
fixedfactorclock_decode(device_t dev,int cc_phandle,const void * data,size_t len)131 fixedfactorclock_decode(device_t dev, int cc_phandle, const void *data,
132 size_t len)
133 {
134 struct fixedfactorclock_softc * const sc = device_private(dev);
135
136 /* #clock-cells for a fixed factor clock is always 0 */
137 if (len != 0)
138 return NULL;
139
140 return &sc->sc_clk.base;
141 }
142
143 static struct clk *
fixedfactorclock_get(void * priv,const char * name)144 fixedfactorclock_get(void *priv, const char *name)
145 {
146 struct fixedfactorclock_softc * const sc = priv;
147
148 if (strcmp(name, sc->sc_clk.base.name) != 0)
149 return NULL;
150
151 return &sc->sc_clk.base;
152 }
153
154 static void
fixedfactorclock_put(void * priv,struct clk * clk)155 fixedfactorclock_put(void *priv, struct clk *clk)
156 {
157 }
158
159 static u_int
fixedfactorclock_get_rate(void * priv,struct clk * clk)160 fixedfactorclock_get_rate(void *priv, struct clk *clk)
161 {
162 struct fixedfactorclock_softc * const sc = priv;
163 struct fixedfactorclock_clk *fclk = (struct fixedfactorclock_clk *)clk;
164 struct clk *clkp_parent;
165
166 clkp_parent = fdtbus_clock_get_index(sc->sc_phandle, 0);
167 if (clkp_parent == NULL)
168 return 0;
169
170 return (clk_get_rate(clkp_parent) * fclk->mult) / fclk->div;
171 }
172