1 /* $NetBSD: ingenic_rng.c,v 1.7 2022/03/19 11:55:03 riastradh Exp $ */
2
3 /*-
4 * Copyright (c) 2015 Michael McConville
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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 __KERNEL_RCSID(0, "$NetBSD: ingenic_rng.c,v 1.7 2022/03/19 11:55:03 riastradh Exp $");
31
32 /*
33 * adapted from Jared McNeill's amlogic_rng.c
34 */
35
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/device.h>
39 #include <sys/mutex.h>
40 #include <sys/kernel.h>
41 #include <sys/mutex.h>
42 #include <sys/bus.h>
43 #include <sys/rndsource.h>
44
45 #include <mips/ingenic/ingenic_var.h>
46 #include <mips/ingenic/ingenic_regs.h>
47
48 #include "opt_ingenic.h"
49
50 struct ingenic_rng_softc;
51
52 static int ingenic_rng_match(device_t, cfdata_t, void *);
53 static void ingenic_rng_attach(device_t, device_t, void *);
54
55 static void ingenic_rng_get(size_t, void *);
56
57 struct ingenic_rng_softc {
58 device_t sc_dev;
59 bus_space_tag_t sc_bst;
60 bus_space_handle_t sc_bsh;
61
62 krndsource_t sc_rndsource;
63 };
64
65 CFATTACH_DECL_NEW(ingenic_rng, sizeof(struct ingenic_rng_softc),
66 ingenic_rng_match, ingenic_rng_attach, NULL, NULL);
67
68 static int
ingenic_rng_match(device_t parent,cfdata_t cf,void * aux)69 ingenic_rng_match(device_t parent, cfdata_t cf, void *aux)
70 {
71 const struct apbus_attach_args *aa = aux;
72
73 return !(strcmp(aa->aa_name, "jzrng"));
74 }
75
76 static void
ingenic_rng_attach(device_t parent,device_t self,void * aux)77 ingenic_rng_attach(device_t parent, device_t self, void *aux)
78 {
79 struct ingenic_rng_softc * const sc = device_private(self);
80 const struct apbus_attach_args * const aa = aux;
81 bus_addr_t addr = aa->aa_addr;
82 int error;
83
84 sc->sc_dev = self;
85 sc->sc_bst = aa->aa_bst;
86 if (addr == 0)
87 addr = JZ_RNG;
88
89 error = bus_space_map(aa->aa_bst, addr, 4, 0, &sc->sc_bsh);
90 if (error) {
91 aprint_error_dev(self,
92 "can't map registers for %s: %d\n", aa->aa_name, error);
93 return;
94 }
95
96 aprint_naive(": Ingenic random number generator\n");
97 aprint_normal(": Ingenic random number generator\n");
98
99 rndsource_setcb(&sc->sc_rndsource, ingenic_rng_get, sc);
100 rnd_attach_source(&sc->sc_rndsource, device_xname(self), RND_TYPE_RNG,
101 RND_FLAG_COLLECT_VALUE|RND_FLAG_HASCB);
102 }
103
104 static void
ingenic_rng_get(size_t bytes_wanted,void * priv)105 ingenic_rng_get(size_t bytes_wanted, void *priv)
106 {
107 struct ingenic_rng_softc * const sc = priv;
108 uint32_t data;
109
110 while (bytes_wanted) {
111 data = bus_space_read_4(sc->sc_bst, sc->sc_bsh, 0);
112 delay(1);
113 rnd_add_data_sync(&sc->sc_rndsource, &data, sizeof(data),
114 sizeof(data) * NBBY);
115 bytes_wanted -= MIN(bytes_wanted, sizeof(data));
116 }
117 explicit_memset(&data, 0, sizeof(data));
118 }
119