1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2017 Poul-Henning Kamp <phk@FreeBSD.org>
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
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/bus.h>
32 #include <sys/cpu.h>
33 #include <sys/kernel.h>
34 #include <sys/lock.h>
35 #include <sys/malloc.h>
36 #include <sys/module.h>
37 #include <sys/mutex.h>
38 #include <sys/rman.h>
39 #include <sys/sema.h>
40 #include <sys/sysctl.h>
41
42 #include <machine/bus.h>
43 #include <machine/cpu.h>
44
45 #include <dev/ofw/ofw_bus.h>
46 #include <dev/ofw/ofw_bus_subr.h>
47
48 #include <arm/broadcom/bcm2835/bcm2835_clkman.h>
49
50 static struct ofw_compat_data compat_data[] = {
51 {"brcm,bcm2711-cprman", 1},
52 {"brcm,bcm2835-cprman", 1},
53 {"broadcom,bcm2835-cprman", 1},
54 {NULL, 0}
55 };
56
57 struct bcm2835_clkman_softc {
58 device_t sc_dev;
59
60 struct resource * sc_m_res;
61 bus_space_tag_t sc_m_bst;
62 bus_space_handle_t sc_m_bsh;
63 };
64
65 #define BCM_CLKMAN_WRITE(_sc, _off, _val) \
66 bus_space_write_4(_sc->sc_m_bst, _sc->sc_m_bsh, _off, _val)
67 #define BCM_CLKMAN_READ(_sc, _off) \
68 bus_space_read_4(_sc->sc_m_bst, _sc->sc_m_bsh, _off)
69
70 #define W_CMCLK(_sc, unit, _val) BCM_CLKMAN_WRITE(_sc, unit, 0x5a000000 | (_val))
71 #define R_CMCLK(_sc, unit) BCM_CLKMAN_READ(_sc, unit)
72 #define W_CMDIV(_sc, unit, _val) BCM_CLKMAN_WRITE(_sc, (unit) + 4, 0x5a000000 | (_val))
73 #define R_CMDIV(_sc, unit) BCM_CLKMAN_READ(_sc, (unit) + 4)
74
75 static int
bcm2835_clkman_probe(device_t dev)76 bcm2835_clkman_probe(device_t dev)
77 {
78
79 if (!ofw_bus_status_okay(dev))
80 return (ENXIO);
81
82 if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
83 return (ENXIO);
84
85 device_set_desc(dev, "BCM283x Clock Manager");
86
87 return (BUS_PROBE_DEFAULT);
88 }
89
90 static int
bcm2835_clkman_attach(device_t dev)91 bcm2835_clkman_attach(device_t dev)
92 {
93 struct bcm2835_clkman_softc *sc;
94 int rid;
95
96 if (device_get_unit(dev) != 0) {
97 device_printf(dev, "only one clk manager supported\n");
98 return (ENXIO);
99 }
100
101 sc = device_get_softc(dev);
102 sc->sc_dev = dev;
103
104 rid = 0;
105 sc->sc_m_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
106 RF_ACTIVE);
107 if (!sc->sc_m_res) {
108 device_printf(dev, "cannot allocate memory window\n");
109 return (ENXIO);
110 }
111
112 sc->sc_m_bst = rman_get_bustag(sc->sc_m_res);
113 sc->sc_m_bsh = rman_get_bushandle(sc->sc_m_res);
114
115 bus_attach_children(dev);
116 return (0);
117 }
118
119 uint32_t
bcm2835_clkman_set_frequency(device_t dev,uint32_t unit,uint32_t hz)120 bcm2835_clkman_set_frequency(device_t dev, uint32_t unit, uint32_t hz)
121 {
122 struct bcm2835_clkman_softc *sc;
123 int i;
124 uint32_t u;
125
126 sc = device_get_softc(dev);
127
128 if (unit != BCM_PWM_CLKSRC) {
129 device_printf(sc->sc_dev,
130 "Unsupported unit 0x%x", unit);
131 return (0);
132 }
133
134 W_CMCLK(sc, unit, 6);
135 for (i = 0; i < 10; i++) {
136 u = R_CMCLK(sc, unit);
137 if (!(u&0x80))
138 break;
139 DELAY(1000);
140 }
141 if (u & 0x80) {
142 device_printf(sc->sc_dev,
143 "Failed to stop clock for unit 0x%x", unit);
144 return (0);
145 }
146 if (hz == 0)
147 return (0);
148
149 u = 500000000/hz;
150 if (u < 4) {
151 device_printf(sc->sc_dev,
152 "Frequency too high for unit 0x%x (max: 125 MHz)",
153 unit);
154 return (0);
155 }
156 if (u > 0xfff) {
157 device_printf(sc->sc_dev,
158 "Frequency too low for unit 0x%x (min: 123 kHz)",
159 unit);
160 return (0);
161 }
162 hz = 500000000/u;
163 W_CMDIV(sc, unit, u << 12);
164
165 W_CMCLK(sc, unit, 0x16);
166 for (i = 0; i < 10; i++) {
167 u = R_CMCLK(sc, unit);
168 if ((u&0x80))
169 break;
170 DELAY(1000);
171 }
172 if (!(u & 0x80)) {
173 device_printf(sc->sc_dev,
174 "Failed to start clock for unit 0x%x", unit);
175 return (0);
176 }
177 return (hz);
178 }
179
180 static int
bcm2835_clkman_detach(device_t dev)181 bcm2835_clkman_detach(device_t dev)
182 {
183 struct bcm2835_clkman_softc *sc;
184
185 bus_generic_detach(dev);
186
187 sc = device_get_softc(dev);
188 if (sc->sc_m_res)
189 bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_m_res);
190
191 return (0);
192 }
193
194 static device_method_t bcm2835_clkman_methods[] = {
195 /* Device interface */
196 DEVMETHOD(device_probe, bcm2835_clkman_probe),
197 DEVMETHOD(device_attach, bcm2835_clkman_attach),
198 DEVMETHOD(device_detach, bcm2835_clkman_detach),
199
200 DEVMETHOD_END
201 };
202
203 static driver_t bcm2835_clkman_driver = {
204 "bcm2835_clkman",
205 bcm2835_clkman_methods,
206 sizeof(struct bcm2835_clkman_softc),
207 };
208
209 DRIVER_MODULE(bcm2835_clkman, simplebus, bcm2835_clkman_driver, 0, 0);
210 MODULE_VERSION(bcm2835_clkman, 1);
211