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 return (bus_generic_attach(dev));
116 }
117
118 uint32_t
bcm2835_clkman_set_frequency(device_t dev,uint32_t unit,uint32_t hz)119 bcm2835_clkman_set_frequency(device_t dev, uint32_t unit, uint32_t hz)
120 {
121 struct bcm2835_clkman_softc *sc;
122 int i;
123 uint32_t u;
124
125 sc = device_get_softc(dev);
126
127 if (unit != BCM_PWM_CLKSRC) {
128 device_printf(sc->sc_dev,
129 "Unsupported unit 0x%x", unit);
130 return (0);
131 }
132
133 W_CMCLK(sc, unit, 6);
134 for (i = 0; i < 10; i++) {
135 u = R_CMCLK(sc, unit);
136 if (!(u&0x80))
137 break;
138 DELAY(1000);
139 }
140 if (u & 0x80) {
141 device_printf(sc->sc_dev,
142 "Failed to stop clock for unit 0x%x", unit);
143 return (0);
144 }
145 if (hz == 0)
146 return (0);
147
148 u = 500000000/hz;
149 if (u < 4) {
150 device_printf(sc->sc_dev,
151 "Frequency too high for unit 0x%x (max: 125 MHz)",
152 unit);
153 return (0);
154 }
155 if (u > 0xfff) {
156 device_printf(sc->sc_dev,
157 "Frequency too low for unit 0x%x (min: 123 kHz)",
158 unit);
159 return (0);
160 }
161 hz = 500000000/u;
162 W_CMDIV(sc, unit, u << 12);
163
164 W_CMCLK(sc, unit, 0x16);
165 for (i = 0; i < 10; i++) {
166 u = R_CMCLK(sc, unit);
167 if ((u&0x80))
168 break;
169 DELAY(1000);
170 }
171 if (!(u & 0x80)) {
172 device_printf(sc->sc_dev,
173 "Failed to start clock for unit 0x%x", unit);
174 return (0);
175 }
176 return (hz);
177 }
178
179 static int
bcm2835_clkman_detach(device_t dev)180 bcm2835_clkman_detach(device_t dev)
181 {
182 struct bcm2835_clkman_softc *sc;
183
184 bus_generic_detach(dev);
185
186 sc = device_get_softc(dev);
187 if (sc->sc_m_res)
188 bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_m_res);
189
190 return (0);
191 }
192
193 static device_method_t bcm2835_clkman_methods[] = {
194 /* Device interface */
195 DEVMETHOD(device_probe, bcm2835_clkman_probe),
196 DEVMETHOD(device_attach, bcm2835_clkman_attach),
197 DEVMETHOD(device_detach, bcm2835_clkman_detach),
198
199 DEVMETHOD_END
200 };
201
202 static driver_t bcm2835_clkman_driver = {
203 "bcm2835_clkman",
204 bcm2835_clkman_methods,
205 sizeof(struct bcm2835_clkman_softc),
206 };
207
208 DRIVER_MODULE(bcm2835_clkman, simplebus, bcm2835_clkman_driver, 0, 0);
209 MODULE_VERSION(bcm2835_clkman, 1);
210