1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2017 Poul-Henning Kamp <[email protected]>
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/cdefs.h>
30 __FBSDID("$FreeBSD$");
31
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/bus.h>
35 #include <sys/cpu.h>
36 #include <sys/kernel.h>
37 #include <sys/lock.h>
38 #include <sys/malloc.h>
39 #include <sys/module.h>
40 #include <sys/mutex.h>
41 #include <sys/rman.h>
42 #include <sys/sema.h>
43 #include <sys/sysctl.h>
44
45 #include <machine/bus.h>
46 #include <machine/cpu.h>
47
48 #include <dev/ofw/ofw_bus.h>
49 #include <dev/ofw/ofw_bus_subr.h>
50
51 #include <arm/broadcom/bcm2835/bcm2835_clkman.h>
52
53 static struct ofw_compat_data compat_data[] = {
54 {"brcm,bcm2835-cprman", 1},
55 {"broadcom,bcm2835-cprman", 1},
56 {NULL, 0}
57 };
58
59 struct bcm2835_clkman_softc {
60 device_t sc_dev;
61
62 struct resource * sc_m_res;
63 bus_space_tag_t sc_m_bst;
64 bus_space_handle_t sc_m_bsh;
65 };
66
67 #define BCM_CLKMAN_WRITE(_sc, _off, _val) \
68 bus_space_write_4(_sc->sc_m_bst, _sc->sc_m_bsh, _off, _val)
69 #define BCM_CLKMAN_READ(_sc, _off) \
70 bus_space_read_4(_sc->sc_m_bst, _sc->sc_m_bsh, _off)
71
72 #define W_CMCLK(_sc, unit, _val) BCM_CLKMAN_WRITE(_sc, unit, 0x5a000000 | (_val))
73 #define R_CMCLK(_sc, unit) BCM_CLKMAN_READ(_sc, unit)
74 #define W_CMDIV(_sc, unit, _val) BCM_CLKMAN_WRITE(_sc, (unit) + 4, 0x5a000000 | (_val))
75 #define R_CMDIV(_sc, unit) BCM_CLKMAN_READ(_sc, (unit) + 4)
76
77 static int
bcm2835_clkman_probe(device_t dev)78 bcm2835_clkman_probe(device_t dev)
79 {
80
81 if (!ofw_bus_status_okay(dev))
82 return (ENXIO);
83
84 if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
85 return (ENXIO);
86
87 device_set_desc(dev, "BCM283x Clock Manager");
88
89 return (BUS_PROBE_DEFAULT);
90 }
91
92 static int
bcm2835_clkman_attach(device_t dev)93 bcm2835_clkman_attach(device_t dev)
94 {
95 struct bcm2835_clkman_softc *sc;
96 int rid;
97
98 if (device_get_unit(dev) != 0) {
99 device_printf(dev, "only one clk manager supported\n");
100 return (ENXIO);
101 }
102
103 sc = device_get_softc(dev);
104 sc->sc_dev = dev;
105
106 rid = 0;
107 sc->sc_m_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
108 RF_ACTIVE);
109 if (!sc->sc_m_res) {
110 device_printf(dev, "cannot allocate memory window\n");
111 return (ENXIO);
112 }
113
114 sc->sc_m_bst = rman_get_bustag(sc->sc_m_res);
115 sc->sc_m_bsh = rman_get_bushandle(sc->sc_m_res);
116
117 return (bus_generic_attach(dev));
118 }
119
120 uint32_t
bcm2835_clkman_set_frequency(device_t dev,uint32_t unit,uint32_t hz)121 bcm2835_clkman_set_frequency(device_t dev, uint32_t unit, uint32_t hz)
122 {
123 struct bcm2835_clkman_softc *sc;
124 int i;
125 uint32_t u;
126
127 sc = device_get_softc(dev);
128
129 if (unit != BCM_PWM_CLKSRC) {
130 device_printf(sc->sc_dev,
131 "Unsupported unit 0x%x", unit);
132 return (0);
133 }
134
135 W_CMCLK(sc, unit, 6);
136 for (i = 0; i < 10; i++) {
137 u = R_CMCLK(sc, unit);
138 if (!(u&0x80))
139 break;
140 DELAY(1000);
141 }
142 if (u & 0x80) {
143 device_printf(sc->sc_dev,
144 "Failed to stop clock for unit 0x%x", unit);
145 return (0);
146 }
147 if (hz == 0)
148 return (0);
149
150 u = 500000000/hz;
151 if (u < 4) {
152 device_printf(sc->sc_dev,
153 "Frequency too high for unit 0x%x (max: 125 MHz)",
154 unit);
155 return (0);
156 }
157 if (u > 0xfff) {
158 device_printf(sc->sc_dev,
159 "Frequency too low for unit 0x%x (min: 123 kHz)",
160 unit);
161 return (0);
162 }
163 hz = 500000000/u;
164 W_CMDIV(sc, unit, u << 12);
165
166 W_CMCLK(sc, unit, 0x16);
167 for (i = 0; i < 10; i++) {
168 u = R_CMCLK(sc, unit);
169 if ((u&0x80))
170 break;
171 DELAY(1000);
172 }
173 if (!(u & 0x80)) {
174 device_printf(sc->sc_dev,
175 "Failed to start clock for unit 0x%x", unit);
176 return (0);
177 }
178 return (hz);
179 }
180
181 static int
bcm2835_clkman_detach(device_t dev)182 bcm2835_clkman_detach(device_t dev)
183 {
184 struct bcm2835_clkman_softc *sc;
185
186 bus_generic_detach(dev);
187
188 sc = device_get_softc(dev);
189 if (sc->sc_m_res)
190 bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_m_res);
191
192 return (0);
193 }
194
195 static device_method_t bcm2835_clkman_methods[] = {
196 /* Device interface */
197 DEVMETHOD(device_probe, bcm2835_clkman_probe),
198 DEVMETHOD(device_attach, bcm2835_clkman_attach),
199 DEVMETHOD(device_detach, bcm2835_clkman_detach),
200
201 DEVMETHOD_END
202 };
203
204 static devclass_t bcm2835_clkman_devclass;
205 static driver_t bcm2835_clkman_driver = {
206 "bcm2835_clkman",
207 bcm2835_clkman_methods,
208 sizeof(struct bcm2835_clkman_softc),
209 };
210
211 DRIVER_MODULE(bcm2835_clkman, simplebus, bcm2835_clkman_driver,
212 bcm2835_clkman_devclass, 0, 0);
213 MODULE_VERSION(bcm2835_clkman, 1);
214