1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 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/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,bcm2711-cprman", 1}, 55 {"brcm,bcm2835-cprman", 1}, 56 {"broadcom,bcm2835-cprman", 1}, 57 {NULL, 0} 58 }; 59 60 struct bcm2835_clkman_softc { 61 device_t sc_dev; 62 63 struct resource * sc_m_res; 64 bus_space_tag_t sc_m_bst; 65 bus_space_handle_t sc_m_bsh; 66 }; 67 68 #define BCM_CLKMAN_WRITE(_sc, _off, _val) \ 69 bus_space_write_4(_sc->sc_m_bst, _sc->sc_m_bsh, _off, _val) 70 #define BCM_CLKMAN_READ(_sc, _off) \ 71 bus_space_read_4(_sc->sc_m_bst, _sc->sc_m_bsh, _off) 72 73 #define W_CMCLK(_sc, unit, _val) BCM_CLKMAN_WRITE(_sc, unit, 0x5a000000 | (_val)) 74 #define R_CMCLK(_sc, unit) BCM_CLKMAN_READ(_sc, unit) 75 #define W_CMDIV(_sc, unit, _val) BCM_CLKMAN_WRITE(_sc, (unit) + 4, 0x5a000000 | (_val)) 76 #define R_CMDIV(_sc, unit) BCM_CLKMAN_READ(_sc, (unit) + 4) 77 78 static int 79 bcm2835_clkman_probe(device_t dev) 80 { 81 82 if (!ofw_bus_status_okay(dev)) 83 return (ENXIO); 84 85 if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0) 86 return (ENXIO); 87 88 device_set_desc(dev, "BCM283x Clock Manager"); 89 90 return (BUS_PROBE_DEFAULT); 91 } 92 93 static int 94 bcm2835_clkman_attach(device_t dev) 95 { 96 struct bcm2835_clkman_softc *sc; 97 int rid; 98 99 if (device_get_unit(dev) != 0) { 100 device_printf(dev, "only one clk manager supported\n"); 101 return (ENXIO); 102 } 103 104 sc = device_get_softc(dev); 105 sc->sc_dev = dev; 106 107 rid = 0; 108 sc->sc_m_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, 109 RF_ACTIVE); 110 if (!sc->sc_m_res) { 111 device_printf(dev, "cannot allocate memory window\n"); 112 return (ENXIO); 113 } 114 115 sc->sc_m_bst = rman_get_bustag(sc->sc_m_res); 116 sc->sc_m_bsh = rman_get_bushandle(sc->sc_m_res); 117 118 return (bus_generic_attach(dev)); 119 } 120 121 uint32_t 122 bcm2835_clkman_set_frequency(device_t dev, uint32_t unit, uint32_t hz) 123 { 124 struct bcm2835_clkman_softc *sc; 125 int i; 126 uint32_t u; 127 128 sc = device_get_softc(dev); 129 130 if (unit != BCM_PWM_CLKSRC) { 131 device_printf(sc->sc_dev, 132 "Unsupported unit 0x%x", unit); 133 return (0); 134 } 135 136 W_CMCLK(sc, unit, 6); 137 for (i = 0; i < 10; i++) { 138 u = R_CMCLK(sc, unit); 139 if (!(u&0x80)) 140 break; 141 DELAY(1000); 142 } 143 if (u & 0x80) { 144 device_printf(sc->sc_dev, 145 "Failed to stop clock for unit 0x%x", unit); 146 return (0); 147 } 148 if (hz == 0) 149 return (0); 150 151 u = 500000000/hz; 152 if (u < 4) { 153 device_printf(sc->sc_dev, 154 "Frequency too high for unit 0x%x (max: 125 MHz)", 155 unit); 156 return (0); 157 } 158 if (u > 0xfff) { 159 device_printf(sc->sc_dev, 160 "Frequency too low for unit 0x%x (min: 123 kHz)", 161 unit); 162 return (0); 163 } 164 hz = 500000000/u; 165 W_CMDIV(sc, unit, u << 12); 166 167 W_CMCLK(sc, unit, 0x16); 168 for (i = 0; i < 10; i++) { 169 u = R_CMCLK(sc, unit); 170 if ((u&0x80)) 171 break; 172 DELAY(1000); 173 } 174 if (!(u & 0x80)) { 175 device_printf(sc->sc_dev, 176 "Failed to start clock for unit 0x%x", unit); 177 return (0); 178 } 179 return (hz); 180 } 181 182 static int 183 bcm2835_clkman_detach(device_t dev) 184 { 185 struct bcm2835_clkman_softc *sc; 186 187 bus_generic_detach(dev); 188 189 sc = device_get_softc(dev); 190 if (sc->sc_m_res) 191 bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_m_res); 192 193 return (0); 194 } 195 196 static device_method_t bcm2835_clkman_methods[] = { 197 /* Device interface */ 198 DEVMETHOD(device_probe, bcm2835_clkman_probe), 199 DEVMETHOD(device_attach, bcm2835_clkman_attach), 200 DEVMETHOD(device_detach, bcm2835_clkman_detach), 201 202 DEVMETHOD_END 203 }; 204 205 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, 0, 0); 212 MODULE_VERSION(bcm2835_clkman, 1); 213