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,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 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 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 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 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