1 /* $NetBSD: fixedfactorclock.c,v 1.4 2021/01/27 03:10:21 thorpej Exp $ */ 2 3 /*- 4 * Copyright (c) 2017 Jared McNeill <jmcneill (at) invisible.ca> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __KERNEL_RCSID(0, "$NetBSD: fixedfactorclock.c,v 1.4 2021/01/27 03:10:21 thorpej Exp $"); 31 32 #include <sys/param.h> 33 #include <sys/systm.h> 34 #include <sys/device.h> 35 #include <sys/kmem.h> 36 #include <sys/bus.h> 37 38 #include <dev/clk/clk_backend.h> 39 40 #include <dev/fdt/fdtvar.h> 41 42 static int fixedfactorclock_match(device_t, cfdata_t, void *); 43 static void fixedfactorclock_attach(device_t, device_t, void *); 44 45 static struct clk *fixedfactorclock_decode(device_t, int, const void *, size_t); 46 47 static const struct fdtbus_clock_controller_func fixedfactorclock_fdt_funcs = { 48 .decode = fixedfactorclock_decode 49 }; 50 51 static struct clk *fixedfactorclock_get(void *, const char *); 52 static void fixedfactorclock_put(void *, struct clk *); 53 static u_int fixedfactorclock_get_rate(void *, struct clk *); 54 55 static const struct clk_funcs fixedfactorclock_clk_funcs = { 56 .get = fixedfactorclock_get, 57 .put = fixedfactorclock_put, 58 .get_rate = fixedfactorclock_get_rate, 59 }; 60 61 struct fixedfactorclock_clk { 62 struct clk base; 63 64 u_int div; 65 u_int mult; 66 }; 67 68 struct fixedfactorclock_softc { 69 device_t sc_dev; 70 int sc_phandle; 71 72 struct clk_domain sc_clkdom; 73 struct fixedfactorclock_clk sc_clk; 74 }; 75 76 CFATTACH_DECL_NEW(ffclock, sizeof(struct fixedfactorclock_softc), 77 fixedfactorclock_match, fixedfactorclock_attach, NULL, NULL); 78 79 static const struct device_compatible_entry compat_data[] = { 80 { .compat = "fixed-factor-clock" }, 81 DEVICE_COMPAT_EOL 82 }; 83 84 static int 85 fixedfactorclock_match(device_t parent, cfdata_t cf, void *aux) 86 { 87 const struct fdt_attach_args *faa = aux; 88 89 return of_compatible_match(faa->faa_phandle, compat_data); 90 } 91 92 static void 93 fixedfactorclock_attach(device_t parent, device_t self, void *aux) 94 { 95 struct fixedfactorclock_softc * const sc = device_private(self); 96 const struct fdt_attach_args *faa = aux; 97 const int phandle = faa->faa_phandle; 98 const char *name; 99 100 sc->sc_dev = self; 101 sc->sc_phandle = phandle; 102 sc->sc_clkdom.name = device_xname(self); 103 sc->sc_clkdom.funcs = &fixedfactorclock_clk_funcs; 104 sc->sc_clkdom.priv = sc; 105 106 of_getprop_uint32(phandle, "clock-div", &sc->sc_clk.div); 107 of_getprop_uint32(phandle, "clock-mult", &sc->sc_clk.mult); 108 109 if (sc->sc_clk.div == 0 || sc->sc_clk.mult == 0) { 110 aprint_error(": invalid properties\n"); 111 return; 112 } 113 114 name = fdtbus_get_string(phandle, "clock-output-names"); 115 if (name == NULL) 116 name = faa->faa_name; 117 118 sc->sc_clk.base.domain = &sc->sc_clkdom; 119 sc->sc_clk.base.name = name; 120 clk_attach(&sc->sc_clk.base); 121 122 aprint_naive("\n"); 123 aprint_normal(": x%u /%u fixed-factor clock\n", 124 sc->sc_clk.mult, sc->sc_clk.div); 125 126 fdtbus_register_clock_controller(self, phandle, 127 &fixedfactorclock_fdt_funcs); 128 } 129 130 static struct clk * 131 fixedfactorclock_decode(device_t dev, int cc_phandle, const void *data, 132 size_t len) 133 { 134 struct fixedfactorclock_softc * const sc = device_private(dev); 135 136 /* #clock-cells for a fixed factor clock is always 0 */ 137 if (len != 0) 138 return NULL; 139 140 return &sc->sc_clk.base; 141 } 142 143 static struct clk * 144 fixedfactorclock_get(void *priv, const char *name) 145 { 146 struct fixedfactorclock_softc * const sc = priv; 147 148 if (strcmp(name, sc->sc_clk.base.name) != 0) 149 return NULL; 150 151 return &sc->sc_clk.base; 152 } 153 154 static void 155 fixedfactorclock_put(void *priv, struct clk *clk) 156 { 157 } 158 159 static u_int 160 fixedfactorclock_get_rate(void *priv, struct clk *clk) 161 { 162 struct fixedfactorclock_softc * const sc = priv; 163 struct fixedfactorclock_clk *fclk = (struct fixedfactorclock_clk *)clk; 164 struct clk *clkp_parent; 165 166 clkp_parent = fdtbus_clock_get_index(sc->sc_phandle, 0); 167 if (clkp_parent == NULL) 168 return 0; 169 170 return (clk_get_rate(clkp_parent) * fclk->mult) / fclk->div; 171 } 172
Indexes created Thu Oct 02 14:10:14 GMT 2025