sun8i_a23_apbclk.c revision 1.1.2.2
1 /* $NetBSD: sun8i_a23_apbclk.c,v 1.1.2.2 2019/06/10 22:05:56 christos 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: sun8i_a23_apbclk.c,v 1.1.2.2 2019/06/10 22:05:56 christos 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 #define APB0_DIV __BITS(1,0) 43 44 static int sun8i_a23_apbclk_match(device_t, cfdata_t, void *); 45 static void sun8i_a23_apbclk_attach(device_t, device_t, void *); 46 47 static struct clk *sun8i_a23_apbclk_decode(device_t, int, const void *, size_t); 48 49 static const struct fdtbus_clock_controller_func sun8i_a23_apbclk_fdt_funcs = { 50 .decode = sun8i_a23_apbclk_decode 51 }; 52 53 static struct clk *sun8i_a23_apbclk_get(void *, const char *); 54 static void sun8i_a23_apbclk_put(void *, struct clk *); 55 static int sun8i_a23_apbclk_set_rate(void *, struct clk *, u_int); 56 static u_int sun8i_a23_apbclk_get_rate(void *, struct clk *); 57 static struct clk *sun8i_a23_apbclk_get_parent(void *, struct clk *); 58 59 static const struct clk_funcs sun8i_a23_apbclk_clk_funcs = { 60 .get = sun8i_a23_apbclk_get, 61 .put = sun8i_a23_apbclk_put, 62 .set_rate = sun8i_a23_apbclk_set_rate, 63 .get_rate = sun8i_a23_apbclk_get_rate, 64 .get_parent = sun8i_a23_apbclk_get_parent, 65 }; 66 67 struct sun8i_a23_apbclk_softc { 68 device_t sc_dev; 69 int sc_phandle; 70 bus_space_tag_t sc_bst; 71 bus_space_handle_t sc_bsh; 72 73 struct clk_domain sc_clkdom; 74 struct clk sc_clk; 75 struct clk *sc_parent; 76 }; 77 78 #define RD4(sc, reg) \ 79 bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg)) 80 #define WR4(sc, reg, val) \ 81 bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val)) 82 83 CFATTACH_DECL_NEW(sunxi_a23_apbclk, sizeof(struct sun8i_a23_apbclk_softc), 84 sun8i_a23_apbclk_match, sun8i_a23_apbclk_attach, NULL, NULL); 85 86 static int 87 sun8i_a23_apbclk_match(device_t parent, cfdata_t cf, void *aux) 88 { 89 const char * const compatible[] = { "allwinner,sun8i-a23-apb0-clk", NULL }; 90 const struct fdt_attach_args *faa = aux; 91 92 return of_match_compatible(faa->faa_phandle, compatible); 93 } 94 95 static void 96 sun8i_a23_apbclk_attach(device_t parent, device_t self, void *aux) 97 { 98 struct sun8i_a23_apbclk_softc * const sc = device_private(self); 99 const struct fdt_attach_args *faa = aux; 100 const int phandle = faa->faa_phandle; 101 bus_addr_t addr; 102 bus_size_t size; 103 104 if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) { 105 aprint_error(": couldn't get registers\n"); 106 return; 107 } 108 109 sc->sc_dev = self; 110 sc->sc_phandle = phandle; 111 sc->sc_bst = faa->faa_bst; 112 if (bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh) != 0) { 113 aprint_error(": couldn't map registers\n"); 114 return; 115 } 116 sc->sc_parent = fdtbus_clock_get_index(phandle, 0); 117 118 sc->sc_clkdom.funcs = &sun8i_a23_apbclk_clk_funcs; 119 sc->sc_clkdom.priv = sc; 120 121 sc->sc_clk.domain = &sc->sc_clkdom; 122 sc->sc_clk.name = kmem_asprintf("%s", faa->faa_name); 123 124 aprint_naive("\n"); 125 aprint_normal(": A23 APB0 clock\n"); 126 127 fdtbus_register_clock_controller(self, phandle, &sun8i_a23_apbclk_fdt_funcs); 128 } 129 130 static struct clk * 131 sun8i_a23_apbclk_decode(device_t dev, int cc_phandle, const void *data, 132 size_t len) 133 { 134 struct sun8i_a23_apbclk_softc * const sc = device_private(dev); 135 136 if (len != 0) 137 return NULL; 138 139 return &sc->sc_clk; 140 } 141 142 static struct clk * 143 sun8i_a23_apbclk_get(void *priv, const char *name) 144 { 145 struct sun8i_a23_apbclk_softc * const sc = priv; 146 147 if (strcmp(name, sc->sc_clk.name) != 0) 148 return NULL; 149 150 return &sc->sc_clk; 151 } 152 153 static void 154 sun8i_a23_apbclk_put(void *priv, struct clk *clk) 155 { 156 } 157 158 static int 159 sun8i_a23_apbclk_set_rate(void *priv, struct clk *clk, u_int rate) 160 { 161 return ENXIO; 162 } 163 164 static u_int 165 sun8i_a23_apbclk_get_rate(void *priv, struct clk *clk) 166 { 167 struct sun8i_a23_apbclk_softc * const sc = priv; 168 struct clk *clk_parent = clk_get_parent(clk); 169 170 const uint32_t val = RD4(sc, 0); 171 const u_int div = __SHIFTOUT(val, APB0_DIV); 172 173 return clk_get_rate(clk_parent) / (div + 1); 174 } 175 176 static struct clk * 177 sun8i_a23_apbclk_get_parent(void *priv, struct clk *clk) 178 { 179 struct sun8i_a23_apbclk_softc * const sc = priv; 180 181 return sc->sc_parent; 182 } 183
Indexes created Sat Oct 25 10:09:55 GMT 2025