1 /* $NetBSD: sunxi_ccu_div.c,v 1.6 2019/11/17 17:33:17 jmcneill 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: sunxi_ccu_div.c,v 1.6 2019/11/17 17:33:17 jmcneill Exp $"); 31 32 #include <sys/param.h> 33 #include <sys/bus.h> 34 35 #include <dev/clk/clk_backend.h> 36 37 #include <arm/sunxi/sunxi_ccu.h> 38 39 int 40 sunxi_ccu_div_enable(struct sunxi_ccu_softc *sc, struct sunxi_ccu_clk *clk, 41 int enable) 42 { 43 struct sunxi_ccu_div *div = &clk->u.div; 44 uint32_t val; 45 46 KASSERT(clk->type == SUNXI_CCU_DIV); 47 48 if (!div->enable) 49 return enable ? 0 : EINVAL; 50 51 val = CCU_READ(sc, div->reg); 52 if (enable) 53 val |= div->enable; 54 else 55 val &= ~div->enable; 56 CCU_WRITE(sc, div->reg, val); 57 58 return 0; 59 } 60 61 u_int 62 sunxi_ccu_div_get_rate(struct sunxi_ccu_softc *sc, 63 struct sunxi_ccu_clk *clk) 64 { 65 struct sunxi_ccu_div *div = &clk->u.div; 66 struct clk *clkp, *clkp_parent; 67 u_int rate, ratio; 68 uint32_t val; 69 70 KASSERT(clk->type == SUNXI_CCU_DIV); 71 72 clkp = &clk->base; 73 clkp_parent = clk_get_parent(clkp); 74 if (clkp_parent == NULL) 75 return 0; 76 77 rate = clk_get_rate(clkp_parent); 78 if (rate == 0) 79 return 0; 80 81 val = CCU_READ(sc, div->reg); 82 if (div->div) 83 ratio = __SHIFTOUT(val, div->div); 84 else 85 ratio = 0; 86 87 if ((div->flags & SUNXI_CCU_DIV_ZERO_IS_ONE) != 0 && ratio == 0) 88 ratio = 1; 89 if (div->flags & SUNXI_CCU_DIV_POWER_OF_TWO) 90 ratio = 1 << ratio; 91 else if (div->flags & SUNXI_CCU_DIV_TIMES_TWO) { 92 ratio = ratio << 1; 93 if (ratio == 0) 94 ratio = 1; 95 } else 96 ratio++; 97 98 return rate / ratio; 99 } 100 101 static int 102 sunxi_ccu_div_select_parent(struct sunxi_ccu_softc *sc, 103 struct sunxi_ccu_clk *clk, u_int new_rate) 104 { 105 struct sunxi_ccu_div *div = &clk->u.div; 106 struct sunxi_ccu_clk *clk_parent; 107 struct clk *best_parent; 108 u_int index, best_diff; 109 const char *pname; 110 111 best_parent = NULL; 112 best_diff = ~0u; 113 for (index = 0; index < div->nparents; index++) { 114 pname = div->parents[index]; 115 if (pname == NULL) 116 continue; 117 clk_parent = sunxi_ccu_clock_find(sc, pname); 118 if (clk_parent == NULL) 119 continue; 120 const u_int rate = clk_get_rate(&clk_parent->base); 121 const u_int diff = abs((int)rate - (int)new_rate); 122 if (diff < best_diff) { 123 best_diff = diff; 124 best_parent = &clk_parent->base; 125 } 126 } 127 if (best_diff == ~0u) 128 return EINVAL; 129 130 return clk_set_parent(&clk->base, best_parent); 131 } 132 133 int 134 sunxi_ccu_div_set_rate(struct sunxi_ccu_softc *sc, 135 struct sunxi_ccu_clk *clk, u_int new_rate) 136 { 137 struct sunxi_ccu_div *div = &clk->u.div; 138 struct clk *clkp, *clkp_parent; 139 int parent_rate; 140 uint32_t val, raw_div; 141 int ratio; 142 143 KASSERT(clk->type == SUNXI_CCU_DIV); 144 145 clkp = &clk->base; 146 clkp_parent = clk_get_parent(clkp); 147 if (clkp_parent == NULL) 148 return ENXIO; 149 150 if (div->div == 0) { 151 if ((div->flags & SUNXI_CCU_DIV_SET_RATE_PARENT) != 0) 152 return clk_set_rate(clkp_parent, new_rate); 153 else 154 return sunxi_ccu_div_select_parent(sc, clk, new_rate); 155 } 156 157 val = CCU_READ(sc, div->reg); 158 159 parent_rate = clk_get_rate(clkp_parent); 160 if (parent_rate == 0) 161 return (new_rate == 0) ? 0 : ERANGE; 162 163 ratio = howmany(parent_rate, new_rate); 164 if ((div->flags & SUNXI_CCU_DIV_TIMES_TWO) != 0) { 165 if (ratio > 1 && (ratio & 1) != 0) 166 ratio++; 167 raw_div = ratio >> 1; 168 } else if ((div->flags & SUNXI_CCU_DIV_POWER_OF_TWO) != 0) { 169 return EINVAL; 170 } else { 171 raw_div = (ratio > 0 ) ? ratio - 1 : 0; 172 } 173 if (raw_div > __SHIFTOUT_MASK(div->div)) 174 return ERANGE; 175 176 val &= ~div->div; 177 val |= __SHIFTIN(raw_div, div->div); 178 CCU_WRITE(sc, div->reg, val); 179 180 return 0; 181 } 182 183 int 184 sunxi_ccu_div_set_parent(struct sunxi_ccu_softc *sc, 185 struct sunxi_ccu_clk *clk, const char *name) 186 { 187 struct sunxi_ccu_div *div = &clk->u.div; 188 uint32_t val; 189 u_int index; 190 191 KASSERT(clk->type == SUNXI_CCU_DIV); 192 193 if (div->sel == 0) 194 return ENODEV; 195 196 for (index = 0; index < div->nparents; index++) { 197 if (div->parents[index] != NULL && 198 strcmp(div->parents[index], name) == 0) 199 break; 200 } 201 if (index == div->nparents) 202 return EINVAL; 203 204 val = CCU_READ(sc, div->reg); 205 val &= ~div->sel; 206 val |= __SHIFTIN(index, div->sel); 207 CCU_WRITE(sc, div->reg, val); 208 209 return 0; 210 } 211 212 const char * 213 sunxi_ccu_div_get_parent(struct sunxi_ccu_softc *sc, 214 struct sunxi_ccu_clk *clk) 215 { 216 struct sunxi_ccu_div *div = &clk->u.div; 217 u_int index; 218 uint32_t val; 219 220 KASSERT(clk->type == SUNXI_CCU_DIV); 221 222 if (div->sel == 0) 223 return div->parents[0]; 224 225 val = CCU_READ(sc, div->reg); 226 index = __SHIFTOUT(val, div->sel); 227 228 return div->parents[index]; 229 } 230
Indexes created Fri Sep 26 20:09:58 GMT 2025