sunxi_ccu_div.c revision 1.4.2.2
1 /* $NetBSD: sunxi_ccu_div.c,v 1.4.2.2 2017/12/03 11:35:56 jdolecek 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 1.4.2.2 2017/12/03 11:35:56 jdolecek 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 int 102 sunxi_ccu_div_set_rate(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 clk *clkp, *clkp_parent; 107 uint32_t val, raw_div; 108 int ratio; 109 110 KASSERT(clk->type == SUNXI_CCU_DIV); 111 112 clkp = &clk->base; 113 clkp_parent = clk_get_parent(clkp); 114 if (clkp_parent == NULL) 115 return ENXIO; 116 117 if (div->div == 0) { 118 if ((div->flags & SUNXI_CCU_DIV_SET_RATE_PARENT) != 0) 119 return clk_set_rate(clkp_parent, new_rate); 120 else 121 return ENXIO; 122 } 123 124 val = CCU_READ(sc, div->reg); 125 126 if ((div->flags & SUNXI_CCU_DIV_TIMES_TWO) != 0) { 127 ratio = howmany(clk_get_rate(clkp_parent), new_rate); 128 if (ratio > 1 && (ratio & 1) != 0) 129 ratio++; 130 raw_div = ratio >> 1; 131 if (raw_div > __SHIFTOUT_MASK(div->div)) 132 return ERANGE; 133 } else { 134 return EINVAL; 135 } 136 137 val &= ~div->div; 138 val |= __SHIFTIN(raw_div, div->div); 139 CCU_WRITE(sc, div->reg, val); 140 141 return 0; 142 } 143 144 int 145 sunxi_ccu_div_set_parent(struct sunxi_ccu_softc *sc, 146 struct sunxi_ccu_clk *clk, const char *name) 147 { 148 struct sunxi_ccu_div *div = &clk->u.div; 149 uint32_t val; 150 u_int index; 151 152 KASSERT(clk->type == SUNXI_CCU_DIV); 153 154 if (div->sel == 0) 155 return ENODEV; 156 157 for (index = 0; index < div->nparents; index++) { 158 if (div->parents[index] != NULL && 159 strcmp(div->parents[index], name) == 0) 160 break; 161 } 162 if (index == div->nparents) 163 return EINVAL; 164 165 val = CCU_READ(sc, div->reg); 166 val &= ~div->sel; 167 val |= __SHIFTIN(index, div->sel); 168 CCU_WRITE(sc, div->reg, val); 169 170 return 0; 171 } 172 173 const char * 174 sunxi_ccu_div_get_parent(struct sunxi_ccu_softc *sc, 175 struct sunxi_ccu_clk *clk) 176 { 177 struct sunxi_ccu_div *div = &clk->u.div; 178 u_int index; 179 uint32_t val; 180 181 KASSERT(clk->type == SUNXI_CCU_DIV); 182 183 if (div->sel == 0) 184 return div->parents[0]; 185 186 val = CCU_READ(sc, div->reg); 187 index = __SHIFTOUT(val, div->sel); 188 189 return div->parents[index]; 190 } 191
Indexes created Fri Oct 31 11:10:07 GMT 2025