1 /* $NetBSD: sunxi_ccu_prediv.c,v 1.3 2017/08/25 00:07:03 jmcneill Exp $ */ 2 3 /*- 4 * Copyright (c) 2017 Jared McNeill <jmcneill@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_prediv.c,v 1.3 2017/08/25 00:07:03 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 u_int 40 sunxi_ccu_prediv_get_rate(struct sunxi_ccu_softc *sc, 41 struct sunxi_ccu_clk *clk) 42 { 43 struct sunxi_ccu_prediv *prediv = &clk->u.prediv; 44 struct clk *clkp, *clkp_parent; 45 u_int rate, pre, div, sel; 46 uint32_t val; 47 48 KASSERT(clk->type == SUNXI_CCU_PREDIV); 49 50 clkp = &clk->base; 51 clkp_parent = clk_get_parent(clkp); 52 if (clkp_parent == NULL) 53 return 0; 54 55 rate = clk_get_rate(clkp_parent); 56 if (rate == 0) 57 return 0; 58 59 val = CCU_READ(sc, prediv->reg); 60 if (prediv->prediv) 61 pre = __SHIFTOUT(val, prediv->prediv); 62 else 63 pre = 0; 64 if (prediv->div) 65 div = __SHIFTOUT(val, prediv->div); 66 else 67 div = 0; 68 sel = __SHIFTOUT(val, prediv->sel); 69 70 if (prediv->flags & SUNXI_CCU_PREDIV_POWER_OF_TWO) 71 div = 1 << div; 72 else 73 div++; 74 75 if (prediv->prediv_fixed) 76 pre = prediv->prediv_fixed; 77 else 78 pre++; 79 80 if (prediv->flags & SUNXI_CCU_PREDIV_DIVIDE_BY_TWO) 81 pre *= 2; 82 83 if (prediv->prediv_sel & __BIT(sel)) 84 return rate / pre / div; 85 else 86 return rate / div; 87 } 88 89 int 90 sunxi_ccu_prediv_set_rate(struct sunxi_ccu_softc *sc, 91 struct sunxi_ccu_clk *clk, u_int new_rate) 92 { 93 return EINVAL; 94 } 95 96 int 97 sunxi_ccu_prediv_set_parent(struct sunxi_ccu_softc *sc, 98 struct sunxi_ccu_clk *clk, const char *name) 99 { 100 struct sunxi_ccu_prediv *prediv = &clk->u.prediv; 101 uint32_t val; 102 u_int index; 103 104 KASSERT(clk->type == SUNXI_CCU_PREDIV); 105 106 if (prediv->sel == 0) 107 return ENODEV; 108 109 for (index = 0; index < prediv->nparents; index++) { 110 if (prediv->parents[index] != NULL && 111 strcmp(prediv->parents[index], name) == 0) 112 break; 113 } 114 if (index == prediv->nparents) 115 return EINVAL; 116 117 val = CCU_READ(sc, prediv->reg); 118 val &= ~prediv->sel; 119 val |= __SHIFTIN(index, prediv->sel); 120 CCU_WRITE(sc, prediv->reg, val); 121 122 return 0; 123 } 124 125 const char * 126 sunxi_ccu_prediv_get_parent(struct sunxi_ccu_softc *sc, 127 struct sunxi_ccu_clk *clk) 128 { 129 struct sunxi_ccu_prediv *prediv = &clk->u.prediv; 130 u_int index; 131 uint32_t val; 132 133 KASSERT(clk->type == SUNXI_CCU_PREDIV); 134 135 val = CCU_READ(sc, prediv->reg); 136 index = __SHIFTOUT(val, prediv->sel); 137 138 return prediv->parents[index]; 139 } 140