1 /* 2 * Copyright (C) 2016 Maxime Ripard 3 * Maxime Ripard <maxime.ripard@free-electrons.com> 4 * 5 * This program is free software; you can redistribute it and/or 6 * modify it under the terms of the GNU General Public License as 7 * published by the Free Software Foundation; either version 2 of 8 * the License, or (at your option) any later version. 9 */ 10 11 #include <linux/clk-provider.h> 12 13 #include "ccu_gate.h" 14 #include "ccu_mp.h" 15 16 static void ccu_mp_find_best(unsigned long parent, unsigned long rate, 17 unsigned int max_m, unsigned int max_p, 18 unsigned int *m, unsigned int *p) 19 { 20 unsigned long best_rate = 0; 21 unsigned int best_m = 0, best_p = 0; 22 unsigned int _m, _p; 23 24 for (_p = 0; _p <= max_p; _p++) { 25 for (_m = 1; _m <= max_m; _m++) { 26 unsigned long tmp_rate = (parent >> _p) / _m; 27 28 if (tmp_rate > rate) 29 continue; 30 31 if ((rate - tmp_rate) < (rate - best_rate)) { 32 best_rate = tmp_rate; 33 best_m = _m; 34 best_p = _p; 35 } 36 } 37 } 38 39 *m = best_m; 40 *p = best_p; 41 } 42 43 static unsigned long ccu_mp_round_rate(struct ccu_mux_internal *mux, 44 unsigned long parent_rate, 45 unsigned long rate, 46 void *data) 47 { 48 struct ccu_mp *cmp = data; 49 unsigned int m, p; 50 51 ccu_mp_find_best(parent_rate, rate, 52 1 << cmp->m.width, (1 << cmp->p.width) - 1, 53 &m, &p); 54 55 return (parent_rate >> p) / m; 56 } 57 58 static void ccu_mp_disable(struct clk_hw *hw) 59 { 60 struct ccu_mp *cmp = hw_to_ccu_mp(hw); 61 62 return ccu_gate_helper_disable(&cmp->common, cmp->enable); 63 } 64 65 static int ccu_mp_enable(struct clk_hw *hw) 66 { 67 struct ccu_mp *cmp = hw_to_ccu_mp(hw); 68 69 return ccu_gate_helper_enable(&cmp->common, cmp->enable); 70 } 71 72 static int ccu_mp_is_enabled(struct clk_hw *hw) 73 { 74 struct ccu_mp *cmp = hw_to_ccu_mp(hw); 75 76 return ccu_gate_helper_is_enabled(&cmp->common, cmp->enable); 77 } 78 79 static unsigned long ccu_mp_recalc_rate(struct clk_hw *hw, 80 unsigned long parent_rate) 81 { 82 struct ccu_mp *cmp = hw_to_ccu_mp(hw); 83 unsigned int m, p; 84 u32 reg; 85 86 reg = readl(cmp->common.base + cmp->common.reg); 87 88 m = reg >> cmp->m.shift; 89 m &= (1 << cmp->m.width) - 1; 90 91 p = reg >> cmp->p.shift; 92 p &= (1 << cmp->p.width) - 1; 93 94 return (parent_rate >> p) / (m + 1); 95 } 96 97 static int ccu_mp_determine_rate(struct clk_hw *hw, 98 struct clk_rate_request *req) 99 { 100 struct ccu_mp *cmp = hw_to_ccu_mp(hw); 101 102 return ccu_mux_helper_determine_rate(&cmp->common, &cmp->mux, 103 req, ccu_mp_round_rate, cmp); 104 } 105 106 static int ccu_mp_set_rate(struct clk_hw *hw, unsigned long rate, 107 unsigned long parent_rate) 108 { 109 struct ccu_mp *cmp = hw_to_ccu_mp(hw); 110 unsigned long flags; 111 unsigned int m, p; 112 u32 reg; 113 114 ccu_mp_find_best(parent_rate, rate, 115 1 << cmp->m.width, (1 << cmp->p.width) - 1, 116 &m, &p); 117 118 119 spin_lock_irqsave(cmp->common.lock, flags); 120 121 reg = readl(cmp->common.base + cmp->common.reg); 122 reg &= ~GENMASK(cmp->m.width + cmp->m.shift - 1, cmp->m.shift); 123 reg &= ~GENMASK(cmp->p.width + cmp->p.shift - 1, cmp->p.shift); 124 125 writel(reg | (p << cmp->p.shift) | ((m - 1) << cmp->m.shift), 126 cmp->common.base + cmp->common.reg); 127 128 spin_unlock_irqrestore(cmp->common.lock, flags); 129 130 return 0; 131 } 132 133 static u8 ccu_mp_get_parent(struct clk_hw *hw) 134 { 135 struct ccu_mp *cmp = hw_to_ccu_mp(hw); 136 137 return ccu_mux_helper_get_parent(&cmp->common, &cmp->mux); 138 } 139 140 static int ccu_mp_set_parent(struct clk_hw *hw, u8 index) 141 { 142 struct ccu_mp *cmp = hw_to_ccu_mp(hw); 143 144 return ccu_mux_helper_set_parent(&cmp->common, &cmp->mux, index); 145 } 146 147 const struct clk_ops ccu_mp_ops = { 148 .disable = ccu_mp_disable, 149 .enable = ccu_mp_enable, 150 .is_enabled = ccu_mp_is_enabled, 151 152 .get_parent = ccu_mp_get_parent, 153 .set_parent = ccu_mp_set_parent, 154 155 .determine_rate = ccu_mp_determine_rate, 156 .recalc_rate = ccu_mp_recalc_rate, 157 .set_rate = ccu_mp_set_rate, 158 }; 159