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 = 1; _p <= max_p; _p <<= 1) { 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 max_m, max_p; 50 unsigned int m, p; 51 52 max_m = cmp->m.max ?: 1 << cmp->m.width; 53 max_p = cmp->p.max ?: 1 << ((1 << cmp->p.width) - 1); 54 55 ccu_mp_find_best(parent_rate, rate, max_m, max_p, &m, &p); 56 57 return parent_rate / p / m; 58 } 59 60 static void ccu_mp_disable(struct clk_hw *hw) 61 { 62 struct ccu_mp *cmp = hw_to_ccu_mp(hw); 63 64 return ccu_gate_helper_disable(&cmp->common, cmp->enable); 65 } 66 67 static int ccu_mp_enable(struct clk_hw *hw) 68 { 69 struct ccu_mp *cmp = hw_to_ccu_mp(hw); 70 71 return ccu_gate_helper_enable(&cmp->common, cmp->enable); 72 } 73 74 static int ccu_mp_is_enabled(struct clk_hw *hw) 75 { 76 struct ccu_mp *cmp = hw_to_ccu_mp(hw); 77 78 return ccu_gate_helper_is_enabled(&cmp->common, cmp->enable); 79 } 80 81 static unsigned long ccu_mp_recalc_rate(struct clk_hw *hw, 82 unsigned long parent_rate) 83 { 84 struct ccu_mp *cmp = hw_to_ccu_mp(hw); 85 unsigned int m, p; 86 u32 reg; 87 88 reg = readl(cmp->common.base + cmp->common.reg); 89 90 m = reg >> cmp->m.shift; 91 m &= (1 << cmp->m.width) - 1; 92 93 p = reg >> cmp->p.shift; 94 p &= (1 << cmp->p.width) - 1; 95 96 return (parent_rate >> p) / (m + 1); 97 } 98 99 static int ccu_mp_determine_rate(struct clk_hw *hw, 100 struct clk_rate_request *req) 101 { 102 struct ccu_mp *cmp = hw_to_ccu_mp(hw); 103 104 return ccu_mux_helper_determine_rate(&cmp->common, &cmp->mux, 105 req, ccu_mp_round_rate, cmp); 106 } 107 108 static int ccu_mp_set_rate(struct clk_hw *hw, unsigned long rate, 109 unsigned long parent_rate) 110 { 111 struct ccu_mp *cmp = hw_to_ccu_mp(hw); 112 unsigned long flags; 113 unsigned int max_m, max_p; 114 unsigned int m, p; 115 u32 reg; 116 117 max_m = cmp->m.max ?: 1 << cmp->m.width; 118 max_p = cmp->p.max ?: 1 << ((1 << cmp->p.width) - 1); 119 120 ccu_mp_find_best(parent_rate, rate, max_m, max_p, &m, &p); 121 122 spin_lock_irqsave(cmp->common.lock, flags); 123 124 reg = readl(cmp->common.base + cmp->common.reg); 125 reg &= ~GENMASK(cmp->m.width + cmp->m.shift - 1, cmp->m.shift); 126 reg &= ~GENMASK(cmp->p.width + cmp->p.shift - 1, cmp->p.shift); 127 128 writel(reg | (ilog2(p) << cmp->p.shift) | ((m - 1) << cmp->m.shift), 129 cmp->common.base + cmp->common.reg); 130 131 spin_unlock_irqrestore(cmp->common.lock, flags); 132 133 return 0; 134 } 135 136 static u8 ccu_mp_get_parent(struct clk_hw *hw) 137 { 138 struct ccu_mp *cmp = hw_to_ccu_mp(hw); 139 140 return ccu_mux_helper_get_parent(&cmp->common, &cmp->mux); 141 } 142 143 static int ccu_mp_set_parent(struct clk_hw *hw, u8 index) 144 { 145 struct ccu_mp *cmp = hw_to_ccu_mp(hw); 146 147 return ccu_mux_helper_set_parent(&cmp->common, &cmp->mux, index); 148 } 149 150 const struct clk_ops ccu_mp_ops = { 151 .disable = ccu_mp_disable, 152 .enable = ccu_mp_enable, 153 .is_enabled = ccu_mp_is_enabled, 154 155 .get_parent = ccu_mp_get_parent, 156 .set_parent = ccu_mp_set_parent, 157 158 .determine_rate = ccu_mp_determine_rate, 159 .recalc_rate = ccu_mp_recalc_rate, 160 .set_rate = ccu_mp_set_rate, 161 }; 162