Maxime Ripard | 2ab836d | 2016-06-29 21:05:29 +0200 | [diff] [blame] | 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 | }; |