2 * Copyright (C) 2016 Maxime Ripard
3 * Maxime Ripard <maxime.ripard@free-electrons.com>
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.
11 #include <linux/clk-provider.h>
17 unsigned long n, min_n, max_n;
18 unsigned long k, min_k, max_k;
21 static void ccu_nk_find_best(unsigned long parent, unsigned long rate,
24 unsigned long best_rate = 0;
25 unsigned int best_k = 0, best_n = 0;
28 for (_k = nk->min_k; _k <= nk->max_k; _k++) {
29 for (_n = nk->min_n; _n <= nk->max_n; _n++) {
30 unsigned long tmp_rate = parent * _n * _k;
35 if ((rate - tmp_rate) < (rate - best_rate)) {
47 static void ccu_nk_disable(struct clk_hw *hw)
49 struct ccu_nk *nk = hw_to_ccu_nk(hw);
51 return ccu_gate_helper_disable(&nk->common, nk->enable);
54 static int ccu_nk_enable(struct clk_hw *hw)
56 struct ccu_nk *nk = hw_to_ccu_nk(hw);
58 return ccu_gate_helper_enable(&nk->common, nk->enable);
61 static int ccu_nk_is_enabled(struct clk_hw *hw)
63 struct ccu_nk *nk = hw_to_ccu_nk(hw);
65 return ccu_gate_helper_is_enabled(&nk->common, nk->enable);
68 static unsigned long ccu_nk_recalc_rate(struct clk_hw *hw,
69 unsigned long parent_rate)
71 struct ccu_nk *nk = hw_to_ccu_nk(hw);
72 unsigned long rate, n, k;
75 reg = readl(nk->common.base + nk->common.reg);
77 n = reg >> nk->n.shift;
78 n &= (1 << nk->n.width) - 1;
83 k = reg >> nk->k.shift;
84 k &= (1 << nk->k.width) - 1;
89 rate = parent_rate * n * k;
90 if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV)
91 rate /= nk->fixed_post_div;
96 static long ccu_nk_round_rate(struct clk_hw *hw, unsigned long rate,
97 unsigned long *parent_rate)
99 struct ccu_nk *nk = hw_to_ccu_nk(hw);
102 if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV)
103 rate *= nk->fixed_post_div;
105 _nk.min_n = nk->n.min ?: 1;
106 _nk.max_n = nk->n.max ?: 1 << nk->n.width;
107 _nk.min_k = nk->k.min ?: 1;
108 _nk.max_k = nk->k.max ?: 1 << nk->k.width;
110 ccu_nk_find_best(*parent_rate, rate, &_nk);
111 rate = *parent_rate * _nk.n * _nk.k;
113 if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV)
114 rate = rate / nk->fixed_post_div;
119 static int ccu_nk_set_rate(struct clk_hw *hw, unsigned long rate,
120 unsigned long parent_rate)
122 struct ccu_nk *nk = hw_to_ccu_nk(hw);
127 if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV)
128 rate = rate * nk->fixed_post_div;
130 _nk.min_n = nk->n.min ?: 1;
131 _nk.max_n = nk->n.max ?: 1 << nk->n.width;
132 _nk.min_k = nk->k.min ?: 1;
133 _nk.max_k = nk->k.max ?: 1 << nk->k.width;
135 ccu_nk_find_best(parent_rate, rate, &_nk);
137 spin_lock_irqsave(nk->common.lock, flags);
139 reg = readl(nk->common.base + nk->common.reg);
140 reg &= ~GENMASK(nk->n.width + nk->n.shift - 1, nk->n.shift);
141 reg &= ~GENMASK(nk->k.width + nk->k.shift - 1, nk->k.shift);
143 reg |= (_nk.k - nk->k.offset) << nk->k.shift;
144 reg |= (_nk.n - nk->n.offset) << nk->n.shift;
145 writel(reg, nk->common.base + nk->common.reg);
147 spin_unlock_irqrestore(nk->common.lock, flags);
149 ccu_helper_wait_for_lock(&nk->common, nk->lock);
154 const struct clk_ops ccu_nk_ops = {
155 .disable = ccu_nk_disable,
156 .enable = ccu_nk_enable,
157 .is_enabled = ccu_nk_is_enabled,
159 .recalc_rate = ccu_nk_recalc_rate,
160 .round_rate = ccu_nk_round_rate,
161 .set_rate = ccu_nk_set_rate,