1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Copyright (C) 2016 Maxime Ripard
4 * Maxime Ripard <maxime.ripard@free-electrons.com>
7 #include <linux/clk-provider.h>
14 unsigned long n, min_n, max_n;
15 unsigned long k, min_k, max_k;
18 static unsigned long ccu_nk_find_best(unsigned long parent, unsigned long rate,
21 unsigned long best_rate = 0;
22 unsigned int best_k = 0, best_n = 0;
25 for (_k = nk->min_k; _k <= nk->max_k; _k++) {
26 for (_n = nk->min_n; _n <= nk->max_n; _n++) {
27 unsigned long tmp_rate = parent * _n * _k;
32 if ((rate - tmp_rate) < (rate - best_rate)) {
46 static void ccu_nk_disable(struct clk_hw *hw)
48 struct ccu_nk *nk = hw_to_ccu_nk(hw);
50 return ccu_gate_helper_disable(&nk->common, nk->enable);
53 static int ccu_nk_enable(struct clk_hw *hw)
55 struct ccu_nk *nk = hw_to_ccu_nk(hw);
57 return ccu_gate_helper_enable(&nk->common, nk->enable);
60 static int ccu_nk_is_enabled(struct clk_hw *hw)
62 struct ccu_nk *nk = hw_to_ccu_nk(hw);
64 return ccu_gate_helper_is_enabled(&nk->common, nk->enable);
67 static unsigned long ccu_nk_recalc_rate(struct clk_hw *hw,
68 unsigned long parent_rate)
70 struct ccu_nk *nk = hw_to_ccu_nk(hw);
71 unsigned long rate, n, k;
74 reg = readl(nk->common.base + nk->common.reg);
76 n = reg >> nk->n.shift;
77 n &= (1 << nk->n.width) - 1;
82 k = reg >> nk->k.shift;
83 k &= (1 << nk->k.width) - 1;
88 rate = parent_rate * n * k;
89 if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV)
90 rate /= nk->fixed_post_div;
95 static long ccu_nk_round_rate(struct clk_hw *hw, unsigned long rate,
96 unsigned long *parent_rate)
98 struct ccu_nk *nk = hw_to_ccu_nk(hw);
101 if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV)
102 rate *= nk->fixed_post_div;
104 _nk.min_n = nk->n.min ?: 1;
105 _nk.max_n = nk->n.max ?: 1 << nk->n.width;
106 _nk.min_k = nk->k.min ?: 1;
107 _nk.max_k = nk->k.max ?: 1 << nk->k.width;
109 rate = ccu_nk_find_best(*parent_rate, rate, &_nk);
111 if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV)
112 rate = rate / nk->fixed_post_div;
117 static int ccu_nk_set_rate(struct clk_hw *hw, unsigned long rate,
118 unsigned long parent_rate)
120 struct ccu_nk *nk = hw_to_ccu_nk(hw);
125 if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV)
126 rate = rate * nk->fixed_post_div;
128 _nk.min_n = nk->n.min ?: 1;
129 _nk.max_n = nk->n.max ?: 1 << nk->n.width;
130 _nk.min_k = nk->k.min ?: 1;
131 _nk.max_k = nk->k.max ?: 1 << nk->k.width;
133 ccu_nk_find_best(parent_rate, rate, &_nk);
135 spin_lock_irqsave(nk->common.lock, flags);
137 reg = readl(nk->common.base + nk->common.reg);
138 reg &= ~GENMASK(nk->n.width + nk->n.shift - 1, nk->n.shift);
139 reg &= ~GENMASK(nk->k.width + nk->k.shift - 1, nk->k.shift);
141 reg |= (_nk.k - nk->k.offset) << nk->k.shift;
142 reg |= (_nk.n - nk->n.offset) << nk->n.shift;
143 writel(reg, nk->common.base + nk->common.reg);
145 spin_unlock_irqrestore(nk->common.lock, flags);
147 ccu_helper_wait_for_lock(&nk->common, nk->lock);
152 const struct clk_ops ccu_nk_ops = {
153 .disable = ccu_nk_disable,
154 .enable = ccu_nk_enable,
155 .is_enabled = ccu_nk_is_enabled,
157 .recalc_rate = ccu_nk_recalc_rate,
158 .round_rate = ccu_nk_round_rate,
159 .set_rate = ccu_nk_set_rate,
161 EXPORT_SYMBOL_NS_GPL(ccu_nk_ops, SUNXI_CCU);