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;
16 unsigned long m, min_m, max_m;
19 static void ccu_nkm_find_best(unsigned long parent, unsigned long rate,
22 unsigned long best_rate = 0;
23 unsigned long best_n = 0, best_k = 0, best_m = 0;
24 unsigned long _n, _k, _m;
26 for (_k = nkm->min_k; _k <= nkm->max_k; _k++) {
27 for (_n = nkm->min_n; _n <= nkm->max_n; _n++) {
28 for (_m = nkm->min_m; _m <= nkm->max_m; _m++) {
29 unsigned long tmp_rate;
31 tmp_rate = parent * _n * _k / _m;
35 if ((rate - tmp_rate) < (rate - best_rate)) {
50 static void ccu_nkm_disable(struct clk_hw *hw)
52 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
54 return ccu_gate_helper_disable(&nkm->common, nkm->enable);
57 static int ccu_nkm_enable(struct clk_hw *hw)
59 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
61 return ccu_gate_helper_enable(&nkm->common, nkm->enable);
64 static int ccu_nkm_is_enabled(struct clk_hw *hw)
66 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
68 return ccu_gate_helper_is_enabled(&nkm->common, nkm->enable);
71 static unsigned long ccu_nkm_recalc_rate(struct clk_hw *hw,
72 unsigned long parent_rate)
74 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
75 unsigned long n, m, k, rate;
78 reg = readl(nkm->common.base + nkm->common.reg);
80 n = reg >> nkm->n.shift;
81 n &= (1 << nkm->n.width) - 1;
86 k = reg >> nkm->k.shift;
87 k &= (1 << nkm->k.width) - 1;
92 m = reg >> nkm->m.shift;
93 m &= (1 << nkm->m.width) - 1;
98 rate = parent_rate * n * k / m;
100 if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
101 rate /= nkm->fixed_post_div;
106 static unsigned long ccu_nkm_round_rate(struct ccu_mux_internal *mux,
108 unsigned long *parent_rate,
112 struct ccu_nkm *nkm = data;
113 struct _ccu_nkm _nkm;
115 _nkm.min_n = nkm->n.min ?: 1;
116 _nkm.max_n = nkm->n.max ?: 1 << nkm->n.width;
117 _nkm.min_k = nkm->k.min ?: 1;
118 _nkm.max_k = nkm->k.max ?: 1 << nkm->k.width;
120 _nkm.max_m = nkm->m.max ?: 1 << nkm->m.width;
122 if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
123 rate *= nkm->fixed_post_div;
125 ccu_nkm_find_best(*parent_rate, rate, &_nkm);
127 rate = *parent_rate * _nkm.n * _nkm.k / _nkm.m;
129 if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
130 rate /= nkm->fixed_post_div;
135 static int ccu_nkm_determine_rate(struct clk_hw *hw,
136 struct clk_rate_request *req)
138 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
140 return ccu_mux_helper_determine_rate(&nkm->common, &nkm->mux,
141 req, ccu_nkm_round_rate, nkm);
144 static int ccu_nkm_set_rate(struct clk_hw *hw, unsigned long rate,
145 unsigned long parent_rate)
147 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
148 struct _ccu_nkm _nkm;
152 if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
153 rate *= nkm->fixed_post_div;
155 _nkm.min_n = nkm->n.min ?: 1;
156 _nkm.max_n = nkm->n.max ?: 1 << nkm->n.width;
157 _nkm.min_k = nkm->k.min ?: 1;
158 _nkm.max_k = nkm->k.max ?: 1 << nkm->k.width;
160 _nkm.max_m = nkm->m.max ?: 1 << nkm->m.width;
162 ccu_nkm_find_best(parent_rate, rate, &_nkm);
164 spin_lock_irqsave(nkm->common.lock, flags);
166 reg = readl(nkm->common.base + nkm->common.reg);
167 reg &= ~GENMASK(nkm->n.width + nkm->n.shift - 1, nkm->n.shift);
168 reg &= ~GENMASK(nkm->k.width + nkm->k.shift - 1, nkm->k.shift);
169 reg &= ~GENMASK(nkm->m.width + nkm->m.shift - 1, nkm->m.shift);
171 reg |= (_nkm.n - nkm->n.offset) << nkm->n.shift;
172 reg |= (_nkm.k - nkm->k.offset) << nkm->k.shift;
173 reg |= (_nkm.m - nkm->m.offset) << nkm->m.shift;
174 writel(reg, nkm->common.base + nkm->common.reg);
176 spin_unlock_irqrestore(nkm->common.lock, flags);
178 ccu_helper_wait_for_lock(&nkm->common, nkm->lock);
183 static u8 ccu_nkm_get_parent(struct clk_hw *hw)
185 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
187 return ccu_mux_helper_get_parent(&nkm->common, &nkm->mux);
190 static int ccu_nkm_set_parent(struct clk_hw *hw, u8 index)
192 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
194 return ccu_mux_helper_set_parent(&nkm->common, &nkm->mux, index);
197 const struct clk_ops ccu_nkm_ops = {
198 .disable = ccu_nkm_disable,
199 .enable = ccu_nkm_enable,
200 .is_enabled = ccu_nkm_is_enabled,
202 .get_parent = ccu_nkm_get_parent,
203 .set_parent = ccu_nkm_set_parent,
205 .determine_rate = ccu_nkm_determine_rate,
206 .recalc_rate = ccu_nkm_recalc_rate,
207 .set_rate = ccu_nkm_set_rate,