1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2016 Maxime Ripard
4 * Maxime Ripard <maxime.ripard@free-electrons.com>
5 */
6
7 #include <linux/clk-provider.h>
8 #include <linux/io.h>
9
10 #include "ccu_gate.h"
11 #include "ccu_nkm.h"
12
13 struct _ccu_nkm {
14 unsigned long n, min_n, max_n;
15 unsigned long k, min_k, max_k;
16 unsigned long m, min_m, max_m;
17 };
18
ccu_nkm_find_best_with_parent_adj(struct ccu_common * common,struct clk_hw * parent_hw,unsigned long * parent,unsigned long rate,struct _ccu_nkm * nkm)19 static unsigned long ccu_nkm_find_best_with_parent_adj(struct ccu_common *common,
20 struct clk_hw *parent_hw,
21 unsigned long *parent, unsigned long rate,
22 struct _ccu_nkm *nkm)
23 {
24 unsigned long best_rate = 0, best_parent_rate = *parent, tmp_parent = *parent;
25 unsigned long best_n = 0, best_k = 0, best_m = 0;
26 unsigned long _n, _k, _m;
27
28 for (_k = nkm->min_k; _k <= nkm->max_k; _k++) {
29 for (_n = nkm->min_n; _n <= nkm->max_n; _n++) {
30 for (_m = nkm->min_m; _m <= nkm->max_m; _m++) {
31 unsigned long tmp_rate;
32
33 tmp_parent = clk_hw_round_rate(parent_hw, rate * _m / (_n * _k));
34
35 tmp_rate = tmp_parent * _n * _k / _m;
36
37 if (ccu_is_better_rate(common, rate, tmp_rate, best_rate) ||
38 (tmp_parent == *parent && tmp_rate == best_rate)) {
39 best_rate = tmp_rate;
40 best_parent_rate = tmp_parent;
41 best_n = _n;
42 best_k = _k;
43 best_m = _m;
44 }
45 }
46 }
47 }
48
49 nkm->n = best_n;
50 nkm->k = best_k;
51 nkm->m = best_m;
52
53 *parent = best_parent_rate;
54
55 return best_rate;
56 }
57
ccu_nkm_find_best(unsigned long parent,unsigned long rate,struct _ccu_nkm * nkm,struct ccu_common * common)58 static unsigned long ccu_nkm_find_best(unsigned long parent, unsigned long rate,
59 struct _ccu_nkm *nkm, struct ccu_common *common)
60 {
61 unsigned long best_rate = 0;
62 unsigned long best_n = 0, best_k = 0, best_m = 0;
63 unsigned long _n, _k, _m;
64
65 for (_k = nkm->min_k; _k <= nkm->max_k; _k++) {
66 for (_n = nkm->min_n; _n <= nkm->max_n; _n++) {
67 for (_m = nkm->min_m; _m <= nkm->max_m; _m++) {
68 unsigned long tmp_rate;
69
70 tmp_rate = parent * _n * _k / _m;
71
72 if (ccu_is_better_rate(common, rate, tmp_rate, best_rate)) {
73 best_rate = tmp_rate;
74 best_n = _n;
75 best_k = _k;
76 best_m = _m;
77 }
78 }
79 }
80 }
81
82 nkm->n = best_n;
83 nkm->k = best_k;
84 nkm->m = best_m;
85
86 return best_rate;
87 }
88
ccu_nkm_disable(struct clk_hw * hw)89 static void ccu_nkm_disable(struct clk_hw *hw)
90 {
91 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
92
93 return ccu_gate_helper_disable(&nkm->common, nkm->enable);
94 }
95
ccu_nkm_enable(struct clk_hw * hw)96 static int ccu_nkm_enable(struct clk_hw *hw)
97 {
98 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
99
100 return ccu_gate_helper_enable(&nkm->common, nkm->enable);
101 }
102
ccu_nkm_is_enabled(struct clk_hw * hw)103 static int ccu_nkm_is_enabled(struct clk_hw *hw)
104 {
105 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
106
107 return ccu_gate_helper_is_enabled(&nkm->common, nkm->enable);
108 }
109
ccu_nkm_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)110 static unsigned long ccu_nkm_recalc_rate(struct clk_hw *hw,
111 unsigned long parent_rate)
112 {
113 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
114 unsigned long n, m, k, rate;
115 u32 reg;
116
117 reg = readl(nkm->common.base + nkm->common.reg);
118
119 n = reg >> nkm->n.shift;
120 n &= (1 << nkm->n.width) - 1;
121 n += nkm->n.offset;
122 if (!n)
123 n++;
124
125 k = reg >> nkm->k.shift;
126 k &= (1 << nkm->k.width) - 1;
127 k += nkm->k.offset;
128 if (!k)
129 k++;
130
131 m = reg >> nkm->m.shift;
132 m &= (1 << nkm->m.width) - 1;
133 m += nkm->m.offset;
134 if (!m)
135 m++;
136
137 rate = parent_rate * n * k / m;
138
139 if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
140 rate /= nkm->fixed_post_div;
141
142 return rate;
143 }
144
ccu_nkm_round_rate(struct ccu_mux_internal * mux,struct clk_hw * parent_hw,unsigned long * parent_rate,unsigned long rate,void * data)145 static unsigned long ccu_nkm_round_rate(struct ccu_mux_internal *mux,
146 struct clk_hw *parent_hw,
147 unsigned long *parent_rate,
148 unsigned long rate,
149 void *data)
150 {
151 struct ccu_nkm *nkm = data;
152 struct _ccu_nkm _nkm;
153
154 _nkm.min_n = nkm->n.min ?: 1;
155 _nkm.max_n = nkm->n.max ?: 1 << nkm->n.width;
156 _nkm.min_k = nkm->k.min ?: 1;
157 _nkm.max_k = nkm->k.max ?: 1 << nkm->k.width;
158 _nkm.min_m = 1;
159 _nkm.max_m = nkm->m.max ?: 1 << nkm->m.width;
160
161 if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
162 rate *= nkm->fixed_post_div;
163
164 if (!clk_hw_can_set_rate_parent(&nkm->common.hw))
165 rate = ccu_nkm_find_best(*parent_rate, rate, &_nkm, &nkm->common);
166 else
167 rate = ccu_nkm_find_best_with_parent_adj(&nkm->common, parent_hw, parent_rate, rate,
168 &_nkm);
169
170 if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
171 rate /= nkm->fixed_post_div;
172
173 return rate;
174 }
175
ccu_nkm_determine_rate(struct clk_hw * hw,struct clk_rate_request * req)176 static int ccu_nkm_determine_rate(struct clk_hw *hw,
177 struct clk_rate_request *req)
178 {
179 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
180
181 return ccu_mux_helper_determine_rate(&nkm->common, &nkm->mux,
182 req, ccu_nkm_round_rate, nkm);
183 }
184
ccu_nkm_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)185 static int ccu_nkm_set_rate(struct clk_hw *hw, unsigned long rate,
186 unsigned long parent_rate)
187 {
188 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
189 struct _ccu_nkm _nkm;
190 unsigned long flags;
191 u32 reg;
192
193 if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
194 rate *= nkm->fixed_post_div;
195
196 _nkm.min_n = nkm->n.min ?: 1;
197 _nkm.max_n = nkm->n.max ?: 1 << nkm->n.width;
198 _nkm.min_k = nkm->k.min ?: 1;
199 _nkm.max_k = nkm->k.max ?: 1 << nkm->k.width;
200 _nkm.min_m = 1;
201 _nkm.max_m = nkm->m.max ?: 1 << nkm->m.width;
202
203 ccu_nkm_find_best(parent_rate, rate, &_nkm, &nkm->common);
204
205 spin_lock_irqsave(nkm->common.lock, flags);
206
207 reg = readl(nkm->common.base + nkm->common.reg);
208 reg &= ~GENMASK(nkm->n.width + nkm->n.shift - 1, nkm->n.shift);
209 reg &= ~GENMASK(nkm->k.width + nkm->k.shift - 1, nkm->k.shift);
210 reg &= ~GENMASK(nkm->m.width + nkm->m.shift - 1, nkm->m.shift);
211
212 reg |= (_nkm.n - nkm->n.offset) << nkm->n.shift;
213 reg |= (_nkm.k - nkm->k.offset) << nkm->k.shift;
214 reg |= (_nkm.m - nkm->m.offset) << nkm->m.shift;
215 writel(reg, nkm->common.base + nkm->common.reg);
216
217 spin_unlock_irqrestore(nkm->common.lock, flags);
218
219 ccu_helper_wait_for_lock(&nkm->common, nkm->lock);
220
221 return 0;
222 }
223
ccu_nkm_get_parent(struct clk_hw * hw)224 static u8 ccu_nkm_get_parent(struct clk_hw *hw)
225 {
226 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
227
228 return ccu_mux_helper_get_parent(&nkm->common, &nkm->mux);
229 }
230
ccu_nkm_set_parent(struct clk_hw * hw,u8 index)231 static int ccu_nkm_set_parent(struct clk_hw *hw, u8 index)
232 {
233 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
234
235 return ccu_mux_helper_set_parent(&nkm->common, &nkm->mux, index);
236 }
237
238 const struct clk_ops ccu_nkm_ops = {
239 .disable = ccu_nkm_disable,
240 .enable = ccu_nkm_enable,
241 .is_enabled = ccu_nkm_is_enabled,
242
243 .get_parent = ccu_nkm_get_parent,
244 .set_parent = ccu_nkm_set_parent,
245
246 .determine_rate = ccu_nkm_determine_rate,
247 .recalc_rate = ccu_nkm_recalc_rate,
248 .set_rate = ccu_nkm_set_rate,
249 };
250 EXPORT_SYMBOL_NS_GPL(ccu_nkm_ops, SUNXI_CCU);
251