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_is_valid_rate(struct ccu_common * common,unsigned long parent,unsigned long n,unsigned long m)19 static bool ccu_nkm_is_valid_rate(struct ccu_common *common, unsigned long parent,
20 unsigned long n, unsigned long m)
21 {
22 struct ccu_nkm *nkm = container_of(common, struct ccu_nkm, common);
23
24 if (nkm->max_m_n_ratio && (m > nkm->max_m_n_ratio * n))
25 return false;
26
27 if (nkm->min_parent_m_ratio && (parent < nkm->min_parent_m_ratio * m))
28 return false;
29
30 return true;
31 }
32
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)33 static unsigned long ccu_nkm_find_best_with_parent_adj(struct ccu_common *common,
34 struct clk_hw *parent_hw,
35 unsigned long *parent, unsigned long rate,
36 struct _ccu_nkm *nkm)
37 {
38 unsigned long best_rate = 0, best_parent_rate = *parent;
39 unsigned long best_n = 0, best_k = 0, best_m = 0;
40 unsigned long _n, _k, _m;
41
42 for (_k = nkm->min_k; _k <= nkm->max_k; _k++) {
43 for (_n = nkm->min_n; _n <= nkm->max_n; _n++) {
44 for (_m = nkm->min_m; _m <= nkm->max_m; _m++) {
45 unsigned long tmp_rate, tmp_parent;
46
47 tmp_parent = clk_hw_round_rate(parent_hw, rate * _m / (_n * _k));
48
49 if (!ccu_nkm_is_valid_rate(common, tmp_parent, _n, _m))
50 continue;
51
52 tmp_rate = tmp_parent * _n * _k / _m;
53
54 if (ccu_is_better_rate(common, rate, tmp_rate, best_rate) ||
55 (tmp_parent == *parent && tmp_rate == best_rate)) {
56 best_rate = tmp_rate;
57 best_parent_rate = tmp_parent;
58 best_n = _n;
59 best_k = _k;
60 best_m = _m;
61 }
62 }
63 }
64 }
65
66 nkm->n = best_n;
67 nkm->k = best_k;
68 nkm->m = best_m;
69
70 *parent = best_parent_rate;
71
72 return best_rate;
73 }
74
ccu_nkm_find_best(unsigned long parent,unsigned long rate,struct _ccu_nkm * nkm,struct ccu_common * common)75 static unsigned long ccu_nkm_find_best(unsigned long parent, unsigned long rate,
76 struct _ccu_nkm *nkm, struct ccu_common *common)
77 {
78 unsigned long best_rate = 0;
79 unsigned long best_n = 0, best_k = 0, best_m = 0;
80 unsigned long _n, _k, _m;
81
82 for (_k = nkm->min_k; _k <= nkm->max_k; _k++) {
83 for (_n = nkm->min_n; _n <= nkm->max_n; _n++) {
84 for (_m = nkm->min_m; _m <= nkm->max_m; _m++) {
85 if (!ccu_nkm_is_valid_rate(common, parent, _n, _m))
86 continue;
87
88 unsigned long tmp_rate;
89
90 tmp_rate = parent * _n * _k / _m;
91
92 if (ccu_is_better_rate(common, rate, tmp_rate, best_rate)) {
93 best_rate = tmp_rate;
94 best_n = _n;
95 best_k = _k;
96 best_m = _m;
97 }
98 }
99 }
100 }
101
102 nkm->n = best_n;
103 nkm->k = best_k;
104 nkm->m = best_m;
105
106 return best_rate;
107 }
108
ccu_nkm_disable(struct clk_hw * hw)109 static void ccu_nkm_disable(struct clk_hw *hw)
110 {
111 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
112
113 return ccu_gate_helper_disable(&nkm->common, nkm->enable);
114 }
115
ccu_nkm_enable(struct clk_hw * hw)116 static int ccu_nkm_enable(struct clk_hw *hw)
117 {
118 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
119
120 return ccu_gate_helper_enable(&nkm->common, nkm->enable);
121 }
122
ccu_nkm_is_enabled(struct clk_hw * hw)123 static int ccu_nkm_is_enabled(struct clk_hw *hw)
124 {
125 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
126
127 return ccu_gate_helper_is_enabled(&nkm->common, nkm->enable);
128 }
129
ccu_nkm_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)130 static unsigned long ccu_nkm_recalc_rate(struct clk_hw *hw,
131 unsigned long parent_rate)
132 {
133 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
134 unsigned long n, m, k, rate;
135 u32 reg;
136
137 reg = readl(nkm->common.base + nkm->common.reg);
138
139 n = reg >> nkm->n.shift;
140 n &= (1 << nkm->n.width) - 1;
141 n += nkm->n.offset;
142 if (!n)
143 n++;
144
145 k = reg >> nkm->k.shift;
146 k &= (1 << nkm->k.width) - 1;
147 k += nkm->k.offset;
148 if (!k)
149 k++;
150
151 m = reg >> nkm->m.shift;
152 m &= (1 << nkm->m.width) - 1;
153 m += nkm->m.offset;
154 if (!m)
155 m++;
156
157 rate = parent_rate * n * k / m;
158
159 if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
160 rate /= nkm->fixed_post_div;
161
162 return rate;
163 }
164
ccu_nkm_round_rate(struct ccu_mux_internal * mux,struct clk_hw * parent_hw,unsigned long * parent_rate,unsigned long rate,void * data)165 static unsigned long ccu_nkm_round_rate(struct ccu_mux_internal *mux,
166 struct clk_hw *parent_hw,
167 unsigned long *parent_rate,
168 unsigned long rate,
169 void *data)
170 {
171 struct ccu_nkm *nkm = data;
172 struct _ccu_nkm _nkm;
173
174 _nkm.min_n = nkm->n.min ?: 1;
175 _nkm.max_n = nkm->n.max ?: 1 << nkm->n.width;
176 _nkm.min_k = nkm->k.min ?: 1;
177 _nkm.max_k = nkm->k.max ?: 1 << nkm->k.width;
178 _nkm.min_m = 1;
179 _nkm.max_m = nkm->m.max ?: 1 << nkm->m.width;
180
181 if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
182 rate *= nkm->fixed_post_div;
183
184 if (!clk_hw_can_set_rate_parent(&nkm->common.hw))
185 rate = ccu_nkm_find_best(*parent_rate, rate, &_nkm, &nkm->common);
186 else
187 rate = ccu_nkm_find_best_with_parent_adj(&nkm->common, parent_hw, parent_rate, rate,
188 &_nkm);
189
190 if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
191 rate /= nkm->fixed_post_div;
192
193 return rate;
194 }
195
ccu_nkm_determine_rate(struct clk_hw * hw,struct clk_rate_request * req)196 static int ccu_nkm_determine_rate(struct clk_hw *hw,
197 struct clk_rate_request *req)
198 {
199 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
200
201 return ccu_mux_helper_determine_rate(&nkm->common, &nkm->mux,
202 req, ccu_nkm_round_rate, nkm);
203 }
204
ccu_nkm_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)205 static int ccu_nkm_set_rate(struct clk_hw *hw, unsigned long rate,
206 unsigned long parent_rate)
207 {
208 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
209 struct _ccu_nkm _nkm;
210 unsigned long flags;
211 u32 reg;
212
213 if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
214 rate *= nkm->fixed_post_div;
215
216 _nkm.min_n = nkm->n.min ?: 1;
217 _nkm.max_n = nkm->n.max ?: 1 << nkm->n.width;
218 _nkm.min_k = nkm->k.min ?: 1;
219 _nkm.max_k = nkm->k.max ?: 1 << nkm->k.width;
220 _nkm.min_m = 1;
221 _nkm.max_m = nkm->m.max ?: 1 << nkm->m.width;
222
223 ccu_nkm_find_best(parent_rate, rate, &_nkm, &nkm->common);
224
225 spin_lock_irqsave(nkm->common.lock, flags);
226
227 reg = readl(nkm->common.base + nkm->common.reg);
228 reg &= ~GENMASK(nkm->n.width + nkm->n.shift - 1, nkm->n.shift);
229 reg &= ~GENMASK(nkm->k.width + nkm->k.shift - 1, nkm->k.shift);
230 reg &= ~GENMASK(nkm->m.width + nkm->m.shift - 1, nkm->m.shift);
231
232 reg |= (_nkm.n - nkm->n.offset) << nkm->n.shift;
233 reg |= (_nkm.k - nkm->k.offset) << nkm->k.shift;
234 reg |= (_nkm.m - nkm->m.offset) << nkm->m.shift;
235 writel(reg, nkm->common.base + nkm->common.reg);
236
237 spin_unlock_irqrestore(nkm->common.lock, flags);
238
239 ccu_helper_wait_for_lock(&nkm->common, nkm->lock);
240
241 return 0;
242 }
243
ccu_nkm_get_parent(struct clk_hw * hw)244 static u8 ccu_nkm_get_parent(struct clk_hw *hw)
245 {
246 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
247
248 return ccu_mux_helper_get_parent(&nkm->common, &nkm->mux);
249 }
250
ccu_nkm_set_parent(struct clk_hw * hw,u8 index)251 static int ccu_nkm_set_parent(struct clk_hw *hw, u8 index)
252 {
253 struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
254
255 return ccu_mux_helper_set_parent(&nkm->common, &nkm->mux, index);
256 }
257
258 const struct clk_ops ccu_nkm_ops = {
259 .disable = ccu_nkm_disable,
260 .enable = ccu_nkm_enable,
261 .is_enabled = ccu_nkm_is_enabled,
262
263 .get_parent = ccu_nkm_get_parent,
264 .set_parent = ccu_nkm_set_parent,
265
266 .determine_rate = ccu_nkm_determine_rate,
267 .recalc_rate = ccu_nkm_recalc_rate,
268 .set_rate = ccu_nkm_set_rate,
269 };
270 EXPORT_SYMBOL_NS_GPL(ccu_nkm_ops, "SUNXI_CCU");
271