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_frac.h"
11#include "ccu_gate.h"
12#include "ccu_nm.h"
13
14struct _ccu_nm {
15 unsigned long n, min_n, max_n;
16 unsigned long m, min_m, max_m;
17};
18
19static unsigned long ccu_nm_calc_rate(unsigned long parent,
20 unsigned long n, unsigned long m)
21{
22 u64 rate = parent;
23
24 rate *= n;
25 do_div(rate, m);
26
27 return rate;
28}
29
30static unsigned long ccu_nm_find_best(struct ccu_common *common, unsigned long parent,
31 unsigned long rate, struct _ccu_nm *nm)
32{
33 unsigned long best_rate = 0;
34 unsigned long best_n = 0, best_m = 0;
35 unsigned long _n, _m;
36
37 for (_n = nm->min_n; _n <= nm->max_n; _n++) {
38 for (_m = nm->min_m; _m <= nm->max_m; _m++) {
39 unsigned long tmp_rate = ccu_nm_calc_rate(parent,
40 n: _n, m: _m);
41
42 if (ccu_is_better_rate(common, target_rate: rate, current_rate: tmp_rate, best_rate)) {
43 best_rate = tmp_rate;
44 best_n = _n;
45 best_m = _m;
46 }
47 }
48 }
49
50 nm->n = best_n;
51 nm->m = best_m;
52
53 return best_rate;
54}
55
56static void ccu_nm_disable(struct clk_hw *hw)
57{
58 struct ccu_nm *nm = hw_to_ccu_nm(hw);
59
60 return ccu_gate_helper_disable(common: &nm->common, gate: nm->enable);
61}
62
63static int ccu_nm_enable(struct clk_hw *hw)
64{
65 struct ccu_nm *nm = hw_to_ccu_nm(hw);
66
67 return ccu_gate_helper_enable(common: &nm->common, gate: nm->enable);
68}
69
70static int ccu_nm_is_enabled(struct clk_hw *hw)
71{
72 struct ccu_nm *nm = hw_to_ccu_nm(hw);
73
74 return ccu_gate_helper_is_enabled(common: &nm->common, gate: nm->enable);
75}
76
77static unsigned long ccu_nm_recalc_rate(struct clk_hw *hw,
78 unsigned long parent_rate)
79{
80 struct ccu_nm *nm = hw_to_ccu_nm(hw);
81 unsigned long rate;
82 unsigned long n, m;
83 u32 reg;
84
85 if (ccu_frac_helper_is_enabled(common: &nm->common, cf: &nm->frac)) {
86 rate = ccu_frac_helper_read_rate(common: &nm->common, cf: &nm->frac);
87
88 if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
89 rate /= nm->fixed_post_div;
90
91 return rate;
92 }
93
94 reg = readl(addr: nm->common.base + nm->common.reg);
95
96 n = reg >> nm->n.shift;
97 n &= (1 << nm->n.width) - 1;
98 n += nm->n.offset;
99 if (!n)
100 n++;
101
102 m = reg >> nm->m.shift;
103 m &= (1 << nm->m.width) - 1;
104 m += nm->m.offset;
105 if (!m)
106 m++;
107
108 if (ccu_sdm_helper_is_enabled(common: &nm->common, sdm: &nm->sdm))
109 rate = ccu_sdm_helper_read_rate(common: &nm->common, sdm: &nm->sdm, m, n);
110 else
111 rate = ccu_nm_calc_rate(parent: parent_rate, n, m);
112
113 if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
114 rate /= nm->fixed_post_div;
115
116 return rate;
117}
118
119static long ccu_nm_round_rate(struct clk_hw *hw, unsigned long rate,
120 unsigned long *parent_rate)
121{
122 struct ccu_nm *nm = hw_to_ccu_nm(hw);
123 struct _ccu_nm _nm;
124
125 if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
126 rate *= nm->fixed_post_div;
127
128 if (rate < nm->min_rate) {
129 rate = nm->min_rate;
130 if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
131 rate /= nm->fixed_post_div;
132 return rate;
133 }
134
135 if (nm->max_rate && rate > nm->max_rate) {
136 rate = nm->max_rate;
137 if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
138 rate /= nm->fixed_post_div;
139 return rate;
140 }
141
142 if (ccu_frac_helper_has_rate(common: &nm->common, cf: &nm->frac, rate)) {
143 if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
144 rate /= nm->fixed_post_div;
145 return rate;
146 }
147
148 if (ccu_sdm_helper_has_rate(common: &nm->common, sdm: &nm->sdm, rate)) {
149 if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
150 rate /= nm->fixed_post_div;
151 return rate;
152 }
153
154 _nm.min_n = nm->n.min ?: 1;
155 _nm.max_n = nm->n.max ?: 1 << nm->n.width;
156 _nm.min_m = 1;
157 _nm.max_m = nm->m.max ?: 1 << nm->m.width;
158
159 rate = ccu_nm_find_best(common: &nm->common, parent: *parent_rate, rate, nm: &_nm);
160
161 if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
162 rate /= nm->fixed_post_div;
163
164 return rate;
165}
166
167static int ccu_nm_set_rate(struct clk_hw *hw, unsigned long rate,
168 unsigned long parent_rate)
169{
170 struct ccu_nm *nm = hw_to_ccu_nm(hw);
171 struct _ccu_nm _nm;
172 unsigned long flags;
173 u32 reg;
174
175 /* Adjust target rate according to post-dividers */
176 if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
177 rate = rate * nm->fixed_post_div;
178
179 if (ccu_frac_helper_has_rate(common: &nm->common, cf: &nm->frac, rate)) {
180 spin_lock_irqsave(nm->common.lock, flags);
181
182 /* most SoCs require M to be 0 if fractional mode is used */
183 reg = readl(addr: nm->common.base + nm->common.reg);
184 reg &= ~GENMASK(nm->m.width + nm->m.shift - 1, nm->m.shift);
185 writel(val: reg, addr: nm->common.base + nm->common.reg);
186
187 spin_unlock_irqrestore(lock: nm->common.lock, flags);
188
189 ccu_frac_helper_enable(common: &nm->common, cf: &nm->frac);
190
191 return ccu_frac_helper_set_rate(common: &nm->common, cf: &nm->frac,
192 rate, lock: nm->lock);
193 } else {
194 ccu_frac_helper_disable(common: &nm->common, cf: &nm->frac);
195 }
196
197 _nm.min_n = nm->n.min ?: 1;
198 _nm.max_n = nm->n.max ?: 1 << nm->n.width;
199 _nm.min_m = 1;
200 _nm.max_m = nm->m.max ?: 1 << nm->m.width;
201
202 if (ccu_sdm_helper_has_rate(common: &nm->common, sdm: &nm->sdm, rate)) {
203 ccu_sdm_helper_enable(common: &nm->common, sdm: &nm->sdm, rate);
204
205 /* Sigma delta modulation requires specific N and M factors */
206 ccu_sdm_helper_get_factors(common: &nm->common, sdm: &nm->sdm, rate,
207 m: &_nm.m, n: &_nm.n);
208 } else {
209 ccu_sdm_helper_disable(common: &nm->common, sdm: &nm->sdm);
210 ccu_nm_find_best(common: &nm->common, parent: parent_rate, rate, nm: &_nm);
211 }
212
213 spin_lock_irqsave(nm->common.lock, flags);
214
215 reg = readl(addr: nm->common.base + nm->common.reg);
216 reg &= ~GENMASK(nm->n.width + nm->n.shift - 1, nm->n.shift);
217 reg &= ~GENMASK(nm->m.width + nm->m.shift - 1, nm->m.shift);
218
219 reg |= (_nm.n - nm->n.offset) << nm->n.shift;
220 reg |= (_nm.m - nm->m.offset) << nm->m.shift;
221 writel(val: reg, addr: nm->common.base + nm->common.reg);
222
223 spin_unlock_irqrestore(lock: nm->common.lock, flags);
224
225 ccu_helper_wait_for_lock(common: &nm->common, lock: nm->lock);
226
227 return 0;
228}
229
230const struct clk_ops ccu_nm_ops = {
231 .disable = ccu_nm_disable,
232 .enable = ccu_nm_enable,
233 .is_enabled = ccu_nm_is_enabled,
234
235 .recalc_rate = ccu_nm_recalc_rate,
236 .round_rate = ccu_nm_round_rate,
237 .set_rate = ccu_nm_set_rate,
238};
239EXPORT_SYMBOL_NS_GPL(ccu_nm_ops, SUNXI_CCU);
240

source code of linux/drivers/clk/sunxi-ng/ccu_nm.c