1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
|
/*
* Copyright (C) 2016 Maxime Ripard
* Maxime Ripard <maxime.ripard@free-electrons.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*/
#include <linux/clk-provider.h>
#include "ccu_frac.h"
#include "ccu_gate.h"
#include "ccu_nm.h"
struct _ccu_nm {
unsigned long n, min_n, max_n;
unsigned long m, min_m, max_m;
};
static unsigned long ccu_nm_calc_rate(unsigned long parent,
unsigned long n, unsigned long m)
{
u64 rate = parent;
rate *= n;
do_div(rate, m);
return rate;
}
static void ccu_nm_find_best(unsigned long parent, unsigned long rate,
struct _ccu_nm *nm)
{
unsigned long best_rate = 0;
unsigned long best_n = 0, best_m = 0;
unsigned long _n, _m;
for (_n = nm->min_n; _n <= nm->max_n; _n++) {
for (_m = nm->min_m; _m <= nm->max_m; _m++) {
unsigned long tmp_rate = ccu_nm_calc_rate(parent,
_n, _m);
if (tmp_rate > rate)
continue;
if ((rate - tmp_rate) < (rate - best_rate)) {
best_rate = tmp_rate;
best_n = _n;
best_m = _m;
}
}
}
nm->n = best_n;
nm->m = best_m;
}
static void ccu_nm_disable(struct clk_hw *hw)
{
struct ccu_nm *nm = hw_to_ccu_nm(hw);
return ccu_gate_helper_disable(&nm->common, nm->enable);
}
static int ccu_nm_enable(struct clk_hw *hw)
{
struct ccu_nm *nm = hw_to_ccu_nm(hw);
return ccu_gate_helper_enable(&nm->common, nm->enable);
}
static int ccu_nm_is_enabled(struct clk_hw *hw)
{
struct ccu_nm *nm = hw_to_ccu_nm(hw);
return ccu_gate_helper_is_enabled(&nm->common, nm->enable);
}
static unsigned long ccu_nm_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct ccu_nm *nm = hw_to_ccu_nm(hw);
unsigned long rate;
unsigned long n, m;
u32 reg;
if (ccu_frac_helper_is_enabled(&nm->common, &nm->frac)) {
rate = ccu_frac_helper_read_rate(&nm->common, &nm->frac);
if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
rate /= nm->fixed_post_div;
return rate;
}
reg = readl(nm->common.base + nm->common.reg);
n = reg >> nm->n.shift;
n &= (1 << nm->n.width) - 1;
n += nm->n.offset;
if (!n)
n++;
m = reg >> nm->m.shift;
m &= (1 << nm->m.width) - 1;
m += nm->m.offset;
if (!m)
m++;
if (ccu_sdm_helper_is_enabled(&nm->common, &nm->sdm))
rate = ccu_sdm_helper_read_rate(&nm->common, &nm->sdm, m, n);
else
rate = ccu_nm_calc_rate(parent_rate, n, m);
if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
rate /= nm->fixed_post_div;
return rate;
}
static long ccu_nm_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *parent_rate)
{
struct ccu_nm *nm = hw_to_ccu_nm(hw);
struct _ccu_nm _nm;
if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
rate *= nm->fixed_post_div;
if (rate < nm->min_rate) {
rate = nm->min_rate;
if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
rate /= nm->fixed_post_div;
return rate;
}
if (nm->max_rate && rate > nm->max_rate) {
rate = nm->max_rate;
if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
rate /= nm->fixed_post_div;
return rate;
}
if (ccu_frac_helper_has_rate(&nm->common, &nm->frac, rate)) {
if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
rate /= nm->fixed_post_div;
return rate;
}
if (ccu_sdm_helper_has_rate(&nm->common, &nm->sdm, rate)) {
if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
rate /= nm->fixed_post_div;
return rate;
}
_nm.min_n = nm->n.min ?: 1;
_nm.max_n = nm->n.max ?: 1 << nm->n.width;
_nm.min_m = 1;
_nm.max_m = nm->m.max ?: 1 << nm->m.width;
ccu_nm_find_best(*parent_rate, rate, &_nm);
rate = ccu_nm_calc_rate(*parent_rate, _nm.n, _nm.m);
if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
rate /= nm->fixed_post_div;
return rate;
}
static int ccu_nm_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct ccu_nm *nm = hw_to_ccu_nm(hw);
struct _ccu_nm _nm;
unsigned long flags;
u32 reg;
/* Adjust target rate according to post-dividers */
if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
rate = rate * nm->fixed_post_div;
if (ccu_frac_helper_has_rate(&nm->common, &nm->frac, rate)) {
spin_lock_irqsave(nm->common.lock, flags);
/* most SoCs require M to be 0 if fractional mode is used */
reg = readl(nm->common.base + nm->common.reg);
reg &= ~GENMASK(nm->m.width + nm->m.shift - 1, nm->m.shift);
writel(reg, nm->common.base + nm->common.reg);
spin_unlock_irqrestore(nm->common.lock, flags);
ccu_frac_helper_enable(&nm->common, &nm->frac);
return ccu_frac_helper_set_rate(&nm->common, &nm->frac,
rate, nm->lock);
} else {
ccu_frac_helper_disable(&nm->common, &nm->frac);
}
_nm.min_n = nm->n.min ?: 1;
_nm.max_n = nm->n.max ?: 1 << nm->n.width;
_nm.min_m = 1;
_nm.max_m = nm->m.max ?: 1 << nm->m.width;
if (ccu_sdm_helper_has_rate(&nm->common, &nm->sdm, rate)) {
ccu_sdm_helper_enable(&nm->common, &nm->sdm, rate);
/* Sigma delta modulation requires specific N and M factors */
ccu_sdm_helper_get_factors(&nm->common, &nm->sdm, rate,
&_nm.m, &_nm.n);
} else {
ccu_sdm_helper_disable(&nm->common, &nm->sdm);
ccu_nm_find_best(parent_rate, rate, &_nm);
}
spin_lock_irqsave(nm->common.lock, flags);
reg = readl(nm->common.base + nm->common.reg);
reg &= ~GENMASK(nm->n.width + nm->n.shift - 1, nm->n.shift);
reg &= ~GENMASK(nm->m.width + nm->m.shift - 1, nm->m.shift);
reg |= (_nm.n - nm->n.offset) << nm->n.shift;
reg |= (_nm.m - nm->m.offset) << nm->m.shift;
writel(reg, nm->common.base + nm->common.reg);
spin_unlock_irqrestore(nm->common.lock, flags);
ccu_helper_wait_for_lock(&nm->common, nm->lock);
return 0;
}
const struct clk_ops ccu_nm_ops = {
.disable = ccu_nm_disable,
.enable = ccu_nm_enable,
.is_enabled = ccu_nm_is_enabled,
.recalc_rate = ccu_nm_recalc_rate,
.round_rate = ccu_nm_round_rate,
.set_rate = ccu_nm_set_rate,
};
|
