1 /*
2 * Copyright (C) 2016 Maxime Ripard
3 * Maxime Ripard <maxime.ripard@free-electrons.com>
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation; either version 2 of
8 * the License, or (at your option) any later version.
9 */
10
11 #include <linux/clk-provider.h>
12
13 #include "ccu_gate.h"
14 #include "ccu_nkmp.h"
15
16 struct _ccu_nkmp {
17 unsigned long n, min_n, max_n;
18 unsigned long k, min_k, max_k;
19 unsigned long m, min_m, max_m;
20 unsigned long p, min_p, max_p;
21 };
22
ccu_nkmp_calc_rate(unsigned long parent,unsigned long n,unsigned long k,unsigned long m,unsigned long p)23 static unsigned long ccu_nkmp_calc_rate(unsigned long parent,
24 unsigned long n, unsigned long k,
25 unsigned long m, unsigned long p)
26 {
27 u64 rate = parent;
28
29 rate *= n * k;
30 do_div(rate, m * p);
31
32 return rate;
33 }
34
ccu_nkmp_find_best(unsigned long parent,unsigned long rate,struct _ccu_nkmp * nkmp)35 static void ccu_nkmp_find_best(unsigned long parent, unsigned long rate,
36 struct _ccu_nkmp *nkmp)
37 {
38 unsigned long best_rate = 0;
39 unsigned long best_n = 0, best_k = 0, best_m = 0, best_p = 0;
40 unsigned long _n, _k, _m, _p;
41
42 for (_k = nkmp->min_k; _k <= nkmp->max_k; _k++) {
43 for (_n = nkmp->min_n; _n <= nkmp->max_n; _n++) {
44 for (_m = nkmp->min_m; _m <= nkmp->max_m; _m++) {
45 for (_p = nkmp->min_p; _p <= nkmp->max_p; _p <<= 1) {
46 unsigned long tmp_rate;
47
48 tmp_rate = ccu_nkmp_calc_rate(parent,
49 _n, _k,
50 _m, _p);
51
52 if (tmp_rate > rate)
53 continue;
54
55 if ((rate - tmp_rate) < (rate - best_rate)) {
56 best_rate = tmp_rate;
57 best_n = _n;
58 best_k = _k;
59 best_m = _m;
60 best_p = _p;
61 }
62 }
63 }
64 }
65 }
66
67 nkmp->n = best_n;
68 nkmp->k = best_k;
69 nkmp->m = best_m;
70 nkmp->p = best_p;
71 }
72
ccu_nkmp_disable(struct clk_hw * hw)73 static void ccu_nkmp_disable(struct clk_hw *hw)
74 {
75 struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw);
76
77 return ccu_gate_helper_disable(&nkmp->common, nkmp->enable);
78 }
79
ccu_nkmp_enable(struct clk_hw * hw)80 static int ccu_nkmp_enable(struct clk_hw *hw)
81 {
82 struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw);
83
84 return ccu_gate_helper_enable(&nkmp->common, nkmp->enable);
85 }
86
ccu_nkmp_is_enabled(struct clk_hw * hw)87 static int ccu_nkmp_is_enabled(struct clk_hw *hw)
88 {
89 struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw);
90
91 return ccu_gate_helper_is_enabled(&nkmp->common, nkmp->enable);
92 }
93
ccu_nkmp_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)94 static unsigned long ccu_nkmp_recalc_rate(struct clk_hw *hw,
95 unsigned long parent_rate)
96 {
97 struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw);
98 unsigned long n, m, k, p, rate;
99 u32 reg;
100
101 reg = readl(nkmp->common.base + nkmp->common.reg);
102
103 n = reg >> nkmp->n.shift;
104 n &= (1 << nkmp->n.width) - 1;
105 n += nkmp->n.offset;
106 if (!n)
107 n++;
108
109 k = reg >> nkmp->k.shift;
110 k &= (1 << nkmp->k.width) - 1;
111 k += nkmp->k.offset;
112 if (!k)
113 k++;
114
115 m = reg >> nkmp->m.shift;
116 m &= (1 << nkmp->m.width) - 1;
117 m += nkmp->m.offset;
118 if (!m)
119 m++;
120
121 p = reg >> nkmp->p.shift;
122 p &= (1 << nkmp->p.width) - 1;
123
124 rate = ccu_nkmp_calc_rate(parent_rate, n, k, m, 1 << p);
125 if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV)
126 rate /= nkmp->fixed_post_div;
127
128 return rate;
129 }
130
ccu_nkmp_round_rate(struct clk_hw * hw,unsigned long rate,unsigned long * parent_rate)131 static long ccu_nkmp_round_rate(struct clk_hw *hw, unsigned long rate,
132 unsigned long *parent_rate)
133 {
134 struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw);
135 struct _ccu_nkmp _nkmp;
136
137 if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV)
138 rate *= nkmp->fixed_post_div;
139
140 _nkmp.min_n = nkmp->n.min ?: 1;
141 _nkmp.max_n = nkmp->n.max ?: 1 << nkmp->n.width;
142 _nkmp.min_k = nkmp->k.min ?: 1;
143 _nkmp.max_k = nkmp->k.max ?: 1 << nkmp->k.width;
144 _nkmp.min_m = 1;
145 _nkmp.max_m = nkmp->m.max ?: 1 << nkmp->m.width;
146 _nkmp.min_p = 1;
147 _nkmp.max_p = nkmp->p.max ?: 1 << ((1 << nkmp->p.width) - 1);
148
149 ccu_nkmp_find_best(*parent_rate, rate, &_nkmp);
150
151 rate = ccu_nkmp_calc_rate(*parent_rate, _nkmp.n, _nkmp.k,
152 _nkmp.m, _nkmp.p);
153 if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV)
154 rate = rate / nkmp->fixed_post_div;
155
156 return rate;
157 }
158
ccu_nkmp_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)159 static int ccu_nkmp_set_rate(struct clk_hw *hw, unsigned long rate,
160 unsigned long parent_rate)
161 {
162 struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw);
163 u32 n_mask = 0, k_mask = 0, m_mask = 0, p_mask = 0;
164 struct _ccu_nkmp _nkmp;
165 unsigned long flags;
166 u32 reg;
167
168 if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV)
169 rate = rate * nkmp->fixed_post_div;
170
171 _nkmp.min_n = nkmp->n.min ?: 1;
172 _nkmp.max_n = nkmp->n.max ?: 1 << nkmp->n.width;
173 _nkmp.min_k = nkmp->k.min ?: 1;
174 _nkmp.max_k = nkmp->k.max ?: 1 << nkmp->k.width;
175 _nkmp.min_m = 1;
176 _nkmp.max_m = nkmp->m.max ?: 1 << nkmp->m.width;
177 _nkmp.min_p = 1;
178 _nkmp.max_p = nkmp->p.max ?: 1 << ((1 << nkmp->p.width) - 1);
179
180 ccu_nkmp_find_best(parent_rate, rate, &_nkmp);
181
182 if (nkmp->n.width)
183 n_mask = GENMASK(nkmp->n.width + nkmp->n.shift - 1,
184 nkmp->n.shift);
185 if (nkmp->k.width)
186 k_mask = GENMASK(nkmp->k.width + nkmp->k.shift - 1,
187 nkmp->k.shift);
188 if (nkmp->m.width)
189 m_mask = GENMASK(nkmp->m.width + nkmp->m.shift - 1,
190 nkmp->m.shift);
191 if (nkmp->p.width)
192 p_mask = GENMASK(nkmp->p.width + nkmp->p.shift - 1,
193 nkmp->p.shift);
194
195 spin_lock_irqsave(nkmp->common.lock, flags);
196
197 reg = readl(nkmp->common.base + nkmp->common.reg);
198 reg &= ~(n_mask | k_mask | m_mask | p_mask);
199
200 reg |= ((_nkmp.n - nkmp->n.offset) << nkmp->n.shift) & n_mask;
201 reg |= ((_nkmp.k - nkmp->k.offset) << nkmp->k.shift) & k_mask;
202 reg |= ((_nkmp.m - nkmp->m.offset) << nkmp->m.shift) & m_mask;
203 reg |= (ilog2(_nkmp.p) << nkmp->p.shift) & p_mask;
204
205 writel(reg, nkmp->common.base + nkmp->common.reg);
206
207 spin_unlock_irqrestore(nkmp->common.lock, flags);
208
209 ccu_helper_wait_for_lock(&nkmp->common, nkmp->lock);
210
211 return 0;
212 }
213
214 const struct clk_ops ccu_nkmp_ops = {
215 .disable = ccu_nkmp_disable,
216 .enable = ccu_nkmp_enable,
217 .is_enabled = ccu_nkmp_is_enabled,
218
219 .recalc_rate = ccu_nkmp_recalc_rate,
220 .round_rate = ccu_nkmp_round_rate,
221 .set_rate = ccu_nkmp_set_rate,
222 };
223