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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
4f728b5d MR |
2 | /* |
3 | * Copyright (C) 2016 Maxime Ripard | |
4 | * Maxime Ripard <maxime.ripard@free-electrons.com> | |
4f728b5d MR |
5 | */ |
6 | ||
7 | #include <linux/clk-provider.h> | |
62e59c4e | 8 | #include <linux/io.h> |
4f728b5d MR |
9 | |
10 | #include "ccu_gate.h" | |
11 | #include "ccu_nkmp.h" | |
12 | ||
13 | struct _ccu_nkmp { | |
6e0d50da MR |
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 | unsigned long p, min_p, max_p; | |
4f728b5d MR |
18 | }; |
19 | ||
a5ebc336 JS |
20 | static unsigned long ccu_nkmp_calc_rate(unsigned long parent, |
21 | unsigned long n, unsigned long k, | |
22 | unsigned long m, unsigned long p) | |
23 | { | |
24 | u64 rate = parent; | |
25 | ||
26 | rate *= n * k; | |
27 | do_div(rate, m * p); | |
28 | ||
29 | return rate; | |
30 | } | |
31 | ||
4f728b5d MR |
32 | static void ccu_nkmp_find_best(unsigned long parent, unsigned long rate, |
33 | struct _ccu_nkmp *nkmp) | |
34 | { | |
35 | unsigned long best_rate = 0; | |
36 | unsigned long best_n = 0, best_k = 0, best_m = 0, best_p = 0; | |
37 | unsigned long _n, _k, _m, _p; | |
38 | ||
6e0d50da MR |
39 | for (_k = nkmp->min_k; _k <= nkmp->max_k; _k++) { |
40 | for (_n = nkmp->min_n; _n <= nkmp->max_n; _n++) { | |
41 | for (_m = nkmp->min_m; _m <= nkmp->max_m; _m++) { | |
42 | for (_p = nkmp->min_p; _p <= nkmp->max_p; _p <<= 1) { | |
ee28648c MR |
43 | unsigned long tmp_rate; |
44 | ||
a5ebc336 JS |
45 | tmp_rate = ccu_nkmp_calc_rate(parent, |
46 | _n, _k, | |
47 | _m, _p); | |
ee28648c MR |
48 | |
49 | if (tmp_rate > rate) | |
50 | continue; | |
51 | ||
52 | if ((rate - tmp_rate) < (rate - best_rate)) { | |
53 | best_rate = tmp_rate; | |
54 | best_n = _n; | |
55 | best_k = _k; | |
56 | best_m = _m; | |
57 | best_p = _p; | |
58 | } | |
59 | } | |
4f728b5d MR |
60 | } |
61 | } | |
62 | } | |
63 | ||
64 | nkmp->n = best_n; | |
65 | nkmp->k = best_k; | |
66 | nkmp->m = best_m; | |
67 | nkmp->p = best_p; | |
68 | } | |
69 | ||
70 | static void ccu_nkmp_disable(struct clk_hw *hw) | |
71 | { | |
72 | struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); | |
73 | ||
74 | return ccu_gate_helper_disable(&nkmp->common, nkmp->enable); | |
75 | } | |
76 | ||
77 | static int ccu_nkmp_enable(struct clk_hw *hw) | |
78 | { | |
79 | struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); | |
80 | ||
81 | return ccu_gate_helper_enable(&nkmp->common, nkmp->enable); | |
82 | } | |
83 | ||
84 | static int ccu_nkmp_is_enabled(struct clk_hw *hw) | |
85 | { | |
86 | struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); | |
87 | ||
88 | return ccu_gate_helper_is_enabled(&nkmp->common, nkmp->enable); | |
89 | } | |
90 | ||
91 | static unsigned long ccu_nkmp_recalc_rate(struct clk_hw *hw, | |
92 | unsigned long parent_rate) | |
93 | { | |
94 | struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); | |
a910f251 | 95 | unsigned long n, m, k, p, rate; |
4f728b5d MR |
96 | u32 reg; |
97 | ||
98 | reg = readl(nkmp->common.base + nkmp->common.reg); | |
99 | ||
100 | n = reg >> nkmp->n.shift; | |
101 | n &= (1 << nkmp->n.width) - 1; | |
e66f81bb MR |
102 | n += nkmp->n.offset; |
103 | if (!n) | |
104 | n++; | |
4f728b5d MR |
105 | |
106 | k = reg >> nkmp->k.shift; | |
107 | k &= (1 << nkmp->k.width) - 1; | |
e66f81bb MR |
108 | k += nkmp->k.offset; |
109 | if (!k) | |
110 | k++; | |
4f728b5d MR |
111 | |
112 | m = reg >> nkmp->m.shift; | |
113 | m &= (1 << nkmp->m.width) - 1; | |
e66f81bb MR |
114 | m += nkmp->m.offset; |
115 | if (!m) | |
116 | m++; | |
4f728b5d MR |
117 | |
118 | p = reg >> nkmp->p.shift; | |
119 | p &= (1 << nkmp->p.width) - 1; | |
120 | ||
a910f251 IZ |
121 | rate = ccu_nkmp_calc_rate(parent_rate, n, k, m, 1 << p); |
122 | if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV) | |
123 | rate /= nkmp->fixed_post_div; | |
124 | ||
125 | return rate; | |
4f728b5d MR |
126 | } |
127 | ||
128 | static long ccu_nkmp_round_rate(struct clk_hw *hw, unsigned long rate, | |
129 | unsigned long *parent_rate) | |
130 | { | |
131 | struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); | |
132 | struct _ccu_nkmp _nkmp; | |
133 | ||
a910f251 IZ |
134 | if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV) |
135 | rate *= nkmp->fixed_post_div; | |
136 | ||
a8e5433c JS |
137 | if (nkmp->max_rate && rate > nkmp->max_rate) { |
138 | rate = nkmp->max_rate; | |
139 | if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV) | |
140 | rate /= nkmp->fixed_post_div; | |
141 | return rate; | |
142 | } | |
143 | ||
4162c5ce | 144 | _nkmp.min_n = nkmp->n.min ?: 1; |
0c3c8e13 | 145 | _nkmp.max_n = nkmp->n.max ?: 1 << nkmp->n.width; |
4162c5ce | 146 | _nkmp.min_k = nkmp->k.min ?: 1; |
0c3c8e13 | 147 | _nkmp.max_k = nkmp->k.max ?: 1 << nkmp->k.width; |
6e0d50da | 148 | _nkmp.min_m = 1; |
87ba9e59 | 149 | _nkmp.max_m = nkmp->m.max ?: 1 << nkmp->m.width; |
6e0d50da | 150 | _nkmp.min_p = 1; |
87ba9e59 | 151 | _nkmp.max_p = nkmp->p.max ?: 1 << ((1 << nkmp->p.width) - 1); |
4f728b5d | 152 | |
87ba9e59 | 153 | ccu_nkmp_find_best(*parent_rate, rate, &_nkmp); |
4f728b5d | 154 | |
a910f251 | 155 | rate = ccu_nkmp_calc_rate(*parent_rate, _nkmp.n, _nkmp.k, |
a5ebc336 | 156 | _nkmp.m, _nkmp.p); |
a910f251 IZ |
157 | if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV) |
158 | rate = rate / nkmp->fixed_post_div; | |
159 | ||
160 | return rate; | |
4f728b5d MR |
161 | } |
162 | ||
163 | static int ccu_nkmp_set_rate(struct clk_hw *hw, unsigned long rate, | |
164 | unsigned long parent_rate) | |
165 | { | |
166 | struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); | |
2abc330c | 167 | u32 n_mask = 0, k_mask = 0, m_mask = 0, p_mask = 0; |
4f728b5d MR |
168 | struct _ccu_nkmp _nkmp; |
169 | unsigned long flags; | |
170 | u32 reg; | |
171 | ||
a910f251 IZ |
172 | if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV) |
173 | rate = rate * nkmp->fixed_post_div; | |
174 | ||
95ad8ed9 | 175 | _nkmp.min_n = nkmp->n.min ?: 1; |
0c3c8e13 | 176 | _nkmp.max_n = nkmp->n.max ?: 1 << nkmp->n.width; |
95ad8ed9 | 177 | _nkmp.min_k = nkmp->k.min ?: 1; |
0c3c8e13 | 178 | _nkmp.max_k = nkmp->k.max ?: 1 << nkmp->k.width; |
6e0d50da | 179 | _nkmp.min_m = 1; |
87ba9e59 | 180 | _nkmp.max_m = nkmp->m.max ?: 1 << nkmp->m.width; |
6e0d50da | 181 | _nkmp.min_p = 1; |
87ba9e59 | 182 | _nkmp.max_p = nkmp->p.max ?: 1 << ((1 << nkmp->p.width) - 1); |
4f728b5d MR |
183 | |
184 | ccu_nkmp_find_best(parent_rate, rate, &_nkmp); | |
185 | ||
1054e4dd JS |
186 | /* |
187 | * If width is 0, GENMASK() macro may not generate expected mask (0) | |
188 | * as it falls under undefined behaviour by C standard due to shifts | |
189 | * which are equal or greater than width of left operand. This can | |
190 | * be easily avoided by explicitly checking if width is 0. | |
191 | */ | |
2abc330c JS |
192 | if (nkmp->n.width) |
193 | n_mask = GENMASK(nkmp->n.width + nkmp->n.shift - 1, | |
194 | nkmp->n.shift); | |
195 | if (nkmp->k.width) | |
196 | k_mask = GENMASK(nkmp->k.width + nkmp->k.shift - 1, | |
197 | nkmp->k.shift); | |
198 | if (nkmp->m.width) | |
199 | m_mask = GENMASK(nkmp->m.width + nkmp->m.shift - 1, | |
200 | nkmp->m.shift); | |
201 | if (nkmp->p.width) | |
202 | p_mask = GENMASK(nkmp->p.width + nkmp->p.shift - 1, | |
203 | nkmp->p.shift); | |
d897ef56 | 204 | |
4f728b5d MR |
205 | spin_lock_irqsave(nkmp->common.lock, flags); |
206 | ||
207 | reg = readl(nkmp->common.base + nkmp->common.reg); | |
d897ef56 JS |
208 | reg &= ~(n_mask | k_mask | m_mask | p_mask); |
209 | ||
210 | reg |= ((_nkmp.n - nkmp->n.offset) << nkmp->n.shift) & n_mask; | |
211 | reg |= ((_nkmp.k - nkmp->k.offset) << nkmp->k.shift) & k_mask; | |
212 | reg |= ((_nkmp.m - nkmp->m.offset) << nkmp->m.shift) & m_mask; | |
213 | reg |= (ilog2(_nkmp.p) << nkmp->p.shift) & p_mask; | |
4f728b5d MR |
214 | |
215 | writel(reg, nkmp->common.base + nkmp->common.reg); | |
216 | ||
217 | spin_unlock_irqrestore(nkmp->common.lock, flags); | |
218 | ||
219 | ccu_helper_wait_for_lock(&nkmp->common, nkmp->lock); | |
220 | ||
221 | return 0; | |
222 | } | |
223 | ||
224 | const struct clk_ops ccu_nkmp_ops = { | |
225 | .disable = ccu_nkmp_disable, | |
226 | .enable = ccu_nkmp_enable, | |
227 | .is_enabled = ccu_nkmp_is_enabled, | |
228 | ||
229 | .recalc_rate = ccu_nkmp_recalc_rate, | |
230 | .round_rate = ccu_nkmp_round_rate, | |
231 | .set_rate = ccu_nkmp_set_rate, | |
232 | }; |