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_nkmp.h" |
12 | |
13 | struct _ccu_nkmp { |
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; |
18 | }; |
19 | |
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 | |
32 | static unsigned long 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 | |
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) { |
43 | unsigned long tmp_rate; |
44 | |
45 | tmp_rate = ccu_nkmp_calc_rate(parent, |
46 | n: _n, k: _k, |
47 | m: _m, p: _p); |
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 | } |
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 | return best_rate; |
70 | } |
71 | |
72 | static void ccu_nkmp_disable(struct clk_hw *hw) |
73 | { |
74 | struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); |
75 | |
76 | return ccu_gate_helper_disable(common: &nkmp->common, gate: nkmp->enable); |
77 | } |
78 | |
79 | static int ccu_nkmp_enable(struct clk_hw *hw) |
80 | { |
81 | struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); |
82 | |
83 | return ccu_gate_helper_enable(common: &nkmp->common, gate: nkmp->enable); |
84 | } |
85 | |
86 | static int ccu_nkmp_is_enabled(struct clk_hw *hw) |
87 | { |
88 | struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); |
89 | |
90 | return ccu_gate_helper_is_enabled(common: &nkmp->common, gate: nkmp->enable); |
91 | } |
92 | |
93 | static unsigned long ccu_nkmp_recalc_rate(struct clk_hw *hw, |
94 | unsigned long parent_rate) |
95 | { |
96 | struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); |
97 | unsigned long n, m, k, p, rate; |
98 | u32 reg; |
99 | |
100 | reg = readl(addr: nkmp->common.base + nkmp->common.reg); |
101 | |
102 | n = reg >> nkmp->n.shift; |
103 | n &= (1 << nkmp->n.width) - 1; |
104 | n += nkmp->n.offset; |
105 | if (!n) |
106 | n++; |
107 | |
108 | k = reg >> nkmp->k.shift; |
109 | k &= (1 << nkmp->k.width) - 1; |
110 | k += nkmp->k.offset; |
111 | if (!k) |
112 | k++; |
113 | |
114 | m = reg >> nkmp->m.shift; |
115 | m &= (1 << nkmp->m.width) - 1; |
116 | m += nkmp->m.offset; |
117 | if (!m) |
118 | m++; |
119 | |
120 | p = reg >> nkmp->p.shift; |
121 | p &= (1 << nkmp->p.width) - 1; |
122 | |
123 | rate = ccu_nkmp_calc_rate(parent: parent_rate, n, k, m, p: 1 << p); |
124 | if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV) |
125 | rate /= nkmp->fixed_post_div; |
126 | |
127 | return rate; |
128 | } |
129 | |
130 | static long ccu_nkmp_round_rate(struct clk_hw *hw, unsigned long rate, |
131 | unsigned long *parent_rate) |
132 | { |
133 | struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); |
134 | struct _ccu_nkmp _nkmp; |
135 | |
136 | if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV) |
137 | rate *= nkmp->fixed_post_div; |
138 | |
139 | if (nkmp->max_rate && rate > nkmp->max_rate) { |
140 | rate = nkmp->max_rate; |
141 | if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV) |
142 | rate /= nkmp->fixed_post_div; |
143 | return rate; |
144 | } |
145 | |
146 | _nkmp.min_n = nkmp->n.min ?: 1; |
147 | _nkmp.max_n = nkmp->n.max ?: 1 << nkmp->n.width; |
148 | _nkmp.min_k = nkmp->k.min ?: 1; |
149 | _nkmp.max_k = nkmp->k.max ?: 1 << nkmp->k.width; |
150 | _nkmp.min_m = 1; |
151 | _nkmp.max_m = nkmp->m.max ?: 1 << nkmp->m.width; |
152 | _nkmp.min_p = 1; |
153 | _nkmp.max_p = nkmp->p.max ?: 1 << ((1 << nkmp->p.width) - 1); |
154 | |
155 | rate = ccu_nkmp_find_best(parent: *parent_rate, rate, nkmp: &_nkmp); |
156 | |
157 | if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV) |
158 | rate = rate / nkmp->fixed_post_div; |
159 | |
160 | return rate; |
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); |
167 | u32 n_mask = 0, k_mask = 0, m_mask = 0, p_mask = 0; |
168 | struct _ccu_nkmp _nkmp; |
169 | unsigned long flags; |
170 | u32 reg; |
171 | |
172 | if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV) |
173 | rate = rate * nkmp->fixed_post_div; |
174 | |
175 | _nkmp.min_n = nkmp->n.min ?: 1; |
176 | _nkmp.max_n = nkmp->n.max ?: 1 << nkmp->n.width; |
177 | _nkmp.min_k = nkmp->k.min ?: 1; |
178 | _nkmp.max_k = nkmp->k.max ?: 1 << nkmp->k.width; |
179 | _nkmp.min_m = 1; |
180 | _nkmp.max_m = nkmp->m.max ?: 1 << nkmp->m.width; |
181 | _nkmp.min_p = 1; |
182 | _nkmp.max_p = nkmp->p.max ?: 1 << ((1 << nkmp->p.width) - 1); |
183 | |
184 | ccu_nkmp_find_best(parent: parent_rate, rate, nkmp: &_nkmp); |
185 | |
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 | */ |
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); |
204 | |
205 | spin_lock_irqsave(nkmp->common.lock, flags); |
206 | |
207 | reg = readl(addr: nkmp->common.base + nkmp->common.reg); |
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; |
214 | |
215 | writel(val: reg, addr: nkmp->common.base + nkmp->common.reg); |
216 | |
217 | spin_unlock_irqrestore(lock: nkmp->common.lock, flags); |
218 | |
219 | ccu_helper_wait_for_lock(common: &nkmp->common, lock: 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 | }; |
233 | EXPORT_SYMBOL_NS_GPL(ccu_nkmp_ops, SUNXI_CCU); |
234 | |