Linux 4.1.16
[linux/fpc-iii.git] / drivers / clk / clk-composite.c
blob956b7e54fa1c5f4f3583ac642c3f3f2ae255fee2
1 /*
2 * Copyright (c) 2013 NVIDIA CORPORATION. All rights reserved.
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms and conditions of the GNU General Public License,
6 * version 2, as published by the Free Software Foundation.
8 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
13 * You should have received a copy of the GNU General Public License
14 * along with this program. If not, see <http://www.gnu.org/licenses/>.
17 #include <linux/clk.h>
18 #include <linux/clk-provider.h>
19 #include <linux/err.h>
20 #include <linux/slab.h>
22 #define to_clk_composite(_hw) container_of(_hw, struct clk_composite, hw)
24 static u8 clk_composite_get_parent(struct clk_hw *hw)
26 struct clk_composite *composite = to_clk_composite(hw);
27 const struct clk_ops *mux_ops = composite->mux_ops;
28 struct clk_hw *mux_hw = composite->mux_hw;
30 __clk_hw_set_clk(mux_hw, hw);
32 return mux_ops->get_parent(mux_hw);
35 static int clk_composite_set_parent(struct clk_hw *hw, u8 index)
37 struct clk_composite *composite = to_clk_composite(hw);
38 const struct clk_ops *mux_ops = composite->mux_ops;
39 struct clk_hw *mux_hw = composite->mux_hw;
41 __clk_hw_set_clk(mux_hw, hw);
43 return mux_ops->set_parent(mux_hw, index);
46 static unsigned long clk_composite_recalc_rate(struct clk_hw *hw,
47 unsigned long parent_rate)
49 struct clk_composite *composite = to_clk_composite(hw);
50 const struct clk_ops *rate_ops = composite->rate_ops;
51 struct clk_hw *rate_hw = composite->rate_hw;
53 __clk_hw_set_clk(rate_hw, hw);
55 return rate_ops->recalc_rate(rate_hw, parent_rate);
58 static long clk_composite_determine_rate(struct clk_hw *hw, unsigned long rate,
59 unsigned long min_rate,
60 unsigned long max_rate,
61 unsigned long *best_parent_rate,
62 struct clk_hw **best_parent_p)
64 struct clk_composite *composite = to_clk_composite(hw);
65 const struct clk_ops *rate_ops = composite->rate_ops;
66 const struct clk_ops *mux_ops = composite->mux_ops;
67 struct clk_hw *rate_hw = composite->rate_hw;
68 struct clk_hw *mux_hw = composite->mux_hw;
69 struct clk *parent;
70 unsigned long parent_rate;
71 long tmp_rate, best_rate = 0;
72 unsigned long rate_diff;
73 unsigned long best_rate_diff = ULONG_MAX;
74 int i;
76 if (rate_hw && rate_ops && rate_ops->determine_rate) {
77 __clk_hw_set_clk(rate_hw, hw);
78 return rate_ops->determine_rate(rate_hw, rate, min_rate,
79 max_rate,
80 best_parent_rate,
81 best_parent_p);
82 } else if (rate_hw && rate_ops && rate_ops->round_rate &&
83 mux_hw && mux_ops && mux_ops->set_parent) {
84 *best_parent_p = NULL;
86 if (__clk_get_flags(hw->clk) & CLK_SET_RATE_NO_REPARENT) {
87 parent = clk_get_parent(mux_hw->clk);
88 *best_parent_p = __clk_get_hw(parent);
89 *best_parent_rate = __clk_get_rate(parent);
91 return rate_ops->round_rate(rate_hw, rate,
92 best_parent_rate);
95 for (i = 0; i < __clk_get_num_parents(mux_hw->clk); i++) {
96 parent = clk_get_parent_by_index(mux_hw->clk, i);
97 if (!parent)
98 continue;
100 parent_rate = __clk_get_rate(parent);
102 tmp_rate = rate_ops->round_rate(rate_hw, rate,
103 &parent_rate);
104 if (tmp_rate < 0)
105 continue;
107 rate_diff = abs(rate - tmp_rate);
109 if (!rate_diff || !*best_parent_p
110 || best_rate_diff > rate_diff) {
111 *best_parent_p = __clk_get_hw(parent);
112 *best_parent_rate = parent_rate;
113 best_rate_diff = rate_diff;
114 best_rate = tmp_rate;
117 if (!rate_diff)
118 return rate;
121 return best_rate;
122 } else if (mux_hw && mux_ops && mux_ops->determine_rate) {
123 __clk_hw_set_clk(mux_hw, hw);
124 return mux_ops->determine_rate(mux_hw, rate, min_rate,
125 max_rate, best_parent_rate,
126 best_parent_p);
127 } else {
128 pr_err("clk: clk_composite_determine_rate function called, but no mux or rate callback set!\n");
129 return 0;
133 static long clk_composite_round_rate(struct clk_hw *hw, unsigned long rate,
134 unsigned long *prate)
136 struct clk_composite *composite = to_clk_composite(hw);
137 const struct clk_ops *rate_ops = composite->rate_ops;
138 struct clk_hw *rate_hw = composite->rate_hw;
140 __clk_hw_set_clk(rate_hw, hw);
142 return rate_ops->round_rate(rate_hw, rate, prate);
145 static int clk_composite_set_rate(struct clk_hw *hw, unsigned long rate,
146 unsigned long parent_rate)
148 struct clk_composite *composite = to_clk_composite(hw);
149 const struct clk_ops *rate_ops = composite->rate_ops;
150 struct clk_hw *rate_hw = composite->rate_hw;
152 __clk_hw_set_clk(rate_hw, hw);
154 return rate_ops->set_rate(rate_hw, rate, parent_rate);
157 static int clk_composite_is_enabled(struct clk_hw *hw)
159 struct clk_composite *composite = to_clk_composite(hw);
160 const struct clk_ops *gate_ops = composite->gate_ops;
161 struct clk_hw *gate_hw = composite->gate_hw;
163 __clk_hw_set_clk(gate_hw, hw);
165 return gate_ops->is_enabled(gate_hw);
168 static int clk_composite_enable(struct clk_hw *hw)
170 struct clk_composite *composite = to_clk_composite(hw);
171 const struct clk_ops *gate_ops = composite->gate_ops;
172 struct clk_hw *gate_hw = composite->gate_hw;
174 __clk_hw_set_clk(gate_hw, hw);
176 return gate_ops->enable(gate_hw);
179 static void clk_composite_disable(struct clk_hw *hw)
181 struct clk_composite *composite = to_clk_composite(hw);
182 const struct clk_ops *gate_ops = composite->gate_ops;
183 struct clk_hw *gate_hw = composite->gate_hw;
185 __clk_hw_set_clk(gate_hw, hw);
187 gate_ops->disable(gate_hw);
190 struct clk *clk_register_composite(struct device *dev, const char *name,
191 const char **parent_names, int num_parents,
192 struct clk_hw *mux_hw, const struct clk_ops *mux_ops,
193 struct clk_hw *rate_hw, const struct clk_ops *rate_ops,
194 struct clk_hw *gate_hw, const struct clk_ops *gate_ops,
195 unsigned long flags)
197 struct clk *clk;
198 struct clk_init_data init;
199 struct clk_composite *composite;
200 struct clk_ops *clk_composite_ops;
202 composite = kzalloc(sizeof(*composite), GFP_KERNEL);
203 if (!composite) {
204 pr_err("%s: could not allocate composite clk\n", __func__);
205 return ERR_PTR(-ENOMEM);
208 init.name = name;
209 init.flags = flags | CLK_IS_BASIC;
210 init.parent_names = parent_names;
211 init.num_parents = num_parents;
213 clk_composite_ops = &composite->ops;
215 if (mux_hw && mux_ops) {
216 if (!mux_ops->get_parent) {
217 clk = ERR_PTR(-EINVAL);
218 goto err;
221 composite->mux_hw = mux_hw;
222 composite->mux_ops = mux_ops;
223 clk_composite_ops->get_parent = clk_composite_get_parent;
224 if (mux_ops->set_parent)
225 clk_composite_ops->set_parent = clk_composite_set_parent;
226 if (mux_ops->determine_rate)
227 clk_composite_ops->determine_rate = clk_composite_determine_rate;
230 if (rate_hw && rate_ops) {
231 if (!rate_ops->recalc_rate) {
232 clk = ERR_PTR(-EINVAL);
233 goto err;
235 clk_composite_ops->recalc_rate = clk_composite_recalc_rate;
237 if (rate_ops->determine_rate)
238 clk_composite_ops->determine_rate =
239 clk_composite_determine_rate;
240 else if (rate_ops->round_rate)
241 clk_composite_ops->round_rate =
242 clk_composite_round_rate;
244 /* .set_rate requires either .round_rate or .determine_rate */
245 if (rate_ops->set_rate) {
246 if (rate_ops->determine_rate || rate_ops->round_rate)
247 clk_composite_ops->set_rate =
248 clk_composite_set_rate;
249 else
250 WARN(1, "%s: missing round_rate op is required\n",
251 __func__);
254 composite->rate_hw = rate_hw;
255 composite->rate_ops = rate_ops;
258 if (gate_hw && gate_ops) {
259 if (!gate_ops->is_enabled || !gate_ops->enable ||
260 !gate_ops->disable) {
261 clk = ERR_PTR(-EINVAL);
262 goto err;
265 composite->gate_hw = gate_hw;
266 composite->gate_ops = gate_ops;
267 clk_composite_ops->is_enabled = clk_composite_is_enabled;
268 clk_composite_ops->enable = clk_composite_enable;
269 clk_composite_ops->disable = clk_composite_disable;
272 init.ops = clk_composite_ops;
273 composite->hw.init = &init;
275 clk = clk_register(dev, &composite->hw);
276 if (IS_ERR(clk))
277 goto err;
279 if (composite->mux_hw)
280 composite->mux_hw->clk = clk;
282 if (composite->rate_hw)
283 composite->rate_hw->clk = clk;
285 if (composite->gate_hw)
286 composite->gate_hw->clk = clk;
288 return clk;
290 err:
291 kfree(composite);
292 return clk;