1 /*
2 * Generic OPP helper interface for CPU device
3 *
4 * Copyright (C) 2009-2014 Texas Instruments Incorporated.
5 * Nishanth Menon
6 * Romit Dasgupta
7 * Kevin Hilman
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 */
13
14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15
16 #include <linux/cpu.h>
17 #include <linux/cpufreq.h>
18 #include <linux/err.h>
19 #include <linux/errno.h>
20 #include <linux/export.h>
21 #include <linux/of.h>
22 #include <linux/slab.h>
23
24 #include "opp.h"
25
26 #ifdef CONFIG_CPU_FREQ
27
28 /**
29 * dev_pm_opp_init_cpufreq_table() - create a cpufreq table for a device
30 * @dev: device for which we do this operation
31 * @table: Cpufreq table returned back to caller
32 *
33 * Generate a cpufreq table for a provided device- this assumes that the
34 * opp list is already initialized and ready for usage.
35 *
36 * This function allocates required memory for the cpufreq table. It is
37 * expected that the caller does the required maintenance such as freeing
38 * the table as required.
39 *
40 * Returns -EINVAL for bad pointers, -ENODEV if the device is not found, -ENOMEM
41 * if no memory available for the operation (table is not populated), returns 0
42 * if successful and table is populated.
43 *
44 * WARNING: It is important for the callers to ensure refreshing their copy of
45 * the table if any of the mentioned functions have been invoked in the interim.
46 *
47 * Locking: The internal device_opp and opp structures are RCU protected.
48 * Since we just use the regular accessor functions to access the internal data
49 * structures, we use RCU read lock inside this function. As a result, users of
50 * this function DONOT need to use explicit locks for invoking.
51 */
dev_pm_opp_init_cpufreq_table(struct device * dev,struct cpufreq_frequency_table ** table)52 int dev_pm_opp_init_cpufreq_table(struct device *dev,
53 struct cpufreq_frequency_table **table)
54 {
55 struct dev_pm_opp *opp;
56 struct cpufreq_frequency_table *freq_table = NULL;
57 int i, max_opps, ret = 0;
58 unsigned long rate;
59
60 rcu_read_lock();
61
62 max_opps = dev_pm_opp_get_opp_count(dev);
63 if (max_opps <= 0) {
64 ret = max_opps ? max_opps : -ENODATA;
65 goto out;
66 }
67
68 freq_table = kcalloc((max_opps + 1), sizeof(*freq_table), GFP_ATOMIC);
69 if (!freq_table) {
70 ret = -ENOMEM;
71 goto out;
72 }
73
74 for (i = 0, rate = 0; i < max_opps; i++, rate++) {
75 /* find next rate */
76 opp = dev_pm_opp_find_freq_ceil(dev, &rate);
77 if (IS_ERR(opp)) {
78 ret = PTR_ERR(opp);
79 goto out;
80 }
81 freq_table[i].driver_data = i;
82 freq_table[i].frequency = rate / 1000;
83
84 /* Is Boost/turbo opp ? */
85 if (dev_pm_opp_is_turbo(opp))
86 freq_table[i].flags = CPUFREQ_BOOST_FREQ;
87 }
88
89 freq_table[i].driver_data = i;
90 freq_table[i].frequency = CPUFREQ_TABLE_END;
91
92 *table = &freq_table[0];
93
94 out:
95 rcu_read_unlock();
96 if (ret)
97 kfree(freq_table);
98
99 return ret;
100 }
101 EXPORT_SYMBOL_GPL(dev_pm_opp_init_cpufreq_table);
102
103 /**
104 * dev_pm_opp_free_cpufreq_table() - free the cpufreq table
105 * @dev: device for which we do this operation
106 * @table: table to free
107 *
108 * Free up the table allocated by dev_pm_opp_init_cpufreq_table
109 */
dev_pm_opp_free_cpufreq_table(struct device * dev,struct cpufreq_frequency_table ** table)110 void dev_pm_opp_free_cpufreq_table(struct device *dev,
111 struct cpufreq_frequency_table **table)
112 {
113 if (!table)
114 return;
115
116 kfree(*table);
117 *table = NULL;
118 }
119 EXPORT_SYMBOL_GPL(dev_pm_opp_free_cpufreq_table);
120 #endif /* CONFIG_CPU_FREQ */
121
122 /* Required only for V1 bindings, as v2 can manage it from DT itself */
dev_pm_opp_set_sharing_cpus(struct device * cpu_dev,cpumask_var_t cpumask)123 int dev_pm_opp_set_sharing_cpus(struct device *cpu_dev, cpumask_var_t cpumask)
124 {
125 struct device_list_opp *list_dev;
126 struct device_opp *dev_opp;
127 struct device *dev;
128 int cpu, ret = 0;
129
130 mutex_lock(&dev_opp_list_lock);
131
132 dev_opp = _find_device_opp(cpu_dev);
133 if (IS_ERR(dev_opp)) {
134 ret = -EINVAL;
135 goto unlock;
136 }
137
138 for_each_cpu(cpu, cpumask) {
139 if (cpu == cpu_dev->id)
140 continue;
141
142 dev = get_cpu_device(cpu);
143 if (!dev) {
144 dev_err(cpu_dev, "%s: failed to get cpu%d device\n",
145 __func__, cpu);
146 continue;
147 }
148
149 list_dev = _add_list_dev(dev, dev_opp);
150 if (!list_dev) {
151 dev_err(dev, "%s: failed to add list-dev for cpu%d device\n",
152 __func__, cpu);
153 continue;
154 }
155 }
156 unlock:
157 mutex_unlock(&dev_opp_list_lock);
158
159 return ret;
160 }
161 EXPORT_SYMBOL_GPL(dev_pm_opp_set_sharing_cpus);
162
163 #ifdef CONFIG_OF
dev_pm_opp_of_cpumask_remove_table(cpumask_var_t cpumask)164 void dev_pm_opp_of_cpumask_remove_table(cpumask_var_t cpumask)
165 {
166 struct device *cpu_dev;
167 int cpu;
168
169 WARN_ON(cpumask_empty(cpumask));
170
171 for_each_cpu(cpu, cpumask) {
172 cpu_dev = get_cpu_device(cpu);
173 if (!cpu_dev) {
174 pr_err("%s: failed to get cpu%d device\n", __func__,
175 cpu);
176 continue;
177 }
178
179 dev_pm_opp_of_remove_table(cpu_dev);
180 }
181 }
182 EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_remove_table);
183
dev_pm_opp_of_cpumask_add_table(cpumask_var_t cpumask)184 int dev_pm_opp_of_cpumask_add_table(cpumask_var_t cpumask)
185 {
186 struct device *cpu_dev;
187 int cpu, ret = 0;
188
189 WARN_ON(cpumask_empty(cpumask));
190
191 for_each_cpu(cpu, cpumask) {
192 cpu_dev = get_cpu_device(cpu);
193 if (!cpu_dev) {
194 pr_err("%s: failed to get cpu%d device\n", __func__,
195 cpu);
196 continue;
197 }
198
199 ret = dev_pm_opp_of_add_table(cpu_dev);
200 if (ret) {
201 pr_err("%s: couldn't find opp table for cpu:%d, %d\n",
202 __func__, cpu, ret);
203
204 /* Free all other OPPs */
205 dev_pm_opp_of_cpumask_remove_table(cpumask);
206 break;
207 }
208 }
209
210 return ret;
211 }
212 EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_add_table);
213
214 /*
215 * Works only for OPP v2 bindings.
216 *
217 * cpumask should be already set to mask of cpu_dev->id.
218 * Returns -ENOENT if operating-points-v2 bindings aren't supported.
219 */
dev_pm_opp_of_get_sharing_cpus(struct device * cpu_dev,cpumask_var_t cpumask)220 int dev_pm_opp_of_get_sharing_cpus(struct device *cpu_dev, cpumask_var_t cpumask)
221 {
222 struct device_node *np, *tmp_np;
223 struct device *tcpu_dev;
224 int cpu, ret = 0;
225
226 /* Get OPP descriptor node */
227 np = _of_get_opp_desc_node(cpu_dev);
228 if (!np) {
229 dev_dbg(cpu_dev, "%s: Couldn't find cpu_dev node.\n", __func__);
230 return -ENOENT;
231 }
232
233 /* OPPs are shared ? */
234 if (!of_property_read_bool(np, "opp-shared"))
235 goto put_cpu_node;
236
237 for_each_possible_cpu(cpu) {
238 if (cpu == cpu_dev->id)
239 continue;
240
241 tcpu_dev = get_cpu_device(cpu);
242 if (!tcpu_dev) {
243 dev_err(cpu_dev, "%s: failed to get cpu%d device\n",
244 __func__, cpu);
245 ret = -ENODEV;
246 goto put_cpu_node;
247 }
248
249 /* Get OPP descriptor node */
250 tmp_np = _of_get_opp_desc_node(tcpu_dev);
251 if (!tmp_np) {
252 dev_err(tcpu_dev, "%s: Couldn't find tcpu_dev node.\n",
253 __func__);
254 ret = -ENOENT;
255 goto put_cpu_node;
256 }
257
258 /* CPUs are sharing opp node */
259 if (np == tmp_np)
260 cpumask_set_cpu(cpu, cpumask);
261
262 of_node_put(tmp_np);
263 }
264
265 put_cpu_node:
266 of_node_put(np);
267 return ret;
268 }
269 EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_sharing_cpus);
270 #endif
271