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8a67f0ef VK |
1 | /* |
2 | * ARM big.LITTLE Platforms CPUFreq support | |
3 | * | |
4 | * Copyright (C) 2013 ARM Ltd. | |
5 | * Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com> | |
6 | * | |
7 | * Copyright (C) 2013 Linaro. | |
8 | * Viresh Kumar <viresh.kumar@linaro.org> | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or modify | |
11 | * it under the terms of the GNU General Public License version 2 as | |
12 | * published by the Free Software Foundation. | |
13 | * | |
14 | * This program is distributed "as is" WITHOUT ANY WARRANTY of any | |
15 | * kind, whether express or implied; without even the implied warranty | |
16 | * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | * GNU General Public License for more details. | |
18 | */ | |
19 | ||
20 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
21 | ||
22 | #include <linux/clk.h> | |
23 | #include <linux/cpu.h> | |
24 | #include <linux/cpufreq.h> | |
25 | #include <linux/cpumask.h> | |
26 | #include <linux/export.h> | |
27 | #include <linux/of_platform.h> | |
28 | #include <linux/opp.h> | |
29 | #include <linux/slab.h> | |
30 | #include <linux/topology.h> | |
31 | #include <linux/types.h> | |
32 | ||
33 | #include "arm_big_little.h" | |
34 | ||
35 | /* Currently we support only two clusters */ | |
36 | #define MAX_CLUSTERS 2 | |
37 | ||
38 | static struct cpufreq_arm_bL_ops *arm_bL_ops; | |
39 | static struct clk *clk[MAX_CLUSTERS]; | |
40 | static struct cpufreq_frequency_table *freq_table[MAX_CLUSTERS]; | |
41 | static atomic_t cluster_usage[MAX_CLUSTERS] = {ATOMIC_INIT(0), ATOMIC_INIT(0)}; | |
42 | ||
8a67f0ef VK |
43 | static unsigned int bL_cpufreq_get(unsigned int cpu) |
44 | { | |
45 | u32 cur_cluster = cpu_to_cluster(cpu); | |
46 | ||
47 | return clk_get_rate(clk[cur_cluster]) / 1000; | |
48 | } | |
49 | ||
50 | /* Validate policy frequency range */ | |
51 | static int bL_cpufreq_verify_policy(struct cpufreq_policy *policy) | |
52 | { | |
53 | u32 cur_cluster = cpu_to_cluster(policy->cpu); | |
54 | ||
55 | return cpufreq_frequency_table_verify(policy, freq_table[cur_cluster]); | |
56 | } | |
57 | ||
58 | /* Set clock frequency */ | |
59 | static int bL_cpufreq_set_target(struct cpufreq_policy *policy, | |
60 | unsigned int target_freq, unsigned int relation) | |
61 | { | |
62 | struct cpufreq_freqs freqs; | |
63 | u32 cpu = policy->cpu, freq_tab_idx, cur_cluster; | |
64 | int ret = 0; | |
65 | ||
66 | cur_cluster = cpu_to_cluster(policy->cpu); | |
67 | ||
68 | freqs.old = bL_cpufreq_get(policy->cpu); | |
69 | ||
70 | /* Determine valid target frequency using freq_table */ | |
71 | cpufreq_frequency_table_target(policy, freq_table[cur_cluster], | |
72 | target_freq, relation, &freq_tab_idx); | |
73 | freqs.new = freq_table[cur_cluster][freq_tab_idx].frequency; | |
74 | ||
8a67f0ef VK |
75 | pr_debug("%s: cpu: %d, cluster: %d, oldfreq: %d, target freq: %d, new freq: %d\n", |
76 | __func__, cpu, cur_cluster, freqs.old, target_freq, | |
77 | freqs.new); | |
78 | ||
79 | if (freqs.old == freqs.new) | |
80 | return 0; | |
81 | ||
ad61f442 | 82 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); |
8a67f0ef VK |
83 | |
84 | ret = clk_set_rate(clk[cur_cluster], freqs.new * 1000); | |
85 | if (ret) { | |
86 | pr_err("clk_set_rate failed: %d\n", ret); | |
87 | return ret; | |
88 | } | |
89 | ||
90 | policy->cur = freqs.new; | |
91 | ||
ad61f442 | 92 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); |
8a67f0ef VK |
93 | |
94 | return ret; | |
95 | } | |
96 | ||
97 | static void put_cluster_clk_and_freq_table(struct device *cpu_dev) | |
98 | { | |
99 | u32 cluster = cpu_to_cluster(cpu_dev->id); | |
100 | ||
101 | if (!atomic_dec_return(&cluster_usage[cluster])) { | |
102 | clk_put(clk[cluster]); | |
103 | opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]); | |
104 | dev_dbg(cpu_dev, "%s: cluster: %d\n", __func__, cluster); | |
105 | } | |
106 | } | |
107 | ||
108 | static int get_cluster_clk_and_freq_table(struct device *cpu_dev) | |
109 | { | |
110 | u32 cluster = cpu_to_cluster(cpu_dev->id); | |
111 | char name[14] = "cpu-cluster."; | |
112 | int ret; | |
113 | ||
114 | if (atomic_inc_return(&cluster_usage[cluster]) != 1) | |
115 | return 0; | |
116 | ||
117 | ret = arm_bL_ops->init_opp_table(cpu_dev); | |
118 | if (ret) { | |
119 | dev_err(cpu_dev, "%s: init_opp_table failed, cpu: %d, err: %d\n", | |
120 | __func__, cpu_dev->id, ret); | |
121 | goto atomic_dec; | |
122 | } | |
123 | ||
124 | ret = opp_init_cpufreq_table(cpu_dev, &freq_table[cluster]); | |
125 | if (ret) { | |
126 | dev_err(cpu_dev, "%s: failed to init cpufreq table, cpu: %d, err: %d\n", | |
127 | __func__, cpu_dev->id, ret); | |
128 | goto atomic_dec; | |
129 | } | |
130 | ||
131 | name[12] = cluster + '0'; | |
132 | clk[cluster] = clk_get_sys(name, NULL); | |
133 | if (!IS_ERR(clk[cluster])) { | |
134 | dev_dbg(cpu_dev, "%s: clk: %p & freq table: %p, cluster: %d\n", | |
135 | __func__, clk[cluster], freq_table[cluster], | |
136 | cluster); | |
137 | return 0; | |
138 | } | |
139 | ||
140 | dev_err(cpu_dev, "%s: Failed to get clk for cpu: %d, cluster: %d\n", | |
141 | __func__, cpu_dev->id, cluster); | |
142 | ret = PTR_ERR(clk[cluster]); | |
143 | opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]); | |
144 | ||
145 | atomic_dec: | |
146 | atomic_dec(&cluster_usage[cluster]); | |
147 | dev_err(cpu_dev, "%s: Failed to get data for cluster: %d\n", __func__, | |
148 | cluster); | |
149 | return ret; | |
150 | } | |
151 | ||
152 | /* Per-CPU initialization */ | |
153 | static int bL_cpufreq_init(struct cpufreq_policy *policy) | |
154 | { | |
155 | u32 cur_cluster = cpu_to_cluster(policy->cpu); | |
156 | struct device *cpu_dev; | |
157 | int ret; | |
158 | ||
159 | cpu_dev = get_cpu_device(policy->cpu); | |
160 | if (!cpu_dev) { | |
161 | pr_err("%s: failed to get cpu%d device\n", __func__, | |
162 | policy->cpu); | |
163 | return -ENODEV; | |
164 | } | |
165 | ||
166 | ret = get_cluster_clk_and_freq_table(cpu_dev); | |
167 | if (ret) | |
168 | return ret; | |
169 | ||
170 | ret = cpufreq_frequency_table_cpuinfo(policy, freq_table[cur_cluster]); | |
171 | if (ret) { | |
172 | dev_err(cpu_dev, "CPU %d, cluster: %d invalid freq table\n", | |
173 | policy->cpu, cur_cluster); | |
174 | put_cluster_clk_and_freq_table(cpu_dev); | |
175 | return ret; | |
176 | } | |
177 | ||
178 | cpufreq_frequency_table_get_attr(freq_table[cur_cluster], policy->cpu); | |
179 | ||
180 | if (arm_bL_ops->get_transition_latency) | |
181 | policy->cpuinfo.transition_latency = | |
182 | arm_bL_ops->get_transition_latency(cpu_dev); | |
183 | else | |
184 | policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; | |
185 | ||
186 | policy->cur = bL_cpufreq_get(policy->cpu); | |
187 | ||
188 | cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu)); | |
189 | ||
190 | dev_info(cpu_dev, "CPU %d initialized\n", policy->cpu); | |
191 | return 0; | |
192 | } | |
193 | ||
194 | static int bL_cpufreq_exit(struct cpufreq_policy *policy) | |
195 | { | |
196 | struct device *cpu_dev; | |
197 | ||
198 | cpu_dev = get_cpu_device(policy->cpu); | |
199 | if (!cpu_dev) { | |
200 | pr_err("%s: failed to get cpu%d device\n", __func__, | |
201 | policy->cpu); | |
202 | return -ENODEV; | |
203 | } | |
204 | ||
205 | put_cluster_clk_and_freq_table(cpu_dev); | |
206 | dev_dbg(cpu_dev, "%s: Exited, cpu: %d\n", __func__, policy->cpu); | |
207 | ||
208 | return 0; | |
209 | } | |
210 | ||
211 | /* Export freq_table to sysfs */ | |
212 | static struct freq_attr *bL_cpufreq_attr[] = { | |
213 | &cpufreq_freq_attr_scaling_available_freqs, | |
214 | NULL, | |
215 | }; | |
216 | ||
217 | static struct cpufreq_driver bL_cpufreq_driver = { | |
218 | .name = "arm-big-little", | |
219 | .flags = CPUFREQ_STICKY, | |
220 | .verify = bL_cpufreq_verify_policy, | |
221 | .target = bL_cpufreq_set_target, | |
222 | .get = bL_cpufreq_get, | |
223 | .init = bL_cpufreq_init, | |
224 | .exit = bL_cpufreq_exit, | |
ad61f442 | 225 | .have_governor_per_policy = true, |
8a67f0ef VK |
226 | .attr = bL_cpufreq_attr, |
227 | }; | |
228 | ||
229 | int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops) | |
230 | { | |
231 | int ret; | |
232 | ||
233 | if (arm_bL_ops) { | |
234 | pr_debug("%s: Already registered: %s, exiting\n", __func__, | |
235 | arm_bL_ops->name); | |
236 | return -EBUSY; | |
237 | } | |
238 | ||
239 | if (!ops || !strlen(ops->name) || !ops->init_opp_table) { | |
240 | pr_err("%s: Invalid arm_bL_ops, exiting\n", __func__); | |
241 | return -ENODEV; | |
242 | } | |
243 | ||
244 | arm_bL_ops = ops; | |
245 | ||
246 | ret = cpufreq_register_driver(&bL_cpufreq_driver); | |
247 | if (ret) { | |
248 | pr_info("%s: Failed registering platform driver: %s, err: %d\n", | |
249 | __func__, ops->name, ret); | |
250 | arm_bL_ops = NULL; | |
251 | } else { | |
252 | pr_info("%s: Registered platform driver: %s\n", __func__, | |
253 | ops->name); | |
254 | } | |
255 | ||
256 | return ret; | |
257 | } | |
258 | EXPORT_SYMBOL_GPL(bL_cpufreq_register); | |
259 | ||
260 | void bL_cpufreq_unregister(struct cpufreq_arm_bL_ops *ops) | |
261 | { | |
262 | if (arm_bL_ops != ops) { | |
263 | pr_err("%s: Registered with: %s, can't unregister, exiting\n", | |
264 | __func__, arm_bL_ops->name); | |
265 | return; | |
266 | } | |
267 | ||
268 | cpufreq_unregister_driver(&bL_cpufreq_driver); | |
269 | pr_info("%s: Un-registered platform driver: %s\n", __func__, | |
270 | arm_bL_ops->name); | |
271 | arm_bL_ops = NULL; | |
272 | } | |
273 | EXPORT_SYMBOL_GPL(bL_cpufreq_unregister); |