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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); | |
3d69dd50 | 87 | freqs.new = freqs.old; |
8a67f0ef VK |
88 | } |
89 | ||
ad61f442 | 90 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); |
8a67f0ef VK |
91 | |
92 | return ret; | |
93 | } | |
94 | ||
95 | static void put_cluster_clk_and_freq_table(struct device *cpu_dev) | |
96 | { | |
97 | u32 cluster = cpu_to_cluster(cpu_dev->id); | |
98 | ||
99 | if (!atomic_dec_return(&cluster_usage[cluster])) { | |
100 | clk_put(clk[cluster]); | |
101 | opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]); | |
102 | dev_dbg(cpu_dev, "%s: cluster: %d\n", __func__, cluster); | |
103 | } | |
104 | } | |
105 | ||
106 | static int get_cluster_clk_and_freq_table(struct device *cpu_dev) | |
107 | { | |
108 | u32 cluster = cpu_to_cluster(cpu_dev->id); | |
109 | char name[14] = "cpu-cluster."; | |
110 | int ret; | |
111 | ||
112 | if (atomic_inc_return(&cluster_usage[cluster]) != 1) | |
113 | return 0; | |
114 | ||
115 | ret = arm_bL_ops->init_opp_table(cpu_dev); | |
116 | if (ret) { | |
117 | dev_err(cpu_dev, "%s: init_opp_table failed, cpu: %d, err: %d\n", | |
118 | __func__, cpu_dev->id, ret); | |
119 | goto atomic_dec; | |
120 | } | |
121 | ||
122 | ret = opp_init_cpufreq_table(cpu_dev, &freq_table[cluster]); | |
123 | if (ret) { | |
124 | dev_err(cpu_dev, "%s: failed to init cpufreq table, cpu: %d, err: %d\n", | |
125 | __func__, cpu_dev->id, ret); | |
126 | goto atomic_dec; | |
127 | } | |
128 | ||
129 | name[12] = cluster + '0'; | |
130 | clk[cluster] = clk_get_sys(name, NULL); | |
131 | if (!IS_ERR(clk[cluster])) { | |
132 | dev_dbg(cpu_dev, "%s: clk: %p & freq table: %p, cluster: %d\n", | |
133 | __func__, clk[cluster], freq_table[cluster], | |
134 | cluster); | |
135 | return 0; | |
136 | } | |
137 | ||
138 | dev_err(cpu_dev, "%s: Failed to get clk for cpu: %d, cluster: %d\n", | |
139 | __func__, cpu_dev->id, cluster); | |
140 | ret = PTR_ERR(clk[cluster]); | |
141 | opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]); | |
142 | ||
143 | atomic_dec: | |
144 | atomic_dec(&cluster_usage[cluster]); | |
145 | dev_err(cpu_dev, "%s: Failed to get data for cluster: %d\n", __func__, | |
146 | cluster); | |
147 | return ret; | |
148 | } | |
149 | ||
150 | /* Per-CPU initialization */ | |
151 | static int bL_cpufreq_init(struct cpufreq_policy *policy) | |
152 | { | |
153 | u32 cur_cluster = cpu_to_cluster(policy->cpu); | |
154 | struct device *cpu_dev; | |
155 | int ret; | |
156 | ||
157 | cpu_dev = get_cpu_device(policy->cpu); | |
158 | if (!cpu_dev) { | |
159 | pr_err("%s: failed to get cpu%d device\n", __func__, | |
160 | policy->cpu); | |
161 | return -ENODEV; | |
162 | } | |
163 | ||
164 | ret = get_cluster_clk_and_freq_table(cpu_dev); | |
165 | if (ret) | |
166 | return ret; | |
167 | ||
168 | ret = cpufreq_frequency_table_cpuinfo(policy, freq_table[cur_cluster]); | |
169 | if (ret) { | |
170 | dev_err(cpu_dev, "CPU %d, cluster: %d invalid freq table\n", | |
171 | policy->cpu, cur_cluster); | |
172 | put_cluster_clk_and_freq_table(cpu_dev); | |
173 | return ret; | |
174 | } | |
175 | ||
176 | cpufreq_frequency_table_get_attr(freq_table[cur_cluster], policy->cpu); | |
177 | ||
178 | if (arm_bL_ops->get_transition_latency) | |
179 | policy->cpuinfo.transition_latency = | |
180 | arm_bL_ops->get_transition_latency(cpu_dev); | |
181 | else | |
182 | policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; | |
183 | ||
184 | policy->cur = bL_cpufreq_get(policy->cpu); | |
185 | ||
186 | cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu)); | |
187 | ||
2b80f313 | 188 | dev_info(cpu_dev, "%s: CPU %d initialized\n", __func__, policy->cpu); |
8a67f0ef VK |
189 | return 0; |
190 | } | |
191 | ||
192 | static int bL_cpufreq_exit(struct cpufreq_policy *policy) | |
193 | { | |
194 | struct device *cpu_dev; | |
195 | ||
196 | cpu_dev = get_cpu_device(policy->cpu); | |
197 | if (!cpu_dev) { | |
198 | pr_err("%s: failed to get cpu%d device\n", __func__, | |
199 | policy->cpu); | |
200 | return -ENODEV; | |
201 | } | |
202 | ||
203 | put_cluster_clk_and_freq_table(cpu_dev); | |
204 | dev_dbg(cpu_dev, "%s: Exited, cpu: %d\n", __func__, policy->cpu); | |
205 | ||
206 | return 0; | |
207 | } | |
208 | ||
209 | /* Export freq_table to sysfs */ | |
210 | static struct freq_attr *bL_cpufreq_attr[] = { | |
211 | &cpufreq_freq_attr_scaling_available_freqs, | |
212 | NULL, | |
213 | }; | |
214 | ||
215 | static struct cpufreq_driver bL_cpufreq_driver = { | |
216 | .name = "arm-big-little", | |
217 | .flags = CPUFREQ_STICKY, | |
218 | .verify = bL_cpufreq_verify_policy, | |
219 | .target = bL_cpufreq_set_target, | |
220 | .get = bL_cpufreq_get, | |
221 | .init = bL_cpufreq_init, | |
222 | .exit = bL_cpufreq_exit, | |
ad61f442 | 223 | .have_governor_per_policy = true, |
8a67f0ef VK |
224 | .attr = bL_cpufreq_attr, |
225 | }; | |
226 | ||
227 | int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops) | |
228 | { | |
229 | int ret; | |
230 | ||
231 | if (arm_bL_ops) { | |
232 | pr_debug("%s: Already registered: %s, exiting\n", __func__, | |
233 | arm_bL_ops->name); | |
234 | return -EBUSY; | |
235 | } | |
236 | ||
237 | if (!ops || !strlen(ops->name) || !ops->init_opp_table) { | |
238 | pr_err("%s: Invalid arm_bL_ops, exiting\n", __func__); | |
239 | return -ENODEV; | |
240 | } | |
241 | ||
242 | arm_bL_ops = ops; | |
243 | ||
244 | ret = cpufreq_register_driver(&bL_cpufreq_driver); | |
245 | if (ret) { | |
246 | pr_info("%s: Failed registering platform driver: %s, err: %d\n", | |
247 | __func__, ops->name, ret); | |
248 | arm_bL_ops = NULL; | |
249 | } else { | |
250 | pr_info("%s: Registered platform driver: %s\n", __func__, | |
251 | ops->name); | |
252 | } | |
253 | ||
254 | return ret; | |
255 | } | |
256 | EXPORT_SYMBOL_GPL(bL_cpufreq_register); | |
257 | ||
258 | void bL_cpufreq_unregister(struct cpufreq_arm_bL_ops *ops) | |
259 | { | |
260 | if (arm_bL_ops != ops) { | |
261 | pr_err("%s: Registered with: %s, can't unregister, exiting\n", | |
262 | __func__, arm_bL_ops->name); | |
263 | return; | |
264 | } | |
265 | ||
266 | cpufreq_unregister_driver(&bL_cpufreq_driver); | |
267 | pr_info("%s: Un-registered platform driver: %s\n", __func__, | |
268 | arm_bL_ops->name); | |
269 | arm_bL_ops = NULL; | |
270 | } | |
271 | EXPORT_SYMBOL_GPL(bL_cpufreq_unregister); |