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defa4c73 TY |
1 | /* |
2 | * Copyright 2013 Freescale Semiconductor, Inc. | |
3 | * | |
4 | * CPU Frequency Scaling driver for Freescale PowerPC corenet SoCs. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | */ | |
10 | ||
11 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
12 | ||
13 | #include <linux/clk.h> | |
14 | #include <linux/cpufreq.h> | |
15 | #include <linux/errno.h> | |
16 | #include <sysdev/fsl_soc.h> | |
17 | #include <linux/init.h> | |
18 | #include <linux/kernel.h> | |
19 | #include <linux/module.h> | |
20 | #include <linux/mutex.h> | |
21 | #include <linux/of.h> | |
22 | #include <linux/slab.h> | |
23 | #include <linux/smp.h> | |
24 | ||
25 | /** | |
26 | * struct cpu_data - per CPU data struct | |
27 | * @clk: the clk of CPU | |
28 | * @parent: the parent node of cpu clock | |
29 | * @table: frequency table | |
30 | */ | |
31 | struct cpu_data { | |
32 | struct clk *clk; | |
33 | struct device_node *parent; | |
34 | struct cpufreq_frequency_table *table; | |
35 | }; | |
36 | ||
37 | /** | |
38 | * struct soc_data - SoC specific data | |
39 | * @freq_mask: mask the disallowed frequencies | |
40 | * @flag: unique flags | |
41 | */ | |
42 | struct soc_data { | |
43 | u32 freq_mask[4]; | |
44 | u32 flag; | |
45 | }; | |
46 | ||
47 | #define FREQ_MASK 1 | |
48 | /* see hardware specification for the allowed frqeuencies */ | |
49 | static const struct soc_data sdata[] = { | |
50 | { /* used by p2041 and p3041 */ | |
51 | .freq_mask = {0x8, 0x8, 0x2, 0x2}, | |
52 | .flag = FREQ_MASK, | |
53 | }, | |
54 | { /* used by p5020 */ | |
55 | .freq_mask = {0x8, 0x2}, | |
56 | .flag = FREQ_MASK, | |
57 | }, | |
58 | { /* used by p4080, p5040 */ | |
59 | .freq_mask = {0}, | |
60 | .flag = 0, | |
61 | }, | |
62 | }; | |
63 | ||
64 | /* | |
65 | * the minimum allowed core frequency, in Hz | |
66 | * for chassis v1.0, >= platform frequency | |
67 | * for chassis v2.0, >= platform frequency / 2 | |
68 | */ | |
69 | static u32 min_cpufreq; | |
70 | static const u32 *fmask; | |
71 | ||
72 | /* serialize frequency changes */ | |
73 | static DEFINE_MUTEX(cpufreq_lock); | |
74 | static DEFINE_PER_CPU(struct cpu_data *, cpu_data); | |
75 | ||
76 | /* cpumask in a cluster */ | |
77 | static DEFINE_PER_CPU(cpumask_var_t, cpu_mask); | |
78 | ||
79 | #ifndef CONFIG_SMP | |
80 | static inline const struct cpumask *cpu_core_mask(int cpu) | |
81 | { | |
82 | return cpumask_of(0); | |
83 | } | |
84 | #endif | |
85 | ||
86 | static unsigned int corenet_cpufreq_get_speed(unsigned int cpu) | |
87 | { | |
88 | struct cpu_data *data = per_cpu(cpu_data, cpu); | |
89 | ||
90 | return clk_get_rate(data->clk) / 1000; | |
91 | } | |
92 | ||
93 | /* reduce the duplicated frequencies in frequency table */ | |
94 | static void freq_table_redup(struct cpufreq_frequency_table *freq_table, | |
95 | int count) | |
96 | { | |
97 | int i, j; | |
98 | ||
99 | for (i = 1; i < count; i++) { | |
100 | for (j = 0; j < i; j++) { | |
101 | if (freq_table[j].frequency == CPUFREQ_ENTRY_INVALID || | |
102 | freq_table[j].frequency != | |
103 | freq_table[i].frequency) | |
104 | continue; | |
105 | ||
106 | freq_table[i].frequency = CPUFREQ_ENTRY_INVALID; | |
107 | break; | |
108 | } | |
109 | } | |
110 | } | |
111 | ||
112 | /* sort the frequencies in frequency table in descenting order */ | |
113 | static void freq_table_sort(struct cpufreq_frequency_table *freq_table, | |
114 | int count) | |
115 | { | |
116 | int i, j, ind; | |
117 | unsigned int freq, max_freq; | |
118 | struct cpufreq_frequency_table table; | |
119 | for (i = 0; i < count - 1; i++) { | |
120 | max_freq = freq_table[i].frequency; | |
121 | ind = i; | |
122 | for (j = i + 1; j < count; j++) { | |
123 | freq = freq_table[j].frequency; | |
124 | if (freq == CPUFREQ_ENTRY_INVALID || | |
125 | freq <= max_freq) | |
126 | continue; | |
127 | ind = j; | |
128 | max_freq = freq; | |
129 | } | |
130 | ||
131 | if (ind != i) { | |
132 | /* exchange the frequencies */ | |
133 | table.driver_data = freq_table[i].driver_data; | |
134 | table.frequency = freq_table[i].frequency; | |
135 | freq_table[i].driver_data = freq_table[ind].driver_data; | |
136 | freq_table[i].frequency = freq_table[ind].frequency; | |
137 | freq_table[ind].driver_data = table.driver_data; | |
138 | freq_table[ind].frequency = table.frequency; | |
139 | } | |
140 | } | |
141 | } | |
142 | ||
143 | static int corenet_cpufreq_cpu_init(struct cpufreq_policy *policy) | |
144 | { | |
145 | struct device_node *np; | |
146 | int i, count, ret; | |
147 | u32 freq, mask; | |
148 | struct clk *clk; | |
149 | struct cpufreq_frequency_table *table; | |
150 | struct cpu_data *data; | |
151 | unsigned int cpu = policy->cpu; | |
152 | ||
153 | np = of_get_cpu_node(cpu, NULL); | |
154 | if (!np) | |
155 | return -ENODEV; | |
156 | ||
157 | data = kzalloc(sizeof(*data), GFP_KERNEL); | |
158 | if (!data) { | |
159 | pr_err("%s: no memory\n", __func__); | |
160 | goto err_np; | |
161 | } | |
162 | ||
163 | data->clk = of_clk_get(np, 0); | |
164 | if (IS_ERR(data->clk)) { | |
165 | pr_err("%s: no clock information\n", __func__); | |
166 | goto err_nomem2; | |
167 | } | |
168 | ||
169 | data->parent = of_parse_phandle(np, "clocks", 0); | |
170 | if (!data->parent) { | |
171 | pr_err("%s: could not get clock information\n", __func__); | |
172 | goto err_nomem2; | |
173 | } | |
174 | ||
175 | count = of_property_count_strings(data->parent, "clock-names"); | |
176 | table = kcalloc(count + 1, sizeof(*table), GFP_KERNEL); | |
177 | if (!table) { | |
178 | pr_err("%s: no memory\n", __func__); | |
179 | goto err_node; | |
180 | } | |
181 | ||
182 | if (fmask) | |
183 | mask = fmask[get_hard_smp_processor_id(cpu)]; | |
184 | else | |
185 | mask = 0x0; | |
186 | ||
187 | for (i = 0; i < count; i++) { | |
188 | clk = of_clk_get(data->parent, i); | |
189 | freq = clk_get_rate(clk); | |
190 | /* | |
191 | * the clock is valid if its frequency is not masked | |
192 | * and large than minimum allowed frequency. | |
193 | */ | |
194 | if (freq < min_cpufreq || (mask & (1 << i))) | |
195 | table[i].frequency = CPUFREQ_ENTRY_INVALID; | |
196 | else | |
197 | table[i].frequency = freq / 1000; | |
198 | table[i].driver_data = i; | |
199 | } | |
200 | freq_table_redup(table, count); | |
201 | freq_table_sort(table, count); | |
202 | table[i].frequency = CPUFREQ_TABLE_END; | |
203 | ||
204 | /* set the min and max frequency properly */ | |
205 | ret = cpufreq_frequency_table_cpuinfo(policy, table); | |
206 | if (ret) { | |
207 | pr_err("invalid frequency table: %d\n", ret); | |
208 | goto err_nomem1; | |
209 | } | |
210 | ||
211 | data->table = table; | |
212 | per_cpu(cpu_data, cpu) = data; | |
213 | ||
214 | /* update ->cpus if we have cluster, no harm if not */ | |
215 | cpumask_copy(policy->cpus, per_cpu(cpu_mask, cpu)); | |
216 | for_each_cpu(i, per_cpu(cpu_mask, cpu)) | |
217 | per_cpu(cpu_data, i) = data; | |
218 | ||
219 | policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; | |
220 | policy->cur = corenet_cpufreq_get_speed(policy->cpu); | |
221 | ||
222 | cpufreq_frequency_table_get_attr(table, cpu); | |
223 | of_node_put(np); | |
224 | ||
225 | return 0; | |
226 | ||
227 | err_nomem1: | |
228 | kfree(table); | |
229 | err_node: | |
230 | of_node_put(data->parent); | |
231 | err_nomem2: | |
232 | per_cpu(cpu_data, cpu) = NULL; | |
233 | kfree(data); | |
234 | err_np: | |
235 | of_node_put(np); | |
236 | ||
237 | return -ENODEV; | |
238 | } | |
239 | ||
240 | static int __exit corenet_cpufreq_cpu_exit(struct cpufreq_policy *policy) | |
241 | { | |
242 | struct cpu_data *data = per_cpu(cpu_data, policy->cpu); | |
243 | unsigned int cpu; | |
244 | ||
245 | cpufreq_frequency_table_put_attr(policy->cpu); | |
246 | of_node_put(data->parent); | |
247 | kfree(data->table); | |
248 | kfree(data); | |
249 | ||
250 | for_each_cpu(cpu, per_cpu(cpu_mask, policy->cpu)) | |
251 | per_cpu(cpu_data, cpu) = NULL; | |
252 | ||
253 | return 0; | |
254 | } | |
255 | ||
256 | static int corenet_cpufreq_verify(struct cpufreq_policy *policy) | |
257 | { | |
258 | struct cpufreq_frequency_table *table = | |
259 | per_cpu(cpu_data, policy->cpu)->table; | |
260 | ||
261 | return cpufreq_frequency_table_verify(policy, table); | |
262 | } | |
263 | ||
264 | static int corenet_cpufreq_target(struct cpufreq_policy *policy, | |
265 | unsigned int target_freq, unsigned int relation) | |
266 | { | |
267 | struct cpufreq_freqs freqs; | |
268 | unsigned int new; | |
269 | struct clk *parent; | |
270 | int ret; | |
271 | struct cpu_data *data = per_cpu(cpu_data, policy->cpu); | |
272 | ||
273 | cpufreq_frequency_table_target(policy, data->table, | |
274 | target_freq, relation, &new); | |
275 | ||
276 | if (policy->cur == data->table[new].frequency) | |
277 | return 0; | |
278 | ||
279 | freqs.old = policy->cur; | |
280 | freqs.new = data->table[new].frequency; | |
281 | ||
282 | mutex_lock(&cpufreq_lock); | |
283 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); | |
284 | ||
285 | parent = of_clk_get(data->parent, data->table[new].driver_data); | |
286 | ret = clk_set_parent(data->clk, parent); | |
287 | if (ret) | |
288 | freqs.new = freqs.old; | |
289 | ||
290 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); | |
291 | mutex_unlock(&cpufreq_lock); | |
292 | ||
293 | return ret; | |
294 | } | |
295 | ||
296 | static struct freq_attr *corenet_cpufreq_attr[] = { | |
297 | &cpufreq_freq_attr_scaling_available_freqs, | |
298 | NULL, | |
299 | }; | |
300 | ||
301 | static struct cpufreq_driver ppc_corenet_cpufreq_driver = { | |
302 | .name = "ppc_cpufreq", | |
defa4c73 TY |
303 | .flags = CPUFREQ_CONST_LOOPS, |
304 | .init = corenet_cpufreq_cpu_init, | |
305 | .exit = __exit_p(corenet_cpufreq_cpu_exit), | |
306 | .verify = corenet_cpufreq_verify, | |
307 | .target = corenet_cpufreq_target, | |
308 | .get = corenet_cpufreq_get_speed, | |
309 | .attr = corenet_cpufreq_attr, | |
310 | }; | |
311 | ||
312 | static const struct of_device_id node_matches[] __initdata = { | |
313 | { .compatible = "fsl,p2041-clockgen", .data = &sdata[0], }, | |
314 | { .compatible = "fsl,p3041-clockgen", .data = &sdata[0], }, | |
315 | { .compatible = "fsl,p5020-clockgen", .data = &sdata[1], }, | |
316 | { .compatible = "fsl,p4080-clockgen", .data = &sdata[2], }, | |
317 | { .compatible = "fsl,p5040-clockgen", .data = &sdata[2], }, | |
318 | { .compatible = "fsl,qoriq-clockgen-2.0", }, | |
319 | {} | |
320 | }; | |
321 | ||
322 | static int __init ppc_corenet_cpufreq_init(void) | |
323 | { | |
324 | int ret; | |
325 | struct device_node *np; | |
326 | const struct of_device_id *match; | |
327 | const struct soc_data *data; | |
328 | unsigned int cpu; | |
329 | ||
330 | np = of_find_matching_node(NULL, node_matches); | |
331 | if (!np) | |
332 | return -ENODEV; | |
333 | ||
334 | for_each_possible_cpu(cpu) { | |
335 | if (!alloc_cpumask_var(&per_cpu(cpu_mask, cpu), GFP_KERNEL)) | |
336 | goto err_mask; | |
337 | cpumask_copy(per_cpu(cpu_mask, cpu), cpu_core_mask(cpu)); | |
338 | } | |
339 | ||
340 | match = of_match_node(node_matches, np); | |
341 | data = match->data; | |
342 | if (data) { | |
343 | if (data->flag) | |
344 | fmask = data->freq_mask; | |
345 | min_cpufreq = fsl_get_sys_freq(); | |
346 | } else { | |
347 | min_cpufreq = fsl_get_sys_freq() / 2; | |
348 | } | |
349 | ||
350 | of_node_put(np); | |
351 | ||
352 | ret = cpufreq_register_driver(&ppc_corenet_cpufreq_driver); | |
353 | if (!ret) | |
354 | pr_info("Freescale PowerPC corenet CPU frequency scaling driver\n"); | |
355 | ||
356 | return ret; | |
357 | ||
358 | err_mask: | |
359 | for_each_possible_cpu(cpu) | |
360 | free_cpumask_var(per_cpu(cpu_mask, cpu)); | |
361 | ||
362 | return -ENOMEM; | |
363 | } | |
364 | module_init(ppc_corenet_cpufreq_init); | |
365 | ||
366 | static void __exit ppc_corenet_cpufreq_exit(void) | |
367 | { | |
368 | unsigned int cpu; | |
369 | ||
370 | for_each_possible_cpu(cpu) | |
371 | free_cpumask_var(per_cpu(cpu_mask, cpu)); | |
372 | ||
373 | cpufreq_unregister_driver(&ppc_corenet_cpufreq_driver); | |
374 | } | |
375 | module_exit(ppc_corenet_cpufreq_exit); | |
376 | ||
377 | MODULE_LICENSE("GPL"); | |
378 | MODULE_AUTHOR("Tang Yuantian <Yuantian.Tang@freescale.com>"); | |
379 | MODULE_DESCRIPTION("cpufreq driver for Freescale e500mc series SoCs"); |