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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> | |
defa4c73 TY |
16 | #include <linux/init.h> |
17 | #include <linux/kernel.h> | |
18 | #include <linux/module.h> | |
19 | #include <linux/mutex.h> | |
20 | #include <linux/of.h> | |
21 | #include <linux/slab.h> | |
22 | #include <linux/smp.h> | |
bfa709bc | 23 | #include <sysdev/fsl_soc.h> |
defa4c73 TY |
24 | |
25 | /** | |
26 | * struct cpu_data - per CPU data struct | |
defa4c73 TY |
27 | * @parent: the parent node of cpu clock |
28 | * @table: frequency table | |
29 | */ | |
30 | struct cpu_data { | |
defa4c73 TY |
31 | struct device_node *parent; |
32 | struct cpufreq_frequency_table *table; | |
33 | }; | |
34 | ||
35 | /** | |
36 | * struct soc_data - SoC specific data | |
37 | * @freq_mask: mask the disallowed frequencies | |
38 | * @flag: unique flags | |
39 | */ | |
40 | struct soc_data { | |
41 | u32 freq_mask[4]; | |
42 | u32 flag; | |
43 | }; | |
44 | ||
45 | #define FREQ_MASK 1 | |
46 | /* see hardware specification for the allowed frqeuencies */ | |
47 | static const struct soc_data sdata[] = { | |
48 | { /* used by p2041 and p3041 */ | |
49 | .freq_mask = {0x8, 0x8, 0x2, 0x2}, | |
50 | .flag = FREQ_MASK, | |
51 | }, | |
52 | { /* used by p5020 */ | |
53 | .freq_mask = {0x8, 0x2}, | |
54 | .flag = FREQ_MASK, | |
55 | }, | |
56 | { /* used by p4080, p5040 */ | |
57 | .freq_mask = {0}, | |
58 | .flag = 0, | |
59 | }, | |
60 | }; | |
61 | ||
62 | /* | |
63 | * the minimum allowed core frequency, in Hz | |
64 | * for chassis v1.0, >= platform frequency | |
65 | * for chassis v2.0, >= platform frequency / 2 | |
66 | */ | |
67 | static u32 min_cpufreq; | |
68 | static const u32 *fmask; | |
69 | ||
defa4c73 TY |
70 | static DEFINE_PER_CPU(struct cpu_data *, cpu_data); |
71 | ||
72 | /* cpumask in a cluster */ | |
73 | static DEFINE_PER_CPU(cpumask_var_t, cpu_mask); | |
74 | ||
75 | #ifndef CONFIG_SMP | |
76 | static inline const struct cpumask *cpu_core_mask(int cpu) | |
77 | { | |
78 | return cpumask_of(0); | |
79 | } | |
80 | #endif | |
81 | ||
defa4c73 TY |
82 | /* reduce the duplicated frequencies in frequency table */ |
83 | static void freq_table_redup(struct cpufreq_frequency_table *freq_table, | |
84 | int count) | |
85 | { | |
86 | int i, j; | |
87 | ||
88 | for (i = 1; i < count; i++) { | |
89 | for (j = 0; j < i; j++) { | |
90 | if (freq_table[j].frequency == CPUFREQ_ENTRY_INVALID || | |
91 | freq_table[j].frequency != | |
92 | freq_table[i].frequency) | |
93 | continue; | |
94 | ||
95 | freq_table[i].frequency = CPUFREQ_ENTRY_INVALID; | |
96 | break; | |
97 | } | |
98 | } | |
99 | } | |
100 | ||
101 | /* sort the frequencies in frequency table in descenting order */ | |
102 | static void freq_table_sort(struct cpufreq_frequency_table *freq_table, | |
103 | int count) | |
104 | { | |
105 | int i, j, ind; | |
106 | unsigned int freq, max_freq; | |
107 | struct cpufreq_frequency_table table; | |
108 | for (i = 0; i < count - 1; i++) { | |
109 | max_freq = freq_table[i].frequency; | |
110 | ind = i; | |
111 | for (j = i + 1; j < count; j++) { | |
112 | freq = freq_table[j].frequency; | |
113 | if (freq == CPUFREQ_ENTRY_INVALID || | |
114 | freq <= max_freq) | |
115 | continue; | |
116 | ind = j; | |
117 | max_freq = freq; | |
118 | } | |
119 | ||
120 | if (ind != i) { | |
121 | /* exchange the frequencies */ | |
122 | table.driver_data = freq_table[i].driver_data; | |
123 | table.frequency = freq_table[i].frequency; | |
124 | freq_table[i].driver_data = freq_table[ind].driver_data; | |
125 | freq_table[i].frequency = freq_table[ind].frequency; | |
126 | freq_table[ind].driver_data = table.driver_data; | |
127 | freq_table[ind].frequency = table.frequency; | |
128 | } | |
129 | } | |
130 | } | |
131 | ||
132 | static int corenet_cpufreq_cpu_init(struct cpufreq_policy *policy) | |
133 | { | |
134 | struct device_node *np; | |
135 | int i, count, ret; | |
136 | u32 freq, mask; | |
137 | struct clk *clk; | |
138 | struct cpufreq_frequency_table *table; | |
139 | struct cpu_data *data; | |
140 | unsigned int cpu = policy->cpu; | |
141 | ||
142 | np = of_get_cpu_node(cpu, NULL); | |
143 | if (!np) | |
144 | return -ENODEV; | |
145 | ||
146 | data = kzalloc(sizeof(*data), GFP_KERNEL); | |
147 | if (!data) { | |
148 | pr_err("%s: no memory\n", __func__); | |
149 | goto err_np; | |
150 | } | |
151 | ||
652ed95d VK |
152 | policy->clk = of_clk_get(np, 0); |
153 | if (IS_ERR(policy->clk)) { | |
defa4c73 TY |
154 | pr_err("%s: no clock information\n", __func__); |
155 | goto err_nomem2; | |
156 | } | |
157 | ||
158 | data->parent = of_parse_phandle(np, "clocks", 0); | |
159 | if (!data->parent) { | |
160 | pr_err("%s: could not get clock information\n", __func__); | |
161 | goto err_nomem2; | |
162 | } | |
163 | ||
164 | count = of_property_count_strings(data->parent, "clock-names"); | |
165 | table = kcalloc(count + 1, sizeof(*table), GFP_KERNEL); | |
166 | if (!table) { | |
167 | pr_err("%s: no memory\n", __func__); | |
168 | goto err_node; | |
169 | } | |
170 | ||
171 | if (fmask) | |
172 | mask = fmask[get_hard_smp_processor_id(cpu)]; | |
173 | else | |
174 | mask = 0x0; | |
175 | ||
176 | for (i = 0; i < count; i++) { | |
177 | clk = of_clk_get(data->parent, i); | |
178 | freq = clk_get_rate(clk); | |
179 | /* | |
180 | * the clock is valid if its frequency is not masked | |
181 | * and large than minimum allowed frequency. | |
182 | */ | |
183 | if (freq < min_cpufreq || (mask & (1 << i))) | |
184 | table[i].frequency = CPUFREQ_ENTRY_INVALID; | |
185 | else | |
186 | table[i].frequency = freq / 1000; | |
187 | table[i].driver_data = i; | |
188 | } | |
189 | freq_table_redup(table, count); | |
190 | freq_table_sort(table, count); | |
191 | table[i].frequency = CPUFREQ_TABLE_END; | |
192 | ||
193 | /* set the min and max frequency properly */ | |
6b4147db | 194 | ret = cpufreq_table_validate_and_show(policy, table); |
defa4c73 TY |
195 | if (ret) { |
196 | pr_err("invalid frequency table: %d\n", ret); | |
197 | goto err_nomem1; | |
198 | } | |
199 | ||
200 | data->table = table; | |
201 | per_cpu(cpu_data, cpu) = data; | |
202 | ||
203 | /* update ->cpus if we have cluster, no harm if not */ | |
204 | cpumask_copy(policy->cpus, per_cpu(cpu_mask, cpu)); | |
205 | for_each_cpu(i, per_cpu(cpu_mask, cpu)) | |
206 | per_cpu(cpu_data, i) = data; | |
207 | ||
bfa709bc | 208 | policy->cpuinfo.transition_latency = |
1612343a | 209 | (12ULL * NSEC_PER_SEC) / fsl_get_sys_freq(); |
defa4c73 TY |
210 | of_node_put(np); |
211 | ||
212 | return 0; | |
213 | ||
214 | err_nomem1: | |
215 | kfree(table); | |
216 | err_node: | |
217 | of_node_put(data->parent); | |
218 | err_nomem2: | |
219 | per_cpu(cpu_data, cpu) = NULL; | |
220 | kfree(data); | |
221 | err_np: | |
222 | of_node_put(np); | |
223 | ||
224 | return -ENODEV; | |
225 | } | |
226 | ||
227 | static int __exit corenet_cpufreq_cpu_exit(struct cpufreq_policy *policy) | |
228 | { | |
229 | struct cpu_data *data = per_cpu(cpu_data, policy->cpu); | |
230 | unsigned int cpu; | |
231 | ||
defa4c73 TY |
232 | of_node_put(data->parent); |
233 | kfree(data->table); | |
234 | kfree(data); | |
235 | ||
236 | for_each_cpu(cpu, per_cpu(cpu_mask, policy->cpu)) | |
237 | per_cpu(cpu_data, cpu) = NULL; | |
238 | ||
239 | return 0; | |
240 | } | |
241 | ||
defa4c73 | 242 | static int corenet_cpufreq_target(struct cpufreq_policy *policy, |
9c0ebcf7 | 243 | unsigned int index) |
defa4c73 | 244 | { |
defa4c73 | 245 | struct clk *parent; |
defa4c73 TY |
246 | struct cpu_data *data = per_cpu(cpu_data, policy->cpu); |
247 | ||
9c0ebcf7 | 248 | parent = of_clk_get(data->parent, data->table[index].driver_data); |
652ed95d | 249 | return clk_set_parent(policy->clk, parent); |
defa4c73 TY |
250 | } |
251 | ||
defa4c73 TY |
252 | static struct cpufreq_driver ppc_corenet_cpufreq_driver = { |
253 | .name = "ppc_cpufreq", | |
defa4c73 TY |
254 | .flags = CPUFREQ_CONST_LOOPS, |
255 | .init = corenet_cpufreq_cpu_init, | |
256 | .exit = __exit_p(corenet_cpufreq_cpu_exit), | |
dc2398d7 | 257 | .verify = cpufreq_generic_frequency_table_verify, |
9c0ebcf7 | 258 | .target_index = corenet_cpufreq_target, |
652ed95d | 259 | .get = cpufreq_generic_get, |
dc2398d7 | 260 | .attr = cpufreq_generic_attr, |
defa4c73 TY |
261 | }; |
262 | ||
263 | static const struct of_device_id node_matches[] __initdata = { | |
264 | { .compatible = "fsl,p2041-clockgen", .data = &sdata[0], }, | |
265 | { .compatible = "fsl,p3041-clockgen", .data = &sdata[0], }, | |
266 | { .compatible = "fsl,p5020-clockgen", .data = &sdata[1], }, | |
267 | { .compatible = "fsl,p4080-clockgen", .data = &sdata[2], }, | |
268 | { .compatible = "fsl,p5040-clockgen", .data = &sdata[2], }, | |
269 | { .compatible = "fsl,qoriq-clockgen-2.0", }, | |
270 | {} | |
271 | }; | |
272 | ||
273 | static int __init ppc_corenet_cpufreq_init(void) | |
274 | { | |
275 | int ret; | |
276 | struct device_node *np; | |
277 | const struct of_device_id *match; | |
278 | const struct soc_data *data; | |
279 | unsigned int cpu; | |
280 | ||
281 | np = of_find_matching_node(NULL, node_matches); | |
282 | if (!np) | |
283 | return -ENODEV; | |
284 | ||
285 | for_each_possible_cpu(cpu) { | |
286 | if (!alloc_cpumask_var(&per_cpu(cpu_mask, cpu), GFP_KERNEL)) | |
287 | goto err_mask; | |
288 | cpumask_copy(per_cpu(cpu_mask, cpu), cpu_core_mask(cpu)); | |
289 | } | |
290 | ||
291 | match = of_match_node(node_matches, np); | |
292 | data = match->data; | |
293 | if (data) { | |
294 | if (data->flag) | |
295 | fmask = data->freq_mask; | |
296 | min_cpufreq = fsl_get_sys_freq(); | |
297 | } else { | |
298 | min_cpufreq = fsl_get_sys_freq() / 2; | |
299 | } | |
300 | ||
301 | of_node_put(np); | |
302 | ||
303 | ret = cpufreq_register_driver(&ppc_corenet_cpufreq_driver); | |
304 | if (!ret) | |
305 | pr_info("Freescale PowerPC corenet CPU frequency scaling driver\n"); | |
306 | ||
307 | return ret; | |
308 | ||
309 | err_mask: | |
310 | for_each_possible_cpu(cpu) | |
311 | free_cpumask_var(per_cpu(cpu_mask, cpu)); | |
312 | ||
313 | return -ENOMEM; | |
314 | } | |
315 | module_init(ppc_corenet_cpufreq_init); | |
316 | ||
317 | static void __exit ppc_corenet_cpufreq_exit(void) | |
318 | { | |
319 | unsigned int cpu; | |
320 | ||
321 | for_each_possible_cpu(cpu) | |
322 | free_cpumask_var(per_cpu(cpu_mask, cpu)); | |
323 | ||
324 | cpufreq_unregister_driver(&ppc_corenet_cpufreq_driver); | |
325 | } | |
326 | module_exit(ppc_corenet_cpufreq_exit); | |
327 | ||
328 | MODULE_LICENSE("GPL"); | |
329 | MODULE_AUTHOR("Tang Yuantian <Yuantian.Tang@freescale.com>"); | |
330 | MODULE_DESCRIPTION("cpufreq driver for Freescale e500mc series SoCs"); |