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Tang Yuantiandefa4c72013-06-05 09:30:48 +00001/*
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>
Tang Yuantiandefa4c72013-06-05 09:30:48 +000016#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>
Zhuoyu Zhangbfa709b2014-03-18 13:41:25 +080023#include <sysdev/fsl_soc.h>
Tang Yuantiandefa4c72013-06-05 09:30:48 +000024
25/**
26 * struct cpu_data - per CPU data struct
Tang Yuantiandefa4c72013-06-05 09:30:48 +000027 * @parent: the parent node of cpu clock
28 * @table: frequency table
29 */
30struct cpu_data {
Tang Yuantiandefa4c72013-06-05 09:30:48 +000031 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 */
40struct 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 */
47static 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 */
67static u32 min_cpufreq;
68static const u32 *fmask;
69
Tang Yuantiandefa4c72013-06-05 09:30:48 +000070static DEFINE_PER_CPU(struct cpu_data *, cpu_data);
71
72/* cpumask in a cluster */
73static DEFINE_PER_CPU(cpumask_var_t, cpu_mask);
74
75#ifndef CONFIG_SMP
76static inline const struct cpumask *cpu_core_mask(int cpu)
77{
78 return cpumask_of(0);
79}
80#endif
81
Tang Yuantiandefa4c72013-06-05 09:30:48 +000082/* reduce the duplicated frequencies in frequency table */
83static 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 */
102static 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
132static 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;
Ed Swarthout906fe032014-06-05 18:56:17 -0500141 u64 u64temp;
Tang Yuantiandefa4c72013-06-05 09:30:48 +0000142
143 np = of_get_cpu_node(cpu, NULL);
144 if (!np)
145 return -ENODEV;
146
147 data = kzalloc(sizeof(*data), GFP_KERNEL);
148 if (!data) {
149 pr_err("%s: no memory\n", __func__);
150 goto err_np;
151 }
152
Viresh Kumar652ed952014-01-09 20:38:43 +0530153 policy->clk = of_clk_get(np, 0);
154 if (IS_ERR(policy->clk)) {
Tang Yuantiandefa4c72013-06-05 09:30:48 +0000155 pr_err("%s: no clock information\n", __func__);
156 goto err_nomem2;
157 }
158
159 data->parent = of_parse_phandle(np, "clocks", 0);
160 if (!data->parent) {
161 pr_err("%s: could not get clock information\n", __func__);
162 goto err_nomem2;
163 }
164
165 count = of_property_count_strings(data->parent, "clock-names");
166 table = kcalloc(count + 1, sizeof(*table), GFP_KERNEL);
167 if (!table) {
168 pr_err("%s: no memory\n", __func__);
169 goto err_node;
170 }
171
172 if (fmask)
173 mask = fmask[get_hard_smp_processor_id(cpu)];
174 else
175 mask = 0x0;
176
177 for (i = 0; i < count; i++) {
178 clk = of_clk_get(data->parent, i);
179 freq = clk_get_rate(clk);
180 /*
181 * the clock is valid if its frequency is not masked
182 * and large than minimum allowed frequency.
183 */
184 if (freq < min_cpufreq || (mask & (1 << i)))
185 table[i].frequency = CPUFREQ_ENTRY_INVALID;
186 else
187 table[i].frequency = freq / 1000;
188 table[i].driver_data = i;
189 }
190 freq_table_redup(table, count);
191 freq_table_sort(table, count);
192 table[i].frequency = CPUFREQ_TABLE_END;
193
194 /* set the min and max frequency properly */
Viresh Kumar6b4147d2013-09-16 18:56:28 +0530195 ret = cpufreq_table_validate_and_show(policy, table);
Tang Yuantiandefa4c72013-06-05 09:30:48 +0000196 if (ret) {
197 pr_err("invalid frequency table: %d\n", ret);
198 goto err_nomem1;
199 }
200
201 data->table = table;
Tang Yuantiandefa4c72013-06-05 09:30:48 +0000202
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
Ed Swarthout906fe032014-06-05 18:56:17 -0500208 /* Minimum transition latency is 12 platform clocks */
209 u64temp = 12ULL * NSEC_PER_SEC;
210 do_div(u64temp, fsl_get_sys_freq());
211 policy->cpuinfo.transition_latency = u64temp + 1;
Tim Gardner6712d292014-04-28 10:18:18 -0600212
Tang Yuantiandefa4c72013-06-05 09:30:48 +0000213 of_node_put(np);
214
215 return 0;
216
217err_nomem1:
218 kfree(table);
219err_node:
220 of_node_put(data->parent);
221err_nomem2:
222 per_cpu(cpu_data, cpu) = NULL;
223 kfree(data);
224err_np:
225 of_node_put(np);
226
227 return -ENODEV;
228}
229
230static int __exit corenet_cpufreq_cpu_exit(struct cpufreq_policy *policy)
231{
232 struct cpu_data *data = per_cpu(cpu_data, policy->cpu);
233 unsigned int cpu;
234
Tang Yuantiandefa4c72013-06-05 09:30:48 +0000235 of_node_put(data->parent);
236 kfree(data->table);
237 kfree(data);
238
239 for_each_cpu(cpu, per_cpu(cpu_mask, policy->cpu))
240 per_cpu(cpu_data, cpu) = NULL;
241
242 return 0;
243}
244
Tang Yuantiandefa4c72013-06-05 09:30:48 +0000245static int corenet_cpufreq_target(struct cpufreq_policy *policy,
Viresh Kumar9c0ebcf2013-10-25 19:45:48 +0530246 unsigned int index)
Tang Yuantiandefa4c72013-06-05 09:30:48 +0000247{
Tang Yuantiandefa4c72013-06-05 09:30:48 +0000248 struct clk *parent;
Tang Yuantiandefa4c72013-06-05 09:30:48 +0000249 struct cpu_data *data = per_cpu(cpu_data, policy->cpu);
250
Viresh Kumar9c0ebcf2013-10-25 19:45:48 +0530251 parent = of_clk_get(data->parent, data->table[index].driver_data);
Viresh Kumar652ed952014-01-09 20:38:43 +0530252 return clk_set_parent(policy->clk, parent);
Tang Yuantiandefa4c72013-06-05 09:30:48 +0000253}
254
Tang Yuantiandefa4c72013-06-05 09:30:48 +0000255static struct cpufreq_driver ppc_corenet_cpufreq_driver = {
256 .name = "ppc_cpufreq",
Tang Yuantiandefa4c72013-06-05 09:30:48 +0000257 .flags = CPUFREQ_CONST_LOOPS,
258 .init = corenet_cpufreq_cpu_init,
259 .exit = __exit_p(corenet_cpufreq_cpu_exit),
Viresh Kumardc2398d2013-10-03 20:28:18 +0530260 .verify = cpufreq_generic_frequency_table_verify,
Viresh Kumar9c0ebcf2013-10-25 19:45:48 +0530261 .target_index = corenet_cpufreq_target,
Viresh Kumar652ed952014-01-09 20:38:43 +0530262 .get = cpufreq_generic_get,
Viresh Kumardc2398d2013-10-03 20:28:18 +0530263 .attr = cpufreq_generic_attr,
Tang Yuantiandefa4c72013-06-05 09:30:48 +0000264};
265
266static const struct of_device_id node_matches[] __initdata = {
267 { .compatible = "fsl,p2041-clockgen", .data = &sdata[0], },
268 { .compatible = "fsl,p3041-clockgen", .data = &sdata[0], },
269 { .compatible = "fsl,p5020-clockgen", .data = &sdata[1], },
270 { .compatible = "fsl,p4080-clockgen", .data = &sdata[2], },
271 { .compatible = "fsl,p5040-clockgen", .data = &sdata[2], },
272 { .compatible = "fsl,qoriq-clockgen-2.0", },
273 {}
274};
275
276static int __init ppc_corenet_cpufreq_init(void)
277{
278 int ret;
279 struct device_node *np;
280 const struct of_device_id *match;
281 const struct soc_data *data;
282 unsigned int cpu;
283
284 np = of_find_matching_node(NULL, node_matches);
285 if (!np)
286 return -ENODEV;
287
288 for_each_possible_cpu(cpu) {
289 if (!alloc_cpumask_var(&per_cpu(cpu_mask, cpu), GFP_KERNEL))
290 goto err_mask;
291 cpumask_copy(per_cpu(cpu_mask, cpu), cpu_core_mask(cpu));
292 }
293
294 match = of_match_node(node_matches, np);
295 data = match->data;
296 if (data) {
297 if (data->flag)
298 fmask = data->freq_mask;
299 min_cpufreq = fsl_get_sys_freq();
300 } else {
301 min_cpufreq = fsl_get_sys_freq() / 2;
302 }
303
304 of_node_put(np);
305
306 ret = cpufreq_register_driver(&ppc_corenet_cpufreq_driver);
307 if (!ret)
308 pr_info("Freescale PowerPC corenet CPU frequency scaling driver\n");
309
310 return ret;
311
312err_mask:
313 for_each_possible_cpu(cpu)
314 free_cpumask_var(per_cpu(cpu_mask, cpu));
315
316 return -ENOMEM;
317}
318module_init(ppc_corenet_cpufreq_init);
319
320static void __exit ppc_corenet_cpufreq_exit(void)
321{
322 unsigned int cpu;
323
324 for_each_possible_cpu(cpu)
325 free_cpumask_var(per_cpu(cpu_mask, cpu));
326
327 cpufreq_unregister_driver(&ppc_corenet_cpufreq_driver);
328}
329module_exit(ppc_corenet_cpufreq_exit);
330
331MODULE_LICENSE("GPL");
332MODULE_AUTHOR("Tang Yuantian <Yuantian.Tang@freescale.com>");
333MODULE_DESCRIPTION("cpufreq driver for Freescale e500mc series SoCs");