1 /*
2 * Copyright (C) STMicroelectronics 2009
3 * Copyright (C) ST-Ericsson SA 2010-2012
4 *
5 * License Terms: GNU General Public License v2
6 * Author: Sundar Iyer <sundar.iyer@stericsson.com>
7 * Author: Martin Persson <martin.persson@stericsson.com>
8 * Author: Jonas Aaberg <jonas.aberg@stericsson.com>
9 */
10
11 #include <linux/module.h>
12 #include <linux/kernel.h>
13 #include <linux/cpufreq.h>
14 #include <linux/delay.h>
15 #include <linux/slab.h>
16 #include <linux/platform_device.h>
17 #include <linux/clk.h>
18
19 static struct cpufreq_frequency_table *freq_table;
20 static struct clk *armss_clk;
21
dbx500_cpufreq_target(struct cpufreq_policy * policy,unsigned int index)22 static int dbx500_cpufreq_target(struct cpufreq_policy *policy,
23 unsigned int index)
24 {
25 /* update armss clk frequency */
26 return clk_set_rate(armss_clk, freq_table[index].frequency * 1000);
27 }
28
dbx500_cpufreq_init(struct cpufreq_policy * policy)29 static int dbx500_cpufreq_init(struct cpufreq_policy *policy)
30 {
31 policy->clk = armss_clk;
32 return cpufreq_generic_init(policy, freq_table, 20 * 1000);
33 }
34
35 static struct cpufreq_driver dbx500_cpufreq_driver = {
36 .flags = CPUFREQ_STICKY | CPUFREQ_CONST_LOOPS |
37 CPUFREQ_NEED_INITIAL_FREQ_CHECK,
38 .verify = cpufreq_generic_frequency_table_verify,
39 .target_index = dbx500_cpufreq_target,
40 .get = cpufreq_generic_get,
41 .init = dbx500_cpufreq_init,
42 .name = "DBX500",
43 .attr = cpufreq_generic_attr,
44 };
45
dbx500_cpufreq_probe(struct platform_device * pdev)46 static int dbx500_cpufreq_probe(struct platform_device *pdev)
47 {
48 struct cpufreq_frequency_table *pos;
49
50 freq_table = dev_get_platdata(&pdev->dev);
51 if (!freq_table) {
52 pr_err("dbx500-cpufreq: Failed to fetch cpufreq table\n");
53 return -ENODEV;
54 }
55
56 armss_clk = clk_get(&pdev->dev, "armss");
57 if (IS_ERR(armss_clk)) {
58 pr_err("dbx500-cpufreq: Failed to get armss clk\n");
59 return PTR_ERR(armss_clk);
60 }
61
62 pr_info("dbx500-cpufreq: Available frequencies:\n");
63 cpufreq_for_each_entry(pos, freq_table)
64 pr_info(" %d Mhz\n", pos->frequency / 1000);
65
66 return cpufreq_register_driver(&dbx500_cpufreq_driver);
67 }
68
69 static struct platform_driver dbx500_cpufreq_plat_driver = {
70 .driver = {
71 .name = "cpufreq-ux500",
72 },
73 .probe = dbx500_cpufreq_probe,
74 };
75
dbx500_cpufreq_register(void)76 static int __init dbx500_cpufreq_register(void)
77 {
78 return platform_driver_register(&dbx500_cpufreq_plat_driver);
79 }
80 device_initcall(dbx500_cpufreq_register);
81
82 MODULE_LICENSE("GPL v2");
83 MODULE_DESCRIPTION("cpufreq driver for DBX500");
84