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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 | ||
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 | ||
29 | static unsigned int dbx500_cpufreq_getspeed(unsigned int cpu) | |
30 | { | |
31 | int i = 0; | |
32 | unsigned long freq = clk_get_rate(armss_clk) / 1000; | |
33 | ||
34 | /* The value is rounded to closest frequency in the defined table. */ | |
35 | while (freq_table[i + 1].frequency != CPUFREQ_TABLE_END) { | |
36 | if (freq < freq_table[i].frequency + | |
37 | (freq_table[i + 1].frequency - freq_table[i].frequency) / 2) | |
38 | return freq_table[i].frequency; | |
39 | i++; | |
40 | } | |
41 | ||
42 | return freq_table[i].frequency; | |
43 | } | |
44 | ||
45 | static int dbx500_cpufreq_init(struct cpufreq_policy *policy) | |
46 | { | |
47 | return cpufreq_generic_init(policy, freq_table, 20 * 1000); | |
48 | } | |
49 | ||
50 | static struct cpufreq_driver dbx500_cpufreq_driver = { | |
51 | .flags = CPUFREQ_STICKY | CPUFREQ_CONST_LOOPS, | |
52 | .verify = cpufreq_generic_frequency_table_verify, | |
53 | .target_index = dbx500_cpufreq_target, | |
54 | .get = dbx500_cpufreq_getspeed, | |
55 | .init = dbx500_cpufreq_init, | |
56 | .name = "DBX500", | |
57 | .attr = cpufreq_generic_attr, | |
58 | }; | |
59 | ||
60 | static int dbx500_cpufreq_probe(struct platform_device *pdev) | |
61 | { | |
62 | int i = 0; | |
63 | ||
64 | freq_table = dev_get_platdata(&pdev->dev); | |
65 | if (!freq_table) { | |
66 | pr_err("dbx500-cpufreq: Failed to fetch cpufreq table\n"); | |
67 | return -ENODEV; | |
68 | } | |
69 | ||
70 | armss_clk = clk_get(&pdev->dev, "armss"); | |
71 | if (IS_ERR(armss_clk)) { | |
72 | pr_err("dbx500-cpufreq: Failed to get armss clk\n"); | |
73 | return PTR_ERR(armss_clk); | |
74 | } | |
75 | ||
76 | pr_info("dbx500-cpufreq: Available frequencies:\n"); | |
77 | while (freq_table[i].frequency != CPUFREQ_TABLE_END) { | |
78 | pr_info(" %d Mhz\n", freq_table[i].frequency/1000); | |
79 | i++; | |
80 | } | |
81 | ||
82 | return cpufreq_register_driver(&dbx500_cpufreq_driver); | |
83 | } | |
84 | ||
85 | static struct platform_driver dbx500_cpufreq_plat_driver = { | |
86 | .driver = { | |
87 | .name = "cpufreq-ux500", | |
88 | .owner = THIS_MODULE, | |
89 | }, | |
90 | .probe = dbx500_cpufreq_probe, | |
91 | }; | |
92 | ||
93 | static int __init dbx500_cpufreq_register(void) | |
94 | { | |
95 | return platform_driver_register(&dbx500_cpufreq_plat_driver); | |
96 | } | |
97 | device_initcall(dbx500_cpufreq_register); | |
98 | ||
99 | MODULE_LICENSE("GPL v2"); | |
100 | MODULE_DESCRIPTION("cpufreq driver for DBX500"); |