Blame view

kernel/linux-rt-4.4.41/drivers/cpufreq/vexpress-spc-cpufreq.c 1.83 KB
5113f6f70   김현기   kernel add
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
  /*
   * Versatile Express SPC CPUFreq Interface driver
   *
   * It provides necessary ops to arm_big_little cpufreq driver.
   *
   * Copyright (C) 2013 ARM Ltd.
   * Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   *
   * This program is distributed "as is" WITHOUT ANY WARRANTY of any
   * kind, whether express or implied; without even the implied warranty
   * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
   * GNU General Public License for more details.
   */
  
  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  
  #include <linux/cpufreq.h>
  #include <linux/module.h>
  #include <linux/platform_device.h>
  #include <linux/pm_opp.h>
  #include <linux/types.h>
  
  #include "arm_big_little.h"
  
  static int ve_spc_init_opp_table(struct device *cpu_dev)
  {
  	/*
  	 * platform specific SPC code must initialise the opp table
  	 * so just check if the OPP count is non-zero
  	 */
  	return dev_pm_opp_get_opp_count(cpu_dev) <= 0;
  }
  
  static int ve_spc_get_transition_latency(struct device *cpu_dev)
  {
  	return 1000000; /* 1 ms */
  }
  
  static struct cpufreq_arm_bL_ops ve_spc_cpufreq_ops = {
  	.name	= "vexpress-spc",
  	.get_transition_latency = ve_spc_get_transition_latency,
  	.init_opp_table = ve_spc_init_opp_table,
  };
  
  static int ve_spc_cpufreq_probe(struct platform_device *pdev)
  {
  	return bL_cpufreq_register(&ve_spc_cpufreq_ops);
  }
  
  static int ve_spc_cpufreq_remove(struct platform_device *pdev)
  {
  	bL_cpufreq_unregister(&ve_spc_cpufreq_ops);
  	return 0;
  }
  
  static struct platform_driver ve_spc_cpufreq_platdrv = {
  	.driver = {
  		.name	= "vexpress-spc-cpufreq",
  	},
  	.probe		= ve_spc_cpufreq_probe,
  	.remove		= ve_spc_cpufreq_remove,
  };
  module_platform_driver(ve_spc_cpufreq_platdrv);
  
  MODULE_LICENSE("GPL");