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kernel/linux-imx6_3.14.28/drivers/cpufreq/dbx500-cpufreq.c 2.24 KB
6b13f685e   김민수   BSP 최초 추가
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  /*
   * Copyright (C) STMicroelectronics 2009
   * Copyright (C) ST-Ericsson SA 2010-2012
   *
   * License Terms: GNU General Public License v2
   * Author: Sundar Iyer <sundar.iyer@stericsson.com>
   * Author: Martin Persson <martin.persson@stericsson.com>
   * Author: Jonas Aaberg <jonas.aberg@stericsson.com>
   */
  
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/cpufreq.h>
  #include <linux/delay.h>
  #include <linux/slab.h>
  #include <linux/platform_device.h>
  #include <linux/clk.h>
  
  static struct cpufreq_frequency_table *freq_table;
  static struct clk *armss_clk;
  
  static int dbx500_cpufreq_target(struct cpufreq_policy *policy,
  				unsigned int index)
  {
  	/* update armss clk frequency */
  	return clk_set_rate(armss_clk, freq_table[index].frequency * 1000);
  }
  
  static int dbx500_cpufreq_init(struct cpufreq_policy *policy)
  {
  	policy->clk = armss_clk;
  	return cpufreq_generic_init(policy, freq_table, 20 * 1000);
  }
  
  static struct cpufreq_driver dbx500_cpufreq_driver = {
  	.flags  = CPUFREQ_STICKY | CPUFREQ_CONST_LOOPS |
  			CPUFREQ_NEED_INITIAL_FREQ_CHECK,
  	.verify = cpufreq_generic_frequency_table_verify,
  	.target_index = dbx500_cpufreq_target,
  	.get    = cpufreq_generic_get,
  	.init   = dbx500_cpufreq_init,
  	.name   = "DBX500",
  	.attr   = cpufreq_generic_attr,
  };
  
  static int dbx500_cpufreq_probe(struct platform_device *pdev)
  {
  	int i = 0;
  
  	freq_table = dev_get_platdata(&pdev->dev);
  	if (!freq_table) {
  		pr_err("dbx500-cpufreq: Failed to fetch cpufreq table
  ");
  		return -ENODEV;
  	}
  
  	armss_clk = clk_get(&pdev->dev, "armss");
  	if (IS_ERR(armss_clk)) {
  		pr_err("dbx500-cpufreq: Failed to get armss clk
  ");
  		return PTR_ERR(armss_clk);
  	}
  
  	pr_info("dbx500-cpufreq: Available frequencies:
  ");
  	while (freq_table[i].frequency != CPUFREQ_TABLE_END) {
  		pr_info("  %d Mhz
  ", freq_table[i].frequency/1000);
  		i++;
  	}
  
  	return cpufreq_register_driver(&dbx500_cpufreq_driver);
  }
  
  static struct platform_driver dbx500_cpufreq_plat_driver = {
  	.driver = {
  		.name = "cpufreq-ux500",
  		.owner = THIS_MODULE,
  	},
  	.probe = dbx500_cpufreq_probe,
  };
  
  static int __init dbx500_cpufreq_register(void)
  {
  	return platform_driver_register(&dbx500_cpufreq_plat_driver);
  }
  device_initcall(dbx500_cpufreq_register);
  
  MODULE_LICENSE("GPL v2");
  MODULE_DESCRIPTION("cpufreq driver for DBX500");