drivers/cpufreq/tango-cpufreq.c

   1 #include <linux/of.h>
   2 #include <linux/cpu.h>
   3 #include <linux/clk.h>
   4 #include <linux/pm_opp.h>
   5 #include <linux/platform_device.h>
   6
   7 static const struct of_device_id machines[] __initconst = {
   8         { .compatible = "sigma,tango4" },
   9         { /* sentinel */ }
  10 };
  11
  12 static int __init tango_cpufreq_init(void)
  13 {
  14         struct device *cpu_dev = get_cpu_device(0);
  15         unsigned long max_freq;
  16         struct clk *cpu_clk;
  17         void *res;
  18
  19         if (!of_match_node(machines, of_root))
  20                 return -ENODEV;
  21
  22         cpu_clk = clk_get(cpu_dev, NULL);
  23         if (IS_ERR(cpu_clk))
  24                 return -ENODEV;
  25
  26         max_freq = clk_get_rate(cpu_clk);
  27
  28         dev_pm_opp_add(cpu_dev, max_freq / 1, 0);
  29         dev_pm_opp_add(cpu_dev, max_freq / 2, 0);
  30         dev_pm_opp_add(cpu_dev, max_freq / 3, 0);
  31         dev_pm_opp_add(cpu_dev, max_freq / 5, 0);
  32         dev_pm_opp_add(cpu_dev, max_freq / 9, 0);
  33
  34         res = platform_device_register_data(NULL, "cpufreq-dt", -1, NULL, 0);
  35
  36         return PTR_ERR_OR_ZERO(res);
  37 }
  38 device_initcall(tango_cpufreq_init);