tango-cpufreq.c 927 B

1234567891011121314151617181920212223242526272829303132333435363738
  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. static const struct of_device_id machines[] __initconst = {
  7. { .compatible = "sigma,tango4" },
  8. { /* sentinel */ }
  9. };
  10. static int __init tango_cpufreq_init(void)
  11. {
  12. struct device *cpu_dev = get_cpu_device(0);
  13. unsigned long max_freq;
  14. struct clk *cpu_clk;
  15. void *res;
  16. if (!of_match_node(machines, of_root))
  17. return -ENODEV;
  18. cpu_clk = clk_get(cpu_dev, NULL);
  19. if (IS_ERR(cpu_clk))
  20. return -ENODEV;
  21. max_freq = clk_get_rate(cpu_clk);
  22. dev_pm_opp_add(cpu_dev, max_freq / 1, 0);
  23. dev_pm_opp_add(cpu_dev, max_freq / 2, 0);
  24. dev_pm_opp_add(cpu_dev, max_freq / 3, 0);
  25. dev_pm_opp_add(cpu_dev, max_freq / 5, 0);
  26. dev_pm_opp_add(cpu_dev, max_freq / 9, 0);
  27. res = platform_device_register_data(NULL, "cpufreq-dt", -1, NULL, 0);
  28. return PTR_ERR_OR_ZERO(res);
  29. }
  30. device_initcall(tango_cpufreq_init);