power.c 1.4 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. /* power.c: Power management driver.
  3. *
  4. * Copyright (C) 1999, 2007, 2008 David S. Miller (davem@davemloft.net)
  5. */
  6. #include <linux/kernel.h>
  7. #include <linux/export.h>
  8. #include <linux/init.h>
  9. #include <linux/interrupt.h>
  10. #include <linux/reboot.h>
  11. #include <linux/of_device.h>
  12. #include <asm/prom.h>
  13. #include <asm/io.h>
  14. static void __iomem *power_reg;
  15. static irqreturn_t power_handler(int irq, void *dev_id)
  16. {
  17. orderly_poweroff(true);
  18. /* FIXME: Check registers for status... */
  19. return IRQ_HANDLED;
  20. }
  21. static int has_button_interrupt(unsigned int irq, struct device_node *dp)
  22. {
  23. if (irq == 0xffffffff)
  24. return 0;
  25. if (!of_find_property(dp, "button", NULL))
  26. return 0;
  27. return 1;
  28. }
  29. static int power_probe(struct platform_device *op)
  30. {
  31. struct resource *res = &op->resource[0];
  32. unsigned int irq = op->archdata.irqs[0];
  33. power_reg = of_ioremap(res, 0, 0x4, "power");
  34. printk(KERN_INFO "%pOFn: Control reg at %llx\n",
  35. op->dev.of_node, res->start);
  36. if (has_button_interrupt(irq, op->dev.of_node)) {
  37. if (request_irq(irq,
  38. power_handler, 0, "power", NULL) < 0)
  39. printk(KERN_ERR "power: Cannot setup IRQ handler.\n");
  40. }
  41. return 0;
  42. }
  43. static const struct of_device_id power_match[] = {
  44. {
  45. .name = "power",
  46. },
  47. {},
  48. };
  49. static struct platform_driver power_driver = {
  50. .probe = power_probe,
  51. .driver = {
  52. .name = "power",
  53. .of_match_table = power_match,
  54. },
  55. };
  56. builtin_platform_driver(power_driver);