power.c 1.5 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.h>
  12. #include <linux/platform_device.h>
  13. #include <asm/prom.h>
  14. #include <asm/io.h>
  15. static void __iomem *power_reg;
  16. static irqreturn_t power_handler(int irq, void *dev_id)
  17. {
  18. orderly_poweroff(true);
  19. /* FIXME: Check registers for status... */
  20. return IRQ_HANDLED;
  21. }
  22. static int has_button_interrupt(unsigned int irq, struct device_node *dp)
  23. {
  24. if (irq == 0xffffffff)
  25. return 0;
  26. if (!of_property_read_bool(dp, "button"))
  27. return 0;
  28. return 1;
  29. }
  30. static int power_probe(struct platform_device *op)
  31. {
  32. struct resource *res = &op->resource[0];
  33. unsigned int irq = op->archdata.irqs[0];
  34. power_reg = of_ioremap(res, 0, 0x4, "power");
  35. printk(KERN_INFO "%pOFn: Control reg at %llx\n",
  36. op->dev.of_node, res->start);
  37. if (has_button_interrupt(irq, op->dev.of_node)) {
  38. if (request_irq(irq,
  39. power_handler, 0, "power", NULL) < 0)
  40. printk(KERN_ERR "power: Cannot setup IRQ handler.\n");
  41. }
  42. return 0;
  43. }
  44. static const struct of_device_id power_match[] = {
  45. {
  46. .name = "power",
  47. },
  48. {},
  49. };
  50. static struct platform_driver power_driver = {
  51. .probe = power_probe,
  52. .driver = {
  53. .name = "power",
  54. .of_match_table = power_match,
  55. },
  56. };
  57. builtin_platform_driver(power_driver);