support.c 1.5 KB

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  1. /*
  2. * support.c - standard functions for the use of pnp protocol drivers
  3. *
  4. * Copyright 2003 Adam Belay <ambx1@neo.rr.com>
  5. */
  6. #include <linux/module.h>
  7. #include <linux/ctype.h>
  8. #include <linux/pnp.h>
  9. #include "base.h"
  10. /**
  11. * pnp_is_active - Determines if a device is active based on its current
  12. * resources
  13. * @dev: pointer to the desired PnP device
  14. */
  15. int pnp_is_active(struct pnp_dev *dev)
  16. {
  17. if (!pnp_port_start(dev, 0) && pnp_port_len(dev, 0) <= 1 &&
  18. !pnp_mem_start(dev, 0) && pnp_mem_len(dev, 0) <= 1 &&
  19. pnp_irq(dev, 0) == -1 && pnp_dma(dev, 0) == -1)
  20. return 0;
  21. else
  22. return 1;
  23. }
  24. EXPORT_SYMBOL(pnp_is_active);
  25. /*
  26. * Functionally similar to acpi_ex_eisa_id_to_string(), but that's
  27. * buried in the ACPI CA, and we can't depend on it being present.
  28. */
  29. void pnp_eisa_id_to_string(u32 id, char *str)
  30. {
  31. id = be32_to_cpu(id);
  32. /*
  33. * According to the specs, the first three characters are five-bit
  34. * compressed ASCII, and the left-over high order bit should be zero.
  35. * However, the Linux ISAPNP code historically used six bits for the
  36. * first character, and there seem to be IDs that depend on that,
  37. * e.g., "nEC8241" in the Linux 8250_pnp serial driver and the
  38. * FreeBSD sys/pc98/cbus/sio_cbus.c driver.
  39. */
  40. str[0] = 'A' + ((id >> 26) & 0x3f) - 1;
  41. str[1] = 'A' + ((id >> 21) & 0x1f) - 1;
  42. str[2] = 'A' + ((id >> 16) & 0x1f) - 1;
  43. str[3] = hex_asc((id >> 12) & 0xf);
  44. str[4] = hex_asc((id >> 8) & 0xf);
  45. str[5] = hex_asc((id >> 4) & 0xf);
  46. str[6] = hex_asc((id >> 0) & 0xf);
  47. str[7] = '\0';
  48. }