View port usage through/proc/ioports (/proc/iomem)

$ CAT/proc/ioports
-0cf7: PCI bus :00
2017-001f: dma1
0020-0021: pic1
0040-0043: timer0
0050-0053: timer1
0060-0060: keyboard
0064-0064: keyboard
0070-0071: rtc0
0080-008f: DMA page Reg
00a0-00a1: pic2
00c0-00df: dma2
00f0-00ff: FPU
0170-0177:. 0
0170-0177: pata_amd
01f0-01f7:. 0
01f0-01f7: pata_amd
0376-0376:. 0
0376-0376: pata_amd
03c0-03df: VGA +
03f6-03f6:. 0
03f6-03f6: pata_amd
03f8-03ff: Serial
04d0-04d1: PNP
0800-080f: pnp
0a00-0a0f: pnp 00: 0b
0a10-0a1f: pnp 00: 0b
0cf8-0cff: PCI conf1
0d00-ffff: PCI Bus :00
4000-407f: pnp
4000-4003: ACPI PM1a_EVT_BLK
4004-4005: ACPI PM1a_CNT_BLK
4008-400b: ACPI PM_TMR
4010-4015: acpi cpu throttle
4020-4027: ACPI GPE0_BLK
4080-40ff: pnp
4400-447f: pnp
4480-44ff: pnp
44a0-44af: ACPI gpew.blk
4800-0000f: pnp
4880-48ff: pnp
4900-493f: :00:01. 1
4c00-4c7f: pnp
4c80-4cff: pnp
4d00-4d3f:. 1
4d00-4d3f: nForce2_smbus
4e00-4e3f: :00:01. 1
4e00-4e3f: nForce2_smbus
4f00-4fff: 0000:00:01. 0
D000-d00f:. 1
D000-d00f: sata_nv
D080-d083:. 1
D080-d083: sata_nv
D400-d407:. 1
D400-d407: sata_nv
D480-d483:. 1
D480-d483: sata_nv
D800-d807:. 1
D800-d807: sata_nv
D880-d88f:. 0
D880-d88f: sata_nv
Dc00-dc03:. 0
Dc00-dc03: sata_nv
E000-e007:. 0
E000-e007: sata_nv
E080-e083:. 0
E080-e083: sata_nv
E400-e407:. 0
E400-e407: sata_nv
E480-e487:. 0
E480-e487: forcedeth
Ffa0-ffaf:. 0
Ffa0-ffaf: pata_amd.
[Root @ ~]

 

When you use the request_region (i8042_data_reg, 16, "i8042") function to request a communication port, a driver gets the resource.

You can view which ports are used in the/proc/ioports file.

/Proc/iomem corresponds to mmio usage