Difference between the function inl () and readl () that access I / O

zhuqi110

Excuse me, the function unsigned inl (unsigned port) for accessing 32-bit I / O ports under Linux;
And I have seen in some books that when accessing directly mapped I / O memory areas, the function unsigned readl (address) is used;
Some dizzy, what's the difference between these two functions? Prawn help solve it!

520manta

Features:

Read data from the memory mapped I/O space.

Readb() Read 8-bit data (1 byte) from I/O

Readw() read 16-bit data (2 bytes) from I/O
Readl() read 8-bit data (4 bytes) from I/O

prototype:

#include <asm/io.h>

Unsigned char readb(unsigned int addr)

Unsigned char readw(unsigned int addr)

Unsigned char readl(unsigned int addr)

variable

Addr is the I/O address

Return value: The value read from the I/O space.