BarinkOS/source/kernel/Drivers/PCI/pci.h

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C
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#pragma once
#include <stdint.h>
#include "io.h"
// Configuration Space Access Mechanism #1
#define CONFIG_ADDRESS 0xCF8 // Configuration adress that is to be accessed
#define CONFIG_DATA 0xCFC // Will do the actual configuration operation
/*
CONFIG_ADDRESS
32 bit register
bit 31 Enable bit (Should CONFIG_DATA be translatedc to configuration cycles)
bit 30 - 24 Reserved
bit 23 - 16 Bus Number (Choose a specific PCI BUS)
bit 15 - 11 Device Number (Selects specific device one the pci bus)
bit 10 - 8 Function Number (Selects a specific function in a device)
bit 7 - 0 Register Offset (Offset in the configuration space of 256 Bytes ) NOTE: lowest two bits will always be zero
*/
/*
PCI Device structure
Register offset bits 31-24 bits 23-16 bits 15-8 bits 7-0
00 00 Device ID <---- Vendor ID <-------
01 04 Status <---- Command <-------
02 08 Class code Sub class Prog IF Revision ID
03 0C BIST Header Type Ltncy Timer Cache line Size
04 10 Base address #0 (BAR0)
05 14 Base address #1 (BAR1)
06 18 Base address #2 (BAR2)
07 1C Base address #3 (BAR3)
08 20 Base address #4 (BAR4)
09 24 Base address #5 (BAR5)
0A 28 Cardbus CIS Pointer
0B 2C Subsystem ID <------ Subsystem Vendor ID <-------
0C 30 Expansion ROM base address
0D 34 Reserved <------- Capabilities Pointer <------
0E 38 Reserved <------- <-------- <--------
0F 3C Max ltncy Min Grant Interrupt PIN Interrupt Line
*/
/*
The idea for now is to support the minimal things necessary to find ATA supported drives
*/
// Lets write some boiler plate configuration code
uint16_t ConfigReadWord (uint8_t bus, uint8_t slot, uint8_t func, uint8_t offset);
uint16_t CheckVendor (uint8_t bus, uint8_t slot);
void checkDevice (uint8_t bus, uint8_t device );