Lvds Backlight Brightness Control - MSI MS-98E6 Manual

if (val) printf ("timeout event occurred");
else printf ("timeout event not occurred");
2.6 Clear WDT Reset Flag
val = Inportb (WDT_BASE + 0x05);
val = val | 0x40;

LVDS Backlight Brightness Control

Outportb (WDT_BASE + 0x05, val);
3. LVDS Backlight Brightness Control
The LVDS controller support 17 level of backlight brightness value from 0 (30%) to 16
(100%) and it is accessible through SMBus. The associated access method
(SMBus_ReadByte, SMBus_WriteByte) are provided in part 4.
MSI Industrial Platform Computing
3.1 Set the Level of LVDS Backlight
1. Write 0xED into address 0x7F on SMBus device 0x42.
2. Write desired backlight level from 0x0 (30%) to 0x10 (100%) into address 0x6E on
SMBus device 0x42.
Example: Set LVDS backlight level to 0x10 (100%)
SMBus_WriteByte (0x42, 0x7F, 0xED);
SMBus_WriteByte (0x42, 0x6E, 0x10);
3.2 Read the Level of LVDS Backlight
1. Write 0xED into address 0x7F on SMBus device 0x42.
2. Read current backlight level from address 0x6E on SMBus device 0x42.
Example: Get LVDS backlight level
SMBus_WriteByte (0x42, 0x7F, 0xED);
BKL_Value = SMBus_ReadByte (0x42, 0x6E);
4. SMBus Access
The base address of SMBus must be known before access. The relevant bus and device
information are as following.
#define IO_SC
#define IO_DA
#define PCIBASEADDRESS
#define PCI_BUS_NUM
#define PCI_DEV_NUM
#define PCI_FUN_NUM
4.1 Get SMBus Base Address
int SMBUS_BASE;
int DATA_ADDR = PCIBASEADDRESS + (PCI_BUS_NUM<<16) +
Outportl
(DATA_ADDR + 0x20, IO_SC);
// Read current WDT setting
// Set 1 to WDTMOUT_STS (bit 6);
// Write back WDT setting
// Set brightness to 100%
0xCF8
0xCFC
0x80000000
0
31
1
(PCI_DEV_NUM<<11) +
(PCI_FUN_NUM<<8);
MS-98E6
3
A-5
4