diff options
Diffstat (limited to 'src/southbridge/intel/i82801dbm/i82801dbm_early_smbus.c')
| -rw-r--r-- | src/southbridge/intel/i82801dbm/i82801dbm_early_smbus.c | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/src/southbridge/intel/i82801dbm/i82801dbm_early_smbus.c b/src/southbridge/intel/i82801dbm/i82801dbm_early_smbus.c new file mode 100644 index 0000000000..ed014f1a86 --- /dev/null +++ b/src/southbridge/intel/i82801dbm/i82801dbm_early_smbus.c @@ -0,0 +1,156 @@ + +//#define SMBUS_IO_BASE 0x1000 +#define SMBUS_IO_BASE 0x0f00 + +#define SMBHSTSTAT 0x0 +#define SMBHSTCTL 0x2 +#define SMBHSTCMD 0x3 +#define SMBXMITADD 0x4 +#define SMBHSTDAT0 0x5 +#define SMBHSTDAT1 0x6 +#define SMBBLKDAT 0x7 +#define SMBTRNSADD 0x9 +#define SMBSLVDATA 0xa +#define SMLINK_PIN_CTL 0xe +#define SMBUS_PIN_CTL 0xf + +/* Between 1-10 seconds, We should never timeout normally + * Longer than this is just painful when a timeout condition occurs. + */ +#define SMBUS_TIMEOUT (100*1000*10) + +static void enable_smbus(void) +{ + device_t dev; + dev = pci_locate_device(PCI_ID(0x8086, 0x24d3), 0); + if (dev == PCI_DEV_INVALID) { + die("SMBUS controller not found\r\n"); + } + + print_debug("SMBus controller enabled\r\n"); + /* set smbus iobase */ + pci_write_config32(dev, 0x20, SMBUS_IO_BASE | 1); + /* Set smbus enable */ + pci_write_config8(dev, 0x40, 0x01); + /* Set smbus iospace enable */ + pci_write_config16(dev, 0x4, 0x01); + /* Disable interrupt generation */ + outb(0, SMBUS_IO_BASE + SMBHSTCTL); + /* clear any lingering errors, so the transaction will run */ + outb(inb(SMBUS_IO_BASE + SMBHSTSTAT), SMBUS_IO_BASE + SMBHSTSTAT); +} + + +static inline void smbus_delay(void) +{ + outb(0x80, 0x80); +} + +static int smbus_wait_until_ready(void) +{ + unsigned long loops; + loops = SMBUS_TIMEOUT; + do { + unsigned char val; + smbus_delay(); + val = inb(SMBUS_IO_BASE + SMBHSTSTAT); + if ((val & 1) == 0) { + break; + } + if(loops == (SMBUS_TIMEOUT / 2)) { + outb(inb(SMBUS_IO_BASE + SMBHSTSTAT), + SMBUS_IO_BASE + SMBHSTSTAT); + } + } while(--loops); + return loops?0:-2; +} + +static int smbus_wait_until_done(void) +{ + unsigned long loops; + loops = SMBUS_TIMEOUT; + do { + unsigned char val; + smbus_delay(); + + val = inb(SMBUS_IO_BASE + SMBHSTSTAT); + if ( (val & 1) == 0) { + break; + } + if ((val & ~((1<<6)|(1<<0)) ) != 0 ) { + break; + } + } while(--loops); + return loops?0:-3; +} + +static int smbus_read_byte(unsigned device, unsigned address) +{ + unsigned char global_control_register; + unsigned char global_status_register; + unsigned char byte; + + if (smbus_wait_until_ready() < 0) { + return -2; + } + + /* setup transaction */ + /* disable interrupts */ + outb(inb(SMBUS_IO_BASE + SMBHSTCTL) & 0xfe, SMBUS_IO_BASE + SMBHSTCTL); + /* set the device I'm talking too */ + outb(((device & 0x7f) << 1) | 1, SMBUS_IO_BASE + SMBXMITADD); + /* set the command/address... */ + outb(address & 0xFF, SMBUS_IO_BASE + SMBHSTCMD); + /* set up for a byte data read */ + outb((inb(SMBUS_IO_BASE + SMBHSTCTL) & 0xe3) | (0x2<<2), SMBUS_IO_BASE + SMBHSTCTL); + + /* clear any lingering errors, so the transaction will run */ + outb(inb(SMBUS_IO_BASE + SMBHSTSTAT), SMBUS_IO_BASE + SMBHSTSTAT); + + /* clear the data byte...*/ + outb(0, SMBUS_IO_BASE + SMBHSTDAT0); + + /* start a byte read, with interrupts disabled */ + outb((inb(SMBUS_IO_BASE + SMBHSTCTL) | 0x40), SMBUS_IO_BASE + SMBHSTCTL); + + + /* poll for transaction completion */ + if (smbus_wait_until_done() < 0) { + return -3; + } + + global_status_register = inb(SMBUS_IO_BASE + SMBHSTSTAT) & ~(1<<6); /* Ignore the In Use Status... */ + + /* read results of transaction */ + byte = inb(SMBUS_IO_BASE + SMBHSTDAT0); + + if (global_status_register != 2) { + return -1; + } + return byte; +} +#if 0 +static void smbus_write_byte(unsigned device, unsigned address, unsigned char val) +{ + if (smbus_wait_until_ready() < 0) { + return; + } + + /* by LYH */ + outb(0x37,SMBUS_IO_BASE + SMBHSTSTAT); + /* set the device I'm talking too */ + outw(((device & 0x7f) << 1) | 0, SMBUS_IO_BASE + SMBHSTADDR); + + /* data to send */ + outb(val, SMBUS_IO_BASE + SMBHSTDAT); + + outb(address & 0xFF, SMBUS_IO_BASE + SMBHSTCMD); + + /* start the command */ + outb(0xa, SMBUS_IO_BASE + SMBHSTCTL); + + /* poll for transaction completion */ + smbus_wait_until_done(); + return; +} +#endif |