#include <device/smbus_def.h> #include "i82371eb.h" #define SMBHST_STATUS 0x0 #define SMBHST_CTL 0x2 #define SMBHST_CMD 0x3 #define SMBHST_ADDR 0x4 #define SMBHST_DAT 0x5 #define SMBUS_TIMEOUT (100*1000*10) #define SMBUS_STATUS_MASK 0x1e #define SMBUS_ERROR_FLAG (1<<2) int do_smbus_read_byte(unsigned smbus_io_base, unsigned device, unsigned address); static inline void smbus_delay(void) { outb(0x80, 0x80); outb(0x80, 0x80); outb(0x80, 0x80); outb(0x80, 0x80); outb(0x80, 0x80); outb(0x80, 0x80); } static int smbus_wait_until_ready(unsigned smbus_io_base) { unsigned long loops; loops = SMBUS_TIMEOUT; do { unsigned char val; smbus_delay(); val = inb(smbus_io_base + SMBHST_STATUS); if ((val & 0x1) == 0) { break; } #if 0 if(loops == (SMBUS_TIMEOUT / 2)) { outw(inw(smbus_io_base + SMBHST_STATUS), smbus_io_base + SMBHST_STATUS); } #endif } while(--loops); return loops?0:SMBUS_WAIT_UNTIL_READY_TIMEOUT; } static int smbus_wait_until_done(unsigned smbus_io_base) { unsigned long loops; loops = SMBUS_TIMEOUT; do { unsigned short val; smbus_delay(); val = inb(smbus_io_base + SMBHST_STATUS); // Make sure the command is done if ((val & 0x1) != 0) { continue; } // Don't break out until one of the interrupt // flags is set. if (val & 0xfe) { break; } } while(--loops); return loops?0:SMBUS_WAIT_UNTIL_DONE_TIMEOUT; } int do_smbus_read_byte(unsigned smbus_io_base, unsigned device, unsigned address) { unsigned status_register; unsigned byte; if (smbus_wait_until_ready(smbus_io_base) < 0) { return SMBUS_WAIT_UNTIL_READY_TIMEOUT; } /* setup transaction */ /* clear any lingering errors, so the transaction will run */ outb(0x1e, smbus_io_base + SMBHST_STATUS); /* set the device I'm talking too */ outb(((device & 0x7f) << 1) | 1, smbus_io_base + SMBHST_ADDR); /* set the command/address... */ outb(address & 0xff, smbus_io_base + SMBHST_CMD); /* clear the data word...*/ outb(0, smbus_io_base + SMBHST_DAT); /* start a byte read with interrupts disabled */ outb( (0x02 << 2)|(1<<6), smbus_io_base + SMBHST_CTL); /* poll for transaction completion */ if (smbus_wait_until_done(smbus_io_base) < 0) { return SMBUS_WAIT_UNTIL_DONE_TIMEOUT; } status_register = inw(smbus_io_base + SMBHST_STATUS); /* read results of transaction */ byte = inw(smbus_io_base + SMBHST_DAT) & 0xff; if (status_register & 0x04) { #if 0 print_debug("Read fail "); print_debug_hex16(status_register); print_debug("\n"); #endif return SMBUS_ERROR; } return byte; }