/* SPDX-License-Identifier: GPL-2.0-only */ #include #include #include #include #include /* warning: Porting.h includes an open #pragma pack(1) */ #include #include #include #include /*----------------------------------------------------------------------------- * * readSmbusByteData - read a single SPD byte from any offset */ static int readSmbusByteData(int iobase, int address, char *buffer, int offset) { unsigned int status; UINT64 limit; address |= 1; // set read bit __outbyte(iobase + 0, 0xFF); // clear error status __outbyte(iobase + 1, 0x1F); // clear error status __outbyte(iobase + 3, offset); // offset in eeprom __outbyte(iobase + 4, address); // slave address and read bit __outbyte(iobase + 2, 0x48); // read byte command // time limit to avoid hanging for unexpected error status (should never happen) limit = __rdtsc() + 2000000000 / 10; for (;;) { status = __inbyte(iobase); if (__rdtsc() > limit) break; if ((status & 2) == 0) continue; // SMBusInterrupt not set, keep waiting if ((status & 1) == 1) continue; // HostBusy set, keep waiting break; } buffer [0] = __inbyte(iobase + 5); if (status == 2) status = 0; // check for done with no errors return status; } /*----------------------------------------------------------------------------- * * readSmbusByte - read a single SPD byte from the default offset * this function is faster function readSmbusByteData */ static int readSmbusByte(int iobase, int address, char *buffer) { unsigned int status; UINT64 limit; __outbyte(iobase + 0, 0xFF); // clear error status __outbyte(iobase + 2, 0x44); // read command // time limit to avoid hanging for unexpected error status limit = __rdtsc() + 2000000000 / 10; for (;;) { status = __inbyte(iobase); if (__rdtsc() > limit) break; if ((status & 2) == 0) continue; // SMBusInterrupt not set, keep waiting if ((status & 1) == 1) continue; // HostBusy set, keep waiting break; } buffer [0] = __inbyte(iobase + 5); if (status == 2) status = 0; // check for done with no errors return status; } /*--------------------------------------------------------------------------- * * readspd - Read one or more SPD bytes from a DIMM. * Start with offset zero and read sequentially. * Optimization relies on autoincrement to avoid * sending offset for every byte. * Reads 128 bytes in 7-8 ms at 400 KHz. */ static int readspd(int iobase, int SmbusSlaveAddress, char *buffer, int count) { int index, error; printk(BIOS_SPEW, "-------------READING SPD-----------\n"); printk(BIOS_SPEW, "iobase: 0x%08X, SmbusSlave: 0x%08X, count: %d\n", iobase, SmbusSlaveAddress, count); /* read the first byte using offset zero */ error = readSmbusByteData(iobase, SmbusSlaveAddress, buffer, 0); if (error) { printk(BIOS_ERR, "-------------SPD READ ERROR-----------\n"); return error; } /* read the remaining bytes using auto-increment for speed */ for (index = 1; index < count; index++) { error = readSmbusByte(iobase, SmbusSlaveAddress, &buffer [index]); if (error) { printk(BIOS_ERR, "-------------SPD READ ERROR-----------\n"); return error; } } printk(BIOS_SPEW, "\n"); printk(BIOS_SPEW, "-------------FINISHED READING SPD-----------\n"); return 0; } static void setupFch(int ioBase) { pm_write16(0x2c, ioBase | 1); __outbyte(ioBase + 0x0E, 66000000 / 400000 / 4); // set SMBus clock to 400 KHz } int hudson_readSpd(int spdAddress, char *buf, size_t len) { int ioBase = 0xB00; setupFch(ioBase); return readspd(ioBase, spdAddress, buf, len); }