add support for writing to SMBus with vt8237

Change-Id: I70fe072f8f3447d0be7b7ac64508a954fe47091d
Signed-off-by: Florian Zumbiehl <florz@florz.de>
Reviewed-on: http://review.coreboot.org/372
Tested-by: build bot (Jenkins)
Reviewed-by: Rudolf Marek <r.marek@assembler.cz>
This commit is contained in:
Florian Zumbiehl 2011-11-01 20:17:13 +01:00 committed by Rudolf Marek
parent 8c4cf18fc4
commit e037f9f174
2 changed files with 22 additions and 10 deletions

View File

@ -87,17 +87,12 @@ static void smbus_reset(void)
PRINT_DEBUG("\n");
}
/**
* Read a byte from the SMBus.
*
* @param dimm The address location of the DIMM on the SMBus.
* @param offset The offset the data is located at.
*/
u8 smbus_read_byte(u8 dimm, u8 offset)
static u8 smbus_transaction(u8 dimm, u8 offset, u8 data, int do_read)
{
u8 val;
PRINT_DEBUG("DIMM ");
PRINT_DEBUG(do_read ? "RD: " : "WR: ");
PRINT_DEBUG("ADDR ");
PRINT_DEBUG_HEX16(dimm);
PRINT_DEBUG(" OFFSET ");
PRINT_DEBUG_HEX16(offset);
@ -106,13 +101,13 @@ u8 smbus_read_byte(u8 dimm, u8 offset)
smbus_reset();
/* Clear host data port. */
outb(0x00, SMBHSTDAT0);
outb(do_read ? 0x00 : data, SMBHSTDAT0);
SMBUS_DELAY();
smbus_wait_until_ready();
/* Actual addr to reg format. */
dimm = (dimm << 1);
dimm |= 1;
dimm |= !!do_read;
outb(dimm, SMBXMITADD);
outb(offset, SMBHSTCMD);
@ -132,6 +127,22 @@ u8 smbus_read_byte(u8 dimm, u8 offset)
return val;
}
/**
* Read a byte from the SMBus.
*
* @param dimm The address location of the DIMM on the SMBus.
* @param offset The offset the data is located at.
*/
u8 smbus_read_byte(u8 dimm, u8 offset)
{
return smbus_transaction(dimm, offset, 0, 1);
}
void smbus_write_byte(u8 dimm, u8 offset, u8 data)
{
smbus_transaction(dimm, offset, data, 0);
}
#define PSONREADY_TIMEOUT 0x7fffffff
static device_t get_vt8237_lpc(void)

View File

@ -148,6 +148,7 @@ __attribute__ ((packed))
#ifdef __PRE_RAM__
#ifndef __ROMCC__
u8 smbus_read_byte(u8 dimm, u8 offset);
void smbus_write_byte(u8 dimm, u8 offset, u8 data);
void enable_smbus(void);
void smbus_fixup(const struct mem_controller *ctrl);
// these are in vt8237_early_smbus.c - do they really belong there?