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Diffstat (limited to 'src/southbridge/intel/bd82x6x')
-rw-r--r--src/southbridge/intel/bd82x6x/smbus.c57
1 files changed, 57 insertions, 0 deletions
diff --git a/src/southbridge/intel/bd82x6x/smbus.c b/src/southbridge/intel/bd82x6x/smbus.c
index 4786d8b6c9..6d4e457db7 100644
--- a/src/southbridge/intel/bd82x6x/smbus.c
+++ b/src/southbridge/intel/bd82x6x/smbus.c
@@ -58,8 +58,65 @@ static int lsmbus_read_byte(device_t dev, u8 address)
return do_smbus_read_byte(res->base, device, address);
}
+static int do_smbus_write_byte(unsigned smbus_base, unsigned device, unsigned address, unsigned data)
+{
+ unsigned char global_status_register;
+
+ if (smbus_wait_until_ready(smbus_base) < 0)
+ return SMBUS_WAIT_UNTIL_READY_TIMEOUT;
+
+ /* Setup transaction */
+ /* Disable interrupts */
+ outb(inb(smbus_base + SMBHSTCTL) & (~1), smbus_base + SMBHSTCTL);
+ /* Set the device I'm talking too */
+ outb(((device & 0x7f) << 1) & ~0x01, smbus_base + SMBXMITADD);
+ /* Set the command/address... */
+ outb(address & 0xff, smbus_base + SMBHSTCMD);
+ /* Set up for a byte data read */
+ outb((inb(smbus_base + SMBHSTCTL) & 0xe3) | (0x2 << 2),
+ (smbus_base + SMBHSTCTL));
+ /* Clear any lingering errors, so the transaction will run */
+ outb(inb(smbus_base + SMBHSTSTAT), smbus_base + SMBHSTSTAT);
+
+ /* Clear the data byte... */
+ outb(data, smbus_base + SMBHSTDAT0);
+
+ /* Start the command */
+ outb((inb(smbus_base + SMBHSTCTL) | 0x40),
+ smbus_base + SMBHSTCTL);
+
+ /* Poll for transaction completion */
+ if (smbus_wait_until_done(smbus_base) < 0)
+ return SMBUS_WAIT_UNTIL_DONE_TIMEOUT;
+
+ global_status_register = inb(smbus_base + SMBHSTSTAT);
+
+ /* Ignore the "In Use" status... */
+ global_status_register &= ~(3 << 5);
+
+ /* Read results of transaction */
+ if (global_status_register != (1 << 1))
+ return SMBUS_ERROR;
+
+ return 0;
+}
+
+static int lsmbus_write_byte(device_t dev, u8 address, u8 val)
+{
+ u16 device;
+ struct resource *res;
+ struct bus *pbus;
+
+ device = dev->path.i2c.device;
+ pbus = get_pbus_smbus(dev);
+ res = find_resource(pbus->dev, 0x20);
+
+ return do_smbus_write_byte(res->base, device, address, val);
+}
+
static struct smbus_bus_operations lops_smbus_bus = {
.read_byte = lsmbus_read_byte,
+ .write_byte = lsmbus_write_byte,
};
static void smbus_set_subsystem(device_t dev, unsigned vendor, unsigned device)