+/* For multiplexing support, we need a global reference to the 1st
+ SMBus channel */
+#if defined CONFIG_I2C_NFORCE2_S4985 || defined CONFIG_I2C_NFORCE2_S4985_MODULE
+struct i2c_adapter *nforce2_smbus;
+EXPORT_SYMBOL_GPL(nforce2_smbus);
+
+static void nforce2_set_reference(struct i2c_adapter *adap)
+{
+ nforce2_smbus = adap;
+}
+#else
+static inline void nforce2_set_reference(struct i2c_adapter *adap) { }
+#endif
+
+static void nforce2_abort(struct i2c_adapter *adap)
+{
+ struct nforce2_smbus *smbus = adap->algo_data;
+ int timeout = 0;
+ unsigned char temp;
+
+ dev_dbg(&adap->dev, "Aborting current transaction\n");
+
+ outb_p(NVIDIA_SMB_CTRL_ABORT, NVIDIA_SMB_CTRL);
+ do {
+ msleep(1);
+ temp = inb_p(NVIDIA_SMB_STATUS_ABRT);
+ } while (!(temp & NVIDIA_SMB_STATUS_ABRT_STS) &&
+ (timeout++ < MAX_TIMEOUT));
+ if (!(temp & NVIDIA_SMB_STATUS_ABRT_STS))
+ dev_err(&adap->dev, "Can't reset the smbus\n");
+ outb_p(NVIDIA_SMB_STATUS_ABRT_STS, NVIDIA_SMB_STATUS_ABRT);
+}
+
+static int nforce2_check_status(struct i2c_adapter *adap)
+{
+ struct nforce2_smbus *smbus = adap->algo_data;
+ int timeout = 0;
+ unsigned char temp;
+
+ do {
+ msleep(1);
+ temp = inb_p(NVIDIA_SMB_STS);
+ } while ((!temp) && (timeout++ < MAX_TIMEOUT));
+
+ if (timeout > MAX_TIMEOUT) {
+ dev_dbg(&adap->dev, "SMBus Timeout!\n");
+ if (smbus->can_abort)
+ nforce2_abort(adap);
+ return -ETIMEDOUT;
+ }
+ if (!(temp & NVIDIA_SMB_STS_DONE) || (temp & NVIDIA_SMB_STS_STATUS)) {
+ dev_dbg(&adap->dev, "Transaction failed (0x%02x)!\n", temp);
+ return -EIO;
+ }
+ return 0;
+}
+
+/* Return negative errno on error */