1 files changed, 31 insertions, 14 deletions

diff --git a/drivers/i2c/busses/i2c-sis630.c b/drivers/i2c/busses/i2c-sis630.c
index e152d36b94ac..b2fa7415f7e4 100644
--- a/drivers/i2c/busses/i2c-sis630.c
+++ b/drivers/i2c/busses/i2c-sis630.c
@@ -81,6 +81,21 @@
 #define SMB_COUNT               0x07    /* byte count */
 #define SMB_BYTE                0x08    /* ~0x8F data byte field */
 
+/* SMB_STS register */
+#define BYTE_DONE_STS           0x10    /* Byte Done Status / Block Array */
+#define SMBCOL_STS              0x04    /* Collision */
+#define SMBERR_STS              0x02    /* Device error */
+
+/* SMB_CNT register */
+#define MSTO_EN                 0x40    /* Host Master Timeout Enable */
+#define SMBCLK_SEL              0x20    /* Host master clock selection */
+#define SMB_PROBE               0x02    /* Bus Probe/Slave busy */
+#define SMB_HOSTBUSY            0x01    /* Host Busy */
+
+/* SMBHOST_CNT register */
+#define SMB_KILL                0x20    /* Kill */
+#define SMB_START               0x10    /* Start */
+
 /* register count for request_region
  * As we don't use SMB_PCOUNT, 20 is ok for SiS630 and SiS964
  */
@@ -140,12 +155,14 @@ static int sis630_transaction_start(struct i2c_adapter *adap, int size, u8 *oldc
         int temp;
 
         /* Make sure the SMBus host is ready to start transmitting. */
-        if ((temp = sis630_read(SMB_CNT) & 0x03) != 0x00) {
-                dev_dbg(&adap->dev, "SMBus busy (%02x).Resetting...\n",temp);
+        temp = sis630_read(SMB_CNT);
+        if ((temp & (SMB_PROBE | SMB_HOSTBUSY)) != 0x00) {
+                dev_dbg(&adap->dev, "SMBus busy (%02x). Resetting...\n", temp);
                 /* kill smbus transaction */
-                sis630_write(SMBHOST_CNT, 0x20);
+                sis630_write(SMBHOST_CNT, SMB_KILL);
 
-                if ((temp = sis630_read(SMB_CNT) & 0x03) != 0x00) {
+                temp = sis630_read(SMB_CNT);
+                if (temp & (SMB_PROBE | SMB_HOSTBUSY)) {
                         dev_dbg(&adap->dev, "Failed! (%02x)\n", temp);
                         return -EBUSY;
                 } else {
@@ -160,16 +177,16 @@ static int sis630_transaction_start(struct i2c_adapter *adap, int size, u8 *oldc
 
         /* disable timeout interrupt , set Host Master Clock to 56KHz if requested */
         if (high_clock)
-                sis630_write(SMB_CNT, 0x20);
+                sis630_write(SMB_CNT, SMBCLK_SEL);
         else
-                sis630_write(SMB_CNT, (*oldclock & ~0x40));
+                sis630_write(SMB_CNT, (*oldclock & ~MSTO_EN));
 
         /* clear all sticky bits */
         temp = sis630_read(SMB_STS);
         sis630_write(SMB_STS, temp & 0x1e);
 
         /* start the transaction by setting bit 4 and size */
-        sis630_write(SMBHOST_CNT,0x10 | (size & 0x07));
+        sis630_write(SMBHOST_CNT, SMB_START | (size & 0x07));
 
         return 0;
 }
@@ -183,7 +200,7 @@ static int sis630_transaction_wait(struct i2c_adapter *adap, int size)
                 msleep(1);
                 temp = sis630_read(SMB_STS);
                 /* check if block transmitted */
-                if (size == SIS630_BLOCK_DATA && (temp & 0x10))
+                if (size == SIS630_BLOCK_DATA && (temp & BYTE_DONE_STS))
                         break;
         } while (!(temp & 0x0e) && (timeout++ < MAX_TIMEOUT));
 
@@ -193,12 +210,12 @@ static int sis630_transaction_wait(struct i2c_adapter *adap, int size)
                 result = -ETIMEDOUT;
         }
 
-        if (temp & 0x02) {
+        if (temp & SMBERR_STS) {
                 dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
                 result = -ENXIO;
         }
 
-        if (temp & 0x04) {
+        if (temp & SMBCOL_STS) {
                 dev_err(&adap->dev, "Bus collision!\n");
                 result = -EAGAIN;
         }
@@ -217,8 +234,8 @@ static void sis630_transaction_end(struct i2c_adapter *adap, u8 oldclock)
          * restore old Host Master Clock if high_clock is set
          * and oldclock was not 56KHz
          */
-        if (high_clock && !(oldclock & 0x20))
-                sis630_write(SMB_CNT,(sis630_read(SMB_CNT) & ~0x20));
+        if (high_clock && !(oldclock & SMBCLK_SEL))
+                sis630_write(SMB_CNT, sis630_read(SMB_CNT) & ~SMBCLK_SEL);
 
         dev_dbg(&adap->dev, "SMB_CNT after clock restore 0x%02x\n", sis630_read(SMB_CNT));
 }
@@ -270,7 +287,7 @@ static int sis630_block_data(struct i2c_adapter *adap, union i2c_smbus_data *dat
                                            we must clear sticky bit.
                                            clear SMBARY_STS
                                         */
-                                        sis630_write(SMB_STS,0x10);
+                                        sis630_write(SMB_STS, BYTE_DONE_STS);
                                 }
                                 rc = sis630_transaction_wait(adap,
                                                 SIS630_BLOCK_DATA);
@@ -312,7 +329,7 @@ static int sis630_block_data(struct i2c_adapter *adap, union i2c_smbus_data *dat
                         dev_dbg(&adap->dev, "clear smbary_sts len=%d i=%d\n",len,i);
 
                         /* clear SMBARY_STS */
-                        sis630_write(SMB_STS,0x10);
+                        sis630_write(SMB_STS, BYTE_DONE_STS);
                 } while(len < data->block[0]);
         }