via: Rationalize vt1636 detection

The code was ugly and didn't check whether i2c operations were succeeding;
make it a little better.

Cc: ScottFang@viatech.com.cn
Cc: JosephChan@via.com.tw
Cc: Harald Welte <laforge@gnumonks.org>
Acked-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

1 files changed, 7 insertions, 13 deletions

diff --git a/drivers/video/via/vt1636.c b/drivers/video/via/vt1636.c
index e9f3661d6b3f..e5f802472883 100644
--- a/drivers/video/via/vt1636.c
+++ b/drivers/video/via/vt1636.c
@@ -167,26 +167,20 @@ bool viafb_lvds_identify_vt1636(u8 i2c_adapter)
 
         /* Sense VT1636 LVDS Transmiter */
         viaparinfo->chip_info->lvds_chip_info.lvds_chip_slave_addr =
-        VT1636_LVDS_I2C_ADDR;
+                VT1636_LVDS_I2C_ADDR;
 
         /* Check vendor ID first: */
-        viafb_i2c_readbyte(i2c_adapter,
-                           (u8) viaparinfo->chip_info->lvds_chip_info.lvds_chip_slave_addr,
-                           0x00, &Buffer[0]);
-        viafb_i2c_readbyte(i2c_adapter,
-                           (u8) viaparinfo->chip_info->lvds_chip_info.lvds_chip_slave_addr,
-                           0x01, &Buffer[1]);
+        if (viafb_i2c_readbyte(i2c_adapter, VT1636_LVDS_I2C_ADDR,
+                                        0x00, &Buffer[0]))
+                return false;
+        viafb_i2c_readbyte(i2c_adapter, VT1636_LVDS_I2C_ADDR, 0x01, &Buffer[1]);
 
         if (!((Buffer[0] == 0x06) && (Buffer[1] == 0x11)))
                 return false;
 
         /* Check Chip ID: */
-        viafb_i2c_readbyte(i2c_adapter,
-                           (u8) viaparinfo->chip_info->lvds_chip_info.lvds_chip_slave_addr,
-                           0x02, &Buffer[0]);
-        viafb_i2c_readbyte(i2c_adapter,
-                           (u8) viaparinfo->chip_info->lvds_chip_info.lvds_chip_slave_addr,
-                           0x03, &Buffer[1]);
+        viafb_i2c_readbyte(i2c_adapter, VT1636_LVDS_I2C_ADDR, 0x02, &Buffer[0]);
+        viafb_i2c_readbyte(i2c_adapter, VT1636_LVDS_I2C_ADDR, 0x03, &Buffer[1]);
         if ((Buffer[0] == 0x45) && (Buffer[1] == 0x33)) {
                 viaparinfo->chip_info->lvds_chip_info.lvds_chip_name =
                         VT1636_LVDS;