i2c: octeon: Fix high-level controller status check

In case the high-level controller (HLC) is used the status code is
reported at a different location. Check that location after HLC
write operations if the ready bit is not set and return an appropriate
error code instead of always returning -EAGAIN.

Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

1 files changed, 14 insertions, 9 deletions

diff --git a/drivers/i2c/busses/i2c-octeon-core.c b/drivers/i2c/busses/i2c-octeon-core.c
index 7d4df8383b38..5e63b17f935d 100644
--- a/drivers/i2c/busses/i2c-octeon-core.c
+++ b/drivers/i2c/busses/i2c-octeon-core.c
@@ -215,7 +215,16 @@ static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c)
 
 static int octeon_i2c_check_status(struct octeon_i2c *i2c, int final_read)
 {
-        u8 stat = octeon_i2c_stat_read(i2c);
+        u8 stat;
+
+        /*
+         * This is ugly... in HLC mode the status is not in the status register
+         * but in the lower 8 bits of SW_TWSI.
+         */
+        if (i2c->hlc_enabled)
+                stat = __raw_readq(i2c->twsi_base + SW_TWSI(i2c));
+        else
+                stat = octeon_i2c_stat_read(i2c);
 
         switch (stat) {
         /* Everything is fine */
@@ -453,7 +462,7 @@ static int octeon_i2c_hlc_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
 
         cmd = __raw_readq(i2c->twsi_base + SW_TWSI(i2c));
         if ((cmd & SW_TWSI_R) == 0)
-                return -EAGAIN;
+                return octeon_i2c_check_status(i2c, false);
 
         for (i = 0, j = msgs[0].len - 1; i  < msgs[0].len && i < 4; i++, j--)
                 msgs[0].buf[j] = (cmd >> (8 * i)) & 0xff;
@@ -506,9 +515,7 @@ static int octeon_i2c_hlc_write(struct octeon_i2c *i2c, struct i2c_msg *msgs)
 
         cmd = __raw_readq(i2c->twsi_base + SW_TWSI(i2c));
         if ((cmd & SW_TWSI_R) == 0)
-                return -EAGAIN;
-
-        ret = octeon_i2c_check_status(i2c, false);
+                return octeon_i2c_check_status(i2c, false);
 
 err:
         return ret;
@@ -553,7 +560,7 @@ static int octeon_i2c_hlc_comp_read(struct octeon_i2c *i2c, struct i2c_msg *msgs
 
         cmd = __raw_readq(i2c->twsi_base + SW_TWSI(i2c));
         if ((cmd & SW_TWSI_R) == 0)
-                return -EAGAIN;
+                return octeon_i2c_check_status(i2c, false);
 
         for (i = 0, j = msgs[1].len - 1; i  < msgs[1].len && i < 4; i++, j--)
                 msgs[1].buf[j] = (cmd >> (8 * i)) & 0xff;
@@ -617,9 +624,7 @@ static int octeon_i2c_hlc_comp_write(struct octeon_i2c *i2c, struct i2c_msg *msg
 
         cmd = __raw_readq(i2c->twsi_base + SW_TWSI(i2c));
         if ((cmd & SW_TWSI_R) == 0)
-                return -EAGAIN;
-
-        ret = octeon_i2c_check_status(i2c, false);
+                return octeon_i2c_check_status(i2c, false);
 
 err:
         return ret;