i2c: fsl_i2c: i2c_read(): dont try to write address w/ alen=0

if alen is 0: no longer start a write cycle before reading data.

Signed-off-by: Dirk Eibach <dirk.eibach@gdsys.cc>
Signed-off-by: Reinhard Pfau <reinhard.pfau@gdsys.cc>
Acked-by: Heiko Schocher <hs@denx.de>
Signed-off-by: Andy Fleming <afleming@freescale.com>

diff --git a/drivers/i2c/fsl_i2c.c b/drivers/i2c/fsl_i2c.c
index 1c7265d897eea8f97fbd6254e3da4208ec7a3560..5d7e010319729a2cb4cb96cccbfd5d742db4d467 100644 (file)
--- a/drivers/i2c/fsl_i2c.c
+++ b/drivers/i2c/fsl_i2c.c
@@ -383,13 +383,16 @@ i2c_read(u8 dev, uint addr, int alen, u8 *data, int length)
        int i = -1; /* signal error */
        u8 *a = (u8*)&addr;
 
-       if (i2c_wait4bus() >= 0
+       if (i2c_wait4bus() < 0)
+               return -1;
+
+       if ((!length || alen > 0)
            && i2c_write_addr(dev, I2C_WRITE_BIT, 0) != 0
            && __i2c_write(&a[4 - alen], alen) == alen)
                i = 0; /* No error so far */
 
-       if (length
-           && i2c_write_addr(dev, I2C_READ_BIT, 1) != 0)
+       if (length &&
+           i2c_write_addr(dev, I2C_READ_BIT, alen ? 1 : 0) != 0)
                i = __i2c_read(data, length);
 
        writeb(I2C_CR_MEN, &i2c_dev[i2c_bus_num]->cr);