[U-Boot] [PATCH 3/6] i2c: fsl_i2c: i2c_read(): dont try to write address w/ alen=0
Dirk Eibach
eibach at gdsys.de
Mon Apr 22 13:06:42 CEST 2013
From: Reinhard Pfau <pfau at gdsys.de>
if alen is 0: no longer start a write cycle before reading data.
Signed-off-by: Dirk Eibach <eibach at gdsys.de>
Signed-off-by: Reinhard Pfau <pfau at gdsys.de>
---
drivers/i2c/fsl_i2c.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/i2c/fsl_i2c.c b/drivers/i2c/fsl_i2c.c
index 1c7265d..276386d 100644
--- 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 (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)
+ && 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);
--
1.7.10.4
More information about the U-Boot
mailing list