I2C: OMAP: NACK without STP
Jan Weitzel [Wed, 7 Dec 2011 19:50:16 +0000 (11:50 -0800)]
On OMAP4 OMAP_I2C_STAT_NACK is causing a timeout on the next access.
The isr cleans all flags in OMAP_I2C_CON_REG by setting OMAP_I2C_CON_STP
OMAP_I2C_CON_STP is also set in omap_i2c_xfer_msg on the last message.

According to the TI TSR the sequence for OMAP_I2C_STAT_NACK and
OMAP_I2C_STAT_AL are nearly the same.
Removing the OMAP_I2C_CON_STP part in the isr fix the problem.
Tested on OMAP4430 and OMAP3530 (here NACK was not a problem)
Fixes also booting on 2430sdp.

Signed-off-by: Jan Weitzel <j.weitzel@phytec.de>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>

drivers/i2c/busses/i2c-omap.c

index 257c1a5..e0733b7 100644 (file)
@@ -830,11 +830,9 @@ complete:
                                ~(OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR |
                                OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR));
 
-               if (stat & OMAP_I2C_STAT_NACK) {
+               if (stat & OMAP_I2C_STAT_NACK)
                        err |= OMAP_I2C_STAT_NACK;
-                       omap_i2c_write_reg(dev, OMAP_I2C_CON_REG,
-                                          OMAP_I2C_CON_STP);
-               }
+
                if (stat & OMAP_I2C_STAT_AL) {
                        dev_err(dev->dev, "Arbitration lost\n");
                        err |= OMAP_I2C_STAT_AL;