Commit 78e1cf42 authored Dec 07, 2011 by Jan Weitzel Committed by Ben Dooks Jan 17, 2012

I2C: OMAP: NACK without STP



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>

parent 2727b175

drivers/i2c/busses/i2c-omap.c

+2 −4

Original line number	Diff line number	Diff line
		@@ -830,11 +830,9 @@ omap_i2c_isr(int this_irq, void *dev_id)
		~(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;