[PATCH] i2c-iop3xx: Avoid addressing self
Avoid addressing self when sending a slave address. Follows instruction
in Intel 80331/80321 manuals.
Ignoring this worked previously on 80321, but causes a hang on i2cdetect
on 80331.
Signed-off-by: Peter Milne <peter.milne@d-tacq.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/i2c/busses/i2c-iop3xx.c b/drivers/i2c/busses/i2c-iop3xx.c
index aca7e16..48c5693 100644
--- a/drivers/i2c/busses/i2c-iop3xx.c
+++ b/drivers/i2c/busses/i2c-iop3xx.c
@@ -21,6 +21,9 @@
* - Make it work with IXP46x chips
* - Cleanup function names, coding style, etc
*
+ * - writing to slave address causes latchup on iop331.
+ * fix: driver refuses to address self.
+ *
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, version 2.
@@ -73,12 +76,6 @@
}
static void
-iop3xx_i2c_set_slave_addr(struct i2c_algo_iop3xx_data *iop3xx_adap)
-{
- __raw_writel(MYSAR, iop3xx_adap->ioaddr + SAR_OFFSET);
-}
-
-static void
iop3xx_i2c_enable(struct i2c_algo_iop3xx_data *iop3xx_adap)
{
u32 cr = IOP3XX_ICR_GCD | IOP3XX_ICR_SCLEN | IOP3XX_ICR_UE;
@@ -248,6 +245,13 @@
int status;
int rc;
+ /* avoid writing to my slave address (hangs on 80331),
+ * forbidden in Intel developer manual
+ */
+ if (msg->addr == MYSAR) {
+ return -EBUSY;
+ }
+
__raw_writel(iic_cook_addr(msg), iop3xx_adap->ioaddr + DBR_OFFSET);
cr &= ~(IOP3XX_ICR_MSTOP | IOP3XX_ICR_NACK);
@@ -498,7 +502,6 @@
spin_lock_init(&adapter_data->lock);
iop3xx_i2c_reset(adapter_data);
- iop3xx_i2c_set_slave_addr(adapter_data);
iop3xx_i2c_enable(adapter_data);
platform_set_drvdata(pdev, new_adapter);