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authorPeter Milne <peter.milne@d-tacq.com>2006-07-01 17:03:20 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2006-07-12 15:43:06 -0700
commit39288e1ac10b3b9a68a629be67d81a0b53512c4e (patch)
tree6919a260a100cf19581d1641b22d1d982080528b /drivers/i2c
parent2369df933f1c632ec3f230774019e37c3969b7ec (diff)
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[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>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/busses/i2c-iop3xx.c17
-rw-r--r--drivers/i2c/busses/i2c-iop3xx.h2
2 files changed, 11 insertions, 8 deletions
diff --git a/drivers/i2c/busses/i2c-iop3xx.c b/drivers/i2c/busses/i2c-iop3xx.c
index aca7e1668605..48c56939c861 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 @@ iop3xx_i2c_reset(struct i2c_algo_iop3xx_data *iop3xx_adap)
}
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 @@ iop3xx_i2c_send_target_addr(struct i2c_algo_iop3xx_data *iop3xx_adap,
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 @@ iop3xx_i2c_probe(struct platform_device *pdev)
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);
diff --git a/drivers/i2c/busses/i2c-iop3xx.h b/drivers/i2c/busses/i2c-iop3xx.h
index e46ebaea7b1e..8485861f6a36 100644
--- a/drivers/i2c/busses/i2c-iop3xx.h
+++ b/drivers/i2c/busses/i2c-iop3xx.h
@@ -80,7 +80,7 @@
#define IOP3XX_GPOD_I2C0 0x00c0 /* clear these bits to enable ch0 */
#define IOP3XX_GPOD_I2C1 0x0030 /* clear these bits to enable ch1 */
-#define MYSAR 0x02 /* SWAG a suitable slave address */
+#define MYSAR 0 /* default slave address */
#define I2C_ERR 321
#define I2C_ERR_BERR (I2C_ERR+0)
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