redonkable/remarkable-linux
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[PATCH] i2c-iop3xx: Avoid addressing self

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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>
This commit is contained in:
Peter Milne 2006-07-01 17:03:20 +02:00 committed by Greg Kroah-Hartman
parent 2369df933f
commit 39288e1ac1
2 changed files with 11 additions and 8 deletions
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17
drivers/i2c/busses/i2c-iop3xx.c
View file

@ -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.
@ -72,12 +75,6 @@ iop3xx_i2c_reset(struct i2c_algo_iop3xx_data *iop3xx_adap)
__raw_writel(0, iop3xx_adap->ioaddr + CR_OFFSET);
}
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)
{
@ -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);

2
drivers/i2c/busses/i2c-iop3xx.h
View file

@ -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)