From 2709781be6141798162f1089df728fb218a590df Mon Sep 17 00:00:00 2001 From: Ben Dooks Date: Tue, 1 Jul 2008 11:59:41 +0100 Subject: I2C: S3C2410: Check ACK on byte transmission We should check for the reception of an ACK after transmitting each data byte. The address send has been correctly checking this, but the data write byte state should have also been checking for these failures. As part of the same fix, we remove the ACK checking from the receive path where it should not have been checking for an ACK which our hardware was sending. Signed-off-by: Ben Dooks --- drivers/i2c/busses/i2c-s3c2410.c | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c index 1305ef1..7ad22c5 100644 --- a/drivers/i2c/busses/i2c-s3c2410.c +++ b/drivers/i2c/busses/i2c-s3c2410.c @@ -323,7 +323,17 @@ static int i2s_s3c_irq_nextbyte(struct s3c24xx_i2c *i2c, unsigned long iicstat) * end of the message, and if so, work out what to do */ + if (!(i2c->msg->flags & I2C_M_IGNORE_NAK)) { + if (iicstat & S3C2410_IICSTAT_LASTBIT) { + dev_dbg(i2c->dev, "WRITE: No Ack\n"); + + s3c24xx_i2c_stop(i2c, -ECONNREFUSED); + goto out_ack; + } + } + retry_write: + if (!is_msgend(i2c)) { byte = i2c->msg->buf[i2c->msg_ptr++]; writeb(byte, i2c->regs + S3C2410_IICDS); @@ -377,17 +387,6 @@ static int i2s_s3c_irq_nextbyte(struct s3c24xx_i2c *i2c, unsigned long iicstat) * going to do any more read/write */ - if (!(i2c->msg->flags & I2C_M_IGNORE_NAK) && - !(is_msglast(i2c) && is_lastmsg(i2c))) { - - if (iicstat & S3C2410_IICSTAT_LASTBIT) { - dev_dbg(i2c->dev, "READ: No Ack\n"); - - s3c24xx_i2c_stop(i2c, -ECONNREFUSED); - goto out_ack; - } - } - byte = readb(i2c->regs + S3C2410_IICDS); i2c->msg->buf[i2c->msg_ptr++] = byte; -- cgit v1.1 From 63f5c2891eae6b4dd0538ef094e5f256d6150d7b Mon Sep 17 00:00:00 2001 From: Ben Dooks Date: Tue, 1 Jul 2008 11:59:42 +0100 Subject: I2C: S3C2410: Fixup error codes returned rom a transfer. The driver should be returning -ENXIO for transfers that do not pass the initial address byte stage. Note, also small tidyups to the driver comments in the area. Signed-off-by: Ben Dooks --- drivers/i2c/busses/i2c-s3c2410.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c index 7ad22c5..d2645da 100644 --- a/drivers/i2c/busses/i2c-s3c2410.c +++ b/drivers/i2c/busses/i2c-s3c2410.c @@ -290,12 +290,12 @@ static int i2s_s3c_irq_nextbyte(struct s3c24xx_i2c *i2c, unsigned long iicstat) * bus, or started a new i2c message */ - if (iicstat & S3C2410_IICSTAT_LASTBIT && + if (iicstat & S3C2410_IICSTAT_LASTBIT && !(i2c->msg->flags & I2C_M_IGNORE_NAK)) { /* ack was not received... */ dev_dbg(i2c->dev, "ack was not received\n"); - s3c24xx_i2c_stop(i2c, -EREMOTEIO); + s3c24xx_i2c_stop(i2c, -ENXIO); goto out_ack; } @@ -305,7 +305,7 @@ static int i2s_s3c_irq_nextbyte(struct s3c24xx_i2c *i2c, unsigned long iicstat) i2c->state = STATE_WRITE; /* terminate the transfer if there is nothing to do - * (used by the i2c probe to find devices */ + * as this is used by the i2c probe to find devices. */ if (is_lastmsg(i2c) && i2c->msg->len == 0) { s3c24xx_i2c_stop(i2c, 0); -- cgit v1.1 From d150a4bbd0e5c6427e66086b139953428680160b Mon Sep 17 00:00:00 2001 From: Ben Dooks Date: Tue, 1 Jul 2008 11:59:43 +0100 Subject: I2C: S3C2410: Add MODULE_ALIAS() for s3c2440 device. Add a MODULE_ALIAS() statement for the i2c-s3c2410 controller to ensure that it can be autoloaded on the S3C2440 systems that we support. Signed-off-by: Ben Dooks --- drivers/i2c/busses/i2c-s3c2410.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c index d2645da..9e8c875 100644 --- a/drivers/i2c/busses/i2c-s3c2410.c +++ b/drivers/i2c/busses/i2c-s3c2410.c @@ -948,3 +948,4 @@ MODULE_DESCRIPTION("S3C24XX I2C Bus driver"); MODULE_AUTHOR("Ben Dooks, "); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:s3c2410-i2c"); +MODULE_ALIAS("platform:s3c2440-i2c"); -- cgit v1.1