mail archive of the barebox mailing list
 help / color / mirror / Atom feed
* [PATCH] i2c-imx: wait for STOP before disabling controller
@ 2010-10-01  3:22 Marc Reilly
  2010-10-01  3:29 ` Jean-Christophe PLAGNIOL-VILLARD
  0 siblings, 1 reply; 2+ messages in thread
From: Marc Reilly @ 2010-10-01  3:22 UTC (permalink / raw)
  To: barebox

Makes sure that the STOP condition is transmitted before the I2C
controller is disabled.
This fixes a problem where writing to an external EEPROM was not working
because the EEPROM waits until the STOP before initiating the write
internally.

Signed-off-by: Marc Reilly <marc@cpdesign.com.au>
---
 drivers/i2c/i2c-imx.c |   10 +++++-----
 1 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/i2c/i2c-imx.c b/drivers/i2c/i2c-imx.c
index cc64d94..3e37441 100644
--- a/drivers/i2c/i2c-imx.c
+++ b/drivers/i2c/i2c-imx.c
@@ -265,7 +265,9 @@ static void i2c_imx_stop(struct i2c_adapter *adapter)
 		temp = readb(base + IMX_I2C_I2CR);
 		temp &= ~(I2CR_MSTA | I2CR_MTX);
 		writeb(temp, base + IMX_I2C_I2CR);
-		i2c_imx->stopped = 1;
+		/* wait for the stop condition to be send, otherwise the i2c 
+		 * controller is disabled before the STOP is sent completely */
+		i2c_imx->stopped = i2c_imx_bus_busy(adapter,0) ? 0 : 1;
 	}
 	if (cpu_is_mx1()) {
 		/*
@@ -275,11 +277,9 @@ static void i2c_imx_stop(struct i2c_adapter *adapter)
 		udelay(i2c_imx->disable_delay);
 	}
 
-	if (!i2c_imx->stopped)
-		i2c_imx_bus_busy(adapter, 0);
-
-	/* Disable I2C controller */
+	/* Disable I2C controller, and force our state to stopped */
 	writeb(0, base + IMX_I2C_I2CR);
+	i2c_imx->stopped = 1;
 }
 
 static void i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
-- 
1.7.1


_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox

^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: [PATCH] i2c-imx: wait for STOP before disabling controller
  2010-10-01  3:22 [PATCH] i2c-imx: wait for STOP before disabling controller Marc Reilly
@ 2010-10-01  3:29 ` Jean-Christophe PLAGNIOL-VILLARD
  0 siblings, 0 replies; 2+ messages in thread
From: Jean-Christophe PLAGNIOL-VILLARD @ 2010-10-01  3:29 UTC (permalink / raw)
  To: Marc Reilly; +Cc: barebox

On 13:22 Fri 01 Oct     , Marc Reilly wrote:
> Makes sure that the STOP condition is transmitted before the I2C
> controller is disabled.
> This fixes a problem where writing to an external EEPROM was not working
> because the EEPROM waits until the STOP before initiating the write
> internally.
> 
> Signed-off-by: Marc Reilly <marc@cpdesign.com.au>
> ---
>  drivers/i2c/i2c-imx.c |   10 +++++-----
>  1 files changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/i2c/i2c-imx.c b/drivers/i2c/i2c-imx.c
> index cc64d94..3e37441 100644
> --- a/drivers/i2c/i2c-imx.c
> +++ b/drivers/i2c/i2c-imx.c
> @@ -265,7 +265,9 @@ static void i2c_imx_stop(struct i2c_adapter *adapter)
>  		temp = readb(base + IMX_I2C_I2CR);
>  		temp &= ~(I2CR_MSTA | I2CR_MTX);
>  		writeb(temp, base + IMX_I2C_I2CR);
> -		i2c_imx->stopped = 1;
> +		/* wait for the stop condition to be send, otherwise the i2c 
> +		 * controller is disabled before the STOP is sent completely */
> +		i2c_imx->stopped = i2c_imx_bus_busy(adapter,0) ? 0 : 1;
	please add a space after the ","

Best Regards,
J.

_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox

^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2010-10-01  3:31 UTC | newest]

Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2010-10-01  3:22 [PATCH] i2c-imx: wait for STOP before disabling controller Marc Reilly
2010-10-01  3:29 ` Jean-Christophe PLAGNIOL-VILLARD

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox