[PATCH v2] i2c-imx: wait for STOP before disabling controller

Marc Reilly marc at cpdesign.com.au
Fri Oct 1 00:30:59 EDT 2010


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 at 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..ef7be65 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




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