i2c-s3c2410: fix calculation of SDA line delay

myungjoo · Ben Dooks · commit 7031307aefb6 · 2010-10-01T00:00:35.000+01:00
S3C2440 style I2C controller uses PCLK to calculate the SDA line delay.
The driver wrongly assumed that this delay is calculated from the
frequency that the controller is operating on. This patch fixes this
issue.

Signed-off-by: MyungJoo Ham &lt;myungjoo.ham@samsung.com&gt;
Signed-off-by: Kyungmin Park &lt;kyungmin.park@samsung.com&gt;
Signed-off-by: Marek Szyprowski &lt;m.szyprowski@samsung.com&gt;
Signed-off-by: Ben Dooks &lt;ben-linux@fluff.org&gt;
diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
@@ -662,8 +662,8 @@ static int s3c24xx_i2c_clockrate(struct s3c24xx_i2c *i2c, unsigned int *got)
 		unsigned long sda_delay;
 
 		if (pdata->sda_delay) {
-			sda_delay = (freq / 1000) * pdata->sda_delay;
-			sda_delay /= 1000000;
+			sda_delay = clkin * pdata->sda_delay;
+			sda_delay = DIV_ROUND_UP(sda_delay, 1000000);
 			sda_delay = DIV_ROUND_UP(sda_delay, 5);
 			if (sda_delay > 3)
 				sda_delay = 3;
