[PATCH v10] i2c-designware: make SDA hold time configurable

[Arnd Bergmann]

On Wednesday 26 June 2013, Wolfram Sang wrote:
>   On Wed, Jun 26, 2013 at 10:55:06AM +0200, Christian Ruppert wrote:
> > This patch makes the SDA hold time configurable through device tree.
> > 
> > Signed-off-by: Christian Ruppert <christian.ruppert at abilis.com>
> > Signed-off-by: Pierrick Hascoet <pierrick.hascoet at abilis.com>
> 
> Applied to for-next, thanks for keeping at it and providing lots of
> useful information. Much appreciated!

Sorry, but I got a regression that I didn't find reported elsewhere
so far, even though it breaks a lot of the ARM defconfig builds:

drivers/built-in.o: In function `dw_i2c_probe':
/git/arm-soc/drivers/i2c/busses/i2c-designware-platdrv.c:125: undefined reference to `__udivdi3'

I suspect you want something like the change below.

Signed-off-by: Arnd Bergmann <arnd at arndb.de>

diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index def79b5..57e3a07 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -119,10 +119,13 @@ static int dw_i2c_probe(struct platform_device *pdev)
 	if (pdev->dev.of_node) {
 		u32 ht = 0;
 		u32 ic_clk = dev->get_clk_rate_khz(dev);
+		u64 hold_time;
 
 		of_property_read_u32(pdev->dev.of_node,
 					"i2c-sda-hold-time-ns", &ht);
-		dev->sda_hold_time = ((u64)ic_clk * ht + 500000) / 1000000;
+		hold_time = (u64)ic_clk * ht + 500000;
+		do_div(hold_time, 1000000);
+		dev->sda_hold_time = hold_time;
 	}
 
 	dev->functionality =