[PATCH] ASoC: tegra: Fix build error due to 64-by-32 division

[Sameer Pujar]

Build errors are seen on 32-bit platforms because of a plain 64-by-32
division. For example, following build erros were reported.

"ERROR: modpost: "__udivdi3" [sound/soc/tegra/snd-soc-tegra210-dmic.ko]
 undefined!"
"ERROR: modpost: "__divdi3" [sound/soc/tegra/snd-soc-tegra210-dmic.ko]
 undefined!"

This can be fixed by using div_u64() helper from 'math64.h' header.

Fixes: 8c8ff982e9e2 ("ASoC: tegra: Add Tegra210 based DMIC driver")
Reported-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Reported-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Signed-off-by: Sameer Pujar <spujar@xxxxxxxxxx>
---
 sound/soc/tegra/tegra210_dmic.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sound/soc/tegra/tegra210_dmic.c b/sound/soc/tegra/tegra210_dmic.c
index ff6fd65..d682414 100644
--- a/sound/soc/tegra/tegra210_dmic.c
+++ b/sound/soc/tegra/tegra210_dmic.c
@@ -6,6 +6,7 @@
 
 #include <linux/clk.h>
 #include <linux/device.h>
+#include <linux/math64.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
@@ -129,7 +130,7 @@ static int tegra210_dmic_hw_params(struct snd_pcm_substream *substream,
 	 * Boost Gain Volume control has 100x factor.
 	 */
 	if (dmic->boost_gain)
-		gain_q23 = (gain_q23 * dmic->boost_gain) / 100;
+		gain_q23 = div_u64(gain_q23 * dmic->boost_gain, 100);
 
 	regmap_write(dmic->regmap, TEGRA210_DMIC_LP_FILTER_GAIN,
 		     (unsigned int)gain_q23);
-- 
2.7.4