linux-kernel - [next] i2c: mediatek: Use div_u64 for 64-bit division to fix 32-bit kernels

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Message-ID: <1589970713-19944-1-git-send-email-qii.wang@mediatek.com>
Date:   Wed, 20 May 2020 18:31:53 +0800
From:   <qii.wang@...iatek.com>
To:     <wsa@...-dreams.de>
CC:     <linux-i2c@...r.kernel.org>, <devicetree@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>,
        <linux-mediatek@...ts.infradead.org>,
        <srv_heupstream@...iatek.com>, <leilk.liu@...iatek.com>,
        <qii.wang@...iatek.com>
Subject: [next] i2c: mediatek: Use div_u64 for 64-bit division to fix 32-bit kernels

From: Qii Wang <qii.wang@...iatek.com>

Use div_u64 for 64-bit division, and change sample_ns type to
unsigned int. Otherwise, the module will reference __udivdi3
under 32-bit kernels, which is not allowed in kernel space.

Signed-off-by: Qii Wang <qii.wang@...iatek.com>
---
 drivers/i2c/busses/i2c-mt65xx.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index 7020618..deef69e 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -551,7 +551,8 @@ static int mtk_i2c_check_ac_timing(struct mtk_i2c *i2c,
 	const struct i2c_spec_values *spec;
 	unsigned int su_sta_cnt, low_cnt, high_cnt, max_step_cnt;
 	unsigned int sda_max, sda_min, clk_ns, max_sta_cnt = 0x3f;
-	long long sample_ns = (1000000000 * (sample_cnt + 1)) / clk_src;
+	unsigned int sample_ns = div_u64(1000000000ULL * (sample_cnt + 1),
+					 clk_src);
 
 	if (!i2c->dev_comp->timing_adjust)
 		return 0;
-- 
1.9.1