From: Arnd Bergmann Date: Tue, 20 May 2025 15:25:45 +0000 (+0200) Subject: i2c: mlxbf: avoid 64-bit division X-Git-Tag: v6.16-rc1~112^2~1^2 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=2b2805404c926b8dcd5c5c13d240722da714906e;p=thirdparty%2Fkernel%2Flinux.git i2c: mlxbf: avoid 64-bit division The 64-bit division in mlxbf_i2c_get_ticks() causes link failures when compile-testing on 32-bit machines: ERROR: modpost: "__udivdi3" [drivers/i2c/busses/i2c-mlxbf.ko] undefined! Change this to a div_u64(), which should replace the constant division with a a multiply/shift combination in the mlxbf_i2c_get_ticks(). The frequency calculation functions require a slow library call but should be used much rarer. Fixes: 053859002c20 ("i2c: mlxbf: Allow build with COMPILE_TEST") Signed-off-by: Arnd Bergmann Link: https://lore.kernel.org/r/20250520152600.1975628-1-arnd@kernel.org Signed-off-by: Andi Shyti --- diff --git a/drivers/i2c/busses/i2c-mlxbf.c b/drivers/i2c/busses/i2c-mlxbf.c index 39359942e4d74..8345f7e6385df 100644 --- a/drivers/i2c/busses/i2c-mlxbf.c +++ b/drivers/i2c/busses/i2c-mlxbf.c @@ -1083,7 +1083,7 @@ static u32 mlxbf_i2c_get_ticks(struct mlxbf_i2c_priv *priv, u64 nanoseconds, * Frequency */ frequency = priv->frequency; - ticks = (nanoseconds * frequency) / MLXBF_I2C_FREQUENCY_1GHZ; + ticks = div_u64(nanoseconds * frequency, MLXBF_I2C_FREQUENCY_1GHZ); /* * The number of ticks is rounded down and if minimum is equal to 1 * then add one tick. @@ -1460,9 +1460,8 @@ static u64 mlxbf_i2c_calculate_freq_from_tyu(struct mlxbf_i2c_resource *corepll_ * and PadFrequency, respectively. */ core_frequency = MLXBF_I2C_PLL_IN_FREQ * (++core_f); - core_frequency /= (++core_r) * (++core_od); - return core_frequency; + return div_u64(core_frequency, (++core_r) * (++core_od)); } static u64 mlxbf_i2c_calculate_freq_from_yu(struct mlxbf_i2c_resource *corepll_res) @@ -1491,9 +1490,8 @@ static u64 mlxbf_i2c_calculate_freq_from_yu(struct mlxbf_i2c_resource *corepll_r * and PadFrequency, respectively. */ corepll_frequency = (MLXBF_I2C_PLL_IN_FREQ * core_f) / MLNXBF_I2C_COREPLL_CONST; - corepll_frequency /= (++core_r) * (++core_od); - return corepll_frequency; + return div_u64(corepll_frequency, (++core_r) * (++core_od)); } static int mlxbf_i2c_calculate_corepll_freq(struct platform_device *pdev,