dlan17/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

i2c: mlxbf: avoid 64-bit division

Browse Source 
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: 053859002c ("i2c: mlxbf: Allow build with COMPILE_TEST")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20250520152600.1975628-1-arnd@kernel.org
Signed-off-by: Andi Shyti <andi@smida.it>
This commit is contained in:
Arnd Bergmann
2025-05-23 10:02:27 +02:00
committed by Andi Shyti
parent 3b7d8d151a
commit 2b2805404c
1 changed files with 3 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files
drivers/i2c/busses/i2c-mlxbf.c
+3 -5
View File
@@ -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,