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media: i2c: Use div64_ul() for u64-by-unsigned-long divide

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div_u64() does a 64-by-32 division, while the divisor max2175.xtal_freq
is unsigned long, thus 64-bit on 64-bit platforms.  Hence the proper
function to call is div64_ul().

Note that this change does not have any functional impact, as the
crystal frequency must be much lower than the 32-bit limit anyway.
On 32-bit platforms, the generated code is the same.  But at least on
arm64, this saves an AND-instruction to truncate xtal_freq to 32-bit.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
This commit is contained in:
Geert Uytterhoeven 2019-08-30 10:48:27 -03:00 committed by Mauro Carvalho Chehab
parent 31218df77e
commit 672c29b916
1 changed files with 2 additions and 2 deletions
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4
drivers/media/i2c/max2175.c
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@ -591,8 +591,8 @@ static int max2175_set_lo_freq(struct max2175 *ctx, u32 lo_freq)
lo_freq *= lo_mult;
int_desired = lo_freq / ctx->xtal_freq;
frac_desired = div_u64((u64)(lo_freq % ctx->xtal_freq) << 20,
ctx->xtal_freq);
frac_desired = div64_ul((u64)(lo_freq % ctx->xtal_freq) << 20,
ctx->xtal_freq);
/* Check CSM is not busy */
ret = max2175_poll_csm_ready(ctx);