[PATCH v1] pwm: th1520: Fix 32-bit build with COMPILE_TEST

[Andreas Hindborg]

"FUJITA Tomonori" <tomo at flapping.org> writes:

> From: FUJITA Tomonori <fujita.tomonori at gmail.com>
>
> Fix the following build error on 32-bit ARM with COMPILE_TEST:
>
>   ERROR: modpost: drivers/pwm/pwm_th1520.ko: symbol '__aeabi_uldivmod' undefined!
>
> The driver divides u64 values when it converts between nanoseconds and
> clock cycles. On 32-bit ARM, these divisions are compiled to calls to
> __aeabi_uldivmod, which the kernel does not provide.
>
> he TH1520 is a 64-bit RISC-V SoC, so the driver is only used on
> 64-bit kernels. There is no point in compile testing it on 32-bit.
> Limit COMPILE_TEST to 64BIT instead of changing the arithmetic to use
> the div64 helpers.
>
> Fixes: 3c180003dffb ("pwm: th1520: Fix missing Kconfig dependencies")
> Signed-off-by: FUJITA Tomonori <fujita.tomonori at gmail.com>

Reviewed-by: Andreas Hindborg <a.hindborg at kernel.org>

Best regards,
Andreas Hindborg