Re: [PATCH-v6 5/6] mfd: 88pm800: Set default interrupt clear method

Vaibhav Hiremath
2015-08-24T15:20:15Z

On Monday 24 August 2015 07:24 PM, Lee Jones wrote:
> On Wed, 08 Jul 2015, Vaibhav Hiremath wrote:
>
>> As per the spec, bit 1 (INT_CLEAR_MODE) of reg addr 0xe
>> (page 0) controls the method of clearing interrupt
>> status of 88pm800 family of devices;
>>
>> 0: clear on read
>> 1: clear on write
>>
>> If pdata is not coming from board file, then set the
>> default irq clear method to "irq clear on write"
>>
>> Also, as suggested by "Lee Jones" renaming variable field
>> to appropriate name and removed unnecessary field
>> pm80x_chip.irq_mode, using platform_data.irq_clr_method.
>>
>> Signed-off-by: Zhao Ye <zhaoy@marvell.com>
>> Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
>> Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
>> ---
>> drivers/mfd/88pm800.c | 15 ++++++++++-----
>> include/linux/mfd/88pm80x.h | 9 +++++++--
>> 2 files changed, 17 insertions(+), 7 deletions(-)
>
> [...]
>
>> +#define PM800_WAKEUP2_INT_READ_CLEAR (0 << 1)
>> +#define PM800_WAKEUP2_INT_WRITE_CLEAR (1 << 1)
>
> Use BIT().
>
>> +/* Used by irq_clr_method */
>> +#define PM800_IRQ_CLR_ON_READ 0
>> +#define PM800_IRQ_CLR_ON_WRITE 1
>
>> - int irq_mode; /* Clear interrupt by read/write(0/1) */
>> + bool irq_clr_method; /* Clear interrupt by read/write(0/1) */
>
>> + irq_clr_mode = pdata->irq_clr_method == PM800_IRQ_CLR_ON_WRITE ?
>> + PM800_WAKEUP2_INT_WRITE_CLEAR : PM800_WAKEUP2_INT_READ_CLEAR;
>> + ret = regmap_update_bits(map, PM800_WAKEUP2, mask, irq_clr_mode);
>
> This is pretty convoluted.
>
> For starters you're abusing the 'bool' type here. Bool is either
> 'true' or 'false', so at the very least you should rename
> 'irq_clr_method' to 'irq_clr_on_write'.
>
> Then you can do:
>
> irq_clr_mode = pdata->irq_clr_on_write ?
> PM800_WAKEUP2_INT_WRITE_CLEAR : PM800_WAKEUP2_INT_READ_CLEAR;
>

We have discussed on this, and went back-n-forth.
I think if I remember correctly, one of the version was using
true/false then we decided to rename it to relevant macro.

If I am not wrong V4 version of this series is exactly same as what you
are referring to.

> However, what I suggest you really do is share
> PM800_WAKEUP2_INT_{READ,WRITE}_CLEAR with platform data and just pass
> the value through directly.
>

I think we discussed about this also, and the reason I recall here is,

we may need to control this from DT in the future so we decided to keep
it boolean in platform_data and have simple check before writing to
register.

And I think that was also another reason we introduced

/* Used by irq_clr_method */
#define PM800_IRQ_CLR_ON_READ 0
#define PM800_IRQ_CLR_ON_WRITE 1

(Earlier it was true/false in V4)

Thanks,
Vaibhav