[PATCH 2/4] [v2] gpiolib: add bitmask for valid GPIO lines
Timur Tabi
timur at codeaurora.org
Tue Dec 12 12:16:54 PST 2017
On 12/12/2017 03:58 AM, Andy Shevchenko wrote:
> On Fri, 2017-12-01 at 17:28 -0600, Timur Tabi wrote:
>> Add support for specifying that some GPIOs within a range are
>> unavailable.
>> Some systems have a sparse list of GPIOs, where a range of GPIOs is
>> specified (usually 0 to n-1), but some subset within that range is
>> absent or unavailable for whatever reason.
>>
>> To support this, allow drivers to specify a bitmask of GPIOs that
>> are present or absent. Gpiolib will then block access to those that
>> are absent.
>
>> - status = gpiochip_irqchip_init_valid_mask(chip);
>> + status = gpiochip_init_valid_mask(chip);
>> if (status)
>> goto err_remove_from_list;
>>
>> + status = gpiochip_irqchip_init_valid_mask(chip);
>> + if (status)
>> + goto err_remove_valid_mask;
>
> Yes, this way it looks good!
I've discovered that I can remove all this code. I don't need a valid
mask, all I need to do is block the request properly.
>> +static bool gpiochip_available(const struct gpio_chip *gpiochip,
>> + unsigned int offset)
>> +{
>
>> + pr_info("%s:%u offset=%u\n", __func__, __LINE__, offset);
>
> Debug leftover?
Fixed, thanks.
>
>> +
>> + /* No mask means all valid */
>> + if (likely(!gpiochip->valid_mask))
>> + return true;
>> +
>> + return test_bit(offset, gpiochip->valid_mask);
>
> Not sure which one is better
> return test_bit();
> or
> return !!test_bit();
I've removed this function also.
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