Re: [PATCH 2/2] gpio: davinci: Remove gpio2regs function to accommodate multi instances

From: Linus Walleij
Date: Wed Jan 11 2017 - 10:53:12 EST


On Wed, Jan 11, 2017 at 1:40 PM, Keerthy <j-keerthy@xxxxxx> wrote:
> On Wednesday 11 January 2017 04:34 PM, Linus Walleij wrote:
>> On Wed, Jan 4, 2017 at 9:26 AM, Keerthy <j-keerthy@xxxxxx> wrote:
>>
>>> gpio2regs is written making an assumption that driver supports only
>>> one instance of gpio controller. Removing this and adding a generic
>>> array so as to support multiple instances of gpio controllers.
>>>
>>> Signed-off-by: Keerthy <j-keerthy@xxxxxx>
>>
>>
>>> - regs = gpio2regs(base);
>>> + regs = gpio_base + offset_array[i];
>>
>>
>> I understand this.
>>
>>> - struct davinci_gpio_regs __iomem *g = gpio2regs(hw);
>>> + struct davinci_gpio_controller *chips =
>>> + (struct davinci_gpio_controller
>>> *)d->host_data;
>>> + struct davinci_gpio_regs __iomem *g = chips[hw / 32].regs;
>>
>>
>> And this, if each instans has 32 GPIOs.
>>
>>> - g = gpio2regs(0);
>>> + g = chips[0].regs;
>>
>>
>> Also makes sense.
>>
>>> - g = gpio2regs(gpio);
>>> + g = chips[bank / 2].regs;
>>
>>
>> But what is this? I don't understand that /2 at all. Please insert a
>> comment explaining it so I can figure it out. Are there two banks
>> per instance?
>
>
> Yes! There are register sets for 32 GPIOs. 2 banks of 16 GPIOs are covered
> by each set of registers hence /2. Shall i add a comment and send this patch
> alone separately?

Yeah.

I am currently confused by several patch sets for davinci in my inbox,
can you rebase on my devel branch when I push it and resend
*all* you have cooking for DaVinci?

Yours,
Linus Walleij