lkml.org 
[lkml]   [2015]   [May]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH v2 2/6] gpio: brcmstb: Add interrupt support
On Fri, May 29, 2015 at 5:10 PM, Brian Norris
<computersforpeace@gmail.com> wrote:
> A few small comments:
>
> On Thu, May 28, 2015 at 07:14:06PM -0700, Gregory Fong wrote:
>> v2:
>> - since imask member of bank struct was removed, just read and write from mask
>> reg and don't maintain a shadow
>
> ^^ this comment may be addressing what I'm going to ask about below? Not
> sure why this was changed, actually.

Yes, see below...

>
>> - warn on invalid IRQs
>> - move some irq setup to a separate function since probe is getting unwieldy
>>
>> drivers/gpio/Kconfig | 1 +
>> drivers/gpio/gpio-brcmstb.c | 276 ++++++++++++++++++++++++++++++++++++++++++++
>> 2 files changed, 277 insertions(+)
>>
> ...
>> diff --git a/drivers/gpio/gpio-brcmstb.c b/drivers/gpio/gpio-brcmstb.c
>> index 7a3cb1f..b9962ff 100644
>> --- a/drivers/gpio/gpio-brcmstb.c
>> +++ b/drivers/gpio/gpio-brcmstb.c
> ...
>> @@ -63,6 +69,231 @@ brcmstb_gpio_gc_to_priv(struct gpio_chip *gc)
> ...
>> +static void brcmstb_gpio_irq_bank_handler(int irq,
>> + struct brcmstb_gpio_bank *bank)
>> +{
>> + struct brcmstb_gpio_priv *priv = bank->parent_priv;
>> + void __iomem *reg_base = priv->reg_base;
>> + unsigned long status;
>> + unsigned long flags;
>> +
>> + spin_lock_irqsave(&bank->bgc.lock, flags);
>> + while ((status = bank->bgc.read_reg(reg_base + GIO_STAT(bank->id)) &
>> + bank->bgc.read_reg(reg_base + GIO_MASK(bank->id)))) {
>
> In case you do run this loop multiple times (multiple interrupts in
> progress?), wouldn't it make sense to stash the mask exactly once,
> outside the loop? It's probably not a real big deal in practice, I
> guess.

I made this change after Linus's remark at
https://lkml.org/lkml/2015/5/12/303 on v1, which I agree with mostly
since it's a premature optimization---I haven't determined whether
keeping a shadow mask actually helps performance at all in practice,
and better to keep it simpler without actual data.

>
>> + int bit;
>> + for_each_set_bit(bit, &status, 32) {
>> + int hwirq = bank->bgc.gc.base -
>> + priv->gpio_base + bit;
>> + int child_irq =
>> + irq_find_mapping(priv->irq_domain,
>> + hwirq);
>> + u32 stat = bank->bgc.read_reg(reg_base +
>> + GIO_STAT(bank->id));
>> + if (bit >= bank->width)
>> + dev_warn(&priv->pdev->dev,
>> + "IRQ for invalid GPIO (bank=%d, offset=%d)\n",
>> + bank->id, bit);
>> + bank->bgc.write_reg(reg_base + GIO_STAT(bank->id),
>> + stat | BIT(bit));
>> + generic_handle_irq(child_irq);
>> + }
>> + }
>> + spin_unlock_irqrestore(&bank->bgc.lock, flags);
>> +}
> ...
>> @@ -153,6 +410,16 @@ static int brcmstb_gpio_probe(struct platform_device *pdev)
>> priv->reg_base = reg_base;
>> priv->pdev = pdev;
>>
>> + if (of_find_property(np, "interrupt-controller", NULL)) {
>
> of_property_read_bool()?

OK.

>
>> + priv->parent_irq = platform_get_irq(pdev, 0);
>> + if (priv->parent_irq < 0) {
>> + dev_err(dev, "Couldn't get IRQ");
>> + return -ENOENT;
>> + }
>> + } else {
>> + priv->parent_irq = -ENOENT;
>> + }
>> +
>> INIT_LIST_HEAD(&priv->bank_list);
>> if (brcmstb_gpio_sanity_check_banks(dev, np, res))
>> return -EINVAL;
>
> Otherwise, looks OK to my inexpert eyes.
>
> Reviewed-by: Brian Norris <computersforpeace@gmail.com>


\
 
 \ /
  Last update: 2015-05-30 04:01    [W:0.060 / U:25.680 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site