Re: [PATCH 2/2] pinctrl: rockchip: Fix enable/disable/mask/unmask

From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
To: Doug Anderson <dianders@chromium.org>
Cc: Heiko Stuebner <heiko@sntech.de>,
	Linus Walleij <linus.walleij@linaro.org>,
	Sonny Rao <sonnyrao@chromium.org>,
	Chris Zhong <zyw@rock-chips.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-rockchip@lists.infradead.org, linux-gpio@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] pinctrl: rockchip: Fix enable/disable/mask/unmask
Date: Wed, 19 Nov 2014 09:56:39 -0800	[thread overview]
Message-ID: <20141119175639.GC37989@dtor-ws> (raw)
In-Reply-To: <1416354596-15013-3-git-send-email-dianders@chromium.org>

On Tue, Nov 18, 2014 at 03:49:56PM -0800, Doug Anderson wrote:
> The Rockchip pinctrl driver was only implementing the "mask" and
> "unmask" operations though the hardware actually has two distinct
> things: enable/disable and mask/unmask.  It was implementing the
> "mask" operations as a hardware enable/disable and always leaving all
> interrupts unmasked.
> 
> I believe that the old system had some downsides, specifically:
> - (Untested) if an interrupt went off while interrupts were "masked"
>   it would be lost.  Now it will be kept track of.
> - If someone wanted to change an interrupt back into a GPIO (is such a
>   thing sensible?) by calling irq_disable() it wouldn't actually take
>   effect.  That's because Linux does some extra optimizations when
>   there's no true "disable" function: it does a lazy mask.
> 
> Let's actually implement enable/disable/mask/unmask properly.
> 
> Signed-off-by: Doug Anderson <dianders@chromium.org>

After chatting a bit with Doug offline:

Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

> ---
>  drivers/pinctrl/pinctrl-rockchip.c | 30 +++++++++++++++++++++++++++---
>  1 file changed, 27 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/pinctrl/pinctrl-rockchip.c b/drivers/pinctrl/pinctrl-rockchip.c
> index e91e845..60d1a49 100644
> --- a/drivers/pinctrl/pinctrl-rockchip.c
> +++ b/drivers/pinctrl/pinctrl-rockchip.c
> @@ -1562,6 +1562,28 @@ static void rockchip_irq_resume(struct irq_data *d)
>  	irq_reg_writel(gc, bank->saved_enables, GPIO_INTEN);
>  }
>  
> +static void rockchip_irq_disable(struct irq_data *d)
> +{
> +	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
> +	u32 val;
> +
> +	irq_gc_lock(gc);
> +	val = irq_reg_readl(gc, GPIO_INTEN);
> +	irq_reg_writel(gc, val & ~d->mask, GPIO_INTEN);
> +	irq_gc_unlock(gc);
> +}
> +
> +static void rockchip_irq_enable(struct irq_data *d)
> +{
> +	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
> +	u32 val;
> +
> +	irq_gc_lock(gc);
> +	val = irq_reg_readl(gc, GPIO_INTEN);
> +	irq_reg_writel(gc, val | d->mask, GPIO_INTEN);
> +	irq_gc_unlock(gc);
> +}
> +
>  static int rockchip_interrupts_register(struct platform_device *pdev,
>  						struct rockchip_pinctrl *info)
>  {
> @@ -1600,11 +1622,13 @@ static int rockchip_interrupts_register(struct platform_device *pdev,
>  		gc = irq_get_domain_generic_chip(bank->domain, 0);
>  		gc->reg_base = bank->reg_base;
>  		gc->private = bank;
> -		gc->chip_types[0].regs.mask = GPIO_INTEN;
> +		gc->chip_types[0].regs.mask = GPIO_INTMASK;
>  		gc->chip_types[0].regs.ack = GPIO_PORTS_EOI;
>  		gc->chip_types[0].chip.irq_ack = irq_gc_ack_set_bit;
> -		gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit;
> -		gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit;
> +		gc->chip_types[0].chip.irq_mask = irq_gc_mask_set_bit;
> +		gc->chip_types[0].chip.irq_unmask = irq_gc_mask_clr_bit;
> +		gc->chip_types[0].chip.irq_enable = rockchip_irq_enable;
> +		gc->chip_types[0].chip.irq_disable = rockchip_irq_disable;
>  		gc->chip_types[0].chip.irq_set_wake = irq_gc_set_wake;
>  		gc->chip_types[0].chip.irq_suspend = rockchip_irq_suspend;
>  		gc->chip_types[0].chip.irq_resume = rockchip_irq_resume;
> -- 
> 2.1.0.rc2.206.gedb03e5
> 

-- 
Dmitry