linux-kernel - Re: [PATCH 2/3 v2] GPIO: gpio-dwapb: Support Debounce

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Message-ID: <1409908999.30155.85.camel@intel.com>
Date:	Fri, 5 Sep 2014 09:23:19 +0000
From:	"Shevchenko, Andriy" <andriy.shevchenko@...el.com>
To:	"Chen, Alvin" <alvin.chen@...el.com>
CC:	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"robh+dt@...nel.org" <robh+dt@...nel.org>,
	"Kweh, Hock Leong" <hock.leong.kweh@...el.com>,
	"sebastian@...akpoint.cc" <sebastian@...akpoint.cc>,
	"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
	"Ong, Boon Leong" <boon.leong.ong@...el.com>,
	"gnurou@...il.com" <gnurou@...il.com>,
	"linus.walleij@...aro.org" <linus.walleij@...aro.org>,
	"linux-gpio@...r.kernel.org" <linux-gpio@...r.kernel.org>,
	"grant.likely@...aro.org" <grant.likely@...aro.org>,
	"Westerberg, Mika" <mika.westerberg@...el.com>,
	"dvhart@...ux.intel.com" <dvhart@...ux.intel.com>,
	"atull@...nsource.altera.com" <atull@...nsource.altera.com>
Subject: Re: [PATCH 2/3 v2] GPIO: gpio-dwapb: Support Debounce

On Fri, 2014-09-05 at 07:53 -0700, Weike Chen wrote:
> This patch enables 'debounce' for the designware GPIO, and
> it is based on Josef Ahmad's previous work.

Can we split dwapb_read/write introducing and changing from this patch
to a separate one?


> Reviewed-by: Hock Leong Kweh <hock.leong.kweh@...el.com>
> Reviewed-by: Shevchenko, Andriy <andriy.shevchenko@...el.com>


> Signed-off-by: Weike Chen <alvin.chen@...el.com>
> ---
>  drivers/gpio/gpio-dwapb.c |   62 +++++++++++++++++++++++++++++++++++++--------
>  1 file changed, 52 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/gpio/gpio-dwapb.c b/drivers/gpio/gpio-dwapb.c
> index f2264a2..6db7501 100644
> --- a/drivers/gpio/gpio-dwapb.c
> +++ b/drivers/gpio/gpio-dwapb.c
> @@ -36,6 +36,7 @@
>  #define GPIO_INTTYPE_LEVEL	0x38
>  #define GPIO_INT_POLARITY	0x3c
>  #define GPIO_INTSTATUS		0x40
> +#define GPIO_PORTA_DEBOUNCE	0x48
>  #define GPIO_PORTA_EOI		0x4c
>  #define GPIO_EXT_PORTA		0x50
>  #define GPIO_EXT_PORTB		0x54
> @@ -63,6 +64,23 @@ struct dwapb_gpio {
>  	struct irq_domain	*domain;
>  };
>  
> +static inline u32 dwapb_read(struct dwapb_gpio *gpio, unsigned int offset)
> +{
> +	struct bgpio_chip *bgc	= &gpio->ports[0].bgc;
> +	void __iomem *reg_base	= gpio->regs;
> +
> +	return bgc->read_reg(reg_base + offset);
> +}
> +
> +static inline void dwapb_write(struct dwapb_gpio *gpio, unsigned int offset,
> +			       u32 val)
> +{
> +	struct bgpio_chip *bgc	= &gpio->ports[0].bgc;
> +	void __iomem *reg_base	= gpio->regs;
> +
> +	bgc->write_reg(reg_base + offset, val);
> +}
> +
>  static int dwapb_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
>  {
>  	struct bgpio_chip *bgc = to_bgpio_chip(gc);
> @@ -75,14 +93,14 @@ static int dwapb_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
>  
>  static void dwapb_toggle_trigger(struct dwapb_gpio *gpio, unsigned int offs)
>  {
> -	u32 v = readl(gpio->regs + GPIO_INT_POLARITY);
> +	u32 v = dwapb_read(gpio, GPIO_INT_POLARITY);
>  
>  	if (gpio_get_value(gpio->ports[0].bgc.gc.base + offs))
>  		v &= ~BIT(offs);
>  	else
>  		v |= BIT(offs);
>  
> -	writel(v, gpio->regs + GPIO_INT_POLARITY);
> +	dwapb_write(gpio, GPIO_INT_POLARITY, v);
>  }
>  
>  static u32 _dwapb_irq_handler(struct dwapb_gpio *gpio)
> @@ -125,9 +143,9 @@ static void dwapb_irq_enable(struct irq_data *d)
>  	u32 val;
>  
>  	spin_lock_irqsave(&bgc->lock, flags);
> -	val = readl(gpio->regs + GPIO_INTEN);
> +	val = dwapb_read(gpio, GPIO_INTEN);
>  	val |= BIT(d->hwirq);
> -	writel(val, gpio->regs + GPIO_INTEN);
> +	dwapb_write(gpio, GPIO_INTEN, val);
>  	spin_unlock_irqrestore(&bgc->lock, flags);
>  }
>  
> @@ -140,9 +158,9 @@ static void dwapb_irq_disable(struct irq_data *d)
>  	u32 val;
>  
>  	spin_lock_irqsave(&bgc->lock, flags);
> -	val = readl(gpio->regs + GPIO_INTEN);
> +	val = dwapb_read(gpio, GPIO_INTEN);
>  	val &= ~BIT(d->hwirq);
> -	writel(val, gpio->regs + GPIO_INTEN);
> +	dwapb_write(gpio, GPIO_INTEN, val);
>  	spin_unlock_irqrestore(&bgc->lock, flags);
>  }
>  
> @@ -182,8 +200,8 @@ static int dwapb_irq_set_type(struct irq_data *d, u32 type)
>  		return -EINVAL;
>  
>  	spin_lock_irqsave(&bgc->lock, flags);
> -	level = readl(gpio->regs + GPIO_INTTYPE_LEVEL);
> -	polarity = readl(gpio->regs + GPIO_INT_POLARITY);
> +	level = dwapb_read(gpio, GPIO_INTTYPE_LEVEL);
> +	polarity = dwapb_read(gpio, GPIO_INT_POLARITY);
>  
>  	switch (type) {
>  	case IRQ_TYPE_EDGE_BOTH:
> @@ -210,8 +228,31 @@ static int dwapb_irq_set_type(struct irq_data *d, u32 type)
>  
>  	irq_setup_alt_chip(d, type);
>  
> -	writel(level, gpio->regs + GPIO_INTTYPE_LEVEL);
> -	writel(polarity, gpio->regs + GPIO_INT_POLARITY);
> +	dwapb_write(gpio, GPIO_INTTYPE_LEVEL, level);
> +	dwapb_write(gpio, GPIO_INT_POLARITY, polarity);
> +	spin_unlock_irqrestore(&bgc->lock, flags);
> +
> +	return 0;
> +}
> +
> +static int dwapb_gpio_set_debounce(struct gpio_chip *gc,
> +				   unsigned offset, unsigned debounce)
> +{
> +	struct bgpio_chip *bgc = to_bgpio_chip(gc);
> +	struct dwapb_gpio_port *port =
> +			container_of(bgc, struct dwapb_gpio_port, bgc);
> +	struct dwapb_gpio *gpio = port->gpio;
> +	unsigned long flags, val_deb;
> +	unsigned long mask = bgc->pin2mask(bgc, offset);
> +
> +	spin_lock_irqsave(&bgc->lock, flags);
> +
> +	val_deb = dwapb_read(gpio, GPIO_PORTA_DEBOUNCE);
> +	if (debounce)
> +		dwapb_write(gpio, GPIO_PORTA_DEBOUNCE, mask | val_deb);
> +	else
> +		dwapb_write(gpio, GPIO_PORTA_DEBOUNCE, ~mask & val_deb);
> +
>  	spin_unlock_irqrestore(&bgc->lock, flags);
>  
>  	return 0;
> @@ -354,6 +395,7 @@ static int dwapb_gpio_add_port(struct dwapb_gpio *gpio,
>  #endif
>  	port->bgc.gc.ngpio = pp->ngpio;
>  	port->bgc.gc.base = pp->gpio_base;
> +	port->bgc.gc.set_debounce = dwapb_gpio_set_debounce;
>  
>  	if (pp->irq)
>  		dwapb_configure_irqs(gpio, port, pp);


-- 
Andy Shevchenko <andriy.shevchenko@...el.com>
Intel Finland Oy
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