Re: [PATCHv3 5/7] basic_mmio_gpio: detect output method at probe time

[Grant Likely <grant.likely@secretlab.ca>]

On Mon, Apr 11, 2011 at 12:21:52PM +0100, Jamie Iles wrote:
> Rather than detecting the output method each time in the .set()
> callback, do it at probe time and set the appropriate callback.
> 
> Changes since v2: moved the reg_dat initialization into
> bgpio_setup_io().
> 
> Signed-off-by: Jamie Iles <jamie@jamieiles.com>
> Cc: Anton Vorontsov <cbouatmailru@gmail.com>
> Cc: Grant Likely <grant.likely@secretlab.ca>

Merged, thanks.

g.

> ---
>  drivers/gpio/basic_mmio_gpio.c |   90 ++++++++++++++++++++++++++--------------
>  1 files changed, 59 insertions(+), 31 deletions(-)
> 
> diff --git a/drivers/gpio/basic_mmio_gpio.c b/drivers/gpio/basic_mmio_gpio.c
> index 90f7f89..728bc67 100644
> --- a/drivers/gpio/basic_mmio_gpio.c
> +++ b/drivers/gpio/basic_mmio_gpio.c
> @@ -161,14 +161,6 @@ static void bgpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
>  	unsigned long mask = bgc->pin2mask(bgc, gpio);
>  	unsigned long flags;
>  
> -	if (bgc->reg_set) {
> -		if (val)
> -			bgc->write_reg(bgc->reg_set, mask);
> -		else
> -			bgc->write_reg(bgc->reg_clr, mask);
> -		return;
> -	}
> -
>  	spin_lock_irqsave(&bgc->lock, flags);
>  
>  	if (val)
> @@ -181,6 +173,18 @@ static void bgpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
>  	spin_unlock_irqrestore(&bgc->lock, flags);
>  }
>  
> +static void bgpio_set_with_clear(struct gpio_chip *gc, unsigned int gpio,
> +				 int val)
> +{
> +	struct bgpio_chip *bgc = to_bgpio_chip(gc);
> +	unsigned long mask = bgc->pin2mask(bgc, gpio);
> +
> +	if (val)
> +		bgc->write_reg(bgc->reg_set, mask);
> +	else
> +		bgc->write_reg(bgc->reg_clr, mask);
> +}
> +
>  static int bgpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
>  {
>  	return 0;
> @@ -188,7 +192,8 @@ static int bgpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
>  
>  static int bgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
>  {
> -	bgpio_set(gc, gpio, val);
> +	gc->set(gc, gpio, val);
> +
>  	return 0;
>  }
>  
> @@ -238,18 +243,25 @@ static int bgpio_setup_accessors(struct platform_device *pdev,
>  	return 0;
>  }
>  
> -static int __devinit bgpio_probe(struct platform_device *pdev)
> +/*
> + * Create the device and allocate the resources.  For setting GPIO's there are
> + * two supported configurations:
> + *
> + *	- single output register resource (named "dat").
> + *	- set/clear pair (named "set" and "clr").
> + *
> + * For the single output register, this drives a 1 by setting a bit and a zero
> + * by clearing a bit.  For the set clr pair, this drives a 1 by setting a bit
> + * in the set register and clears it by setting a bit in the clear register.
> + * The configuration is detected by which resources are present.
> + */
> +static int bgpio_setup_io(struct platform_device *pdev,
> +			  struct bgpio_chip *bgc)
>  {
> -	struct device *dev = &pdev->dev;
> -	struct bgpio_pdata *pdata = dev_get_platdata(dev);
> -	struct bgpio_chip *bgc;
> -	struct resource *res_dat;
>  	struct resource *res_set;
>  	struct resource *res_clr;
> +	struct resource *res_dat;
>  	resource_size_t dat_sz;
> -	int bits;
> -	int ret;
> -	int ngpio;
>  
>  	res_dat = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dat");
>  	if (!res_dat)
> @@ -259,16 +271,11 @@ static int __devinit bgpio_probe(struct platform_device *pdev)
>  	if (!is_power_of_2(dat_sz))
>  		return -EINVAL;
>  
> -	bits = dat_sz * 8;
> -	ngpio = bits;
> -	if (bits > BITS_PER_LONG)
> +	bgc->bits = dat_sz * 8;
> +	if (bgc->bits > BITS_PER_LONG)
>  		return -EINVAL;
>  
> -	bgc = devm_kzalloc(dev, sizeof(*bgc), GFP_KERNEL);
> -	if (!bgc)
> -		return -ENOMEM;
> -
> -	bgc->reg_dat = bgpio_request_and_map(dev, res_dat);
> +	bgc->reg_dat = bgpio_request_and_map(&pdev->dev, res_dat);
>  	if (!bgc->reg_dat)
>  		return -ENOMEM;
>  
> @@ -276,19 +283,41 @@ static int __devinit bgpio_probe(struct platform_device *pdev)
>  	res_clr = platform_get_resource_byname(pdev, IORESOURCE_MEM, "clr");
>  	if (res_set && res_clr) {
>  		if (resource_size(res_set) != resource_size(res_clr) ||
> -				resource_size(res_set) != dat_sz)
> +		    resource_size(res_set) != resource_size(res_dat))
>  			return -EINVAL;
>  
> -		bgc->reg_set = bgpio_request_and_map(dev, res_set);
> -		bgc->reg_clr = bgpio_request_and_map(dev, res_clr);
> +		bgc->reg_set = bgpio_request_and_map(&pdev->dev, res_set);
> +		bgc->reg_clr = bgpio_request_and_map(&pdev->dev, res_clr);
>  		if (!bgc->reg_set || !bgc->reg_clr)
>  			return -ENOMEM;
> +
> +		bgc->gc.set = bgpio_set_with_clear;
>  	} else if (res_set || res_clr) {
>  		return -EINVAL;
> +	} else {
> +		bgc->gc.set = bgpio_set;
>  	}
>  
> -	spin_lock_init(&bgc->lock);
> +	return 0;
> +}
> +
> +static int __devinit bgpio_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct bgpio_pdata *pdata = dev_get_platdata(dev);
> +	struct bgpio_chip *bgc;
> +	int ret;
> +	int ngpio;
> +
> +	bgc = devm_kzalloc(dev, sizeof(*bgc), GFP_KERNEL);
> +	if (!bgc)
> +		return -ENOMEM;
> +
> +	ret = bgpio_setup_io(pdev, bgc);
> +	if (ret)
> +		return ret;
>  
> +	ngpio = bgc->bits;
>  	if (pdata) {
>  		bgc->gc.base = pdata->base;
>  		if (pdata->ngpio > 0)
> @@ -297,18 +326,17 @@ static int __devinit bgpio_probe(struct platform_device *pdev)
>  		bgc->gc.base = -1;
>  	}
>  
> -	bgc->bits = bits;
>  	ret = bgpio_setup_accessors(pdev, bgc);
>  	if (ret)
>  		return ret;
>  
> +	spin_lock_init(&bgc->lock);
>  	bgc->data = bgc->read_reg(bgc->reg_dat);
>  
>  	bgc->gc.ngpio = ngpio;
>  	bgc->gc.direction_input = bgpio_dir_in;
>  	bgc->gc.direction_output = bgpio_dir_out;
>  	bgc->gc.get = bgpio_get;
> -	bgc->gc.set = bgpio_set;
>  	bgc->gc.dev = dev;
>  	bgc->gc.label = dev_name(dev);
>  
> -- 
> 1.7.4.2
>