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Message-ID: <20110503194203.GE9401@ponder.secretlab.ca>
Date: Tue, 3 May 2011 13:42:03 -0600
From: Grant Likely <grant.likely@...retlab.ca>
To: Jamie Iles <jamie@...ieiles.com>
Cc: linux-kernel@...r.kernel.org, linux@....linux.org.uk,
tglx@...utronix.de, cbouatmailru@...il.com, arnd@...db.de,
nico@...xnic.net
Subject: Re: [PATCHv3 5/7] basic_mmio_gpio: detect output method at probe time
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@...ieiles.com>
> Cc: Anton Vorontsov <cbouatmailru@...il.com>
> Cc: Grant Likely <grant.likely@...retlab.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
>
--
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