Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754787Ab1ECTmq (ORCPT ); Tue, 3 May 2011 15:42:46 -0400 Received: from mail-pv0-f174.google.com ([74.125.83.174]:35921 "EHLO mail-pv0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754745Ab1ECTmo (ORCPT ); Tue, 3 May 2011 15:42:44 -0400 Date: Tue, 3 May 2011 13:42:29 -0600 From: Grant Likely To: Jamie Iles Cc: linux-kernel@vger.kernel.org, linux@arm.linux.org.uk, tglx@linutronix.de, cbouatmailru@gmail.com, arnd@arndb.de, nico@fluxnic.net Subject: Re: [PATCHv3 7/7] basic_mmio_gpio: support direction registers Message-ID: <20110503194229.GG9401@ponder.secretlab.ca> References: <1302520914-22816-1-git-send-email-jamie@jamieiles.com> <1302520914-22816-8-git-send-email-jamie@jamieiles.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1302520914-22816-8-git-send-email-jamie@jamieiles.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5942 Lines: 197 On Mon, Apr 11, 2011 at 12:21:54PM +0100, Jamie Iles wrote: > Most controllers require the direction of a GPIO to be set by writing to > a direction register. Add support for either an input direction > register or an output direction register. > > Signed-off-by: Jamie Iles > Acked-by: Anton Vorontsov > Cc: Grant Likely Merged, thanks. g. > --- > drivers/gpio/basic_mmio_gpio.c | 114 +++++++++++++++++++++++++++++++++++++++- > 1 files changed, 112 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpio/basic_mmio_gpio.c b/drivers/gpio/basic_mmio_gpio.c > index 6b99489..f4afd96 100644 > --- a/drivers/gpio/basic_mmio_gpio.c > +++ b/drivers/gpio/basic_mmio_gpio.c > @@ -70,6 +70,7 @@ struct bgpio_chip { > void __iomem *reg_dat; > void __iomem *reg_set; > void __iomem *reg_clr; > + void __iomem *reg_dir; > > /* Number of bits (GPIOs): * 8. */ > int bits; > @@ -88,6 +89,9 @@ struct bgpio_chip { > > /* Shadowed data register to clear/set bits safely. */ > unsigned long data; > + > + /* Shadowed direction registers to clear/set direction safely. */ > + unsigned long dir; > }; > > static struct bgpio_chip *to_bgpio_chip(struct gpio_chip *gc) > @@ -203,15 +207,80 @@ static void bgpio_set_set(struct gpio_chip *gc, unsigned int gpio, int val) > spin_unlock_irqrestore(&bgc->lock, flags); > } > > +static int bgpio_simple_dir_in(struct gpio_chip *gc, unsigned int gpio) > +{ > + return 0; > +} > + > +static int bgpio_simple_dir_out(struct gpio_chip *gc, unsigned int gpio, > + int val) > +{ > + gc->set(gc, gpio, val); > + > + return 0; > +} > + > static int bgpio_dir_in(struct gpio_chip *gc, unsigned int gpio) > { > + struct bgpio_chip *bgc = to_bgpio_chip(gc); > + unsigned long flags; > + > + spin_lock_irqsave(&bgc->lock, flags); > + > + bgc->dir &= ~bgc->pin2mask(bgc, gpio); > + bgc->write_reg(bgc->reg_dir, bgc->dir); > + > + spin_unlock_irqrestore(&bgc->lock, flags); > + > return 0; > } > > static int bgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val) > { > + struct bgpio_chip *bgc = to_bgpio_chip(gc); > + unsigned long flags; > + > + gc->set(gc, gpio, val); > + > + spin_lock_irqsave(&bgc->lock, flags); > + > + bgc->dir |= bgc->pin2mask(bgc, gpio); > + bgc->write_reg(bgc->reg_dir, bgc->dir); > + > + spin_unlock_irqrestore(&bgc->lock, flags); > + > + return 0; > +} > + > +static int bgpio_dir_in_inv(struct gpio_chip *gc, unsigned int gpio) > +{ > + struct bgpio_chip *bgc = to_bgpio_chip(gc); > + unsigned long flags; > + > + spin_lock_irqsave(&bgc->lock, flags); > + > + bgc->dir |= bgc->pin2mask(bgc, gpio); > + bgc->write_reg(bgc->reg_dir, bgc->dir); > + > + spin_unlock_irqrestore(&bgc->lock, flags); > + > + return 0; > +} > + > +static int bgpio_dir_out_inv(struct gpio_chip *gc, unsigned int gpio, int val) > +{ > + struct bgpio_chip *bgc = to_bgpio_chip(gc); > + unsigned long flags; > + > gc->set(gc, gpio, val); > > + spin_lock_irqsave(&bgc->lock, flags); > + > + bgc->dir &= ~bgc->pin2mask(bgc, gpio); > + bgc->write_reg(bgc->reg_dir, bgc->dir); > + > + spin_unlock_irqrestore(&bgc->lock, flags); > + > return 0; > } > > @@ -274,6 +343,14 @@ static int bgpio_setup_accessors(struct platform_device *pdev, > * 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. > + * > + * For setting the GPIO direction, there are three supported configurations: > + * > + * - simple bidirection GPIO that requires no configuration. > + * - an output direction register (named "dirout") where a 1 bit > + * indicates the GPIO is an output. > + * - an input direction register (named "dirin") where a 1 bit indicates > + * the GPIO is an input. > */ > static int bgpio_setup_io(struct platform_device *pdev, > struct bgpio_chip *bgc) > @@ -330,6 +407,37 @@ static int bgpio_setup_io(struct platform_device *pdev, > return 0; > } > > +static int bgpio_setup_direction(struct platform_device *pdev, > + struct bgpio_chip *bgc) > +{ > + struct resource *res_dirout; > + struct resource *res_dirin; > + > + res_dirout = platform_get_resource_byname(pdev, IORESOURCE_MEM, > + "dirout"); > + res_dirin = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dirin"); > + if (res_dirout && res_dirin) { > + return -EINVAL; > + } else if (res_dirout) { > + bgc->reg_dir = bgpio_request_and_map(&pdev->dev, res_dirout); > + if (!bgc->reg_dir) > + return -ENOMEM; > + bgc->gc.direction_output = bgpio_dir_out; > + bgc->gc.direction_input = bgpio_dir_in; > + } else if (res_dirin) { > + bgc->reg_dir = bgpio_request_and_map(&pdev->dev, res_dirin); > + if (!bgc->reg_dir) > + return -ENOMEM; > + bgc->gc.direction_output = bgpio_dir_out_inv; > + bgc->gc.direction_input = bgpio_dir_in_inv; > + } else { > + bgc->gc.direction_output = bgpio_simple_dir_out; > + bgc->gc.direction_input = bgpio_simple_dir_in; > + } > + > + return 0; > +} > + > static int __devinit bgpio_probe(struct platform_device *pdev) > { > struct device *dev = &pdev->dev; > @@ -360,11 +468,13 @@ static int __devinit bgpio_probe(struct platform_device *pdev) > return ret; > > spin_lock_init(&bgc->lock); > + ret = bgpio_setup_direction(pdev, bgc); > + if (ret) > + return ret; > + > 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.dev = dev; > bgc->gc.label = dev_name(dev); > > -- > 1.7.4.2 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/