Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756047Ab1DKLW2 (ORCPT ); Mon, 11 Apr 2011 07:22:28 -0400 Received: from mail-ww0-f44.google.com ([74.125.82.44]:41908 "EHLO mail-ww0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755933Ab1DKLWM (ORCPT ); Mon, 11 Apr 2011 07:22:12 -0400 From: Jamie Iles To: linux-kernel@vger.kernel.org Cc: linux@arm.linux.org.uk, tglx@linutronix.de, cbouatmailru@gmail.com, grant.likely@secretlab.ca, arnd@arndb.de, nico@fluxnic.net, Jamie Iles Subject: [PATCHv3 7/7] basic_mmio_gpio: support direction registers Date: Mon, 11 Apr 2011 12:21:54 +0100 Message-Id: <1302520914-22816-8-git-send-email-jamie@jamieiles.com> X-Mailer: git-send-email 1.7.4.2 In-Reply-To: <1302520914-22816-1-git-send-email-jamie@jamieiles.com> References: <1302520914-22816-1-git-send-email-jamie@jamieiles.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5488 Lines: 191 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 --- 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/