Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757189Ab1DHORa (ORCPT ); Fri, 8 Apr 2011 10:17:30 -0400 Received: from mail-ww0-f42.google.com ([74.125.82.42]:62446 "EHLO mail-ww0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757294Ab1DHORZ (ORCPT ); Fri, 8 Apr 2011 10:17:25 -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: [PATCHv2 7/7] basic_mmio_gpio: support direction registers Date: Fri, 8 Apr 2011 15:16:51 +0100 Message-Id: <1302272211-30242-8-git-send-email-jamie@jamieiles.com> X-Mailer: git-send-email 1.7.4.2 In-Reply-To: <1302272211-30242-1-git-send-email-jamie@jamieiles.com> References: <1302272211-30242-1-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: 5268 Lines: 179 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 | 102 +++++++++++++++++++++++++++++++++++++++- 1 files changed, 100 insertions(+), 2 deletions(-) diff --git a/drivers/gpio/basic_mmio_gpio.c b/drivers/gpio/basic_mmio_gpio.c index ed4b0c6..9e0157a 100644 --- a/drivers/gpio/basic_mmio_gpio.c +++ b/drivers/gpio/basic_mmio_gpio.c @@ -71,6 +71,7 @@ struct bgpio_chip { void __iomem *reg_set; void __iomem *reg_clr; void __iomem *reg_in; + void __iomem *reg_dir; /* Number of bits (GPIOs): * 8. */ int bits; @@ -89,6 +90,9 @@ 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) @@ -193,15 +197,72 @@ static void bgpio_set_with_clear(struct gpio_chip *gc, unsigned int gpio, bgc->write_reg(bgc->reg_clr, mask); } +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; } @@ -268,6 +329,13 @@ static int bgpio_setup_accessors(struct platform_device *pdev, * - single output/input register resource (named "dat"). * - separate output/input register resources (named "dat" and "in"). * + * 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) @@ -308,6 +376,34 @@ 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; } @@ -361,11 +457,13 @@ 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/