diff options
Diffstat (limited to 'drivers/gpio')
| -rw-r--r-- | 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 6b99489e0ebb..f4afd96303c1 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): <register width> * 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); |