Some GPIO controllers have an enable register which needs to be written to before a GPIO can be used.
Add support for enabling the GPIO. At this time inverted logic for enabling the GPIO is not supported. This can be done by adding a disable register as and when a controller with this comes along. Signed-off-by: Sekhar Nori <nsek...@ti.com> --- drivers/gpio/gpio-ep93xx.c | 2 +- drivers/gpio/gpio-generic.c | 45 ++++++++++++++++++++++++++++++++++++++- drivers/gpio/gpio-mxc.c | 2 +- drivers/gpio/gpio-mxs.c | 2 +- include/linux/basic_mmio_gpio.h | 5 ++++ 5 files changed, 52 insertions(+), 4 deletions(-) diff --git a/drivers/gpio/gpio-ep93xx.c b/drivers/gpio/gpio-ep93xx.c index 3bfd341..8ed498a 100644 --- a/drivers/gpio/gpio-ep93xx.c +++ b/drivers/gpio/gpio-ep93xx.c @@ -314,7 +314,7 @@ static int ep93xx_gpio_add_bank(struct bgpio_chip *bgc, struct device *dev, void __iomem *dir = mmio_base + bank->dir; int err; - err = bgpio_init(bgc, dev, 1, data, NULL, NULL, dir, NULL, false); + err = bgpio_init(bgc, dev, 1, data, NULL, NULL, dir, NULL, NULL, false); if (err) return err; diff --git a/drivers/gpio/gpio-generic.c b/drivers/gpio/gpio-generic.c index 231714d..cf7d596 100644 --- a/drivers/gpio/gpio-generic.c +++ b/drivers/gpio/gpio-generic.c @@ -247,6 +247,34 @@ static int bgpio_dir_out_inv(struct gpio_chip *gc, unsigned int gpio, int val) return 0; } +static int bgpio_request(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->en |= bgc->pin2mask(bgc, gpio); + bgc->write_reg(bgc->reg_en, bgc->en); + + spin_unlock_irqrestore(&bgc->lock, flags); + + return 0; +} + +static void bgpio_free(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->en &= ~bgc->pin2mask(bgc, gpio); + bgc->write_reg(bgc->reg_en, bgc->en); + + spin_unlock_irqrestore(&bgc->lock, flags); +} + static int bgpio_setup_accessors(struct device *dev, struct bgpio_chip *bgc, bool be) @@ -302,6 +330,10 @@ static int bgpio_setup_accessors(struct device *dev, * indicates the GPIO is an output. * - an input direction register (named "dirin") where a 1 bit indicates * the GPIO is an input. + * + * To enable and disable a GPIO at the time of requesting it there is a + * a simple enable register supported where a 1 bit indicates that the GPIO + * is enabled. */ static int bgpio_setup_io(struct bgpio_chip *bgc, void __iomem *dat, @@ -369,6 +401,7 @@ int __devinit bgpio_init(struct bgpio_chip *bgc, void __iomem *clr, void __iomem *dirout, void __iomem *dirin, + void __iomem *en, bool big_endian) { int ret; @@ -398,6 +431,11 @@ int __devinit bgpio_init(struct bgpio_chip *bgc, if (ret) return ret; + if (en) { + bgc->gc.request = bgpio_request; + bgc->gc.free = bgpio_free; + } + bgc->data = bgc->read_reg(bgc->reg_dat); return ret; @@ -453,6 +491,7 @@ static int __devinit bgpio_pdev_probe(struct platform_device *pdev) void __iomem *clr; void __iomem *dirout; void __iomem *dirin; + void __iomem *en; unsigned long sz; bool be; int err; @@ -485,13 +524,17 @@ static int __devinit bgpio_pdev_probe(struct platform_device *pdev) if (err) return err; + en = bgpio_map(pdev, "en", sz, &err); + if (err) + return err; + be = !strcmp(platform_get_device_id(pdev)->name, "basic-mmio-gpio-be"); bgc = devm_kzalloc(&pdev->dev, sizeof(*bgc), GFP_KERNEL); if (!bgc) return -ENOMEM; - err = bgpio_init(bgc, dev, sz, dat, set, clr, dirout, dirin, be); + err = bgpio_init(bgc, dev, sz, dat, set, clr, dirout, dirin, en, be); if (err) return err; diff --git a/drivers/gpio/gpio-mxc.c b/drivers/gpio/gpio-mxc.c index 2f6a81b..5ce98c6 100644 --- a/drivers/gpio/gpio-mxc.c +++ b/drivers/gpio/gpio-mxc.c @@ -300,7 +300,7 @@ static int __devinit mxc_gpio_probe(struct platform_device *pdev) err = bgpio_init(&port->bgc, &pdev->dev, 4, port->base + GPIO_PSR, port->base + GPIO_DR, NULL, - port->base + GPIO_GDIR, NULL, false); + port->base + GPIO_GDIR, NULL, NULL, false); if (err) goto out_iounmap; diff --git a/drivers/gpio/gpio-mxs.c b/drivers/gpio/gpio-mxs.c index d8cafba..f3b78bf 100644 --- a/drivers/gpio/gpio-mxs.c +++ b/drivers/gpio/gpio-mxs.c @@ -241,7 +241,7 @@ static int __devinit mxs_gpio_probe(struct platform_device *pdev) err = bgpio_init(&port->bgc, &pdev->dev, 4, port->base + PINCTRL_DIN(port->id), port->base + PINCTRL_DOUT(port->id), NULL, - port->base + PINCTRL_DOE(port->id), NULL, false); + port->base + PINCTRL_DOE(port->id), NULL, NULL, false); if (err) goto out_iounmap; diff --git a/include/linux/basic_mmio_gpio.h b/include/linux/basic_mmio_gpio.h index 98999cf..fc2e1cc 100644 --- a/include/linux/basic_mmio_gpio.h +++ b/include/linux/basic_mmio_gpio.h @@ -35,6 +35,7 @@ struct bgpio_chip { void __iomem *reg_set; void __iomem *reg_clr; void __iomem *reg_dir; + void __iomem *reg_en; /* Number of bits (GPIOs): <register width> * 8. */ int bits; @@ -56,6 +57,9 @@ struct bgpio_chip { /* Shadowed direction registers to clear/set direction safely. */ unsigned long dir; + + /* Shadowed enable register to enable/disable safely. */ + unsigned long en; }; static inline struct bgpio_chip *to_bgpio_chip(struct gpio_chip *gc) @@ -72,6 +76,7 @@ int __devinit bgpio_init(struct bgpio_chip *bgc, void __iomem *clr, void __iomem *dirout, void __iomem *dirin, + void __iomem *en, bool big_endian); #endif /* __BASIC_MMIO_GPIO_H */ -- 1.7.3.2 _______________________________________________ Davinci-linux-open-source mailing list Davinci-linux-open-source@linux.davincidsp.com http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source