On Tue, Oct 28, 2014 at 1:01 AM, Dmitry Eremin-Solenikov <dbaryshkov@xxxxxxxxx> wrote: > Add gpiolib driver for gpio pins placed on the LoCoMo GA. > > Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@xxxxxxxxx> (...) > +static int locomo_gpio_get(struct gpio_chip *chip, > + unsigned offset) > +{ > + struct locomo_gpio *lg = container_of(chip, struct locomo_gpio, gpio); > + > + return readw(lg->regs + LOCOMO_GPL) & (1 << offset); Do this: #include <linux/bitops.h> return !!(readw(lg->regs + LOCOMO_GPL) & BIT(offset)); So you clamp the returned value to a bool. > +static void __locomo_gpio_set(struct gpio_chip *chip, > + unsigned offset, int value) > +{ > + struct locomo_gpio *lg = container_of(chip, struct locomo_gpio, gpio); > + u16 r; > + > + r = readw(lg->regs + LOCOMO_GPO); > + if (value) > + r |= 1 << offset; r |= BIT(offset); > + else > + r &= ~(1 << offset); r &= BIT(offset); (etc, everywhere this pattern occurs). > +static void locomo_gpio_set(struct gpio_chip *chip, > + unsigned offset, int value) > +{ > + struct locomo_gpio *lg = container_of(chip, struct locomo_gpio, gpio); > + unsigned long flags; > + > + spin_lock_irqsave(&lg->lock, flags); > + > + __locomo_gpio_set(chip, offset, value); > + > + spin_unlock_irqrestore(&lg->lock, flags); If you actually always have to be getting and releasing a spin lock around the register writes, contemplate using regmap-mmio because that is part of what it does. But is this locking really necessary? > +static int locomo_gpio_remove(struct platform_device *pdev) > +{ > + struct locomo_gpio *lg = platform_get_drvdata(pdev); > + int ret; > + > + ret = gpiochip_remove(&lg->gpio); > + if (ret) { > + dev_err(&pdev->dev, "Can't remove gpio chip: %d\n", ret); > + return ret; > + } The return value from gpiochip_remove() has been removed in v3.18-rc1 so this will not compile. Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html