From 2a3cf6a3599e901528d3e0025a1bd0722a8d3575 Mon Sep 17 00:00:00 2001 From: Alexandre Courbot Date: Wed, 11 Dec 2013 11:32:28 +0900 Subject: gpiolib: return -ENOENT if no GPIO mapping exists Some devices drivers make use of optional GPIO parameters. For such drivers, it is important to discriminate between the case where no GPIO mapping has been defined for the function they are requesting, and the case where a mapping exists but an error occured while resolving it or when acquiring the GPIO. This patch changes the family of gpiod_get() functions such that they will return -ENOENT if and only if no GPIO mapping is defined for the requested function. Other error codes are used when an actual error occured during the GPIO resolution. Signed-off-by: Alexandre Courbot Reviewed-by: Andy Shevchenko Reviewed-by: Mika Westerberg Signed-off-by: Linus Walleij --- drivers/gpio/gpiolib.c | 34 +++++++++++++++++----------------- 1 file changed, 17 insertions(+), 17 deletions(-) (limited to 'drivers/gpio') diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 12e47df..c0b06a9 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -2367,7 +2367,7 @@ static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id, unsigned int idx, enum gpio_lookup_flags *flags) { - struct gpio_desc *desc = ERR_PTR(-ENODEV); + struct gpio_desc *desc = ERR_PTR(-ENOENT); struct gpiod_lookup_table *table; struct gpiod_lookup *p; @@ -2389,19 +2389,22 @@ static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id, chip = find_chip_by_name(p->chip_label); if (!chip) { - dev_warn(dev, "cannot find GPIO chip %s\n", - p->chip_label); - continue; + dev_err(dev, "cannot find GPIO chip %s\n", + p->chip_label); + return ERR_PTR(-ENODEV); } if (chip->ngpio <= p->chip_hwnum) { - dev_warn(dev, "GPIO chip %s has %d GPIOs\n", - chip->label, chip->ngpio); - continue; + dev_err(dev, + "requested GPIO %d is out of range [0..%d] for chip %s\n", + idx, chip->ngpio, chip->label); + return ERR_PTR(-EINVAL); } desc = gpiochip_offset_to_desc(chip, p->chip_hwnum); *flags = p->flags; + + return desc; } return desc; @@ -2413,7 +2416,8 @@ static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id, * @con_id: function within the GPIO consumer * * Return the GPIO descriptor corresponding to the function con_id of device - * dev, or an IS_ERR() condition if an error occured. + * dev, -ENOENT if no GPIO has been assigned to the requested function, or + * another IS_ERR() code if an error occured while trying to acquire the GPIO. */ struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id) { @@ -2430,7 +2434,9 @@ EXPORT_SYMBOL_GPL(gpiod_get); * This variant of gpiod_get() allows to access GPIOs other than the first * defined one for functions that define several GPIOs. * - * Return a valid GPIO descriptor, or an IS_ERR() condition in case of error. + * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the + * requested function and/or index, or another IS_ERR() code if an error + * occured while trying to acquire the GPIO. */ struct gpio_desc *__must_check gpiod_get_index(struct device *dev, const char *con_id, @@ -2455,15 +2461,9 @@ struct gpio_desc *__must_check gpiod_get_index(struct device *dev, * Either we are not using DT or ACPI, or their lookup did not return * a result. In that case, use platform lookup as a fallback. */ - if (!desc || IS_ERR(desc)) { - struct gpio_desc *pdesc; - + if (!desc || desc == ERR_PTR(-ENOENT)) { dev_dbg(dev, "using lookup tables for GPIO lookup"); - pdesc = gpiod_find(dev, con_id, idx, &flags); - - /* If used as fallback, do not replace the previous error */ - if (!IS_ERR(pdesc) || !desc) - desc = pdesc; + desc = gpiod_find(dev, con_id, idx, &flags); } if (IS_ERR(desc)) { -- cgit v1.1