diff options
Diffstat (limited to 'drivers/gpio')
| -rw-r--r-- | drivers/gpio/Kconfig | 6 | ||||
| -rw-r--r-- | drivers/gpio/gpiolib.c | 19 |
2 files changed, 17 insertions, 8 deletions
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 3d2565441b36..edb02530e461 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -42,9 +42,9 @@ config DEBUG_GPIO depends on DEBUG_KERNEL help Say Y here to add some extra checks and diagnostics to GPIO calls. - The checks help ensure that GPIOs have been properly initialized - before they are used and that sleeping calls aren not made from - nonsleeping contexts. They can make bitbanged serial protocols + These checks help ensure that GPIOs have been properly initialized + before they are used, and that sleeping calls are not made from + non-sleeping contexts. They can make bitbanged serial protocols slower. The diagnostics help catch the type of setup errors that are most common when setting up new platforms or boards. diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 42fb2fd24c0c..51a8d4103be5 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -69,20 +69,24 @@ static inline void desc_set_label(struct gpio_desc *d, const char *label) * those calls have no teeth) we can't avoid autorequesting. This nag * message should motivate switching to explicit requests... so should * the weaker cleanup after faults, compared to gpio_request(). + * + * NOTE: the autorequest mechanism is going away; at this point it's + * only "legal" in the sense that (old) code using it won't break yet, + * but instead only triggers a WARN() stack dump. */ static int gpio_ensure_requested(struct gpio_desc *desc, unsigned offset) { - if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) { - struct gpio_chip *chip = desc->chip; - int gpio = chip->base + offset; + const struct gpio_chip *chip = desc->chip; + const int gpio = chip->base + offset; + if (WARN(test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0, + "autorequest GPIO-%d\n", gpio)) { if (!try_module_get(chip->owner)) { pr_err("GPIO-%d: module can't be gotten \n", gpio); clear_bit(FLAG_REQUESTED, &desc->flags); /* lose */ return -EIO; } - pr_warning("GPIO-%d autorequested\n", gpio); desc_set_label(desc, "[auto]"); /* caller must chip->request() w/o spinlock */ if (chip->request) @@ -438,6 +442,7 @@ int gpio_export(unsigned gpio, bool direction_may_change) unsigned long flags; struct gpio_desc *desc; int status = -EINVAL; + char *ioname = NULL; /* can't export until sysfs is available ... */ if (!gpio_class.p) { @@ -461,11 +466,14 @@ int gpio_export(unsigned gpio, bool direction_may_change) } spin_unlock_irqrestore(&gpio_lock, flags); + if (desc->chip->names && desc->chip->names[gpio - desc->chip->base]) + ioname = desc->chip->names[gpio - desc->chip->base]; + if (status == 0) { struct device *dev; dev = device_create(&gpio_class, desc->chip->dev, MKDEV(0, 0), - desc, "gpio%d", gpio); + desc, ioname ? ioname : "gpio%d", gpio); if (dev) { if (direction_may_change) status = sysfs_create_group(&dev->kobj, @@ -513,6 +521,7 @@ void gpio_unexport(unsigned gpio) mutex_lock(&sysfs_lock); desc = &gpio_desc[gpio]; + if (test_bit(FLAG_EXPORT, &desc->flags)) { struct device *dev = NULL; |