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authorLinus Walleij <linus.walleij@linaro.org>2016-02-10 12:57:36 +0300
committerLinus Walleij <linus.walleij@linaro.org>2016-02-11 22:29:46 +0300
commitfdeb8e1547cb9dd39d5d7223b33f3565cf86c28e (patch)
tree65016a6cdaaa86565803c77f662c4b298c7b19f1 /drivers/gpio/gpiolib-sysfs.c
parent6cee3821e4e4bd6e6cdf0870b6c72d455460bd39 (diff)
downloadlinux-fdeb8e1547cb9dd39d5d7223b33f3565cf86c28e.tar.xz
gpio: reflect base and ngpio into gpio_device
Some information about the GPIO chip need to stay around also after the gpio_chip has been removed and only the gpio_device persist. The base and ngpio are such things, for example we don't want a new chip arriving to overlap the number space of a dangling gpio_device, and the chardev may still query the device for the number of lines etc. Note that the code that assigns base and insert gpio_device into the global list no longer check for a missing gpio_chip: we respect the number space allocated by any other gpio_device. As a consequence of the gdev being referenced directly from the gpio_desc, we need to verify it differently from all in-kernel API calls that fall through to direct queries to the gpio_chip vtable: we first check that desc is !NULL, then that desc->gdev is !NULL, then, if desc->gdev->chip is NULL, we *BAIL OUT* without any error, so as to manage the case where operations are requested on a device that is gone. These checks were non-uniform and partly missing in the past: so to simplify: create the macros VALIDATE_DESC() that will return -EINVAL if the desc or desc->gdev is missing and just 0 if the chip is gone, and conversely VALIDATE_DESC_VOID() for the case where the function does not return an error. By using these macros, we get warning messages about missing gdev with reference to the right function in the kernel log. Despite the macro business this simplifies the code and make it more readable than if we copy/paste the same descriptor checking code into all code ABI call sites (IMHO). Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio/gpiolib-sysfs.c')
-rw-r--r--drivers/gpio/gpiolib-sysfs.c12
1 files changed, 6 insertions, 6 deletions
diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
index de65633471af..c56309491e8b 100644
--- a/drivers/gpio/gpiolib-sysfs.c
+++ b/drivers/gpio/gpiolib-sysfs.c
@@ -180,7 +180,7 @@ static int gpio_sysfs_request_irq(struct device *dev, unsigned char flags)
* Remove this redundant call (along with the corresponding
* unlock) when those drivers have been fixed.
*/
- ret = gpiochip_lock_as_irq(desc->chip, gpio_chip_hwgpio(desc));
+ ret = gpiochip_lock_as_irq(desc->gdev->chip, gpio_chip_hwgpio(desc));
if (ret < 0)
goto err_put_kn;
@@ -194,7 +194,7 @@ static int gpio_sysfs_request_irq(struct device *dev, unsigned char flags)
return 0;
err_unlock:
- gpiochip_unlock_as_irq(desc->chip, gpio_chip_hwgpio(desc));
+ gpiochip_unlock_as_irq(desc->gdev->chip, gpio_chip_hwgpio(desc));
err_put_kn:
sysfs_put(data->value_kn);
@@ -212,7 +212,7 @@ static void gpio_sysfs_free_irq(struct device *dev)
data->irq_flags = 0;
free_irq(data->irq, data);
- gpiochip_unlock_as_irq(desc->chip, gpio_chip_hwgpio(desc));
+ gpiochip_unlock_as_irq(desc->gdev->chip, gpio_chip_hwgpio(desc));
sysfs_put(data->value_kn);
}
@@ -566,8 +566,8 @@ int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
return -EINVAL;
}
- chip = desc->chip;
- gdev = chip->gpiodev;
+ gdev = desc->gdev;
+ chip = gdev->chip;
mutex_lock(&sysfs_lock);
@@ -765,7 +765,7 @@ void gpiochip_sysfs_unregister(struct gpio_device *gdev)
/* unregister gpiod class devices owned by sysfs */
for (i = 0; i < chip->ngpio; i++) {
- desc = &chip->gpiodev->descs[i];
+ desc = &gdev->descs[i];
if (test_and_clear_bit(FLAG_SYSFS, &desc->flags))
gpiod_free(desc);
}