Commit be1a4b13 authored by Linus Walleij's avatar Linus Walleij

gpio: improve error path in gpiolib

At several places the gpiolib will proceed to handle a GPIO
descriptor even if it's ->chip member is NULL and no gpiochip
is associated.

Fix this by checking that both the descriptor cookie *and*
the chip pointer are valid.

Also bail out earlier with more specific diagnostic messages
on missing operations for setting as input/output or debounce.

ChangeLog v1->v2:
- Also return -EIO on gpiod_set_debounce() with missing
  operations in the vtable
- Fix indentations.
Suggested-by: default avatarAlexandre Courbot <acourbot@nvidia.com>
Acked-by: default avatarAlexandre Courbot <acourbot@nvidia.com>
Reviewed-by: default avatarFrank Rowand <frank.rowand@sonymobile.com>
Cc: Tim Bird <tim.bird@sonymobile.com>
Signed-off-by: Linus Walleij's avatarLinus Walleij <linus.walleij@linaro.org>
parent 6c17aa01
......@@ -1398,7 +1398,7 @@ static int gpiod_request(struct gpio_desc *desc, const char *label)
int status = -EPROBE_DEFER;
unsigned long flags;
if (!desc) {
if (!desc || !desc->chip) {
pr_warn("%s: invalid GPIO\n", __func__);
return -EINVAL;
}
......@@ -1406,8 +1406,6 @@ static int gpiod_request(struct gpio_desc *desc, const char *label)
spin_lock_irqsave(&gpio_lock, flags);
chip = desc->chip;
if (chip == NULL)
goto done;
if (!try_module_get(chip->owner))
goto done;
......@@ -1630,16 +1628,20 @@ static int gpiod_direction_input(struct gpio_desc *desc)
int status = -EINVAL;
int offset;
if (!desc) {
if (!desc || !desc->chip) {
pr_warn("%s: invalid GPIO\n", __func__);
return -EINVAL;
}
chip = desc->chip;
if (!chip->get || !chip->direction_input) {
pr_warn("%s: missing get() or direction_input() operations\n",
__func__);
return -EIO;
}
spin_lock_irqsave(&gpio_lock, flags);
chip = desc->chip;
if (!chip || !chip->get || !chip->direction_input)
goto fail;
status = gpio_ensure_requested(desc);
if (status < 0)
goto fail;
......@@ -1691,7 +1693,7 @@ static int gpiod_direction_output(struct gpio_desc *desc, int value)
int status = -EINVAL;
int offset;
if (!desc) {
if (!desc || !desc->chip) {
pr_warn("%s: invalid GPIO\n", __func__);
return -EINVAL;
}
......@@ -1704,11 +1706,15 @@ static int gpiod_direction_output(struct gpio_desc *desc, int value)
if (!value && test_bit(FLAG_OPEN_SOURCE, &desc->flags))
return gpiod_direction_input(desc);
chip = desc->chip;
if (!chip->set || !chip->direction_output) {
pr_warn("%s: missing set() or direction_output() operations\n",
__func__);
return -EIO;
}
spin_lock_irqsave(&gpio_lock, flags);
chip = desc->chip;
if (!chip || !chip->set || !chip->direction_output)
goto fail;
status = gpio_ensure_requested(desc);
if (status < 0)
goto fail;
......@@ -1765,16 +1771,19 @@ static int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
int status = -EINVAL;
int offset;
if (!desc) {
if (!desc || !desc->chip) {
pr_warn("%s: invalid GPIO\n", __func__);
return -EINVAL;
}
spin_lock_irqsave(&gpio_lock, flags);
chip = desc->chip;
if (!chip || !chip->set || !chip->set_debounce)
goto fail;
if (!chip->set || !chip->set_debounce) {
pr_warn("%s: missing set() or set_debounce() operations\n",
__func__);
return -EIO;
}
spin_lock_irqsave(&gpio_lock, flags);
status = gpio_ensure_requested(desc);
if (status < 0)
......
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