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authorAndy Shevchenko <andriy.shevchenko@linux.intel.com>2019-10-09 17:34:44 +0300
committerLinus Walleij <linus.walleij@linaro.org>2019-10-15 01:18:46 +0200
commit9411e3aaa6342eb730daa55cf3377463a37d2aa7 (patch)
tree0fd5450050bc17c4b1282918cf378df6a8a1679b /drivers/gpio
parent6658f87f219427ee776c498e07c878eb5cad1be2 (diff)
downloadlinux-9411e3aaa6342eb730daa55cf3377463a37d2aa7.tar.bz2
gpiolib: Initialize the hardware with a callback
After changing the drivers to use GPIO core to add an IRQ chip it appears that some of them requires a hardware initialization before adding the IRQ chip. Add an optional callback ->init_hw() to allow that drivers to initialize hardware if needed. This change is a part of the fix NULL pointer dereference brought to the several drivers recently. Cc: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio')
-rw-r--r--drivers/gpio/gpiolib.c22
1 files changed, 21 insertions, 1 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 5833e4f380d6..104ed299d5ea 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -86,6 +86,7 @@ static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
struct lock_class_key *lock_key,
struct lock_class_key *request_key);
static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
+static int gpiochip_irqchip_init_hw(struct gpio_chip *gpiochip);
static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip);
static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip);
@@ -1406,6 +1407,10 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
machine_gpiochip_add(chip);
+ ret = gpiochip_irqchip_init_hw(chip);
+ if (ret)
+ goto err_remove_acpi_chip;
+
ret = gpiochip_irqchip_init_valid_mask(chip);
if (ret)
goto err_remove_acpi_chip;
@@ -1622,6 +1627,16 @@ static struct gpio_chip *find_chip_by_name(const char *name)
* The following is irqchip helper code for gpiochips.
*/
+static int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
+{
+ struct gpio_irq_chip *girq = &gc->irq;
+
+ if (!girq->init_hw)
+ return 0;
+
+ return girq->init_hw(gc);
+}
+
static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
{
struct gpio_irq_chip *girq = &gc->irq;
@@ -2446,8 +2461,13 @@ static inline int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
{
return 0;
}
-
static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
+
+static inline int gpiochip_irqchip_init_hw(struct gpio_chip *gpiochip)
+{
+ return 0;
+}
+
static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
{
return 0;