diff options
| author | Andy Shevchenko <andriy.shevchenko@linux.intel.com> | 2019-10-09 17:34:44 +0300 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2019-10-15 01:18:46 +0200 |
| commit | 9411e3aaa6342eb730daa55cf3377463a37d2aa7 (patch) | |
| tree | 0fd5450050bc17c4b1282918cf378df6a8a1679b | |
| parent | 6658f87f219427ee776c498e07c878eb5cad1be2 (diff) | |
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>
| -rw-r--r-- | drivers/gpio/gpiolib.c | 22 | ||||
| -rw-r--r-- | include/linux/gpio/driver.h | 8 |
2 files changed, 29 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; diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h index f8245d67f070..5dd9c982e2cb 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -202,6 +202,14 @@ struct gpio_irq_chip { bool threaded; /** + * @init_hw: optional routine to initialize hardware before + * an IRQ chip will be added. This is quite useful when + * a particular driver wants to clear IRQ related registers + * in order to avoid undesired events. + */ + int (*init_hw)(struct gpio_chip *chip); + + /** * @init_valid_mask: optional routine to initialize @valid_mask, to be * used if not all GPIO lines are valid interrupts. Sometimes some * lines just cannot fire interrupts, and this routine, when defined, |