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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 /include
parent6658f87f219427ee776c498e07c878eb5cad1be2 (diff)
downloadlinux-9411e3aaa6342eb730daa55cf3377463a37d2aa7.tar.gz
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 'include')
-rw-r--r--include/linux/gpio/driver.h8
1 files changed, 8 insertions, 0 deletions
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,