On Thu, Sep 15, 2016 at 05:07:58PM +0100, Marc Zyngier wrote:

Mika,

On 15/09/16 16:52, Mika Westerberg wrote:

quoted

When using GPIO irqchip helpers to setup irqchip for a gpiolib based
driver, it is not possible to select which GPIOs to add to the IRQ domain.
Instead it just adds all GPIOs which is not always desired. For example
there might be GPIOs that for some reason just cannot be used as interrupts
at all.

To make this possible we add valid_mask to each gpio_chip and by default
assume all GPIOs can be used as interrupts. Drivers can then tune this
using clear_bit() or similar before they call gpiochip_irqchip_add().

Suggested-by: Linus Walleij <redacted>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 drivers/gpio/gpiolib.c      | 32 +++++++++++++++++++++++++++++---
 include/linux/gpio/driver.h |  1 +
 2 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 53ff25ac66d8..d84c23b47f44 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c

@@ -1186,6 +1186,18 @@ int gpiochip_add_data(struct gpio_chip *chip, void *data)
 		if (status)
 			goto err_remove_chip;
 	}
+
+#ifdef CONFIG_GPIOLIB_IRQCHIP
+	chip->valid_mask = kcalloc(BITS_TO_LONGS(chip->ngpio), sizeof(long),
+				   GFP_KERNEL);

Do we really want to make this a mandatory thing? In most cases, I'd
expect this valid_mask to have all bits set, so you might as well not
allocate it at all in that case (and only allocate it if you actually
need it).

We can make drivers to allocate it and only if set use it in core.

quoted

+	if (!chip->valid_mask)
+		return -ENOMEM;

You really want to revise your error handling here.

Oops, right. It should be:

	if (!chip->valid_mask) {
		status = -ENOMEM;
		goto err_remove_chip;
	}