gpio: max77620: Initialize hardware state of interrupts (e6827bc3) · Commits · 戴 / test

I noticed on Nexus 7 that after rebooting from downstream kernel to upstream, the GPIO interrupt is triggering non-stop despite interrupts being disabled for all of GPIOs. This happens because Nexus 7 uses a soft-reboot, meaning that bootloader should take care of resetting hardware, but the bootloader doesn't do it well. As a result, GPIO interrupt may be left ON at a boot time. Let's mask all GPIO interrupts at the driver's initialization time in order to resolve the issue. Signed-off-by:

Dmitry Osipenko <digetx@gmail.com> Reviewed-by:

Andy Shevchenko <andy.shevchenko@gmail.com> Acked-by:

Laxman Dewangan <ldewangan@nvidia.com> Link: https://lore.kernel.org/r/20200709171203.12950-7-digetx@gmail.com Signed-off-by:

Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-max77620.c

+25 −0

Original line number	Diff line number	Diff line
		@@ -260,6 +260,30 @@ static int max77620_gpio_set_config(struct gpio_chip *gc, unsigned int offset,
		return -ENOTSUPP;
		}

		static int max77620_gpio_irq_init_hw(struct gpio_chip *gc)
		{
		struct max77620_gpio *gpio = gpiochip_get_data(gc);
		unsigned int i;
		int err;

		/*
		* GPIO interrupts may be left ON after bootloader, hence let's
		* pre-initialize hardware to the expected state by disabling all
		* the interrupts.
		*/
		for (i = 0; i < MAX77620_GPIO_NR; i++) {
		err = regmap_update_bits(gpio->rmap, GPIO_REG_ADDR(i),
		MAX77620_CNFG_GPIO_INT_MASK, 0);
		if (err < 0) {
		dev_err(gpio->dev,
		"failed to disable interrupt: %d\n", err);
		return err;
		}
		}

		return 0;
		}

		static int max77620_gpio_probe(struct platform_device *pdev)
		{
		struct max77620_chip *chip = dev_get_drvdata(pdev->dev.parent);
		@@ -295,6 +319,7 @@ static int max77620_gpio_probe(struct platform_device *pdev)
		mgpio->gpio_chip.irq.chip = &max77620_gpio_irqchip;
		mgpio->gpio_chip.irq.default_type = IRQ_TYPE_NONE;
		mgpio->gpio_chip.irq.handler = handle_edge_irq;
		mgpio->gpio_chip.irq.init_hw = max77620_gpio_irq_init_hw,
		mgpio->gpio_chip.irq.threaded = true;

		platform_set_drvdata(pdev, mgpio);

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