Commit 19b60f84 authored by Michal Smulski's avatar Michal Smulski Committed by Bartosz Golaszewski
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gpio: mpc8xxx: latch GPIOs state on module load when configured as output 



Qoriq and related devices allow reading out state of GPIO set as output.
However, currently on driver's init, all outputs are configured as driven
low. So, any changes to GPIO confiuration will drive all pins (configured
as output) as output-low.
This patch latches state of output GPIOs before any GPIO configuration
takes place. This preserves any output settings done prior to loading
the driver (for example, by u-boot).

Signed-off-by: default avatarMichal Smulski <michal.smulski@ooma.com>
Signed-off-by: default avatarBartosz Golaszewski <bartosz.golaszewski@linaro.org>
parent 61c65a8b

drivers/gpio/gpio-mpc8xxx.c

+5 −1
Original line number Diff line number Diff line
@@ -375,8 +375,12 @@ static int mpc8xxx_probe(struct platform_device *pdev) 
	if (of_device_is_compatible(np, "fsl,qoriq-gpio") ||

	    of_device_is_compatible(np, "fsl,ls1028a-gpio") ||

	    of_device_is_compatible(np, "fsl,ls1088a-gpio") ||

	    is_acpi_node(fwnode))

	    is_acpi_node(fwnode)) {

		gc->write_reg(mpc8xxx_gc->regs + GPIO_IBE, 0xffffffff);

		/* Also, latch state of GPIOs configured as output by bootloader. */

		gc->bgpio_data = gc->read_reg(mpc8xxx_gc->regs + GPIO_DAT) &

			gc->read_reg(mpc8xxx_gc->regs + GPIO_DIR);

	}



	ret = devm_gpiochip_add_data(&pdev->dev, gc, mpc8xxx_gc);

	if (ret) {