From: Michal Smulski Date: Thu, 1 Jun 2023 23:02:00 +0000 (-0700) Subject: gpio: mpc8xxx: latch GPIOs state on module load when configured as output X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=19b60f8410ad6b2c8e8bd7ec74a43ab8ede3de05;p=linux.git 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: Michal Smulski Signed-off-by: Bartosz Golaszewski --- diff --git a/drivers/gpio/gpio-mpc8xxx.c b/drivers/gpio/gpio-mpc8xxx.c index 3eb08cd1fdc08..6340e738c912a 100644 --- a/drivers/gpio/gpio-mpc8xxx.c +++ b/drivers/gpio/gpio-mpc8xxx.c @@ -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) {