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authorMichal Smulski <michal.smulski@ooma.com>2023-06-01 16:02:00 -0700
committerBartosz Golaszewski <bartosz.golaszewski@linaro.org>2023-06-16 11:11:27 +0200
commit19b60f8410ad6b2c8e8bd7ec74a43ab8ede3de05 (patch)
tree896990cf6e5464d92bca8c72a07913999810806b /drivers/gpio
parent61c65a8b50c22ef17839df6f342df44a5631400a (diff)
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 <michal.smulski@ooma.com> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Diffstat (limited to 'drivers/gpio')
-rw-r--r--drivers/gpio/gpio-mpc8xxx.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/gpio/gpio-mpc8xxx.c b/drivers/gpio/gpio-mpc8xxx.c
index 3eb08cd1fdc0..6340e738c912 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) {