The bootloader can leave the GPIO expander in a state which doesn't have
output drivers enabled so GPIOs will properly work for input but output
operations will have no effect.
To avoid disrupting the boot in case the bootloader left direction and
data registers in an inconsistent state (e.g. pulling SoC's reset to 0)
reconfigure everything as input.
Thanks to Sander Vanheule for telling about LED_Start.
Signed-off-by: Paul Fertser <fercer...@gmail.com>
---
My previous patch to this part of the code is marked Accepted in the
Patchwork so this one is on top of it. Feel free to squash them
together.
.../realtek/files-5.4/drivers/gpio/gpio-rtl8231.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/target/linux/realtek/files-5.4/drivers/gpio/gpio-rtl8231.c
b/target/linux/realtek/files-5.4/drivers/gpio/gpio-rtl8231.c
index a8ffcdc31368..405c2c151368 100644
--- a/target/linux/realtek/files-5.4/drivers/gpio/gpio-rtl8231.c
+++ b/target/linux/realtek/files-5.4/drivers/gpio/gpio-rtl8231.c
@@ -254,11 +254,15 @@ int rtl8231_init(struct rtl8231_gpios *gpios)
sw_w32_mask(3, 1, RTL838X_DMY_REG5);
}
- /* Select GPIO functionality for pins 0-34 */
+ /* Select GPIO functionality and force input direction for pins 0-34 */
rtl8231_write(gpios, RTL8231_GPIO_PIN_SEL(0), 0xffff);
+ rtl8231_write(gpios, RTL8231_GPIO_DIR(0), 0xffff);
rtl8231_write(gpios, RTL8231_GPIO_PIN_SEL(16), 0xffff);
- v = rtl8231_read(gpios, RTL8231_GPIO_PIN_SEL(32));
- rtl8231_write(gpios, RTL8231_GPIO_PIN_SEL(32), v | 0x7);
+ rtl8231_write(gpios, RTL8231_GPIO_DIR(16), 0xffff);
+ rtl8231_write(gpios, RTL8231_GPIO_PIN_SEL(32), 0x03ff);
+
+ /* Set LED_Start to enable drivers for output mode */
+ rtl8231_write(gpios, RTL8231_LED_FUNC0, 1 << 1);
return 0;
}
--
2.17.1
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