The PS/2 bus defines the data and clock line be open drain, therefore
document this in the dt-binding and enforce the particular flag in the
driver.
Without enforcing to flag at least the clock gpio as open drain we run
into the following warning:
WARNING: CPU: 1 PID: 40 at drivers/gpio/gpiolib.c:3175 gpiochip_enable_irq+0x54/0x90
gpiochip_enable_irq() warns on a GPIO being configured as output and
using IRQ without being flagged as open drain.
Signed-off-by: Danilo Krummrich <danilokrummrich@xxxxxxxxxxxxx>
---
.../devicetree/bindings/serio/ps2-gpio.yaml | 14 ++++++++++----
drivers/input/serio/ps2-gpio.c | 9 +++++++--
2 files changed, 17 insertions(+), 6 deletions(-)
diff --git a/Documentation/devicetree/bindings/serio/ps2-gpio.yaml b/Documentation/devicetree/bindings/serio/ps2-gpio.yaml
index ec6fa7b40851..5e1951b4f511 100644
--- a/Documentation/devicetree/bindings/serio/ps2-gpio.yaml
+++ b/Documentation/devicetree/bindings/serio/ps2-gpio.yaml
@@ -16,12 +16,18 @@ properties:
data-gpios:
description:
- the gpio used for the data signal
+ the gpio used for the data signal - this should be flagged as
+ active high using open drain with (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)
+ from <dt-bindings/gpio/gpio.h> since the signal is open drain by
+ definition
maxItems: 1
clk-gpios:
description:
- the gpio used for the clock signal
+ the gpio used for the clock signal - this should be flagged as
+ active high using open drain with (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)
+ from <dt-bindings/gpio/gpio.h> since the signal is open drain by
+ definition
maxItems: 1
interrupts:
@@ -46,7 +52,7 @@ examples:
compatible = "ps2-gpio";
interrupt-parent = <&gpio>;
interrupts = <23 IRQ_TYPE_EDGE_FALLING>;
- data-gpios = <&gpio 24 GPIO_ACTIVE_HIGH>;
- clk-gpios = <&gpio 23 GPIO_ACTIVE_HIGH>;
+ data-gpios = <&gpio 24 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
+ clk-gpios = <&gpio 23 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
write-enable;
};
diff --git a/drivers/input/serio/ps2-gpio.c b/drivers/input/serio/ps2-gpio.c
index 460d520ac865..fdaff7a415cd 100644
--- a/drivers/input/serio/ps2-gpio.c
+++ b/drivers/input/serio/ps2-gpio.c
@@ -362,14 +362,19 @@ static irqreturn_t ps2_gpio_irq(int irq, void *dev_id)
static int ps2_gpio_get_props(struct device *dev,
struct ps2_gpio_data *drvdata)
{
- drvdata->gpio_data = devm_gpiod_get(dev, "data", GPIOD_IN);
+ enum gpiod_flags gflags;
+
+ /* Enforce open drain, since this is required by the PS/2 bus. */
+ gflags = GPIOD_IN | GPIOD_FLAGS_BIT_OPEN_DRAIN;
+
+ drvdata->gpio_data = devm_gpiod_get(dev, "data", gflags);
if (IS_ERR(drvdata->gpio_data)) {
dev_err(dev, "failed to request data gpio: %ld",
PTR_ERR(drvdata->gpio_data));
return PTR_ERR(drvdata->gpio_data);
}
- drvdata->gpio_clk = devm_gpiod_get(dev, "clk", GPIOD_IN);
+ drvdata->gpio_clk = devm_gpiod_get(dev, "clk", gflags);
if (IS_ERR(drvdata->gpio_clk)) {
dev_err(dev, "failed to request clock gpio: %ld",
PTR_ERR(drvdata->gpio_clk));
--
2.34.1
