From: Thierry Reding <treding@xxxxxxxxxx>
The GPIO controller found on Tegra186 and later supports debouncing for
inputs for up to 255 ms.
Signed-off-by: Thierry Reding <treding@xxxxxxxxxx>
---
drivers/gpio/gpio-tegra186.c | 38 ++++++++++++++++++++++++++++++++++++
1 file changed, 38 insertions(+)
diff --git a/drivers/gpio/gpio-tegra186.c b/drivers/gpio/gpio-tegra186.c
index 404ebb82bfa2..c4e23f530664 100644
--- a/drivers/gpio/gpio-tegra186.c
+++ b/drivers/gpio/gpio-tegra186.c
@@ -32,6 +32,7 @@
#define TEGRA186_GPIO_ENABLE_CONFIG_TRIGGER_TYPE_DOUBLE_EDGE (0x3 << 2)
#define TEGRA186_GPIO_ENABLE_CONFIG_TRIGGER_TYPE_MASK (0x3 << 2)
#define TEGRA186_GPIO_ENABLE_CONFIG_TRIGGER_LEVEL BIT(4)
+#define TEGRA186_GPIO_ENABLE_CONFIG_DEBOUNCE BIT(5)
#define TEGRA186_GPIO_ENABLE_CONFIG_INTERRUPT BIT(6)
#define TEGRA186_GPIO_DEBOUNCE_CONTROL 0x04
@@ -217,6 +218,42 @@ static void tegra186_gpio_set(struct gpio_chip *chip, unsigned int offset,
writel(value, base + TEGRA186_GPIO_OUTPUT_VALUE);
}
+static int tegra186_gpio_set_config(struct gpio_chip *chip,
+ unsigned int offset,
+ unsigned long config)
+{
+ struct tegra_gpio *gpio = gpiochip_get_data(chip);
+ u32 debounce, value;
+ void __iomem *base;
+
+ base = tegra186_gpio_get_base(gpio, offset);
+ if (base == NULL)
+ return -ENXIO;
+
+ if (pinconf_to_config_param(config) != PIN_CONFIG_INPUT_DEBOUNCE)
+ return -ENOTSUPP;
+
+ debounce = pinconf_to_config_argument(config);
+
+ /*
+ * The Tegra186 GPIO controller supports a maximum of 255 ms debounce
+ * time.
+ */
+ if (debounce > 255000)
+ return -EINVAL;
+
+ debounce = DIV_ROUND_UP(debounce, USEC_PER_MSEC);
+
+ value = TEGRA186_GPIO_DEBOUNCE_CONTROL_THRESHOLD(debounce);
+ writel(value, base + TEGRA186_GPIO_DEBOUNCE_CONTROL);
+
+ value = readl(base + TEGRA186_GPIO_ENABLE_CONFIG);
+ value |= TEGRA186_GPIO_ENABLE_CONFIG_DEBOUNCE;
+ writel(value, base + TEGRA186_GPIO_ENABLE_CONFIG);
+
+ return 0;
+}
+
static int tegra186_gpio_of_xlate(struct gpio_chip *chip,
const struct of_phandle_args *spec,
u32 *flags)
@@ -539,6 +576,7 @@ static int tegra186_gpio_probe(struct platform_device *pdev)
gpio->gpio.direction_output = tegra186_gpio_direction_output;
gpio->gpio.get = tegra186_gpio_get,
gpio->gpio.set = tegra186_gpio_set;
+ gpio->gpio.set_config = tegra186_gpio_set_config;
gpio->gpio.base = -1;
--
2.23.0
