Linux-GPIO Archive on lore.kernel.org
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From: Thierry Reding <thierry.reding@gmail.com>
To: Linus Walleij <linus.walleij@linaro.org>,
	Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Jon Hunter <jonathanh@nvidia.com>,
	Vidya Sagar <vidyas@nvidia.com>,
	linux-gpio@vger.kernel.org, linux-tegra@vger.kernel.org
Subject: [PATCH 3/3] gpio: tegra186: Add debounce support
Date: Fri,  8 Nov 2019 16:33:53 +0100
Message-ID: <20191108153353.3149078-3-thierry.reding@gmail.com> (raw)
In-Reply-To: <20191108153353.3149078-1-thierry.reding@gmail.com>

From: Thierry Reding <treding@nvidia.com>

The GPIO controller found on Tegra186 and later supports debouncing for
inputs for up to 255 ms.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 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


  parent reply index

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-08 15:33 [PATCH 1/3] gpio: tegra186: Derive register offsets from bank/port Thierry Reding
2019-11-08 15:33 ` [PATCH 2/3] gpio: tegra186: Program interrupt route mapping Thierry Reding
2019-11-12 10:11   ` Bartosz Golaszewski
2019-11-12 14:10     ` Greg KH
2019-11-12 15:33       ` Bartosz Golaszewski
2019-11-08 15:33 ` Thierry Reding [this message]
2019-11-12 15:33 ` [PATCH 1/3] gpio: tegra186: Derive register offsets from bank/port Bartosz Golaszewski

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