gpiolib: Add HTE support

Some GPIO chip can provide hardware timestamp support on its GPIO lines
, in order to support that, additional API needs to be added which
can talk to both GPIO chip and HTE (hardware timestamping engine)
providers if there is any dependencies. This patch introduces optional
hooks to enable and disable hardware timestamping related features
in the GPIO controller chip.

Signed-off-by: Dipen Patel <dipenp@nvidia.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

1 files changed, 58 insertions, 0 deletions

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index e59884cc12a7..60cd7cc33647 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -2435,6 +2435,64 @@ set_output_flag:
 EXPORT_SYMBOL_GPL(gpiod_direction_output);
 
 /**
+ * gpiod_enable_hw_timestamp_ns - Enable hardware timestamp in nanoseconds.
+ *
+ * @desc: GPIO to enable.
+ * @flags: Flags related to GPIO edge.
+ *
+ * Return 0 in case of success, else negative error code.
+ */
+int gpiod_enable_hw_timestamp_ns(struct gpio_desc *desc, unsigned long flags)
+{
+	int ret = 0;
+	struct gpio_chip *gc;
+
+	VALIDATE_DESC(desc);
+
+	gc = desc->gdev->chip;
+	if (!gc->en_hw_timestamp) {
+		gpiod_warn(desc, "%s: hw ts not supported\n", __func__);
+		return -ENOTSUPP;
+	}
+
+	ret = gc->en_hw_timestamp(gc, gpio_chip_hwgpio(desc), flags);
+	if (ret)
+		gpiod_warn(desc, "%s: hw ts request failed\n", __func__);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(gpiod_enable_hw_timestamp_ns);
+
+/**
+ * gpiod_disable_hw_timestamp_ns - Disable hardware timestamp.
+ *
+ * @desc: GPIO to disable.
+ * @flags: Flags related to GPIO edge, same value as used during enable call.
+ *
+ * Return 0 in case of success, else negative error code.
+ */
+int gpiod_disable_hw_timestamp_ns(struct gpio_desc *desc, unsigned long flags)
+{
+	int ret = 0;
+	struct gpio_chip *gc;
+
+	VALIDATE_DESC(desc);
+
+	gc = desc->gdev->chip;
+	if (!gc->dis_hw_timestamp) {
+		gpiod_warn(desc, "%s: hw ts not supported\n", __func__);
+		return -ENOTSUPP;
+	}
+
+	ret = gc->dis_hw_timestamp(gc, gpio_chip_hwgpio(desc), flags);
+	if (ret)
+		gpiod_warn(desc, "%s: hw ts release failed\n", __func__);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(gpiod_disable_hw_timestamp_ns);
+
+/**
  * gpiod_set_config - sets @config for a GPIO
  * @desc: descriptor of the GPIO for which to set the configuration
  * @config: Same packed config format as generic pinconf