by Dipen Patel

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Subject: [RFC v4 07/11] gpio: tegra186: Add HTE in gpio-tegra186 driver

Tegra194 AON GPIO controller with the use of its internal hardware
timestamping engine (HTE) also known as GTE can timestamp GPIO
lines through system counter. This patch implements enable/disable
callbacks for the GPIO controller. In enable call, it will set
timestamp function bit and GPIO line rising/falling edges in the
config register. In disable call, it restores the state.

Signed-off-by: Dipen Patel <[email protected]>
---
Changes in v4:
- Added edge setup and hardware timestamping enable/disable APIs.

drivers/gpio/gpio-tegra186.c | 81 +++++++++++++++++++++++++++++++++++-
1 file changed, 80 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpio-tegra186.c b/drivers/gpio/gpio-tegra186.c
index 91c77fccc1e6..3bf6f7e18dcc 100644
--- a/drivers/gpio/gpio-tegra186.c
+++ b/drivers/gpio/gpio-tegra186.c
@@ -1,8 +1,9 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
- * Copyright (c) 2016-2017 NVIDIA Corporation
+ * Copyright (c) 2016-2022 NVIDIA Corporation
*
* Author: Thierry Reding <[email protected]>
+ * Dipen Patel <[email protected]>
*/

#include <linux/gpio/driver.h>
@@ -11,6 +12,7 @@
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
+#include <linux/hte.h>

#include <dt-bindings/gpio/tegra186-gpio.h>
#include <dt-bindings/gpio/tegra194-gpio.h>
@@ -35,6 +37,7 @@
#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_ENABLE_CONFIG_TIMESTAMP_FUNC BIT(7)

#define TEGRA186_GPIO_DEBOUNCE_CONTROL 0x04
#define TEGRA186_GPIO_DEBOUNCE_CONTROL_THRESHOLD(x) ((x) & 0xff)
@@ -75,6 +78,7 @@ struct tegra_gpio_soc {
const struct tegra186_pin_range *pin_ranges;
unsigned int num_pin_ranges;
const char *pinmux;
+ bool has_gte;
};

struct tegra_gpio {
@@ -193,6 +197,76 @@ static int tegra186_gpio_direction_output(struct gpio_chip *chip,
return 0;
}

+#define HTE_BOTH_EDGES (HTE_RISING_EDGE_TS | HTE_FALLING_EDGE_TS)
+
+static int tegra186_gpio_en_hw_ts(struct gpio_chip *gc, u32 offset,
+ unsigned long flags)
+{
+ struct tegra_gpio *gpio;
+ void __iomem *base;
+ int value;
+
+ if (!gc)
+ return -EINVAL;
+
+ gpio = gpiochip_get_data(gc);
+ if (!gpio)
+ return -ENODEV;
+
+ base = tegra186_gpio_get_base(gpio, offset);
+ if (WARN_ON(base == NULL))
+ return -EINVAL;
+
+ value = readl(base + TEGRA186_GPIO_ENABLE_CONFIG);
+ value |= TEGRA186_GPIO_ENABLE_CONFIG_TIMESTAMP_FUNC;
+
+ if (flags == HTE_BOTH_EDGES) {
+ value |= TEGRA186_GPIO_ENABLE_CONFIG_TRIGGER_TYPE_DOUBLE_EDGE;
+ } else if (flags == HTE_RISING_EDGE_TS) {
+ value |= TEGRA186_GPIO_ENABLE_CONFIG_TRIGGER_TYPE_SINGLE_EDGE;
+ value |= TEGRA186_GPIO_ENABLE_CONFIG_TRIGGER_LEVEL;
+ } else if (flags == HTE_FALLING_EDGE_TS) {
+ value |= TEGRA186_GPIO_ENABLE_CONFIG_TRIGGER_TYPE_SINGLE_EDGE;
+ }
+
+ writel(value, base + TEGRA186_GPIO_ENABLE_CONFIG);
+
+ return 0;
+}
+
+static int tegra186_gpio_dis_hw_ts(struct gpio_chip *gc, u32 offset,
+ unsigned long flags)
+{
+ struct tegra_gpio *gpio;
+ void __iomem *base;
+ int value;
+
+ if (!gc)
+ return -EINVAL;
+
+ gpio = gpiochip_get_data(gc);
+ if (!gpio)
+ return -ENODEV;
+
+ base = tegra186_gpio_get_base(gpio, offset);
+ if (WARN_ON(base == NULL))
+ return -EINVAL;
+
+ value = readl(base + TEGRA186_GPIO_ENABLE_CONFIG);
+ value &= ~TEGRA186_GPIO_ENABLE_CONFIG_TIMESTAMP_FUNC;
+ if (flags == HTE_BOTH_EDGES) {
+ value &= ~TEGRA186_GPIO_ENABLE_CONFIG_TRIGGER_TYPE_DOUBLE_EDGE;
+ } else if (flags == HTE_RISING_EDGE_TS) {
+ value &= ~TEGRA186_GPIO_ENABLE_CONFIG_TRIGGER_TYPE_SINGLE_EDGE;
+ value &= ~TEGRA186_GPIO_ENABLE_CONFIG_TRIGGER_LEVEL;
+ } else if (flags == HTE_FALLING_EDGE_TS) {
+ value &= ~TEGRA186_GPIO_ENABLE_CONFIG_TRIGGER_TYPE_SINGLE_EDGE;
+ }
+ writel(value, base + TEGRA186_GPIO_ENABLE_CONFIG);
+
+ return 0;
+}
+
static int tegra186_gpio_get(struct gpio_chip *chip, unsigned int offset)
{
struct tegra_gpio *gpio = gpiochip_get_data(chip);
@@ -719,6 +793,10 @@ static int tegra186_gpio_probe(struct platform_device *pdev)
gpio->gpio.set = tegra186_gpio_set;
gpio->gpio.set_config = tegra186_gpio_set_config;
gpio->gpio.add_pin_ranges = tegra186_gpio_add_pin_ranges;
+ if (gpio->soc->has_gte) {
+ gpio->gpio.en_hw_timestamp = tegra186_gpio_en_hw_ts;
+ gpio->gpio.dis_hw_timestamp = tegra186_gpio_dis_hw_ts;
+ }

gpio->gpio.base = -1;

@@ -971,6 +1049,7 @@ static const struct tegra_gpio_soc tegra194_aon_soc = {
.name = "tegra194-gpio-aon",
.instance = 1,
.num_irqs_per_bank = 8,
+ .has_gte = true,
};

#define TEGRA234_MAIN_GPIO_PORT(_name, _bank, _port, _pins) \
--
2.17.1