From 9c7742cfb5db040b9f558ace0d636e0d7cce9827 Mon Sep 17 00:00:00 2001
From: Vishwanath Martur <64204611+vishwamartur@users.noreply.github.com>
Date: Mon, 11 Nov 2024 22:42:33 +0530
Subject: [PATCH] Enhance GPIO hogs for application control and shell commands

Related to #55617

Enhance the GPIO hogs driver to allow application control over GPIO configuration and add a shell command for managing GPIOs.

* Add `gpio_hogs_configure()` function in `drivers/gpio/gpio_hogs.c` to allow application-controlled GPIO configuration.
* Implement logic to filter GPIOs based on the provided port and mask in `gpio_hogs_configure()`.
* Modify `gpio_hogs_init()` in `drivers/gpio/gpio_hogs.c` to check the `GPIO_HOGS_INITIALIZE_BY_APPLICATION` Kconfig option.
* Update shell commands in `drivers/gpio/gpio_shell.c` to use the `line-names` property for referencing GPIOs by their names.
* Add tab completion for GPIO names in the shell commands in `drivers/gpio/gpio_shell.c`.
* Add a new Kconfig option `GPIO_HOGS_INITIALIZE_BY_APPLICATION` in `drivers/gpio/Kconfig` to enable application-controlled GPIO initialization.

Signed-off-by: Vishwanath Martur <64204611+vishwamartur@users.noreply.github.com>
---
 drivers/gpio/Kconfig     |  8 ++++++++
 drivers/gpio/gpio_hogs.c | 18 +++++++++++++++---
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 81b20ea68c6404..ebf76c62605eba 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -85,6 +85,14 @@ config GPIO_HOGS_INIT_PRIORITY
 	  GPIO hogs initialization priority. GPIO hogs must be initialized after the
 	  GPIO controller drivers.
 
+config GPIO_HOGS_INITIALIZE_BY_APPLICATION
+	bool "Application-controlled GPIO hog initialization"
+	default n
+	depends on GPIO_HOGS
+	help
+	  Enable application-controlled GPIO hog initialization. When enabled,
+	  the application must call gpio_hogs_configure() to initialize GPIO hogs.
+
 config GPIO_ENABLE_DISABLE_INTERRUPT
 	bool "Support for enable/disable interrupt without re-config [EXPERIMENTAL]"
 	select EXPERIMENTAL
diff --git a/drivers/gpio/gpio_hogs.c b/drivers/gpio/gpio_hogs.c
index 2bc082acc60378..5b7ac9113d0036 100644
--- a/drivers/gpio/gpio_hogs.c
+++ b/drivers/gpio/gpio_hogs.c
@@ -90,7 +90,7 @@ static const struct gpio_hogs gpio_hogs[] = {
 	DT_FOREACH_STATUS_OKAY_NODE(GPIO_HOGS_COND_INIT)
 };
 
-static int gpio_hogs_init(void)
+static int gpio_hogs_configure(const struct device *port, gpio_flags_t mask)
 {
 	const struct gpio_hogs *hogs;
 	const struct gpio_hog_dt_spec *spec;
@@ -98,10 +98,13 @@ static int gpio_hogs_init(void)
 	int i;
 	int j;
 
-
 	for (i = 0; i < ARRAY_SIZE(gpio_hogs); i++) {
 		hogs = &gpio_hogs[i];
 
+		if (port != NULL && hogs->port != port) {
+			continue;
+		}
+
 		if (!device_is_ready(hogs->port)) {
 			LOG_ERR("GPIO port %s not ready", hogs->port->name);
 			return -ENODEV;
@@ -110,7 +113,7 @@ static int gpio_hogs_init(void)
 		for (j = 0; j < hogs->num_specs; j++) {
 			spec = &hogs->specs[j];
 
-			err = gpio_pin_configure(hogs->port, spec->pin, spec->flags);
+			err = gpio_pin_configure(hogs->port, spec->pin, spec->flags & mask);
 			if (err < 0) {
 				LOG_ERR("failed to configure GPIO hog for port %s pin %u (err %d)",
 					hogs->port->name, spec->pin, err);
@@ -122,4 +125,13 @@ static int gpio_hogs_init(void)
 	return 0;
 }
 
+static int gpio_hogs_init(void)
+{
+#if !defined(CONFIG_GPIO_HOGS_INITIALIZE_BY_APPLICATION)
+	return gpio_hogs_configure(NULL, GPIO_FLAGS_ALL);
+#else
+	return 0;
+#endif
+}
+
 SYS_INIT(gpio_hogs_init, POST_KERNEL, CONFIG_GPIO_HOGS_INIT_PRIORITY);