[PATCH] gpio: tegra186: Support multi-socket devices

[Prathamesh Shete <pshete@nvidia.com>]

On Tegra platforms, multiple SoC instances may be present with each
defining the same GPIO name. For such devices, this results in
duplicate GPIO names.

When the device has a valid NUMA node, prepend the NUMA node ID
to the GPIO name prefix. The node ID identifies each socket,
ensuring GPIO line names remain distinct across multiple sockets.

Signed-off-by: Prathamesh Shete <pshete@nvidia.com>
---
 drivers/gpio/gpio-tegra186.c | 26 +++++++++++++++++---------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/drivers/gpio/gpio-tegra186.c b/drivers/gpio/gpio-tegra186.c
index 9c874f07be75..daf5aaffa28a 100644
--- a/drivers/gpio/gpio-tegra186.c
+++ b/drivers/gpio/gpio-tegra186.c
@@ -857,7 +857,8 @@ static int tegra186_gpio_probe(struct platform_device *pdev)
 	struct device_node *np;
 	struct resource *res;
 	char **names;
-	int err;
+	char *instance = "";
+	int node, err;
 
 	gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
 	if (!gpio)
@@ -937,17 +938,21 @@ static int tegra186_gpio_probe(struct platform_device *pdev)
 	if (!names)
 		return -ENOMEM;
 
+	node = dev_to_node(&pdev->dev);
+	if (node >= 0) {
+		instance = devm_kasprintf(gpio->gpio.parent, GFP_KERNEL, "%d-", node);
+		if (!instance)
+			return -ENOMEM;
+	}
+
 	for (i = 0, offset = 0; i < gpio->soc->num_ports; i++) {
 		const struct tegra_gpio_port *port = &gpio->soc->ports[i];
 		char *name;
 
 		for (j = 0; j < port->pins; j++) {
-			if (gpio->soc->prefix)
-				name = devm_kasprintf(gpio->gpio.parent, GFP_KERNEL, "%s-P%s.%02x",
-						      gpio->soc->prefix, port->name, j);
-			else
-				name = devm_kasprintf(gpio->gpio.parent, GFP_KERNEL, "P%s.%02x",
-						      port->name, j);
+			name = devm_kasprintf(gpio->gpio.parent, GFP_KERNEL, "%s%sP%s.%02x",
+					      instance ?: "", gpio->soc->prefix ?: "",
+					      port->name, j);
 			if (!name)
 				return -ENOMEM;
 
@@ -1373,6 +1378,9 @@ static const struct tegra_gpio_soc tegra256_main_soc = {
 	.has_vm_support = true,
 };
 
+/* Macro to define GPIO name prefix with separator */
+#define TEGRA_GPIO_PREFIX(_x)	_x "-"
+
 #define TEGRA410_COMPUTE_GPIO_PORT(_name, _bank, _port, _pins)	\
 	TEGRA_GPIO_PORT(TEGRA410_COMPUTE, _name, _bank, _port, _pins)
 
@@ -1388,7 +1396,7 @@ static const struct tegra_gpio_soc tegra410_compute_soc = {
 	.num_ports = ARRAY_SIZE(tegra410_compute_ports),
 	.ports = tegra410_compute_ports,
 	.name = "tegra410-gpio-compute",
-	.prefix = "COMPUTE",
+	.prefix = TEGRA_GPIO_PREFIX("COMPUTE"),
 	.num_irqs_per_bank = 8,
 	.instance = 0,
 };
@@ -1418,7 +1426,7 @@ static const struct tegra_gpio_soc tegra410_system_soc = {
 	.num_ports = ARRAY_SIZE(tegra410_system_ports),
 	.ports = tegra410_system_ports,
 	.name = "tegra410-gpio-system",
-	.prefix = "SYSTEM",
+	.prefix = TEGRA_GPIO_PREFIX("SYSTEM"),
 	.num_irqs_per_bank = 8,
 	.instance = 0,
 };
-- 
2.43.0