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

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

[Prathamesh Shete]

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

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

[Bartosz Golaszewski]

On Mon, 16 Feb 2026 05:58:42 +0100, Prathamesh Shete <pshete@nvidia.com> said:
> 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);

I've never noticed it before (and it's not introduced by this patch) but I
really dislike the child device registering devres nodes with its parent...

> +		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 ?: "",

instance can't be NULL here, can it? Either print it unconditionally or
initialize it to NULL.

> +					      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 "-"
> +

This doesn't look like it belongs to this patch, why are you doing it?

Bart

>  #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
>
>

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

[Jon Hunter]

On 16/02/2026 11:29, Bartosz Golaszewski wrote:
> On Mon, 16 Feb 2026 05:58:42 +0100, Prathamesh Shete <pshete@nvidia.com> said:
>> 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);
> 
> I've never noticed it before (and it's not introduced by this patch) but I
> really dislike the child device registering devres nodes with its parent...

While it looks a bit odd, the parent is initialised as ...

  gpio->gpio.parent = &pdev->dev

> 
>> +		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)
>> -				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 ?: "",
> 
> instance can't be NULL here, can it? Either print it unconditionally or
> initialize it to NULL.

Probably best to drop 'instance' altogether and just ...

  if (node >= 0)
        name = devm_kasprintf(gpio->gpio.parent, GFP_KERNEL,
                              "%d-%sP%s.%02x", node,
                              gpio->soc->prefix ?: "",
                              port->name, j);
  else
        name = devm_kasprintf(gpio->gpio.parent, GFP_KERNEL,
                              "%sP%s.%02x",
                              gpio->soc->prefix ?: "",
                              port->name, j);

> 
>> +					      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 "-"
>> +
> 
> This doesn't look like it belongs to this patch, why are you doing it

Yes we should split this into two patches; one to simplify the prefix 
handling and one to handle the socket.

Jon

-- 
nvpublic

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

[Bartosz Golaszewski]

On Mon, Feb 16, 2026 at 6:22 PM Jon Hunter <jonathanh@nvidia.com> wrote:
>
>
> On 16/02/2026 11:29, Bartosz Golaszewski wrote:
> > On Mon, 16 Feb 2026 05:58:42 +0100, Prathamesh Shete <pshete@nvidia.com> said:
> >> 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);
> >
> > I've never noticed it before (and it's not introduced by this patch) but I
> > really dislike the child device registering devres nodes with its parent...
>
> While it looks a bit odd, the parent is initialised as ...
>
>   gpio->gpio.parent = &pdev->dev
>

Right. Nevermind my comment then.

Bart

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

[Jon Hunter]

On 16/02/2026 11:29, Bartosz Golaszewski wrote:
> On Mon, 16 Feb 2026 05:58:42 +0100, Prathamesh Shete <pshete@nvidia.com> said:
>> 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);
> 
> I've never noticed it before (and it's not introduced by this patch) but I
> really dislike the child device registering devres nodes with its parent...
> 
>> +		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 ?: "",
> 
> instance can't be NULL here, can it? Either print it unconditionally or
> initialize it to NULL.

The other alternative here is that we just use 'instance' without the 
ternary operator because we initialise to "" ...

  name = devm_kasprintf(gpio->gpio.parent, GFP_KERNEL, "%s%sP%s.%02x",
                        instance, gpio->soc->prefix ?: "",
                        port->name, j);

Jon

-- 
nvpublic