Subject: [PATCH 2/2] gpio/tegra: Dynamically allocate IRQ base, and support DT

From: [email-masked] (Rob Herring)
Date: Thu, 01 Dec 2011 07:42:57 -0600

On 11/30/2011 06:45 PM, Stephen Warren wrote:
> Enhance  the driver to dynamically allocate the base IRQ number, and
> create an IRQ domain for itself. The use of an IRQ domain ensures that
> any device tree node interrupts properties are correctly parsed.
> 
> Fix the DT binding documentation to describe interrupt-related properties,
> and the contents of "child" node interrupts property.
> 
> Update tegra20.dtsi to specify the required interrupt-related properties.
> 
> Finally, remove the definition of TEGRA_GPIO_TO_IRQ; this macro no longer
> gives correct results since the IRQ numbers for GPIOs are dynamically
> allocated.
> 
> Signed-off-by: Stephen Warren <[email-masked]>

Looks good. A few minor things.
> ---
>  .../devicetree/bindings/gpio/gpio_nvidia.txt       |   10 ++++++
>  arch/arm/boot/dts/tegra20.dtsi                     |    2 +
>  arch/arm/mach-tegra/include/mach/gpio-tegra.h      |    2 -
>  drivers/gpio/gpio-tegra.c                          |   32 +++++++++++++++----
>  4 files changed, 37 insertions(+), 9 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/gpio/gpio_nvidia.txt b/Documentation/devicetree/bindings/gpio/gpio_nvidia.txt
> index eb4b530..20b991d 100644
> --- a/Documentation/devicetree/bindings/gpio/gpio_nvidia.txt
> +++ b/Documentation/devicetree/bindings/gpio/gpio_nvidia.txt
> @@ -6,3 +6,13 @@ Required properties:
>    second cell is used to specify optional parameters:
>    - bit 0 specifies polarity (0 for normal, 1 for inverted)
>  - gpio-controller : Marks the device node as a GPIO controller.
> +- #interrupt-cells : Should be 2.
> +  The first cell is the GPIO number.
> +  The second cell is used to specify flags:
> +    bits[3:0] trigger type and level flags:
> +      1 = low-to-high edge triggered.
> +      2 = high-to-low edge triggered.
> +      4 = active high level-sensitive.
> +      8 = active low level-sensitive.
> +      Valid combinations are 1, 2, 3, 4, 8.
> +- interrupt-controller : Marks the device node as an interrupt controller.
> diff --git a/arch/arm/boot/dts/tegra20.dtsi b/arch/arm/boot/dts/tegra20.dtsi
> index db6f562..e25f4a6 100644
> --- a/arch/arm/boot/dts/tegra20.dtsi
> +++ b/arch/arm/boot/dts/tegra20.dtsi
> @@ -79,6 +79,8 @@
>  			       0 55 0x04
>  			       0 87 0x04
>  			       0 89 0x04 >;
> +		interrupt-controller;
> +		#interrupt-cells = <2>;
>  		#gpio-cells = <2>;
>  		gpio-controller;
>  	};
> diff --git a/arch/arm/mach-tegra/include/mach/gpio-tegra.h b/arch/arm/mach-tegra/include/mach/gpio-tegra.h
> index 87d37fd..6140820 100644
> --- a/arch/arm/mach-tegra/include/mach/gpio-tegra.h
> +++ b/arch/arm/mach-tegra/include/mach/gpio-tegra.h
> @@ -25,8 +25,6 @@
>  
>  #define TEGRA_NR_GPIOS		INT_GPIO_NR

Can INT_GPIO_NR be killed?

>  
> -#define TEGRA_GPIO_TO_IRQ(gpio) (INT_GPIO_BASE + (gpio))
> -
>  struct tegra_gpio_table {
>  	int	gpio;	/* GPIO number */
>  	bool	enable;	/* Enable for GPIO at init? */
> diff --git a/drivers/gpio/gpio-tegra.c b/drivers/gpio/gpio-tegra.c
> index 61044c8..9fa5783 100644
> --- a/drivers/gpio/gpio-tegra.c
> +++ b/drivers/gpio/gpio-tegra.c
> @@ -25,6 +25,7 @@
>  #include <linux/of.h>
>  #include <linux/platform_device.h>
>  #include <linux/module.h>
> +#include <linux/irqdomain.h>
>  
>  #include <asm/mach/irq.h>
>  
> @@ -74,7 +75,8 @@ struct tegra_gpio_bank {
>  #endif
>  };
>  
> -
> +static struct irq_domain irq_domain;
> +static struct irq_domain_ops irq_domain_ops;
>  static void __iomem *regs;
>  static struct tegra_gpio_bank tegra_gpio_banks[7];
>  
> @@ -139,7 +141,7 @@ static int tegra_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
>  
>  static int tegra_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
>  {
> -	return TEGRA_GPIO_TO_IRQ(offset);
> +	return irq_domain_to_irq(&irq_domain, offset);
>  }
>  
>  static struct gpio_chip tegra_gpio_chip = {
> @@ -155,28 +157,28 @@ static struct gpio_chip tegra_gpio_chip = {
>  
>  static void tegra_gpio_irq_ack(struct irq_data *d)
>  {
> -	int gpio = d->irq - INT_GPIO_BASE;
> +	int gpio = d->hwirq;
>  
>  	tegra_gpio_writel(1 << GPIO_BIT(gpio), GPIO_INT_CLR(gpio));
>  }
>  
>  static void tegra_gpio_irq_mask(struct irq_data *d)
>  {
> -	int gpio = d->irq - INT_GPIO_BASE;
> +	int gpio = d->hwirq;
>  
>  	tegra_gpio_mask_write(GPIO_MSK_INT_ENB(gpio), gpio, 0);
>  }
>  
>  static void tegra_gpio_irq_unmask(struct irq_data *d)
>  {
> -	int gpio = d->irq - INT_GPIO_BASE;
> +	int gpio = d->hwirq;
>  
>  	tegra_gpio_mask_write(GPIO_MSK_INT_ENB(gpio), gpio, 1);
>  }
>  
>  static int tegra_gpio_irq_set_type(struct irq_data *d, unsigned int type)
>  {
> -	int gpio = d->irq - INT_GPIO_BASE;
> +	int gpio = d->hwirq;
>  	struct tegra_gpio_bank *bank = irq_data_get_irq_chip_data(d);
>  	int port = GPIO_PORT(gpio);
>  	int lvl_type;
> @@ -343,6 +345,22 @@ static int __devinit tegra_gpio_probe(struct platform_device *pdev)
>  	int i;
>  	int j;
>  
> +	irq_domain.irq_base = irq_alloc_descs(-1, 0, TEGRA_NR_GPIOS, 0);
> +	if (irq_domain.irq_base < 0) {
> +		dev_err(&pdev->dev, "Couldn't allocate IRQ numbers\n");
> +		return -ENODEV;
> +	}
> +	irq_domain.nr_irq = TEGRA_NR_GPIOS;
> +	irq_domain.ops = &irq_domain_ops;

Why don't you just use irq_domain_simple_ops?

> +#ifdef CONFIG_OF
> +	if (pdev->dev.of_node) {
> +		irq_domain.of_node = pdev->dev.of_node;
> +		irq_domain_ops.dt_translate =
> +			irq_domain_simple_ops.dt_translate;
> +	}
> +#endif

Then you don't need the ifdef (or the if statement).

> +	irq_domain_add(&irq_domain);
> +
>  	for (i = 0; i < ARRAY_SIZE(tegra_gpio_banks); i++) {
>  		res = platform_get_resource(pdev, IORESOURCE_IRQ, i);
>  		if (!res) {
> @@ -388,7 +406,7 @@ static int __devinit tegra_gpio_probe(struct platform_device *pdev)
>  	gpiochip_add(&tegra_gpio_chip);
>  
>  	for (gpio = 0; gpio < TEGRA_NR_GPIOS; gpio++) {
> -		int irq = TEGRA_GPIO_TO_IRQ(gpio);
> +		int irq = irq_domain_to_irq(&irq_domain, gpio);
>  		/* No validity check; all Tegra GPIOs are valid IRQs */
>  
>  		bank = &tegra_gpio_banks[GPIO_BANK(gpio)];