Re: [PATCH v3 1/2] mfd: add irq domain support for max8997 interrupts

[Grant Likely]

On Thu, 23 Feb 2012 18:08:07 +0530, Thomas Abraham <thomas.abraham@xxxxxxxxxx> wrote:
> Add irq domain support for max8997 interrupts. The reverse mapping method
> used is linear mapping since the sub-drivers of max8997 such as regulator
> and charger drivers can use the max8997 irq_domain to get the linux irq
> number for max8997 interrupts. All uses of irq_base in platform data and
> max8997 driver private data are removed.
> 
> Cc: Grant Likely <grant.likely@xxxxxxxxxxxx>
> Cc: MyungJoo Ham <myungjoo.ham@xxxxxxxxxxx>
> Signed-off-by: Thomas Abraham <thomas.abraham@xxxxxxxxxx>
> ---
>  arch/arm/mach-exynos/mach-nuri.c    |    4 --
>  arch/arm/mach-exynos/mach-origen.c  |    1 -
>  drivers/mfd/max8997-irq.c           |   60 ++++++++++++++++++++--------------
>  drivers/mfd/max8997.c               |    1 -
>  include/linux/mfd/max8997-private.h |    4 ++-
>  include/linux/mfd/max8997.h         |    1 -
>  6 files changed, 38 insertions(+), 33 deletions(-)

Nice patch.  Nice diffstat too.  Some comments below, but I'm happy with where
this is at.

Acked-by: Grant Likely <grant.likely@xxxxxxxxxxxx>

> 
> diff --git a/arch/arm/mach-exynos/mach-nuri.c b/arch/arm/mach-exynos/mach-nuri.c
> index a6b9162..1e9ba12 100644
> --- a/arch/arm/mach-exynos/mach-nuri.c
> +++ b/arch/arm/mach-exynos/mach-nuri.c
> @@ -1078,12 +1078,8 @@ static struct platform_device nuri_max8903_device = {
>  static void __init nuri_power_init(void)
>  {
>  	int gpio;
> -	int irq_base = IRQ_GPIO_END + 1;
>  	int ta_en = 0;
>  
> -	nuri_max8997_pdata.irq_base = irq_base;
> -	irq_base += MAX8997_IRQ_NR;
> -
>  	gpio = EXYNOS4_GPX0(7);
>  	gpio_request(gpio, "AP_PMIC_IRQ");
>  	s3c_gpio_cfgpin(gpio, S3C_GPIO_SFN(0xf));
> diff --git a/arch/arm/mach-exynos/mach-origen.c b/arch/arm/mach-exynos/mach-origen.c
> index 02c242e..328dadb 100644
> --- a/arch/arm/mach-exynos/mach-origen.c
> +++ b/arch/arm/mach-exynos/mach-origen.c
> @@ -424,7 +424,6 @@ static struct max8997_platform_data __initdata origen_max8997_pdata = {
>  	.buck1_gpiodvs	= false,
>  	.buck2_gpiodvs	= false,
>  	.buck5_gpiodvs	= false,
> -	.irq_base	= IRQ_GPIO_END + 1,
>  
>  	.ignore_gpiodvs_side_effect = true,
>  	.buck125_default_idx = 0x0,
> diff --git a/drivers/mfd/max8997-irq.c b/drivers/mfd/max8997-irq.c
> index 09274cf..3d8c9d1 100644
> --- a/drivers/mfd/max8997-irq.c
> +++ b/drivers/mfd/max8997-irq.c
> @@ -142,7 +142,8 @@ static void max8997_irq_sync_unlock(struct irq_data *data)
>  static const inline struct max8997_irq_data *
>  irq_to_max8997_irq(struct max8997_dev *max8997, int irq)
>  {
> -	return &max8997_irqs[irq - max8997->irq_base];
> +	struct irq_data *data = irq_get_irq_data(irq);
> +	return &max8997_irqs[data->hwirq];

Hahaha.  The max8997_irqs table is kind of overdone when the group and mask values
can be arithmetically derived from the hwirq number..

This change is fine, but the driver could use some refactoring.  :-)

>  }
>  
>  static void max8997_irq_mask(struct irq_data *data)
> @@ -182,7 +183,7 @@ static irqreturn_t max8997_irq_thread(int irq, void *data)
>  	u8 irq_reg[MAX8997_IRQ_GROUP_NR] = {};
>  	u8 irq_src;
>  	int ret;
> -	int i;
> +	int i, cur_irq;
>  
>  	ret = max8997_read_reg(max8997->i2c, MAX8997_REG_INTSRC, &irq_src);
>  	if (ret < 0) {
> @@ -269,8 +270,10 @@ static irqreturn_t max8997_irq_thread(int irq, void *data)
>  
>  	/* Report */
>  	for (i = 0; i < MAX8997_IRQ_NR; i++) {
> -		if (irq_reg[max8997_irqs[i].group] & max8997_irqs[i].mask)
> -			handle_nested_irq(max8997->irq_base + i);
> +		if (irq_reg[max8997_irqs[i].group] & max8997_irqs[i].mask) {
> +			cur_irq = irq_find_mapping(max8997->irq_domain, i);
> +			handle_nested_irq(cur_irq);
> +		}

Well, if you're using the linear mapping, then only actually allocated irqs will
have a mapping set up.  So the driver could simply do:

	for (i = 0; i < MAX8997_IRQ_NR; i++) {
		cur_irq = irq_find_mapping(max8997->irq_domain, i);
		if (cur_irq)
			handle_nested_irq(cur_irq);
	}

>  	}
>  
>  	return IRQ_HANDLED;
> @@ -278,26 +281,40 @@ static irqreturn_t max8997_irq_thread(int irq, void *data)
>  
>  int max8997_irq_resume(struct max8997_dev *max8997)
>  {
> -	if (max8997->irq && max8997->irq_base)
> -		max8997_irq_thread(max8997->irq_base, max8997);
> +	if (max8997->irq && max8997->irq_domain)
> +		max8997_irq_thread(0, max8997);
> +	return 0;
> +}
> +
> +static int max8997_irq_domain_map(struct irq_domain *d, unsigned int irq,
> +					irq_hw_number_t hw)
> +{
> +	struct max8997_dev *max8997 = d->host_data;
> +
> +	irq_set_chip_data(irq, max8997);
> +	irq_set_chip_and_handler(irq, &max8997_irq_chip, handle_edge_irq);
> +	irq_set_nested_thread(irq, 1);
> +#ifdef CONFIG_ARM
> +	set_irq_flags(irq, IRQF_VALID);
> +#else
> +	irq_set_noprobe(irq);
> +#endif
>  	return 0;
>  }
>  
> +static struct irq_domain_ops max8997_irq_domain_ops = {
> +	.map = max8997_irq_domain_map,
> +};
> +
>  int max8997_irq_init(struct max8997_dev *max8997)
>  {
> +	struct irq_domain *domain;
>  	int i;
> -	int cur_irq;
>  	int ret;
>  	u8 val;
>  
>  	if (!max8997->irq) {
>  		dev_warn(max8997->dev, "No interrupt specified.\n");
> -		max8997->irq_base = 0;
> -		return 0;
> -	}
> -
> -	if (!max8997->irq_base) {
> -		dev_err(max8997->dev, "No interrupt base specified.\n");
>  		return 0;
>  	}
>  
> @@ -327,18 +344,11 @@ int max8997_irq_init(struct max8997_dev *max8997)
>  					true : false;
>  	}
>  
> -	/* Register with genirq */
> -	for (i = 0; i < MAX8997_IRQ_NR; i++) {
> -		cur_irq = i + max8997->irq_base;
> -		irq_set_chip_data(cur_irq, max8997);
> -		irq_set_chip_and_handler(cur_irq, &max8997_irq_chip,
> -				handle_edge_irq);
> -		irq_set_nested_thread(cur_irq, 1);
> -#ifdef CONFIG_ARM
> -		set_irq_flags(cur_irq, IRQF_VALID);
> -#else
> -		irq_set_noprobe(cur_irq);
> -#endif
> +	domain = irq_domain_add_linear(NULL, MAX8997_IRQ_NR,
> +					&max8997_irq_domain_ops, &max8997);
> +	if (!domain) {
> +		dev_err(max8997->dev, "could not create irq domain\n");
> +		return -ENODEV;
>  	}
>  
>  	ret = request_threaded_irq(max8997->irq, NULL, max8997_irq_thread,
> diff --git a/drivers/mfd/max8997.c b/drivers/mfd/max8997.c
> index cb83a7a..20ecad3 100644
> --- a/drivers/mfd/max8997.c
> +++ b/drivers/mfd/max8997.c
> @@ -143,7 +143,6 @@ static int max8997_i2c_probe(struct i2c_client *i2c,
>  	if (!pdata)
>  		goto err;
>  
> -	max8997->irq_base = pdata->irq_base;
>  	max8997->ono = pdata->ono;
>  
>  	mutex_init(&max8997->iolock);
> diff --git a/include/linux/mfd/max8997-private.h b/include/linux/mfd/max8997-private.h
> index 3f4deb6..830152c 100644
> --- a/include/linux/mfd/max8997-private.h
> +++ b/include/linux/mfd/max8997-private.h
> @@ -23,6 +23,8 @@
>  #define __LINUX_MFD_MAX8997_PRIV_H
>  
>  #include <linux/i2c.h>
> +#include <linux/export.h>
> +#include <linux/irqdomain.h>
>  
>  #define MAX8997_REG_INVALID	(0xff)
>  
> @@ -325,7 +327,7 @@ struct max8997_dev {
>  
>  	int irq;
>  	int ono;
> -	int irq_base;
> +	struct irq_domain *irq_domain;
>  	struct mutex irqlock;
>  	int irq_masks_cur[MAX8997_IRQ_GROUP_NR];
>  	int irq_masks_cache[MAX8997_IRQ_GROUP_NR];
> diff --git a/include/linux/mfd/max8997.h b/include/linux/mfd/max8997.h
> index fff5905..818486c 100644
> --- a/include/linux/mfd/max8997.h
> +++ b/include/linux/mfd/max8997.h
> @@ -155,7 +155,6 @@ struct max8997_led_platform_data {
>  
>  struct max8997_platform_data {
>  	/* IRQ */
> -	int irq_base;
>  	int ono;
>  	int wakeup;
>  
> -- 
> 1.6.6.rc2
> 

-- 
Grant Likely, B.Sc, P.Eng.
Secret Lab Technologies,Ltd.
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