Re: [PATCH v2 17/18] GPIO: OMAP: Use PM runtime framework

[Kevin Hilman <khilman@ti.com>]

Tarun Kanti DebBarma <tarun.kanti@ti.com> writes:

> From: Charulatha V <charu@ti.com>
>
> Call runtime pm APIs pm_runtime_get_sync() and pm_runtime_put_sync()
> for enabling/disabling clocks appropriately. Remove syscore_ops and
> instead use dev_pm_ops now.
>
> Signed-off-by: Charulatha V <charu@ti.com>
> Signed-off-by: Tarun Kanti DebBarma <tarun.kanti@ti.com>

Approach is fine.  some minor comments below..

> ---
>  drivers/gpio/gpio-omap.c |  100 ++++++++++++++++++++++++++++++++++++---------
>  1 files changed, 80 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
> index ea984fd..f5bb469 100644
> --- a/drivers/gpio/gpio-omap.c
> +++ b/drivers/gpio/gpio-omap.c
> @@ -80,6 +80,8 @@ struct gpio_bank {
>  	struct omap_gpio_reg_offs *regs;
>  };
>  
> +static void omap_gpio_mod_init(struct gpio_bank *bank);
> +
>  #define GPIO_INDEX(bank, gpio) (gpio % bank->width)
>  #define GPIO_BIT(bank, gpio) (1 << GPIO_INDEX(bank, gpio))
>  #define GPIO_MOD_CTRL_BIT	BIT(0)
> @@ -492,6 +494,22 @@ static int omap_gpio_request(struct gpio_chip *chip, unsigned offset)
>  	struct gpio_bank *bank = container_of(chip, struct gpio_bank, chip);
>  	unsigned long flags;
>  
> +	/*
> +	 * If this is the first gpio_request for the bank,
> +	 * enable the bank module.
> +	 */
> +	if (!bank->mod_usage) {
> +		if (IS_ERR_VALUE(pm_runtime_get_sync(bank->dev) < 0)) {
> +			dev_err(bank->dev, "%s: GPIO bank %d "
> +					"pm_runtime_get_sync failed\n",
> +					__func__, bank->id);
> +			return -EINVAL;
> +		}
> +
> +		/* Initialize the gpio bank registers to init time value */
> +		omap_gpio_mod_init(bank);
> +	}
> +
>  	spin_lock_irqsave(&bank->lock, flags);
>  
>  	/* Set trigger to none. You need to enable the desired trigger with
> @@ -548,6 +566,18 @@ static void omap_gpio_free(struct gpio_chip *chip, unsigned offset)
>  
>  	_reset_gpio(bank, bank->chip.base + offset);
>  	spin_unlock_irqrestore(&bank->lock, flags);
> +
> +	/*
> +	 * If this is the last gpio to be freed in the bank,
> +	 * disable the bank module.
> +	 */
> +	if (!bank->mod_usage) {
> +		if (IS_ERR_VALUE(pm_runtime_put_sync(bank->dev) < 0)) {
> +			dev_err(bank->dev, "%s: GPIO bank %d "
> +					"pm_runtime_put_sync failed\n",
> +					__func__, bank->id);
> +		}
> +	}
>  }
>  
>  /*
> @@ -572,6 +602,9 @@ static void gpio_irq_handler(unsigned int irq, struct irq_desc *desc)
>  	chained_irq_enter(chip, desc);
>  
>  	bank = irq_get_handler_data(irq);
> +
> +	pm_runtime_get_sync(bank->dev);
> +
>  	isr_reg = bank->base + bank->regs->irqstatus;
>  
>  	if (WARN_ON(!isr_reg))
> @@ -640,6 +673,8 @@ static void gpio_irq_handler(unsigned int irq, struct irq_desc *desc)
>  exit:
>  	if (!unmasked)
>  		chained_irq_exit(chip, desc);
> +
> +	pm_runtime_put_sync(bank->dev);
>  }
>  
>  static void gpio_irq_shutdown(struct irq_data *d)
> @@ -1120,12 +1155,25 @@ static int __devinit omap_gpio_probe(struct platform_device *pdev)
>  	}
>  
>  	pm_runtime_enable(bank->dev);
> -	pm_runtime_get_sync(bank->dev);
> +	pm_runtime_irq_safe(bank->dev);
> +	if (IS_ERR_VALUE(pm_runtime_get_sync(bank->dev) < 0)) {
> +		dev_err(bank->dev, "%s: GPIO bank %d pm_runtime_get_sync "
> +				"failed\n", __func__, bank->id);
> +		iounmap(bank->base);
> +		return -EINVAL;
> +	}
>  
>  	omap_gpio_mod_init(bank);
>  	omap_gpio_chip_init(bank);
>  	omap_gpio_show_rev(bank);
>  
> +	if (IS_ERR_VALUE(pm_runtime_put_sync(bank->dev) < 0)) {
> +		dev_err(bank->dev, "%s: GPIO bank %d pm_runtime_put_sync "
> +				"failed\n", __func__, bank->id);
> +		iounmap(bank->base);
> +		return -EINVAL;
> +	}
> +
>  	list_add_tail(&bank->node, &omap_gpio_list);
>  
>  	return ret;
> @@ -1136,7 +1184,7 @@ err_exit:
>  	return ret;
>  }
>  
> -static int omap_gpio_suspend(void)
> +static int omap_gpio_suspend(struct device *dev)
>  {
>  	struct gpio_bank *bank;
>  
> @@ -1163,7 +1211,7 @@ static int omap_gpio_suspend(void)
>  	return 0;
>  }
>  
> -static void omap_gpio_resume(void)
> +static int omap_gpio_resume(struct device *dev)
>  {
>  	struct gpio_bank *bank;
>  
> @@ -1173,7 +1221,7 @@ static void omap_gpio_resume(void)
>  		unsigned long flags;
>  
>  		if (!bank->suspend_support)
> -			return;
> +			return 0;
>  
>  		wake_clear = bank->base + bank->regs->wkup_clear;
>  		wake_set = bank->base + bank->regs->wkup_set;
> @@ -1183,12 +1231,18 @@ static void omap_gpio_resume(void)
>  		__raw_writel(bank->saved_wakeup, wake_set);
>  		spin_unlock_irqrestore(&bank->lock, flags);
>  	}
> +	return 0;
>  }
>  
> -static struct syscore_ops omap_gpio_syscore_ops = {
> -	.suspend	= omap_gpio_suspend,
> -	.resume		= omap_gpio_resume,
> -};
> +static int omap_gpio_pm_runtime_suspend(struct device *dev)

Please drop the 'pm_' in these function names.

> +{
> +	return 0;
> +}
> +
> +static int omap_gpio_pm_runtime_resume(struct device *dev)
> +{
> +	return 0;
> +}

Actually,  empty functions should not even be added.  Just add them in
the patch that uses them.

Kevin