Subject: Re: [PATCH v2 4/4] powerpc/52xx: Convert to use fwnode API

From: Michael Ellerman <[email-masked]>
Date: Mon, 16 May 2022 23:48:05 +1000

Andy Shevchenko <[email-masked]> writes:
> We may convert the GPT driver to use fwnode API for the sake
> of consistency of the used APIs inside the driver.

I'm not sure about this one.

It's more consistent to use fwnode in this driver, but it's very
inconsistent with the rest of the powerpc code. We have basically no
uses of the fwnode APIs at the moment.

It seems like a pretty straight-forward conversion, but there could
easily be a bug in there, I don't have any way to test it. Do you?

cheers

> diff --git a/arch/powerpc/platforms/52xx/mpc52xx_gpt.c b/arch/powerpc/platforms/52xx/mpc52xx_gpt.c
> index ae47fdcc8a96..58c3651034bd 100644
> --- a/arch/powerpc/platforms/52xx/mpc52xx_gpt.c
> +++ b/arch/powerpc/platforms/52xx/mpc52xx_gpt.c
> @@ -53,10 +53,9 @@
>  #include <linux/interrupt.h>
>  #include <linux/io.h>
>  #include <linux/list.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/module.h>
>  #include <linux/mutex.h>
> -#include <linux/of.h>
> -#include <linux/of_platform.h>
> -#include <linux/of_gpio.h>
>  #include <linux/kernel.h>
>  #include <linux/property.h>
>  #include <linux/slab.h>
> @@ -64,7 +63,7 @@
>  #include <linux/watchdog.h>
>  #include <linux/miscdevice.h>
>  #include <linux/uaccess.h>
> -#include <linux/module.h>
> +
>  #include <asm/div64.h>
>  #include <asm/mpc52xx.h>
>  
> @@ -235,18 +234,17 @@ static const struct irq_domain_ops mpc52xx_gpt_irq_ops = {
>  	.xlate = mpc52xx_gpt_irq_xlate,
>  };
>  
> -static void
> -mpc52xx_gpt_irq_setup(struct mpc52xx_gpt_priv *gpt, struct device_node *node)
> +static void mpc52xx_gpt_irq_setup(struct mpc52xx_gpt_priv *gpt)
>  {
>  	int cascade_virq;
>  	unsigned long flags;
>  	u32 mode;
>  
> -	cascade_virq = irq_of_parse_and_map(node, 0);
> -	if (!cascade_virq)
> +	cascade_virq = platform_get_irq(to_platform_device(gpt->dev), 0);
> +	if (cascade_virq < 0)
>  		return;
>  
> -	gpt->irqhost = irq_domain_add_linear(node, 1, &mpc52xx_gpt_irq_ops, gpt);
> +	gpt->irqhost = irq_domain_create_linear(dev_fwnode(gpt->dev), 1, &mpc52xx_gpt_irq_ops, gpt);
>  	if (!gpt->irqhost) {
>  		dev_err(gpt->dev, "irq_domain_add_linear() failed\n");
>  		return;
> @@ -670,8 +668,7 @@ static int mpc52xx_gpt_wdt_init(void)
>  	return err;
>  }
>  
> -static int mpc52xx_gpt_wdt_setup(struct mpc52xx_gpt_priv *gpt,
> -				 const u32 *period)
> +static int mpc52xx_gpt_wdt_setup(struct mpc52xx_gpt_priv *gpt, const u32 period)
>  {
>  	u64 real_timeout;
>  
> @@ -679,14 +676,14 @@ static int mpc52xx_gpt_wdt_setup(struct mpc52xx_gpt_priv *gpt,
>  	mpc52xx_gpt_wdt = gpt;
>  
>  	/* configure the wdt if the device tree contained a timeout */
> -	if (!period || *period == 0)
> +	if (period == 0)
>  		return 0;
>  
> -	real_timeout = (u64) *period * 1000000000ULL;
> +	real_timeout = (u64)period * 1000000000ULL;
>  	if (mpc52xx_gpt_do_start(gpt, real_timeout, 0, 1))
>  		dev_warn(gpt->dev, "starting as wdt failed\n");
>  	else
> -		dev_info(gpt->dev, "watchdog set to %us timeout\n", *period);
> +		dev_info(gpt->dev, "watchdog set to %us timeout\n", period);
>  	return 0;
>  }
>  
> @@ -697,8 +694,7 @@ static int mpc52xx_gpt_wdt_init(void)
>  	return 0;
>  }
>  
> -static inline int mpc52xx_gpt_wdt_setup(struct mpc52xx_gpt_priv *gpt,
> -					const u32 *period)
> +static inline int mpc52xx_gpt_wdt_setup(struct mpc52xx_gpt_priv *gpt, const u32 period)
>  {
>  	return 0;
>  }
> @@ -726,25 +722,26 @@ static int mpc52xx_gpt_probe(struct platform_device *ofdev)
>  	dev_set_drvdata(&ofdev->dev, gpt);
>  
>  	mpc52xx_gpt_gpio_setup(gpt);
> -	mpc52xx_gpt_irq_setup(gpt, ofdev->dev.of_node);
> +	mpc52xx_gpt_irq_setup(gpt);
>  
>  	mutex_lock(&mpc52xx_gpt_list_mutex);
>  	list_add(&gpt->list, &mpc52xx_gpt_list);
>  	mutex_unlock(&mpc52xx_gpt_list_mutex);
>  
>  	/* check if this device could be a watchdog */
> -	if (of_get_property(ofdev->dev.of_node, "fsl,has-wdt", NULL) ||
> -	    of_get_property(ofdev->dev.of_node, "has-wdt", NULL)) {
> -		const u32 *on_boot_wdt;
> +	if (device_property_present(gpt->dev, "fsl,has-wdt") ||
> +	    device_property_present(gpt->dev, "has-wdt")) {
> +		u32 on_boot_wdt = 0;
> +		int ret;
>  
>  		gpt->wdt_mode = MPC52xx_GPT_CAN_WDT;
> -		on_boot_wdt = of_get_property(ofdev->dev.of_node,
> -					      "fsl,wdt-on-boot", NULL);
> -		if (on_boot_wdt) {
> +		ret = device_property_read_u32(gpt->dev, "fsl,wdt-on-boot", &on_boot_wdt);
> +		if (ret) {
> +			dev_info(gpt->dev, "can function as watchdog\n");
> +		} else {
>  			dev_info(gpt->dev, "used as watchdog\n");
>  			gpt->wdt_mode |= MPC52xx_GPT_IS_WDT;
> -		} else
> -			dev_info(gpt->dev, "can function as watchdog\n");
> +		}
>  		mpc52xx_gpt_wdt_setup(gpt, on_boot_wdt);
>  	}
>  
> -- 
> 2.35.1