linux-kernel - Re: [PATCH v8 8/9] pwm: pwm-omap-dmtimer: Adapt driver to utilize dmtimer pdata ops

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Message-ID: <20180124072432.GA11294@lenoch>
Date:   Wed, 24 Jan 2018 08:24:32 +0100
From:   Ladislav Michl <ladis@...ux-mips.org>
To:     Keerthy <j-keerthy@...com>
Cc:     daniel.lezcano@...aro.org, thierry.reding@...il.com,
        tony@...mide.com, aaro.koskinen@....fi,
        Claudiu.Beznea@...rochip.com, narmstrong@...libre.com,
        linux-pwm@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org,
        sebastian.reichel@...labora.co.uk, linux-omap@...r.kernel.org,
        robh+dt@...nel.org, t-kristo@...com, grygorii.strashko@...com
Subject: Re: [PATCH v8 8/9] pwm: pwm-omap-dmtimer: Adapt driver to utilize
 dmtimer pdata ops

Keerthy,

On Wed, Jan 24, 2018 at 11:14:40AM +0530, Keerthy wrote:
> Adapt driver to utilize dmtimer pdata ops instead of pdata-quirks.
> 
> Signed-off-by: Keerthy <j-keerthy@...com>
> Acked-by: Neil Armstrong <narmstrong@...libre.com>
> Reviewed-by: Claudiu Beznea <claudiu.beznea@...rochip.com>
> ---
> 
> Changes in v8:
> 
>   * Added of_node_put call in success case of probe.
> 
> Boot tested on am437x-gp-evm and dra7xx-evm.
> Also compile tested omap1_defconfig with other patches of v7
> posted here:
> 
> https://www.spinics.net/lists/linux-omap/msg141100.html
> 
> With v8 version of Patch 8/9.
> 
>  drivers/pwm/pwm-omap-dmtimer.c | 68 ++++++++++++++++++++++++++----------------
>  1 file changed, 42 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/pwm/pwm-omap-dmtimer.c b/drivers/pwm/pwm-omap-dmtimer.c
> index 5ad42f3..c00e474 100644
> --- a/drivers/pwm/pwm-omap-dmtimer.c
> +++ b/drivers/pwm/pwm-omap-dmtimer.c
> @@ -23,6 +23,7 @@
>  #include <linux/mutex.h>
>  #include <linux/of.h>
>  #include <linux/of_platform.h>
> +#include <linux/platform_data/dmtimer-omap.h>
>  #include <linux/platform_data/pwm_omap_dmtimer.h>
>  #include <linux/platform_device.h>
>  #include <linux/pm_runtime.h>
> @@ -37,7 +38,7 @@ struct pwm_omap_dmtimer_chip {
>  	struct pwm_chip chip;
>  	struct mutex mutex;
>  	pwm_omap_dmtimer *dm_timer;
> -	struct pwm_omap_dmtimer_pdata *pdata;
> +	struct omap_dm_timer_ops *pdata;
>  	struct platform_device *dm_timer_pdev;
>  };
>  
> @@ -242,19 +243,35 @@ static int pwm_omap_dmtimer_probe(struct platform_device *pdev)
>  {
>  	struct device_node *np = pdev->dev.of_node;
>  	struct device_node *timer;
> +	struct platform_device *timer_pdev;
>  	struct pwm_omap_dmtimer_chip *omap;
> -	struct pwm_omap_dmtimer_pdata *pdata;
> +	struct dmtimer_platform_data *timer_pdata;
> +	struct omap_dm_timer_ops *pdata;
>  	pwm_omap_dmtimer *dm_timer;
>  	u32 v;
> -	int status;
> +	int status, ret = 0;
>  
> -	pdata = dev_get_platdata(&pdev->dev);
> -	if (!pdata) {
> -		dev_err(&pdev->dev, "Missing dmtimer platform data\n");
> -		return -EINVAL;
> +	timer = of_parse_phandle(np, "ti,timers", 0);
> +	if (!timer)
> +		return -ENODEV;
> +
> +	timer_pdev = of_find_device_by_node(timer);
> +	if (!timer_pdev) {
> +		dev_err(&pdev->dev, "Unable to find Timer pdev\n");
> +		ret = -ENODEV;
> +		goto put;
>  	}
>  
> -	if (!pdata->request_by_node ||
> +	timer_pdata = dev_get_platdata(&timer_pdev->dev);
> +	if (!timer_pdata) {
> +		dev_err(&pdev->dev, "dmtimer pdata structure NULL\n");
> +		ret = -EINVAL;
> +		goto put;
> +	}
> +
> +	pdata = timer_pdata->timer_ops;
> +
> +	if (!pdata || !pdata->request_by_node ||
>  	    !pdata->free ||
>  	    !pdata->enable ||
>  	    !pdata->disable ||
> @@ -267,37 +284,32 @@ static int pwm_omap_dmtimer_probe(struct platform_device *pdev)
>  	    !pdata->set_prescaler ||
>  	    !pdata->write_counter) {
>  		dev_err(&pdev->dev, "Incomplete dmtimer pdata structure\n");
> -		return -EINVAL;
> +		ret = -EINVAL;
> +		goto put;
>  	}
>  
> -	timer = of_parse_phandle(np, "ti,timers", 0);
> -	if (!timer)
> -		return -ENODEV;
> -
>  	if (!of_get_property(timer, "ti,timer-pwm", NULL)) {
>  		dev_err(&pdev->dev, "Missing ti,timer-pwm capability\n");
> -		return -ENODEV;
> +		ret = -ENODEV;
> +		goto put;

Should we call of_node_put() even from here? of_get_property() failed, so
reference was not updated.

>  	}
>  
>  	dm_timer = pdata->request_by_node(timer);

And timer seems to be used only here, so calling
	of_node_put(timer);
just here should be enough.

> -	if (!dm_timer)
> -		return -EPROBE_DEFER;
> +	if (!dm_timer) {
> +		ret = -EPROBE_DEFER;
> +		goto put;
> +	}
>  
>  	omap = devm_kzalloc(&pdev->dev, sizeof(*omap), GFP_KERNEL);
>  	if (!omap) {
>  		pdata->free(dm_timer);
> -		return -ENOMEM;
> +		ret = -ENOMEM;
> +		goto put;
>  	}
>  
>  	omap->pdata = pdata;
>  	omap->dm_timer = dm_timer;
> -
> -	omap->dm_timer_pdev = of_find_device_by_node(timer);
> -	if (!omap->dm_timer_pdev) {
> -		dev_err(&pdev->dev, "Unable to find timer pdev\n");
> -		omap->pdata->free(dm_timer);
> -		return -EINVAL;
> -	}
> +	omap->dm_timer_pdev = timer_pdev;
>  
>  	/*
>  	 * Ensure that the timer is stopped before we allow PWM core to call
> @@ -326,12 +338,16 @@ static int pwm_omap_dmtimer_probe(struct platform_device *pdev)
>  	if (status < 0) {
>  		dev_err(&pdev->dev, "failed to register PWM\n");
>  		omap->pdata->free(omap->dm_timer);
> -		return status;
> +		ret = status;
> +		goto put;
>  	}
>  
>  	platform_set_drvdata(pdev, omap);
>  
> -	return 0;
> +put:
> +	of_node_put(timer);
> +
> +	return ret;
>  }
>  
>  static int pwm_omap_dmtimer_remove(struct platform_device *pdev)
> -- 
> 1.9.1