From mboxrd@z Thu Jan  1 00:00:00 1970
From: khilman@baylibre.com (Kevin Hilman)
Date: Fri, 22 Jul 2016 15:00:51 -0700
Subject: [PATCH v3] thermal: tango: add resume support
In-Reply-To: <578CC9C9.3050806@free.fr> (Mason's message of "Mon, 18 Jul 2016
 14:21:29 +0200")
References: <57726196.5060909@free.fr> <578CC9C9.3050806@free.fr>
Message-ID: <m2wpkd1gfg.fsf@baylibre.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

Mason <slash.tmp@free.fr> writes:

> From: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>
>
> When this platform is suspended, firmware powers the entire SoC down,
> except a few hardware blocks waiting for wakeup events. And there is
> no context to save for this particular block.
>
> Therefore, there is nothing useful for the driver to do on suspend;
> so we define a NULL suspend hook. On resume, the driver initializes
> the block exactly as is done in the probe callback.
>
> Signed-off-by: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>
> ---
> Changes in v3
> Drop the DEV_PM_OPS macro, which caused some confusion.
> Note: tango_thermal_pm struct only exists when CONFIG_PM_SLEEP is defined
> @Kevin, can I add your Reviewed-by tag back?
> ---
>  drivers/thermal/tango_thermal.c | 23 +++++++++++++++++++++--
>  1 file changed, 21 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/thermal/tango_thermal.c b/drivers/thermal/tango_thermal.c
> index 70e0d9f406e9..957f8937e126 100644
> --- a/drivers/thermal/tango_thermal.c
> +++ b/drivers/thermal/tango_thermal.c
> @@ -64,6 +64,12 @@ static const struct thermal_zone_of_device_ops ops = {
>  	.get_temp	= tango_get_temp,
>  };
>  
> +static void tango_thermal_init(struct tango_thermal_priv *priv)
> +{
> +	writel(0, priv->base + TEMPSI_CFG);
> +	writel(CMD_ON, priv->base + TEMPSI_CMD);
> +}
> +
>  static int tango_thermal_probe(struct platform_device *pdev)
>  {
>  	struct resource *res;
> @@ -79,14 +85,24 @@ static int tango_thermal_probe(struct platform_device *pdev)
>  	if (IS_ERR(priv->base))
>  		return PTR_ERR(priv->base);
>  
> +	platform_set_drvdata(pdev, priv);
>  	priv->thresh_idx = IDX_MIN;
> -	writel(0, priv->base + TEMPSI_CFG);
> -	writel(CMD_ON, priv->base + TEMPSI_CMD);
> +	tango_thermal_init(priv);
>  
>  	tzdev = devm_thermal_zone_of_sensor_register(&pdev->dev, 0, priv, &ops);
>  	return PTR_ERR_OR_ZERO(tzdev);
>  }
>  
> +#ifdef CONFIG_PM_SLEEP
> +static int tango_thermal_resume(struct device *dev)
> +{
> +	tango_thermal_init(dev_get_drvdata(dev));
> +	return 0;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(tango_thermal_pm, NULL, tango_thermal_resume);
> +#endif

#else
#define tango_thermal_resume NULL
#endif

And then move the SIMPLE_DEV_PM_OPS here...

> +
>  static const struct of_device_id tango_sensor_ids[] = {
>  	{
>  		.compatible = "sigma,smp8758-thermal",
> @@ -99,6 +115,9 @@ static struct platform_driver tango_thermal_driver = {
>  	.driver	= {
>  		.name		= "tango-thermal",
>  		.of_match_table	= tango_sensor_ids,
> +#ifdef CONFIG_PM_SLEEP
> +		.pm		= &tango_thermal_pm,
> +#endif

... which allows you to get rid of the ugly ifdef here.
(c.f. CodingStyle, Chapter 20,)

Kevin