Re: [PATCH V2 4/4] can: flexcan: add LPSR mode support

[Marc Kleine-Budde <mkl@pengutronix.de>]

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On 11/27/19 6:56 AM, Joakim Zhang wrote:
> For i.MX7D LPSR mode, the controller will lost power and got the
> configuration state lost after system resume back. (coming i.MX8QM/QXP
> will also completely power off the domain, the controller state will be
> lost and needs restore).
> So we need to set pinctrl state again and re-start chip to do
> re-configuration after resume.
> 
> For wakeup case, it should not set pinctrl to sleep state by
> pinctrl_pm_select_sleep_state.
> For interface is not up before suspend case, we don't need
> re-configure as it will be configured by user later by interface up.
> 
> Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
> ------
> ChangeLog:
> 	V1->V2: no change.
> ---
>  drivers/net/can/flexcan.c | 21 ++++++++++++++-------
>  1 file changed, 14 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
> index d178146b3da5..d1509cffdd24 100644
> --- a/drivers/net/can/flexcan.c
> +++ b/drivers/net/can/flexcan.c
> @@ -26,6 +26,7 @@
>  #include <linux/platform_device.h>
>  #include <linux/pm_runtime.h>
>  #include <linux/regulator/consumer.h>
> +#include <linux/pinctrl/consumer.h>
>  #include <linux/regmap.h>
>  
>  #define DRV_NAME			"flexcan"
> @@ -1707,7 +1708,7 @@ static int __maybe_unused flexcan_suspend(struct device *device)
>  {
>  	struct net_device *dev = dev_get_drvdata(device);
>  	struct flexcan_priv *priv = netdev_priv(dev);
> -	int err = 0;
> +	int err;
>  
>  	if (netif_running(dev)) {
>  		/* if wakeup is enabled, enter stop mode
> @@ -1719,25 +1720,27 @@ static int __maybe_unused flexcan_suspend(struct device *device)
>  			if (err)
>  				return err;
>  		} else {
> -			err = flexcan_chip_disable(priv);
> +			flexcan_chip_stop(dev);
> +
> +			err = pm_runtime_force_suspend(device);
>  			if (err)
>  				return err;
>  
> -			err = pm_runtime_force_suspend(device);
> +			pinctrl_pm_select_sleep_state(device);

Please add error handling for pinctrl_pm_select_sleep_state().

>  		}
>  		netif_stop_queue(dev);
>  		netif_device_detach(dev);
>  	}
>  	priv->can.state = CAN_STATE_SLEEPING;
>  
> -	return err;
> +	return 0;
>  }
>  
>  static int __maybe_unused flexcan_resume(struct device *device)
>  {
>  	struct net_device *dev = dev_get_drvdata(device);
>  	struct flexcan_priv *priv = netdev_priv(dev);
> -	int err = 0;
> +	int err;
>  
>  	priv->can.state = CAN_STATE_ERROR_ACTIVE;
>  	if (netif_running(dev)) {
> @@ -1749,15 +1752,19 @@ static int __maybe_unused flexcan_resume(struct device *device)
>  			if (err)
>  				return err;
>  		} else {
> +			pinctrl_pm_select_default_state(device);

same here

> +
>  			err = pm_runtime_force_resume(device);
>  			if (err)
>  				return err;
>  
> -			err = flexcan_chip_enable(priv);
> +			err = flexcan_chip_start(dev);
> +			if (err)
> +				return err;
>  		}
>  	}
>  
> -	return err;
> +	return 0;
>  }
>  
>  static int __maybe_unused flexcan_runtime_suspend(struct device *device)
> 

Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
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