# RE: \[PATCH\] can: flexcan: add LPSR mode support for i.MX7D

- From: Joakim Zhang \<hidden\>
- Date: 2019-08-16 06:47:29 
- List: netdev
- Page: https://ratatoskr.run/netdev/2019/08/9353128
- Thread: https://ratatoskr.run/linux-can/2019/07/9353106/t.md

```text

Kindly Ping...

Best Regards,
Joakim Zhang

> -----Original Message-----
> From: Joakim Zhang
> Sent: 2019年7月31日 13:57
> To: mkl@pengutronix.de; <redacted>
> Cc: <redacted>; <redacted>; dl-linux-imx
> [ref]; Joakim Zhang [ref]
> Subject: [PATCH] can: flexcan: add LPSR mode support for i.MX7D
> 
> 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 <redacted>
> ---
>  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
> c21b3507123e..228d07e84ddc 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"
> @@ -1889,7 +1890,7 @@ 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 @@ -1899,25 +1900,27
> @@ static int __maybe_unused flexcan_suspend(struct device *device)
>  			enable_irq_wake(dev->irq);
>  			flexcan_enter_stop_mode(priv);
>  		} 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);
>  		}
>  		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)) {
> @@ -1926,15 +1929,19 @@ static int __maybe_unused
> flexcan_resume(struct device *device)
>  		if (device_may_wakeup(device)) {
>  			disable_irq_wake(dev->irq);
>  		} else {
> +			pinctrl_pm_select_default_state(device);
> +
>  			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)
> --
> 2.17.1

```