Subject: Re: [PATCH v3 6/8] net: can: c_can: Disable pins when CAN interface is down

From: Marc Kleine-Budde <[email-masked]>
Date: Wed, 05 Nov 2014 14:24:33 +0100

On 11/04/2014 11:20 AM, Roger Quadros wrote:
> DRA7 CAN IP suffers from a problem which causes it to be prevented
> from fully turning OFF (i.e. stuck in transition) if the module was
> disabled while there was traffic on the CAN_RX line.
> 
> To work around this issue we select the SLEEP pin state by default
> on probe and use the DEFAULT pin state on CAN up and back to the
> SLEEP pin state on CAN down.
> 
> Signed-off-by: Roger Quadros <[email-masked]>
> ---
>  drivers/net/can/c_can/c_can.c          | 20 ++++++++++++++++++++
>  drivers/net/can/c_can/c_can.h          |  1 +
>  drivers/net/can/c_can/c_can_platform.c | 20 ++++++++++++++++++++
>  3 files changed, 41 insertions(+)
> 
> diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
> index 8e78bb4..4dfc3ce 100644
> --- a/drivers/net/can/c_can/c_can.c
> +++ b/drivers/net/can/c_can/c_can.c
> @@ -35,6 +35,7 @@
>  #include <linux/list.h>
>  #include <linux/io.h>
>  #include <linux/pm_runtime.h>
> +#include <linux/pinctrl/consumer.h>
>  
>  #include <linux/can.h>
>  #include <linux/can/dev.h>
> @@ -603,6 +604,15 @@ static int c_can_start(struct net_device *dev)
>  
>  	priv->can.state = CAN_STATE_ERROR_ACTIVE;
>  
> +	/* activate pins */
> +	if (!IS_ERR(priv->pinctrl)) {
> +		struct pinctrl_state *s;
> +
> +		s = pinctrl_lookup_state(priv->pinctrl, PINCTRL_STATE_DEFAULT);
> +		if (!IS_ERR(s))
> +			pinctrl_select_state(priv->pinctrl, s);
> +	}

Can you factor this into a common function? Which is used like this:

c_can_pinctrl_select_state(priv, PINCTRL_STATE_DEFAULT)

Otherwise looks god.

Marc

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