Re: [PATCH 1/2] extcon: Add extcon_set_cable_line_state() to inform the additional state of external connectors

[Peter Chen <peter.chen@freescale.com>]

On Fri, May 22, 2015 at 07:49:49PM +0900, Chanwoo Choi wrote:
> This patch adds the extcon_set_cable_line_state() function to inform
> the additional state of each external connector and 'enum extcon_line_state'
> enumeration which include the specific states of each external connector.
> 
> The each external connector might need the different line state. So, current
> 'extcon_line_state' enumeration contains the specific state for USB as
> following:
> 
> - Following the state mean the state of both ID and VBUS line for USB:
> enum extcon_line_state {
> 	EXTCON_USB_ID_LOW	= BIT(1),	/* ID line is low. */
> 	EXTCON_USB_ID_HIGH	= BIT(2),	/* ID line is high. */
> 	EXTCON_USB_VBUS_LOW	= BIT(3),	/* VBUS line is low. */
> 	EXTCON_USB_VBUS_HIGH	= BIT(4),	/* VBUS line is high. */
> };
> 
> Cc: Myungjoo Ham <cw00.choi@samsung.com>
> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
> ---
>  drivers/extcon/extcon.c | 74 ++++++++++++++++++++++++++++++++++++++++++++++++-
>  include/linux/extcon.h  | 24 ++++++++++++++++
>  2 files changed, 97 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/extcon/extcon.c b/drivers/extcon/extcon.c
> index 5099c11..2f7db54 100644
> --- a/drivers/extcon/extcon.c
> +++ b/drivers/extcon/extcon.c
> @@ -279,7 +279,9 @@ int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
>  
>  		for (index = 0; index < edev->max_supported; index++) {
>  			if (is_extcon_changed(edev->state, state, index, &attached))
> -				raw_notifier_call_chain(&edev->nh[index], attached, edev);
> +				raw_notifier_call_chain(&edev->nh[index],
> +					attached ? EXTCON_ATTACHED :
> +					EXTCON_DETACHED, edev);
>  		}
>  
>  		edev->state &= ~mask;
> @@ -418,6 +420,69 @@ int extcon_set_cable_state(struct extcon_dev *edev,
>  EXPORT_SYMBOL_GPL(extcon_set_cable_state);
>  
>  /**
> + * extcon_set_cable_line_state() - Set the line state of specific cable.
> + * @edev:		the extcon device that has the cable.
> + * @id:			the unique id of each external connector.
> + * @state:		the line state for specific cable.
> + *
> + * Note that this function support the only USB connector to inform the state
> + * of both ID and VBUS line until now. This function may be extended to support
> + * the additional external connectors.
> + *
> + * If the id is EXTCON_USB, it can support only following line states:
> + * - EXTCON_USB_ID_LOW
> + * - EXTCON_USB_ID_HIGH,
> + * - EXTCON_USB_VBUS_LOW
> + * - EXTCON_USB_VBUS_HIGH
> + */
> +int extcon_set_cable_line_state(struct extcon_dev *edev, enum extcon id,
> +				enum extcon_line_state state)
> +{
> +	unsigned long flags;
> +	unsigned long line_state;
> +	int ret = 0, index;
> +
> +	index = find_cable_index_by_id(edev, id);
> +	if (index < 0)
> +		return index;
> +
> +	spin_lock_irqsave(&edev->lock, flags);
> +	line_state = edev->line_state[index];
> +
> +	switch (id) {
> +	case EXTCON_USB:
> +		if (line_state & state) {
> +			dev_info(&edev->dev,
> +				"0x%x state is already set for %s\n",
> +				state, extcon_name[id]);
> +			goto err;
> +		}

dev_warning?


-- 

Best Regards,
Peter Chen