2012/3/23 Eric Lapuyade <eric.lapuyade@xxxxxxxxxxxxxxx>:
> Some HW/drivers get notifications when a tag moves out of the radio field.
> This notification is now forwarded to user space through netlink.
I think to put a timer in the NFC core is not the best solution for
this problem.
This solution is not suitable for devices that receive an event when
the tag moves out of the field.
It would be better the NFC core to receive this as an event and to
move the timer to the device driver.
Regards,
Lauro
>
> Signed-off-by: Eric Lapuyade <eric.lapuyade@xxxxxxxxx>
> Signed-off-by: Samuel Ortiz <sameo@xxxxxxxxxxxxxxx>
> ---
> include/net/nfc/nfc.h | 5 +++
> net/nfc/core.c | 84 ++++++++++++++++++++++++++++++++++++++++++++++++-
> 2 files changed, 88 insertions(+), 1 deletions(-)
>
> diff --git a/include/net/nfc/nfc.h b/include/net/nfc/nfc.h
> index 7273ff1..313d00f 100644
> --- a/include/net/nfc/nfc.h
> +++ b/include/net/nfc/nfc.h
> @@ -62,6 +62,7 @@ struct nfc_ops {
> int (*data_exchange)(struct nfc_dev *dev, u32 target_idx,
> struct sk_buff *skb, data_exchange_cb_t cb,
> void *cb_context);
> + int (*check_presence)(struct nfc_dev *dev, u32 target_idx);
> };
>
> #define NFC_TARGET_IDX_ANY -1
> @@ -107,6 +108,10 @@ struct nfc_dev {
> int tx_headroom;
> int tx_tailroom;
>
> + struct timer_list check_pres_timer;
> + struct workqueue_struct *check_pres_wq;
> + struct work_struct check_pres_work;
> +
> struct nfc_ops *ops;
> };
> #define to_nfc_dev(_dev) container_of(_dev, struct nfc_dev, dev)
> diff --git a/net/nfc/core.c b/net/nfc/core.c
> index e9936d9..a580926 100644
> --- a/net/nfc/core.c
> +++ b/net/nfc/core.c
> @@ -33,6 +33,8 @@
>
> #define VERSION "0.1"
>
> +#define NFC_CHECK_PRES_FREQ_MS 2000
> +
> int nfc_devlist_generation;
> DEFINE_MUTEX(nfc_devlist_mutex);
>
> @@ -289,9 +291,14 @@ int nfc_activate_target(struct nfc_dev *dev, u32 target_idx, u32 protocol)
> }
>
> rc = dev->ops->activate_target(dev, target_idx, protocol);
> - if (!rc)
> + if (!rc) {
> dev->activated_target_idx = target_idx;
>
> + if (dev->ops->check_presence)
> + mod_timer(&dev->check_pres_timer, jiffies +
> + msecs_to_jiffies(NFC_CHECK_PRES_FREQ_MS));
> + }
> +
> error:
> device_unlock(&dev->dev);
> return rc;
> @@ -317,6 +324,9 @@ int nfc_deactivate_target(struct nfc_dev *dev, u32 target_idx)
> goto error;
> }
>
> + if (dev->ops->check_presence)
> + del_timer_sync(&dev->check_pres_timer);
> +
> dev->ops->deactivate_target(dev, target_idx);
> dev->activated_target_idx = NFC_TARGET_IDX_NONE;
>
> @@ -352,8 +362,27 @@ int nfc_data_exchange(struct nfc_dev *dev, u32 target_idx, struct sk_buff *skb,
> goto error;
> }
>
> + if (dev->activated_target_idx == NFC_TARGET_IDX_NONE) {
> + rc = -ENOTCONN;
> + kfree_skb(skb);
> + goto error;
> + }
> +
> + if (target_idx != dev->activated_target_idx) {
> + rc = -EADDRNOTAVAIL;
> + kfree_skb(skb);
> + goto error;
> + }
> +
> + if (dev->ops->check_presence)
> + del_timer_sync(&dev->check_pres_timer);
> +
> rc = dev->ops->data_exchange(dev, target_idx, skb, cb, cb_context);
>
> + if (!rc && dev->ops->check_presence)
> + mod_timer(&dev->check_pres_timer, jiffies +
> + msecs_to_jiffies(NFC_CHECK_PRES_FREQ_MS));
> +
> error:
> device_unlock(&dev->dev);
> return rc;
> @@ -517,11 +546,46 @@ static void nfc_release(struct device *d)
>
> pr_debug("dev_name=%s\n", dev_name(&dev->dev));
>
> + if (dev->ops->check_presence) {
> + del_timer_sync(&dev->check_pres_timer);
> + destroy_workqueue(dev->check_pres_wq);
> + }
> +
> nfc_genl_data_exit(&dev->genl_data);
> kfree(dev->targets);
> kfree(dev);
> }
>
> +static void nfc_check_pres_work(struct work_struct *work)
> +{
> + struct nfc_dev *dev = container_of(work, struct nfc_dev,
> + check_pres_work);
> + int rc;
> +
> + device_lock(&dev->dev);
> +
> + if (dev->activated_target_idx != NFC_TARGET_IDX_NONE &&
> + timer_pending(&dev->check_pres_timer) == 0) {
> + rc = dev->ops->check_presence(dev, dev->activated_target_idx);
> + if (!rc) {
> + mod_timer(&dev->check_pres_timer, jiffies +
> + msecs_to_jiffies(NFC_CHECK_PRES_FREQ_MS));
> + } else {
> + nfc_target_lost(dev, dev->activated_target_idx);
> + dev->activated_target_idx = NFC_TARGET_IDX_NONE;
> + }
> + }
> +
> + device_unlock(&dev->dev);
> +}
> +
> +static void nfc_check_pres_timeout(unsigned long data)
> +{
> + struct nfc_dev *dev = (struct nfc_dev *)data;
> +
> + queue_work(dev->check_pres_wq, &dev->check_pres_work);
> +}
> +
> struct class nfc_class = {
> .name = "nfc",
> .dev_release = nfc_release,
> @@ -589,6 +653,24 @@ struct nfc_dev *nfc_allocate_device(struct nfc_ops *ops,
>
> dev->activated_target_idx = NFC_TARGET_IDX_NONE;
>
> + if (ops->check_presence) {
> + char name[32];
> + init_timer(&dev->check_pres_timer);
> + dev->check_pres_timer.data = (unsigned long)dev;
> + dev->check_pres_timer.function = nfc_check_pres_timeout;
> +
> + INIT_WORK(&dev->check_pres_work, nfc_check_pres_work);
> + snprintf(name, sizeof(name), "nfc%d_check_pres_wq", dev->idx);
> + dev->check_pres_wq = alloc_workqueue(name, WQ_NON_REENTRANT |
> + WQ_UNBOUND |
> + WQ_MEM_RECLAIM, 1);
> + if (dev->check_pres_wq == NULL) {
> + kfree(dev);
> + return NULL;
> + }
> + }
> +
> +
> return dev;
> }
> EXPORT_SYMBOL(nfc_allocate_device);
> --
> 1.7.6.5
>
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