From c8d56ae78653c02fc6e6f304a18f860302481c2d Mon Sep 17 00:00:00 2001 From: Eric Lapuyade Date: Tue, 10 Apr 2012 19:43:12 +0200 Subject: [PATCH] NFC: Add Core support to generate tag lost event Some HW/drivers get notifications when a tag moves out of the radio field. This notification is now forwarded to user space through netlink. Signed-off-by: Eric Lapuyade Signed-off-by: Samuel Ortiz Signed-off-by: John W. Linville --- include/net/nfc/nfc.h | 5 +++ net/nfc/core.c | 72 ++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 76 insertions(+), 1 deletion(-) diff --git a/include/net/nfc/nfc.h b/include/net/nfc/nfc.h index 7273ff169bb8..313d00fac276 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 44a701806ba5..da353275fbc6 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); @@ -292,9 +294,14 @@ 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; @@ -320,6 +327,9 @@ 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; @@ -367,8 +377,15 @@ int nfc_data_exchange(struct nfc_dev *dev, u32 target_idx, struct sk_buff *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; @@ -521,11 +538,46 @@ 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, @@ -593,6 +645,24 @@ 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); -- 2.20.1