diff options
| -rw-r--r-- | drivers/nfc/Kconfig | 10 | ||||
| -rw-r--r-- | drivers/nfc/Makefile | 1 | ||||
| -rw-r--r-- | drivers/nfc/nfcsim.c | 541 |
3 files changed, 552 insertions, 0 deletions
diff --git a/drivers/nfc/Kconfig b/drivers/nfc/Kconfig index 74a852e4e41f..b0b64ccb7d7d 100644 --- a/drivers/nfc/Kconfig +++ b/drivers/nfc/Kconfig @@ -36,6 +36,16 @@ config NFC_MEI_PHY If unsure, say N. +config NFC_SIM + tristate "NFC hardware simulator driver" + help + This driver declares two virtual NFC devices supporting NFC-DEP + protocol. An LLCP connection can be established between them and + all packets sent from one device is sent back to the other, acting as + loopback devices. + + If unsure, say N. + source "drivers/nfc/pn544/Kconfig" source "drivers/nfc/microread/Kconfig" diff --git a/drivers/nfc/Makefile b/drivers/nfc/Makefile index aa6bd657ef40..be7636abcb3f 100644 --- a/drivers/nfc/Makefile +++ b/drivers/nfc/Makefile @@ -7,5 +7,6 @@ obj-$(CONFIG_NFC_MICROREAD) += microread/ obj-$(CONFIG_NFC_PN533) += pn533.o obj-$(CONFIG_NFC_WILINK) += nfcwilink.o obj-$(CONFIG_NFC_MEI_PHY) += mei_phy.o +obj-$(CONFIG_NFC_SIM) += nfcsim.o ccflags-$(CONFIG_NFC_DEBUG) := -DDEBUG diff --git a/drivers/nfc/nfcsim.c b/drivers/nfc/nfcsim.c new file mode 100644 index 000000000000..c5c30fb1d7bf --- /dev/null +++ b/drivers/nfc/nfcsim.c @@ -0,0 +1,541 @@ +/* + * NFC hardware simulation driver + * Copyright (c) 2013, Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + */ + +#include <linux/device.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/nfc.h> +#include <net/nfc/nfc.h> + +#define DEV_ERR(_dev, fmt, args...) nfc_dev_err(&_dev->nfc_dev->dev, \ + "%s: " fmt, __func__, ## args) + +#define DEV_DBG(_dev, fmt, args...) nfc_dev_dbg(&_dev->nfc_dev->dev, \ + "%s: " fmt, __func__, ## args) + +#define NFCSIM_VERSION "0.1" + +#define NFCSIM_POLL_NONE 0 +#define NFCSIM_POLL_INITIATOR 1 +#define NFCSIM_POLL_TARGET 2 +#define NFCSIM_POLL_DUAL (NFCSIM_POLL_INITIATOR | NFCSIM_POLL_TARGET) + +struct nfcsim { + struct nfc_dev *nfc_dev; + + struct mutex lock; + + struct delayed_work recv_work; + + struct sk_buff *clone_skb; + + struct delayed_work poll_work; + u8 polling_mode; + u8 curr_polling_mode; + + u8 shutting_down; + + u8 up; + + u8 initiator; + + data_exchange_cb_t cb; + void *cb_context; + + struct nfcsim *peer_dev; +}; + +static struct nfcsim *dev0; +static struct nfcsim *dev1; + +struct workqueue_struct *wq; + +static void nfcsim_cleanup_dev(struct nfcsim *dev, u8 shutdown) +{ + DEV_DBG(dev, "shutdown=%d", shutdown); + + mutex_lock(&dev->lock); + + dev->polling_mode = NFCSIM_POLL_NONE; + dev->shutting_down = shutdown; + dev->cb = NULL; + dev_kfree_skb(dev->clone_skb); + dev->clone_skb = NULL; + + mutex_unlock(&dev->lock); + + cancel_delayed_work_sync(&dev->poll_work); + cancel_delayed_work_sync(&dev->recv_work); +} + +static int nfcsim_target_found(struct nfcsim *dev) +{ + struct nfc_target nfc_tgt; + + DEV_DBG(dev, ""); + + memset(&nfc_tgt, 0, sizeof(struct nfc_target)); + + nfc_tgt.supported_protocols = NFC_PROTO_NFC_DEP_MASK; + nfc_targets_found(dev->nfc_dev, &nfc_tgt, 1); + + return 0; +} + +static int nfcsim_dev_up(struct nfc_dev *nfc_dev) +{ + struct nfcsim *dev = nfc_get_drvdata(nfc_dev); + + DEV_DBG(dev, ""); + + mutex_lock(&dev->lock); + + dev->up = 1; + + mutex_unlock(&dev->lock); + + return 0; +} + +static int nfcsim_dev_down(struct nfc_dev *nfc_dev) +{ + struct nfcsim *dev = nfc_get_drvdata(nfc_dev); + + DEV_DBG(dev, ""); + + mutex_lock(&dev->lock); + + dev->up = 0; + + mutex_unlock(&dev->lock); + + return 0; +} + +static int nfcsim_dep_link_up(struct nfc_dev *nfc_dev, + struct nfc_target *target, + u8 comm_mode, u8 *gb, size_t gb_len) +{ + int rc; + struct nfcsim *dev = nfc_get_drvdata(nfc_dev); + struct nfcsim *peer = dev->peer_dev; + u8 *remote_gb; + size_t remote_gb_len; + + DEV_DBG(dev, "target_idx: %d, comm_mode: %d\n", target->idx, comm_mode); + + mutex_lock(&peer->lock); + + nfc_tm_activated(peer->nfc_dev, NFC_PROTO_NFC_DEP_MASK, + NFC_COMM_ACTIVE, gb, gb_len); + + remote_gb = nfc_get_local_general_bytes(peer->nfc_dev, &remote_gb_len); + if (!remote_gb) { + DEV_ERR(peer, "Can't get remote general bytes"); + + mutex_unlock(&peer->lock); + return -EINVAL; + } + + mutex_unlock(&peer->lock); + + mutex_lock(&dev->lock); + + rc = nfc_set_remote_general_bytes(nfc_dev, remote_gb, remote_gb_len); + if (rc) { + DEV_ERR(dev, "Can't set remote general bytes"); + mutex_unlock(&dev->lock); + return rc; + } + + rc = nfc_dep_link_is_up(nfc_dev, target->idx, NFC_COMM_ACTIVE, + NFC_RF_INITIATOR); + + mutex_unlock(&dev->lock); + + return rc; +} + +static int nfcsim_dep_link_down(struct nfc_dev *nfc_dev) +{ + struct nfcsim *dev = nfc_get_drvdata(nfc_dev); + + DEV_DBG(dev, ""); + + nfcsim_cleanup_dev(dev, 0); + + return 0; +} + +static int nfcsim_start_poll(struct nfc_dev *nfc_dev, + u32 im_protocols, u32 tm_protocols) +{ + struct nfcsim *dev = nfc_get_drvdata(nfc_dev); + int rc; + + mutex_lock(&dev->lock); + + if (dev->polling_mode != NFCSIM_POLL_NONE) { + DEV_ERR(dev, "Already in polling mode"); + rc = -EBUSY; + goto exit; + } + + if (im_protocols & NFC_PROTO_NFC_DEP_MASK) + dev->polling_mode |= NFCSIM_POLL_INITIATOR; + + if (tm_protocols & NFC_PROTO_NFC_DEP_MASK) + dev->polling_mode |= NFCSIM_POLL_TARGET; + + if (dev->polling_mode == NFCSIM_POLL_NONE) { + DEV_ERR(dev, "Unsupported polling mode"); + rc = -EINVAL; + goto exit; + } + + dev->initiator = 0; + dev->curr_polling_mode = NFCSIM_POLL_NONE; + + queue_delayed_work(wq, &dev->poll_work, 0); + + DEV_DBG(dev, "Start polling: im: 0x%X, tm: 0x%X", im_protocols, + tm_protocols); + + rc = 0; +exit: + mutex_unlock(&dev->lock); + + return rc; +} + +static void nfcsim_stop_poll(struct nfc_dev *nfc_dev) +{ + struct nfcsim *dev = nfc_get_drvdata(nfc_dev); + + DEV_DBG(dev, "Stop poll"); + + mutex_lock(&dev->lock); + + dev->polling_mode = NFCSIM_POLL_NONE; + + mutex_unlock(&dev->lock); + + cancel_delayed_work_sync(&dev->poll_work); +} + +static int nfcsim_activate_target(struct nfc_dev *nfc_dev, + struct nfc_target *target, u32 protocol) +{ + struct nfcsim *dev = nfc_get_drvdata(nfc_dev); + + DEV_DBG(dev, ""); + + return -ENOTSUPP; +} + +static void nfcsim_deactivate_target(struct nfc_dev *nfc_dev, + struct nfc_target *target) +{ + struct nfcsim *dev = nfc_get_drvdata(nfc_dev); + + DEV_DBG(dev, ""); +} + +static void nfcsim_wq_recv(struct work_struct *work) +{ + struct nfcsim *dev = container_of(work, struct nfcsim, + recv_work.work); + + mutex_lock(&dev->lock); + + if (dev->shutting_down || !dev->up || !dev->clone_skb) { + dev_kfree_skb(dev->clone_skb); + goto exit; + } + + if (dev->initiator) { + if (!dev->cb) { + DEV_ERR(dev, "Null recv callback"); + dev_kfree_skb(dev->clone_skb); + goto exit; + } + + dev->cb(dev->cb_context, dev->clone_skb, 0); + dev->cb = NULL; + } else { + nfc_tm_data_received(dev->nfc_dev, dev->clone_skb); + } + +exit: + dev->clone_skb = NULL; + + mutex_unlock(&dev->lock); +} + +static int nfcsim_tx(struct nfc_dev *nfc_dev, struct nfc_target *target, + struct sk_buff *skb, data_exchange_cb_t cb, + void *cb_context) +{ + struct nfcsim *dev = nfc_get_drvdata(nfc_dev); + struct nfcsim *peer = dev->peer_dev; + int err; + + mutex_lock(&dev->lock); + + if (dev->shutting_down || !dev->up) { + mutex_unlock(&dev->lock); + err = -ENODEV; + goto exit; + } + + dev->cb = cb; + dev->cb_context = cb_context; + + mutex_unlock(&dev->lock); + + mutex_lock(&peer->lock); + + peer->clone_skb = skb_clone(skb, GFP_KERNEL); + + if (!peer->clone_skb) { + DEV_ERR(dev, "skb_clone failed"); + mutex_unlock(&peer->lock); + err = -ENOMEM; + goto exit; + } + + /* This simulates an arbitrary transmission delay between the 2 devices. + * If packet transmission occurs immediately between them, we have a + * non-stop flow of several tens of thousands SYMM packets per second + * and a burning cpu. + * + * TODO: Add support for a sysfs entry to control this delay. + */ + queue_delayed_work(wq, &peer->recv_work, msecs_to_jiffies(5)); + + mutex_unlock(&peer->lock); + + err = 0; +exit: + dev_kfree_skb(skb); + + return err; +} + +static int nfcsim_im_transceive(struct nfc_dev *nfc_dev, + struct nfc_target *target, struct sk_buff *skb, + data_exchange_cb_t cb, void *cb_context) +{ + return nfcsim_tx(nfc_dev, target, skb, cb, cb_context); +} + +static int nfcsim_tm_send(struct nfc_dev *nfc_dev, struct sk_buff *skb) +{ + return nfcsim_tx(nfc_dev, NULL, skb, NULL, NULL); +} + +static struct nfc_ops nfcsim_nfc_ops = { + .dev_up = nfcsim_dev_up, + .dev_down = nfcsim_dev_down, + .dep_link_up = nfcsim_dep_link_up, + .dep_link_down = nfcsim_dep_link_down, + .start_poll = nfcsim_start_poll, + .stop_poll = nfcsim_stop_poll, + .activate_target = nfcsim_activate_target, + .deactivate_target = nfcsim_deactivate_target, + .im_transceive = nfcsim_im_transceive, + .tm_send = nfcsim_tm_send, +}; + +static void nfcsim_set_polling_mode(struct nfcsim *dev) +{ + if (dev->polling_mode == NFCSIM_POLL_NONE) { + dev->curr_polling_mode = NFCSIM_POLL_NONE; + return; + } + + if (dev->curr_polling_mode == NFCSIM_POLL_NONE) { + if (dev->polling_mode & NFCSIM_POLL_INITIATOR) + dev->curr_polling_mode = NFCSIM_POLL_INITIATOR; + else + dev->curr_polling_mode = NFCSIM_POLL_TARGET; + + return; + } + + if (dev->polling_mode == NFCSIM_POLL_DUAL) { + if (dev->curr_polling_mode == NFCSIM_POLL_TARGET) + dev->curr_polling_mode = NFCSIM_POLL_INITIATOR; + else + dev->curr_polling_mode = NFCSIM_POLL_TARGET; + } +} + +static void nfcsim_wq_poll(struct work_struct *work) +{ + struct nfcsim *dev = container_of(work, struct nfcsim, poll_work.work); + struct nfcsim *peer = dev->peer_dev; + + /* These work items run on an ordered workqueue and are therefore + * serialized. So we can take both mutexes without being dead locked. + */ + mutex_lock(&dev->lock); + mutex_lock(&peer->lock); + + nfcsim_set_polling_mode(dev); + + if (dev->curr_polling_mode == NFCSIM_POLL_NONE) { + DEV_DBG(dev, "Not polling"); + goto unlock; + } + + DEV_DBG(dev, "Polling as %s", + dev->curr_polling_mode == NFCSIM_POLL_INITIATOR ? + "initiator" : "target"); + + if (dev->curr_polling_mode == NFCSIM_POLL_TARGET) + goto sched_work; + + if (peer->curr_polling_mode == NFCSIM_POLL_TARGET) { + peer->polling_mode = NFCSIM_POLL_NONE; + dev->polling_mode = NFCSIM_POLL_NONE; + + dev->initiator = 1; + + nfcsim_target_found(dev); + + goto unlock; + } + +sched_work: + /* This defines the delay for an initiator to check if the other device + * is polling in target mode. + * If the device starts in dual mode polling, it switches between + * initiator and target at every round. + * Because the wq is ordered and only 1 work item is executed at a time, + * we'll always have one device polling as initiator and the other as + * target at some point, even if both are started in dual mode. + */ + queue_delayed_work(wq, &dev->poll_work, msecs_to_jiffies(200)); + +unlock: + mutex_unlock(&peer->lock); + mutex_unlock(&dev->lock); +} + +static struct nfcsim *nfcsim_init_dev(void) +{ + struct nfcsim *dev; + int rc = -ENOMEM; + + dev = kzalloc(sizeof(*dev), GFP_KERNEL); + if (dev == NULL) + return ERR_PTR(-ENOMEM); + + mutex_init(&dev->lock); + + INIT_DELAYED_WORK(&dev->recv_work, nfcsim_wq_recv); + INIT_DELAYED_WORK(&dev->poll_work, nfcsim_wq_poll); + + dev->nfc_dev = nfc_allocate_device(&nfcsim_nfc_ops, + NFC_PROTO_NFC_DEP_MASK, + 0, 0); + if (!dev->nfc_dev) + goto error; + + nfc_set_drvdata(dev->nfc_dev, dev); + + rc = nfc_register_device(dev->nfc_dev); + if (rc) + goto free_nfc_dev; + + return dev; + +free_nfc_dev: + nfc_free_device(dev->nfc_dev); + +error: + kfree(dev); + + return ERR_PTR(rc); +} + +static void nfcsim_free_device(struct nfcsim *dev) +{ + nfc_unregister_device(dev->nfc_dev); + + nfc_free_device(dev->nfc_dev); + + kfree(dev); +} + +int __init nfcsim_init(void) +{ + int rc; + + /* We need an ordered wq to ensure that poll_work items are executed + * one at a time. + */ + wq = alloc_ordered_workqueue("nfcsim", 0); + if (!wq) { + rc = -ENOMEM; + goto exit; + } + + dev0 = nfcsim_init_dev(); + if (IS_ERR(dev0)) { + rc = PTR_ERR(dev0); + goto exit; + } + + dev1 = nfcsim_init_dev(); + if (IS_ERR(dev1)) { + kfree(dev0); + + rc = PTR_ERR(dev1); + goto exit; + } + + dev0->peer_dev = dev1; + dev1->peer_dev = dev0; + + pr_debug("NFCsim " NFCSIM_VERSION " initialized\n"); + + rc = 0; +exit: + if (rc) + pr_err("Failed to initialize nfcsim driver (%d)\n", + rc); + + return rc; +} + +void __exit nfcsim_exit(void) +{ + nfcsim_cleanup_dev(dev0, 1); + nfcsim_cleanup_dev(dev1, 1); + + nfcsim_free_device(dev0); + nfcsim_free_device(dev1); + + destroy_workqueue(wq); +} + +module_init(nfcsim_init); +module_exit(nfcsim_exit); + +MODULE_DESCRIPTION("NFCSim driver ver " NFCSIM_VERSION); +MODULE_VERSION(NFCSIM_VERSION); +MODULE_LICENSE("GPL"); |