From 59ee2361c9248f07846f7a6e585768dcce18fb16 Mon Sep 17 00:00:00 2001 From: Thierry Escande Date: Thu, 19 Sep 2013 17:55:26 +0200 Subject: NFC Digital: Implement driver commands mechanism This implements the mechanism used to send commands to the driver in initiator mode through in_send_cmd(). Commands are serialized and sent to the driver by using a work item on the system workqueue. Responses are handled asynchronously by another work item. Once the digital stack receives the response through the command_complete callback, the next command is sent to the driver. This also implements the polling mechanism. It's handled by a work item cycling on all supported protocols. The start poll command for a given protocol is sent to the driver using the mechanism described above. The process continues until a peer is discovered or stop_poll is called. This patch implements the poll function for NFC-A that sends a SENS_REQ command and waits for the SENS_RES response. Signed-off-by: Thierry Escande Signed-off-by: Samuel Ortiz --- net/nfc/digital_core.c | 340 ++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 333 insertions(+), 7 deletions(-) (limited to 'net/nfc/digital_core.c') diff --git a/net/nfc/digital_core.c b/net/nfc/digital_core.c index 471188a0d2e0..13abd293ca37 100644 --- a/net/nfc/digital_core.c +++ b/net/nfc/digital_core.c @@ -17,24 +17,319 @@ #include "digital.h" +#define DIGITAL_PROTO_NFCA_RF_TECH \ + (NFC_PROTO_JEWEL_MASK | NFC_PROTO_MIFARE_MASK) + +struct digital_cmd { + struct list_head queue; + + u8 type; + u8 pending; + + u16 timeout; + struct sk_buff *req; + struct sk_buff *resp; + + nfc_digital_cmd_complete_t cmd_cb; + void *cb_context; +}; + +struct sk_buff *digital_skb_alloc(struct nfc_digital_dev *ddev, + unsigned int len) +{ + struct sk_buff *skb; + + skb = alloc_skb(len + ddev->tx_headroom + ddev->tx_tailroom, + GFP_KERNEL); + if (skb) + skb_reserve(skb, ddev->tx_headroom); + + return skb; +} + +static inline void digital_switch_rf(struct nfc_digital_dev *ddev, bool on) +{ + ddev->ops->switch_rf(ddev, on); +} + +static inline void digital_abort_cmd(struct nfc_digital_dev *ddev) +{ + ddev->ops->abort_cmd(ddev); +} + +static void digital_wq_cmd_complete(struct work_struct *work) +{ + struct digital_cmd *cmd; + struct nfc_digital_dev *ddev = container_of(work, + struct nfc_digital_dev, + cmd_complete_work); + + mutex_lock(&ddev->cmd_lock); + + cmd = list_first_entry_or_null(&ddev->cmd_queue, struct digital_cmd, + queue); + if (!cmd) { + mutex_unlock(&ddev->cmd_lock); + return; + } + + list_del(&cmd->queue); + + mutex_unlock(&ddev->cmd_lock); + + if (!IS_ERR(cmd->resp)) + print_hex_dump_debug("DIGITAL RX: ", DUMP_PREFIX_NONE, 16, 1, + cmd->resp->data, cmd->resp->len, false); + + cmd->cmd_cb(ddev, cmd->cb_context, cmd->resp); + + kfree(cmd); + + schedule_work(&ddev->cmd_work); +} + +static void digital_send_cmd_complete(struct nfc_digital_dev *ddev, + void *arg, struct sk_buff *resp) +{ + struct digital_cmd *cmd = arg; + + cmd->resp = resp; + + schedule_work(&ddev->cmd_complete_work); +} + +static void digital_wq_cmd(struct work_struct *work) +{ + int rc; + struct digital_cmd *cmd; + struct nfc_digital_dev *ddev = container_of(work, + struct nfc_digital_dev, + cmd_work); + + mutex_lock(&ddev->cmd_lock); + + cmd = list_first_entry_or_null(&ddev->cmd_queue, struct digital_cmd, + queue); + if (!cmd || cmd->pending) { + mutex_unlock(&ddev->cmd_lock); + return; + } + + mutex_unlock(&ddev->cmd_lock); + + if (cmd->req) + print_hex_dump_debug("DIGITAL TX: ", DUMP_PREFIX_NONE, 16, 1, + cmd->req->data, cmd->req->len, false); + + switch (cmd->type) { + case DIGITAL_CMD_IN_SEND: + rc = ddev->ops->in_send_cmd(ddev, cmd->req, cmd->timeout, + digital_send_cmd_complete, cmd); + break; + default: + PR_ERR("Unknown cmd type %d", cmd->type); + return; + } + + if (!rc) + return; + + PR_ERR("in_send_command returned err %d", rc); + + mutex_lock(&ddev->cmd_lock); + list_del(&cmd->queue); + mutex_unlock(&ddev->cmd_lock); + + kfree_skb(cmd->req); + kfree(cmd); + + schedule_work(&ddev->cmd_work); +} + +int digital_send_cmd(struct nfc_digital_dev *ddev, u8 cmd_type, + struct sk_buff *skb, u16 timeout, + nfc_digital_cmd_complete_t cmd_cb, void *cb_context) +{ + struct digital_cmd *cmd; + + cmd = kzalloc(sizeof(struct digital_cmd), GFP_KERNEL); + if (!cmd) + return -ENOMEM; + + cmd->type = cmd_type; + cmd->timeout = timeout; + cmd->req = skb; + cmd->cmd_cb = cmd_cb; + cmd->cb_context = cb_context; + INIT_LIST_HEAD(&cmd->queue); + + mutex_lock(&ddev->cmd_lock); + list_add_tail(&cmd->queue, &ddev->cmd_queue); + mutex_unlock(&ddev->cmd_lock); + + schedule_work(&ddev->cmd_work); + + return 0; +} + +int digital_in_configure_hw(struct nfc_digital_dev *ddev, int type, int param) +{ + int rc; + + rc = ddev->ops->in_configure_hw(ddev, type, param); + if (rc) + PR_ERR("in_configure_hw failed: %d", rc); + + return rc; +} + +void digital_poll_next_tech(struct nfc_digital_dev *ddev) +{ + digital_switch_rf(ddev, 0); + + mutex_lock(&ddev->poll_lock); + + if (!ddev->poll_tech_count) { + mutex_unlock(&ddev->poll_lock); + return; + } + + ddev->poll_tech_index = (ddev->poll_tech_index + 1) % + ddev->poll_tech_count; + + mutex_unlock(&ddev->poll_lock); + + schedule_work(&ddev->poll_work); +} + +static void digital_wq_poll(struct work_struct *work) +{ + int rc; + struct digital_poll_tech *poll_tech; + struct nfc_digital_dev *ddev = container_of(work, + struct nfc_digital_dev, + poll_work); + mutex_lock(&ddev->poll_lock); + + if (!ddev->poll_tech_count) { + mutex_unlock(&ddev->poll_lock); + return; + } + + poll_tech = &ddev->poll_techs[ddev->poll_tech_index]; + + mutex_unlock(&ddev->poll_lock); + + rc = poll_tech->poll_func(ddev, poll_tech->rf_tech); + if (rc) + digital_poll_next_tech(ddev); +} + +static void digital_add_poll_tech(struct nfc_digital_dev *ddev, u8 rf_tech, + digital_poll_t poll_func) +{ + struct digital_poll_tech *poll_tech; + + if (ddev->poll_tech_count >= NFC_DIGITAL_POLL_MODE_COUNT_MAX) + return; + + poll_tech = &ddev->poll_techs[ddev->poll_tech_count++]; + + poll_tech->rf_tech = rf_tech; + poll_tech->poll_func = poll_func; +} + +/** + * start_poll operation + * + * For every supported protocol, the corresponding polling function is added + * to the table of polling technologies (ddev->poll_techs[]) using + * digital_add_poll_tech(). + * When a polling function fails (by timeout or protocol error) the next one is + * schedule by digital_poll_next_tech() on the poll workqueue (ddev->poll_work). + */ static int digital_start_poll(struct nfc_dev *nfc_dev, __u32 im_protocols, __u32 tm_protocols) { - return -EOPNOTSUPP; + struct nfc_digital_dev *ddev = nfc_get_drvdata(nfc_dev); + u32 matching_im_protocols, matching_tm_protocols; + + PR_DBG("protocols: im 0x%x, tm 0x%x, supported 0x%x", im_protocols, + tm_protocols, ddev->protocols); + + matching_im_protocols = ddev->protocols & im_protocols; + matching_tm_protocols = ddev->protocols & tm_protocols; + + if (!matching_im_protocols && !matching_tm_protocols) { + PR_ERR("No known protocol"); + return -EINVAL; + } + + if (ddev->poll_tech_count) { + PR_ERR("Already polling"); + return -EBUSY; + } + + if (ddev->curr_protocol) { + PR_ERR("A target is already active"); + return -EBUSY; + } + + ddev->poll_tech_count = 0; + ddev->poll_tech_index = 0; + + if (matching_im_protocols & DIGITAL_PROTO_NFCA_RF_TECH) + digital_add_poll_tech(ddev, NFC_DIGITAL_RF_TECH_106A, + digital_in_send_sens_req); + + if (!ddev->poll_tech_count) { + PR_ERR("Unsupported protocols: im=0x%x, tm=0x%x", + matching_im_protocols, matching_tm_protocols); + return -EINVAL; + } + + schedule_work(&ddev->poll_work); + + return 0; } static void digital_stop_poll(struct nfc_dev *nfc_dev) { + struct nfc_digital_dev *ddev = nfc_get_drvdata(nfc_dev); + + mutex_lock(&ddev->poll_lock); + + if (!ddev->poll_tech_count) { + PR_ERR("Polling operation was not running"); + mutex_unlock(&ddev->poll_lock); + return; + } + + ddev->poll_tech_count = 0; + + mutex_unlock(&ddev->poll_lock); + + cancel_work_sync(&ddev->poll_work); + + digital_abort_cmd(ddev); } static int digital_dev_up(struct nfc_dev *nfc_dev) { - return -EOPNOTSUPP; + struct nfc_digital_dev *ddev = nfc_get_drvdata(nfc_dev); + + digital_switch_rf(ddev, 1); + + return 0; } static int digital_dev_down(struct nfc_dev *nfc_dev) { - return -EOPNOTSUPP; + struct nfc_digital_dev *ddev = nfc_get_drvdata(nfc_dev); + + digital_switch_rf(ddev, 0); + + return 0; } static int digital_dep_link_up(struct nfc_dev *nfc_dev, @@ -52,12 +347,15 @@ static int digital_dep_link_down(struct nfc_dev *nfc_dev) static int digital_activate_target(struct nfc_dev *nfc_dev, struct nfc_target *target, __u32 protocol) { - return -EOPNOTSUPP; + return 0; } static void digital_deactivate_target(struct nfc_dev *nfc_dev, struct nfc_target *target) { + struct nfc_digital_dev *ddev = nfc_get_drvdata(nfc_dev); + + ddev->curr_protocol = 0; } static int digital_tg_send(struct nfc_dev *dev, struct sk_buff *skb) @@ -106,8 +404,22 @@ struct nfc_digital_dev *nfc_digital_allocate_device(struct nfc_digital_ops *ops, ddev->driver_capabilities = driver_capabilities; ddev->ops = ops; - ddev->tx_headroom = tx_headroom; - ddev->tx_tailroom = tx_tailroom; + mutex_init(&ddev->cmd_lock); + INIT_LIST_HEAD(&ddev->cmd_queue); + + INIT_WORK(&ddev->cmd_work, digital_wq_cmd); + INIT_WORK(&ddev->cmd_complete_work, digital_wq_cmd_complete); + + mutex_init(&ddev->poll_lock); + INIT_WORK(&ddev->poll_work, digital_wq_poll); + + if (supported_protocols & NFC_PROTO_JEWEL_MASK) + ddev->protocols |= NFC_PROTO_JEWEL_MASK; + if (supported_protocols & NFC_PROTO_MIFARE_MASK) + ddev->protocols |= NFC_PROTO_MIFARE_MASK; + + ddev->tx_headroom = tx_headroom + DIGITAL_MAX_HEADER_LEN; + ddev->tx_tailroom = tx_tailroom + DIGITAL_CRC_LEN; ddev->nfc_dev = nfc_allocate_device(&digital_nfc_ops, ddev->protocols, ddev->tx_headroom, @@ -131,7 +443,6 @@ EXPORT_SYMBOL(nfc_digital_allocate_device); void nfc_digital_free_device(struct nfc_digital_dev *ddev) { nfc_free_device(ddev->nfc_dev); - kfree(ddev); } EXPORT_SYMBOL(nfc_digital_free_device); @@ -144,7 +455,22 @@ EXPORT_SYMBOL(nfc_digital_register_device); void nfc_digital_unregister_device(struct nfc_digital_dev *ddev) { + struct digital_cmd *cmd, *n; + nfc_unregister_device(ddev->nfc_dev); + + mutex_lock(&ddev->poll_lock); + ddev->poll_tech_count = 0; + mutex_unlock(&ddev->poll_lock); + + cancel_work_sync(&ddev->poll_work); + cancel_work_sync(&ddev->cmd_work); + cancel_work_sync(&ddev->cmd_complete_work); + + list_for_each_entry_safe(cmd, n, &ddev->cmd_queue, queue) { + list_del(&cmd->queue); + kfree(cmd); + } } EXPORT_SYMBOL(nfc_digital_unregister_device); -- cgit