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 <thierry.escande@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/net/nfc/digital_core.c b/net/nfc/digital_core.c
index 471188a..13abd29 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_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 @@
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 @@
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 @@
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);