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>

include/net/nfc/digital.h

@@ -146,6 +146,15 @@ struct nfc_digital_ops {
 	void (*abort_cmd)(struct nfc_digital_dev *ddev);
 };
 
+#define NFC_DIGITAL_POLL_MODE_COUNT_MAX	6 /* 106A, 212F, and 424F in & tg */
+
+typedef int (*digital_poll_t)(struct nfc_digital_dev *ddev, u8 rf_tech);
+
+struct digital_poll_tech {
+	u8 rf_tech;
+	digital_poll_t poll_func;
+};
+
 /**
  * Driver capabilities - bit mask made of the following values
  *
@@ -168,6 +177,22 @@ struct nfc_digital_dev {
 
 	u32 driver_capabilities;
 	void *driver_data;
+
+	struct digital_poll_tech poll_techs[NFC_DIGITAL_POLL_MODE_COUNT_MAX];
+	u8 poll_tech_count;
+	u8 poll_tech_index;
+	struct mutex poll_lock;
+
+	struct work_struct cmd_work;
+	struct work_struct cmd_complete_work;
+	struct list_head cmd_queue;
+	struct mutex cmd_lock;
+
+	struct work_struct poll_work;
+
+	u8 curr_protocol;
+	u8 curr_rf_tech;
+	u8 curr_nfc_dep_pni;
 };
 
 struct nfc_digital_dev *nfc_digital_allocate_device(struct nfc_digital_ops *ops,

net/nfc/Makefile

@@ -10,4 +10,4 @@ obj-$(CONFIG_NFC_DIGITAL) += nfc_digital.o
 nfc-objs := core.o netlink.o af_nfc.o rawsock.o llcp_core.o llcp_commands.o \
 		llcp_sock.o
 
-nfc_digital-objs := digital_core.o
+nfc_digital-objs := digital_core.o digital_technology.o

net/nfc/digital.h

@@ -24,4 +24,33 @@
 #define PROTOCOL_ERR(req) pr_err("%s:%d: NFC Digital Protocol error: %s\n", \
 				 __func__, __LINE__, req)
 
+#define DIGITAL_CMD_IN_SEND        0
+#define DIGITAL_CMD_TG_SEND        1
+#define DIGITAL_CMD_TG_LISTEN      2
+#define DIGITAL_CMD_TG_LISTEN_MDAA 3
+
+#define DIGITAL_MAX_HEADER_LEN 7
+#define DIGITAL_CRC_LEN        2
+
+struct sk_buff *digital_skb_alloc(struct nfc_digital_dev *ddev,
+				  unsigned int len);
+
+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);
+
+int digital_in_configure_hw(struct nfc_digital_dev *ddev, int type, int param);
+static inline int digital_in_send_cmd(struct nfc_digital_dev *ddev,
+				      struct sk_buff *skb, u16 timeout,
+				      nfc_digital_cmd_complete_t cmd_cb,
+				      void *cb_context)
+{
+	return digital_send_cmd(ddev, DIGITAL_CMD_IN_SEND, skb, timeout, cmd_cb,
+				cb_context);
+}
+
+void digital_poll_next_tech(struct nfc_digital_dev *ddev);
+
+int digital_in_send_sens_req(struct nfc_digital_dev *ddev, u8 rf_tech);
+
 #endif /* __DIGITAL_H */