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>

1 files changed, 64 insertions, 0 deletions

diff --git a/net/nfc/digital_technology.c b/net/nfc/digital_technology.c
new file mode 100644
index 000000000000..084b0fba5f4d
--- /dev/null
+++ b/net/nfc/digital_technology.c
@@ -0,0 +1,64 @@
+/*
+ * NFC Digital Protocol stack
+ * 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 "digital.h"
+
+#define DIGITAL_CMD_SENS_REQ    0x26
+#define DIGITAL_CMD_ALL_REQ     0x52
+#define DIGITAL_CMD_SEL_REQ_CL1 0x93
+#define DIGITAL_CMD_SEL_REQ_CL2 0x95
+#define DIGITAL_CMD_SEL_REQ_CL3 0x97
+
+#define DIGITAL_SDD_REQ_SEL_PAR 0x20
+
+#define DIGITAL_SDD_RES_CT  0x88
+#define DIGITAL_SDD_RES_LEN 5
+
+static void digital_in_recv_sens_res(struct nfc_digital_dev *ddev, void *arg,
+				     struct sk_buff *resp)
+{
+	if (!IS_ERR(resp))
+		dev_kfree_skb(resp);
+
+	digital_poll_next_tech(ddev);
+}
+
+int digital_in_send_sens_req(struct nfc_digital_dev *ddev, u8 rf_tech)
+{
+	struct sk_buff *skb;
+	int rc;
+
+	rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
+				     NFC_DIGITAL_RF_TECH_106A);
+	if (rc)
+		return rc;
+
+	rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
+				     NFC_DIGITAL_FRAMING_NFCA_SHORT);
+	if (rc)
+		return rc;
+
+	skb = digital_skb_alloc(ddev, 1);
+	if (!skb)
+		return -ENOMEM;
+
+	*skb_put(skb, sizeof(u8)) = DIGITAL_CMD_SENS_REQ;
+
+	rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sens_res, NULL);
+	if (rc)
+		kfree_skb(skb);
+
+	return rc;
+}