NFC: digital: Add 'tg_listen_md' and 'tg_get_rf_tech' driver hooks

The digital layer of the NFC subsystem currently
supports a 'tg_listen_mdaa' driver hook that supports
devices that can do mode detection and automatic
anticollision.  However, there are some devices that
can do mode detection but not automatic anitcollision
so add the 'tg_listen_md' hook to support those devices.

In order for the digital layer to get the RF technology
detected by the device from the driver, add the
'tg_get_rf_tech' hook.  It is only valid to call this
hook immediately after a successful call to 'tg_listen_md'.

CC: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

include/net/nfc/digital.h

@@ -127,6 +127,15 @@ typedef void (*nfc_digital_cmd_complete_t)(struct nfc_digital_dev *ddev,
  *	the NFC-DEP ATR_REQ command through cb. The digital stack deducts the RF
  *	tech by analyzing the SoD of the frame containing the ATR_REQ command.
  *	This is an asynchronous function.
+ * @tg_listen_md: If supported, put the device in automatic listen mode with
+ *	mode detection but without automatic anti-collision. In this mode, the
+ *	device automatically detects the RF technology.  What the actual
+ *	RF technology is can be retrieved by calling @tg_get_rf_tech.
+ *	The digital stack will then perform the appropriate anti-collision
+ *	sequence.  This is an asynchronous function.
+ * @tg_get_rf_tech: Required when @tg_listen_md is supported, unused otherwise.
+ *	Return the RF Technology that was detected by the @tg_listen_md call.
+ *	This is a synchronous function.
  *
  * @switch_rf: Turns device radio on or off. The stack does not call explicitly
  *	switch_rf to turn the radio on. A call to in|tg_configure_hw must turn
@@ -161,6 +170,9 @@ struct nfc_digital_ops {
 			      struct digital_tg_mdaa_params *mdaa_params,
 			      u16 timeout, nfc_digital_cmd_complete_t cb,
 			      void *arg);
+	int (*tg_listen_md)(struct nfc_digital_dev *ddev, u16 timeout,
+			    nfc_digital_cmd_complete_t cb, void *arg);
+	int (*tg_get_rf_tech)(struct nfc_digital_dev *ddev, u8 *rf_tech);
 
 	int (*switch_rf)(struct nfc_digital_dev *ddev, bool on);
 	void (*abort_cmd)(struct nfc_digital_dev *ddev);

net/nfc/digital.h

@@ -29,6 +29,7 @@
 #define DIGITAL_CMD_TG_SEND        1
 #define DIGITAL_CMD_TG_LISTEN      2
 #define DIGITAL_CMD_TG_LISTEN_MDAA 3
+#define DIGITAL_CMD_TG_LISTEN_MD   4
 
 #define DIGITAL_MAX_HEADER_LEN 7
 #define DIGITAL_CRC_LEN        2
@@ -121,6 +122,8 @@ int digital_tg_send_dep_res(struct nfc_digital_dev *ddev, struct sk_buff *skb);
 
 int digital_tg_listen_nfca(struct nfc_digital_dev *ddev, u8 rf_tech);
 int digital_tg_listen_nfcf(struct nfc_digital_dev *ddev, u8 rf_tech);
+void digital_tg_recv_md_req(struct nfc_digital_dev *ddev, void *arg,
+			    struct sk_buff *resp);
 
 typedef u16 (*crc_func_t)(u16, const u8 *, size_t);
 

net/nfc/digital_core.c

@@ -201,6 +201,11 @@ static void digital_wq_cmd(struct work_struct *work)
 					       digital_send_cmd_complete, cmd);
 		break;
 
+	case DIGITAL_CMD_TG_LISTEN_MD:
+		rc = ddev->ops->tg_listen_md(ddev, cmd->timeout,
+					       digital_send_cmd_complete, cmd);
+		break;
+
 	default:
 		pr_err("Unknown cmd type %d\n", cmd->type);
 		return;
@@ -293,6 +298,12 @@ static int digital_tg_listen_mdaa(struct nfc_digital_dev *ddev, u8 rf_tech)
 				500, digital_tg_recv_atr_req, NULL);
 }
 
+static int digital_tg_listen_md(struct nfc_digital_dev *ddev, u8 rf_tech)
+{
+	return digital_send_cmd(ddev, DIGITAL_CMD_TG_LISTEN_MD, NULL, NULL, 500,
+				digital_tg_recv_md_req, NULL);
+}
+
 int digital_target_found(struct nfc_digital_dev *ddev,
 			 struct nfc_target *target, u8 protocol)
 {
@@ -510,6 +521,9 @@ static int digital_start_poll(struct nfc_dev *nfc_dev, __u32 im_protocols,
 		if (ddev->ops->tg_listen_mdaa) {
 			digital_add_poll_tech(ddev, 0,
 					      digital_tg_listen_mdaa);
+		} else if (ddev->ops->tg_listen_md) {
+			digital_add_poll_tech(ddev, 0,
+					      digital_tg_listen_md);
 		} else {
 			digital_add_poll_tech(ddev, NFC_DIGITAL_RF_TECH_106A,
 					      digital_tg_listen_nfca);
@@ -737,7 +751,7 @@ struct nfc_digital_dev *nfc_digital_allocate_device(struct nfc_digital_ops *ops,
 
 	if (!ops->in_configure_hw || !ops->in_send_cmd || !ops->tg_listen ||
 	    !ops->tg_configure_hw || !ops->tg_send_cmd || !ops->abort_cmd ||
-	    !ops->switch_rf)
+	    !ops->switch_rf || (ops->tg_listen_md && !ops->tg_get_rf_tech))
 		return NULL;
 
 	ddev = kzalloc(sizeof(struct nfc_digital_dev), GFP_KERNEL);

net/nfc/digital_technology.c

@@ -1218,33 +1218,48 @@ exit:
 	dev_kfree_skb(resp);
 }
 
-int digital_tg_listen_nfca(struct nfc_digital_dev *ddev, u8 rf_tech)
+static int digital_tg_config_nfca(struct nfc_digital_dev *ddev)
 {
 	int rc;
 
-	rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH, rf_tech);
+	rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
+				     NFC_DIGITAL_RF_TECH_106A);
 	if (rc)
 		return rc;
 
-	rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
-				     NFC_DIGITAL_FRAMING_NFCA_NFC_DEP);
+	return digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
+				       NFC_DIGITAL_FRAMING_NFCA_NFC_DEP);
+}
+
+int digital_tg_listen_nfca(struct nfc_digital_dev *ddev, u8 rf_tech)
+{
+	int rc;
+
+	rc = digital_tg_config_nfca(ddev);
 	if (rc)
 		return rc;
 
 	return digital_tg_listen(ddev, 300, digital_tg_recv_sens_req, NULL);
 }
 
-int digital_tg_listen_nfcf(struct nfc_digital_dev *ddev, u8 rf_tech)
+static int digital_tg_config_nfcf(struct nfc_digital_dev *ddev, u8 rf_tech)
 {
 	int rc;
-	u8 *nfcid2;
 
 	rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH, rf_tech);
 	if (rc)
 		return rc;
 
-	rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
-				     NFC_DIGITAL_FRAMING_NFCF_NFC_DEP);
+	return digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
+				       NFC_DIGITAL_FRAMING_NFCF_NFC_DEP);
+}
+
+int digital_tg_listen_nfcf(struct nfc_digital_dev *ddev, u8 rf_tech)
+{
+	int rc;
+	u8 *nfcid2;
+
+	rc = digital_tg_config_nfcf(ddev, rf_tech);
 	if (rc)
 		return rc;
 
@@ -1258,3 +1273,43 @@ int digital_tg_listen_nfcf(struct nfc_digital_dev *ddev, u8 rf_tech)
 
 	return digital_tg_listen(ddev, 300, digital_tg_recv_sensf_req, nfcid2);
 }
+
+void digital_tg_recv_md_req(struct nfc_digital_dev *ddev, void *arg,
+			    struct sk_buff *resp)
+{
+	u8 rf_tech;
+	int rc;
+
+	if (IS_ERR(resp)) {
+		resp = NULL;
+		goto exit_free_skb;
+	}
+
+	rc = ddev->ops->tg_get_rf_tech(ddev, &rf_tech);
+	if (rc)
+		goto exit_free_skb;
+
+	switch (rf_tech) {
+	case NFC_DIGITAL_RF_TECH_106A:
+		rc = digital_tg_config_nfca(ddev);
+		if (rc)
+			goto exit_free_skb;
+		digital_tg_recv_sens_req(ddev, arg, resp);
+		break;
+	case NFC_DIGITAL_RF_TECH_212F:
+	case NFC_DIGITAL_RF_TECH_424F:
+		rc = digital_tg_config_nfcf(ddev, rf_tech);
+		if (rc)
+			goto exit_free_skb;
+		digital_tg_recv_sensf_req(ddev, arg, resp);
+		break;
+	default:
+		goto exit_free_skb;
+	}
+
+	return;
+
+exit_free_skb:
+	digital_poll_next_tech(ddev);
+	dev_kfree_skb(resp);
+}