NFC: pn544: Add MEI physical layer

With the new mei_phy NFC driver API, the pn544 MEI physical layer is
minimal and similar to the microread one.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/nfc/pn544/Kconfig

@@ -21,3 +21,14 @@ config NFC_PN544_I2C
 
 	  If you choose to build a module, it'll be called pn544_i2c.
 	  Say N if unsure.
+
+config NFC_PN544_MEI
+	tristate "NFC PN544 MEI support"
+	depends on NFC_PN544 && NFC_MEI_PHY
+	---help---
+	  This module adds support for the mei interface of adapters using
+	  NXP pn544 chipsets.  Select this if your pn544 chipset
+	  is handled by Intel's Management Engine Interface on your platform.
+
+	  If you choose to build a module, it'll be called pn544_mei.
+	  Say N if unsure.

drivers/nfc/pn544/Makefile

@@ -3,6 +3,8 @@
 #
 
 pn544_i2c-objs  = i2c.o
+pn544_mei-objs  = mei.o
 
 obj-$(CONFIG_NFC_PN544)     += pn544.o
 obj-$(CONFIG_NFC_PN544_I2C) += pn544_i2c.o
+obj-$(CONFIG_NFC_PN544_MEI) += pn544_mei.o

drivers/nfc/pn544/mei.c

+/*
+ * HCI based Driver for NXP pn544 NFC Chip
+ *
+ * Copyright (C) 2013  Intel Corporation. All rights reserved.
+ *
+ * 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 that 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the
+ * Free Software Foundation, Inc.,
+ * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/nfc.h>
+#include <net/nfc/hci.h>
+#include <net/nfc/llc.h>
+
+#include "../mei_phy.h"
+#include "pn544.h"
+
+#define PN544_DRIVER_NAME "pn544"
+
+static int pn544_mei_probe(struct mei_cl_device *device,
+			       const struct mei_cl_device_id *id)
+{
+	struct nfc_mei_phy *phy;
+	int r;
+
+	pr_info("Probing NFC pn544\n");
+
+	phy = nfc_mei_phy_alloc(device);
+	if (!phy) {
+		pr_err("Cannot allocate memory for pn544 mei phy.\n");
+		return -ENOMEM;
+	}
+
+	r = mei_cl_register_event_cb(device, nfc_mei_event_cb, phy);
+	if (r) {
+		pr_err(PN544_DRIVER_NAME ": event cb registration failed\n");
+		goto err_out;
+	}
+
+	r = pn544_hci_probe(phy, &mei_phy_ops, LLC_NOP_NAME,
+			    MEI_NFC_HEADER_SIZE, 0, MEI_NFC_MAX_HCI_PAYLOAD,
+			    &phy->hdev);
+	if (r < 0)
+		goto err_out;
+
+	return 0;
+
+err_out:
+	nfc_mei_phy_free(phy);
+
+	return r;
+}
+
+static int pn544_mei_remove(struct mei_cl_device *device)
+{
+	struct nfc_mei_phy *phy = mei_cl_get_drvdata(device);
+
+	pr_info("Removing pn544\n");
+
+	pn544_hci_remove(phy->hdev);
+
+	nfc_mei_phy_disable(phy);
+
+	nfc_mei_phy_free(phy);
+
+	return 0;
+}
+
+static struct mei_cl_device_id pn544_mei_tbl[] = {
+	{ PN544_DRIVER_NAME },
+
+	/* required last entry */
+	{ }
+};
+MODULE_DEVICE_TABLE(mei, pn544_mei_tbl);
+
+static struct mei_cl_driver pn544_driver = {
+	.id_table = pn544_mei_tbl,
+	.name = PN544_DRIVER_NAME,
+
+	.probe = pn544_mei_probe,
+	.remove = pn544_mei_remove,
+};
+
+static int pn544_mei_init(void)
+{
+	int r;
+
+	pr_debug(DRIVER_DESC ": %s\n", __func__);
+
+	r = mei_cl_driver_register(&pn544_driver);
+	if (r) {
+		pr_err(PN544_DRIVER_NAME ": driver registration failed\n");
+		return r;
+	}
+
+	return 0;
+}
+
+static void pn544_mei_exit(void)
+{
+	mei_cl_driver_unregister(&pn544_driver);
+}
+
+module_init(pn544_mei_init);
+module_exit(pn544_mei_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION(DRIVER_DESC);