Fixed MTP to work with TWRP

drivers/nfc/mei_phy.c

@@ -0,0 +1,173 @@
+/*
+ * MEI Library for mei bus nfc device access
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/nfc.h>
+
+#include "mei_phy.h"
+
+struct mei_nfc_hdr {
+	u8 cmd;
+	u8 status;
+	u16 req_id;
+	u32 reserved;
+	u16 data_size;
+} __packed;
+
+#define MEI_NFC_MAX_READ (MEI_NFC_HEADER_SIZE + MEI_NFC_MAX_HCI_PAYLOAD)
+
+#define MEI_DUMP_SKB_IN(info, skb)				\
+do {								\
+	pr_debug("%s:\n", info);				\
+	print_hex_dump_debug("mei in : ", DUMP_PREFIX_OFFSET,	\
+			16, 1, (skb)->data, (skb)->len, false);	\
+} while (0)
+
+#define MEI_DUMP_SKB_OUT(info, skb)				\
+do {								\
+	pr_debug("%s:\n", info);				\
+	print_hex_dump_debug("mei out: ", DUMP_PREFIX_OFFSET,	\
+		       16, 1, (skb)->data, (skb)->len, false);	\
+} while (0)
+
+int nfc_mei_phy_enable(void *phy_id)
+{
+	int r;
+	struct nfc_mei_phy *phy = phy_id;
+
+	pr_info("%s\n", __func__);
+
+	if (phy->powered == 1)
+		return 0;
+
+	r = mei_cl_enable_device(phy->device);
+	if (r < 0) {
+		pr_err("Could not enable device\n");
+		return r;
+	}
+
+	r = mei_cl_register_event_cb(phy->device, nfc_mei_event_cb, phy);
+	if (r) {
+		pr_err("Event cb registration failed\n");
+		mei_cl_disable_device(phy->device);
+		phy->powered = 0;
+
+		return r;
+	}
+
+	phy->powered = 1;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nfc_mei_phy_enable);
+
+void nfc_mei_phy_disable(void *phy_id)
+{
+	struct nfc_mei_phy *phy = phy_id;
+
+	pr_info("%s\n", __func__);
+
+	mei_cl_disable_device(phy->device);
+
+	phy->powered = 0;
+}
+EXPORT_SYMBOL_GPL(nfc_mei_phy_disable);
+
+/*
+ * Writing a frame must not return the number of written bytes.
+ * It must return either zero for success, or <0 for error.
+ * In addition, it must not alter the skb
+ */
+static int nfc_mei_phy_write(void *phy_id, struct sk_buff *skb)
+{
+	struct nfc_mei_phy *phy = phy_id;
+	int r;
+
+	MEI_DUMP_SKB_OUT("mei frame sent", skb);
+
+	r = mei_cl_send(phy->device, skb->data, skb->len);
+	if (r > 0)
+		r = 0;
+
+	return r;
+}
+
+void nfc_mei_event_cb(struct mei_cl_device *device, u32 events, void *context)
+{
+	struct nfc_mei_phy *phy = context;
+
+	if (phy->hard_fault != 0)
+		return;
+
+	if (events & BIT(MEI_CL_EVENT_RX)) {
+		struct sk_buff *skb;
+		int reply_size;
+
+		skb = alloc_skb(MEI_NFC_MAX_READ, GFP_KERNEL);
+		if (!skb)
+			return;
+
+		reply_size = mei_cl_recv(device, skb->data, MEI_NFC_MAX_READ);
+		if (reply_size < MEI_NFC_HEADER_SIZE) {
+			kfree_skb(skb);
+			return;
+		}
+
+		skb_put(skb, reply_size);
+		skb_pull(skb, MEI_NFC_HEADER_SIZE);
+
+		MEI_DUMP_SKB_IN("mei frame read", skb);
+
+		nfc_hci_recv_frame(phy->hdev, skb);
+	}
+}
+EXPORT_SYMBOL_GPL(nfc_mei_event_cb);
+
+struct nfc_phy_ops mei_phy_ops = {
+	.write = nfc_mei_phy_write,
+	.enable = nfc_mei_phy_enable,
+	.disable = nfc_mei_phy_disable,
+};
+EXPORT_SYMBOL_GPL(mei_phy_ops);
+
+struct nfc_mei_phy *nfc_mei_phy_alloc(struct mei_cl_device *device)
+{
+	struct nfc_mei_phy *phy;
+
+	phy = kzalloc(sizeof(struct nfc_mei_phy), GFP_KERNEL);
+	if (!phy)
+		return NULL;
+
+	phy->device = device;
+	mei_cl_set_drvdata(device, phy);
+
+	return phy;
+}
+EXPORT_SYMBOL_GPL(nfc_mei_phy_alloc);
+
+void nfc_mei_phy_free(struct nfc_mei_phy *phy)
+{
+	kfree(phy);
+}
+EXPORT_SYMBOL_GPL(nfc_mei_phy_free);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("mei bus NFC device interface");