Fixed MTP to work with TWRP

drivers/usb/class/Kconfig

@@ -0,0 +1,48 @@
+#
+# USB Class driver configuration
+#
+comment "USB Device Class drivers"
+
+config USB_ACM
+	tristate "USB Modem (CDC ACM) support"
+	depends on TTY
+	---help---
+	  This driver supports USB modems and ISDN adapters which support the
+	  Communication Device Class Abstract Control Model interface.
+	  Please read <file:Documentation/usb/acm.txt> for details.
+
+	  If your modem only reports "Cls=ff(vend.)" in the descriptors in
+	  /proc/bus/usb/devices, then your modem will not work with this
+	  driver.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called cdc-acm.
+
+config USB_PRINTER
+	tristate "USB Printer support"
+	help
+	  Say Y here if you want to connect a USB printer to your computer's
+	  USB port.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called usblp.
+
+config USB_WDM
+	tristate "USB Wireless Device Management support"
+	---help---
+	  This driver supports the WMC Device Management functionality
+	  of cell phones compliant to the CDC WMC specification. You can use
+	  AT commands over this device.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called cdc-wdm.
+
+config USB_TMC
+	tristate "USB Test and Measurement Class support"
+	help
+	  Say Y here if you want to connect a USB device that follows
+	  the USB.org specification for USB Test and Measurement devices
+	  to your computer's USB port.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called usbtmc.

drivers/usb/class/Makefile

@@ -0,0 +1,9 @@
+#
+# Makefile for USB Class drivers
+# (one step up from the misc category)
+#
+
+obj-$(CONFIG_USB_ACM)		+= cdc-acm.o
+obj-$(CONFIG_USB_PRINTER)	+= usblp.o
+obj-$(CONFIG_USB_WDM)		+= cdc-wdm.o
+obj-$(CONFIG_USB_TMC)		+= usbtmc.o

drivers/usb/class/cdc-acm.h

@@ -0,0 +1,136 @@
+/*
+ *
+ * Includes for cdc-acm.c
+ *
+ * Mainly take from usbnet's cdc-ether part
+ *
+ */
+
+/*
+ * CMSPAR, some architectures can't have space and mark parity.
+ */
+
+#ifndef CMSPAR
+#define CMSPAR			0
+#endif
+
+/*
+ * Major and minor numbers.
+ */
+
+#define ACM_TTY_MAJOR		166
+#define ACM_TTY_MINORS		32
+
+/*
+ * Requests.
+ */
+
+#define USB_RT_ACM		(USB_TYPE_CLASS | USB_RECIP_INTERFACE)
+
+/*
+ * Output control lines.
+ */
+
+#define ACM_CTRL_DTR		0x01
+#define ACM_CTRL_RTS		0x02
+
+/*
+ * Input control lines and line errors.
+ */
+
+#define ACM_CTRL_DCD		0x01
+#define ACM_CTRL_DSR		0x02
+#define ACM_CTRL_BRK		0x04
+#define ACM_CTRL_RI		0x08
+
+#define ACM_CTRL_FRAMING	0x10
+#define ACM_CTRL_PARITY		0x20
+#define ACM_CTRL_OVERRUN	0x40
+
+/*
+ * Internal driver structures.
+ */
+
+/*
+ * The only reason to have several buffers is to accommodate assumptions
+ * in line disciplines. They ask for empty space amount, receive our URB size,
+ * and proceed to issue several 1-character writes, assuming they will fit.
+ * The very first write takes a complete URB. Fortunately, this only happens
+ * when processing onlcr, so we only need 2 buffers. These values must be
+ * powers of 2.
+ */
+#define ACM_NW  16
+#define ACM_NR  16
+
+struct acm_wb {
+	unsigned char *buf;
+	dma_addr_t dmah;
+	int len;
+	int use;
+	struct urb		*urb;
+	struct acm		*instance;
+};
+
+struct acm_rb {
+	int			size;
+	unsigned char		*base;
+	dma_addr_t		dma;
+	int			index;
+	struct acm		*instance;
+};
+
+struct acm {
+	struct usb_device *dev;				/* the corresponding usb device */
+	struct usb_interface *control;			/* control interface */
+	struct usb_interface *data;			/* data interface */
+	struct tty_port port;			 	/* our tty port data */
+	struct urb *ctrlurb;				/* urbs */
+	u8 *ctrl_buffer;				/* buffers of urbs */
+	dma_addr_t ctrl_dma;				/* dma handles of buffers */
+	u8 *country_codes;				/* country codes from device */
+	unsigned int country_code_size;			/* size of this buffer */
+	unsigned int country_rel_date;			/* release date of version */
+	struct acm_wb wb[ACM_NW];
+	unsigned long read_urbs_free;
+	struct urb *read_urbs[ACM_NR];
+	struct acm_rb read_buffers[ACM_NR];
+	int rx_buflimit;
+	int rx_endpoint;
+	spinlock_t read_lock;
+	int write_used;					/* number of non-empty write buffers */
+	int transmitting;
+	spinlock_t write_lock;
+	struct mutex mutex;
+	bool disconnected;
+	struct usb_cdc_line_coding line;		/* bits, stop, parity */
+	struct work_struct work;			/* work queue entry for line discipline waking up */
+	unsigned int ctrlin;				/* input control lines (DCD, DSR, RI, break, overruns) */
+	unsigned int ctrlout;				/* output control lines (DTR, RTS) */
+	struct async_icount iocount;			/* counters for control line changes */
+	struct async_icount oldcount;			/* for comparison of counter */
+	wait_queue_head_t wioctl;			/* for ioctl */
+	unsigned int writesize;				/* max packet size for the output bulk endpoint */
+	unsigned int readsize,ctrlsize;			/* buffer sizes for freeing */
+	unsigned int minor;				/* acm minor number */
+	unsigned char clocal;				/* termios CLOCAL */
+	unsigned int ctrl_caps;				/* control capabilities from the class specific header */
+	unsigned int susp_count;			/* number of suspended interfaces */
+	unsigned int combined_interfaces:1;		/* control and data collapsed */
+	unsigned int is_int_ep:1;			/* interrupt endpoints contrary to spec used */
+	unsigned int throttled:1;			/* actually throttled */
+	unsigned int throttle_req:1;			/* throttle requested */
+	u8 bInterval;
+	struct usb_anchor delayed;			/* writes queued for a device about to be woken */
+	unsigned long quirks;
+};
+
+#define CDC_DATA_INTERFACE_TYPE	0x0a
+
+/* constants describing various quirks and errors */
+#define NO_UNION_NORMAL			BIT(0)
+#define SINGLE_RX_URB			BIT(1)
+#define NO_CAP_LINE			BIT(2)
+#define NOT_A_MODEM			BIT(3)
+#define NO_DATA_INTERFACE		BIT(4)
+#define IGNORE_DEVICE			BIT(5)
+#define QUIRK_CONTROL_LINE_STATE	BIT(6)