Fixed MTP to work with TWRP

drivers/misc/samsung/scsc/cpacket_buffer.h

@@ -0,0 +1,140 @@
+/****************************************************************************
+ *
+ * Copyright (c) 2014 - 2016 Samsung Electronics Co., Ltd. All rights reserved
+ *
+ ****************************************************************************/
+
+/**
+ * Circular buffer backed packet stream (Interface)
+ */
+
+#ifndef CPACKET_BUFFER_H__
+#define CPACKET_BUFFER_H__
+
+/* Uses */
+#include <linux/types.h>
+#include "scsc_mx_impl.h"
+#include "mxconf.h"
+
+struct cpacketbuffer;
+
+/**
+ * Initialises the circular buffer.
+ * The memory buffer length must be a multiple of the packet size.
+ */
+int cpacketbuffer_init(struct cpacketbuffer *buffer, uint32_t num_packets, uint32_t packet_size, struct scsc_mx *mx);
+void cpacketbuffer_release(struct cpacketbuffer *buffer);
+
+/**
+ * Reads the gven amount of data from the buffer, copying it to the provided address.
+ * This automatically removes the read data from the buffer.
+ *
+ * If the amount of data requested is not a multiple of the packet size
+ * only the requested number of bytes will be read, but the partially read packet
+ * will still be removed from the buffer.
+ *
+ * Returns true if the packet was read.
+ */
+uint32_t cpacketbuffer_read(struct cpacketbuffer *buffer, void *buf, uint32_t num_bytes);
+
+/**
+ * Returns a pointer to the next packet of data within the buffer, without
+ * removing it. This can be used to processss data in place without needing to
+ * copy it first.
+ *
+ * If multiple packets are present these can be read in turn by setting the value
+ * of current_packet to the returned value from the previous call to cpacketbuffer_peek.
+ *
+ * cpacketbuffer_peek_complete must be called to remove the packet(s) from the buffer.
+ *
+ * Returns a pointer to the beginning of the packet to read, or NULL if there is no
+ * packet to process.
+ *
+ * Example use:
+ *   // Get the first data packet
+ *   void *current_packet = cpacketbuffer_peek( buffer, NULL );
+ *   void *last_packet = NULL;
+ *   while( current_packet != NULL )
+ *   {
+ *      // Process data packet
+ *      ...
+ *
+ *      // Get the next data packet
+ *      last_packet = current_packet;
+ *      current_packet = cpacketbuffer_peek( buffer, current_packet );
+ *   }
+ *
+ *   // Remove all processed packets from the buffer
+ *   if( last_packet != NULL )
+ *   {
+ *      cpacketbuffer_peek_complete( buffer, last_packet );
+ *   }
+ */
+const void *cpacketbuffer_peek(struct cpacketbuffer *buffer, const void *current_packet);
+
+/**
+ * Removes all packets from the buffer up to and including the given
+ * packet.
+ *
+ * This must be called after using cpacketbuffer_peek to indicate that packet(s)
+ * can be removed from the buffer.
+ */
+void cpacketbuffer_peek_complete(struct cpacketbuffer *buffer, const void *packet);
+
+/**
+ * Writes a number of bytes to the buffer. This will always use up whole packets in the buffer
+ * even if the amount of data written is not an exact multiple of the packet size.
+ *
+ * Returns true if the data was written, false if there is not enough free space in the buffer.
+ */
+bool cpacketbuffer_write(struct cpacketbuffer *buffer, const void *buf, uint32_t num_bytes);
+
+/**
+ * Writes a set of non-contiguous data blocks to the buffer as a contiguous set.
+ * This will always use up whole packets even if the
+ * amount of data written is not an exact multiple of the packet size.
+ *
+ * Returns true if the blocks were written, false if there is not enough
+ * free space in the buffer for all the blocks.
+ */
+bool cpacketbuffer_write_gather(struct cpacketbuffer *buffer, const void **bufs, uint32_t *num_bytes, uint32_t num_bufs);
+
+/**
+ * Returns the number of free packets in the buffer.
+ */
+uint32_t cpacketbuffer_free_space(const struct cpacketbuffer *buffer);
+
+/**
+ * Returns true if the buffer is empty.
+ */
+bool cpacketbuffer_is_empty(const struct cpacketbuffer *buffer);
+
+/**
+ * Returns true if the buffer is full.
+ */
+bool cpacketbuffer_is_full(const struct cpacketbuffer *buffer);
+
+/**
+ * Returns the packet size the buffer was initialised with. This is the same value
+ * as the packet_size argument passed to cpacketbuffer_init().
+ */
+uint32_t cpacketbuffer_packet_size(const struct cpacketbuffer *buffer);
+
+void cpacketbuffer_config_serialise(const struct cpacketbuffer *buffer, struct mxcbufconf *buf_conf);
+/**
+ * Buffer context object.
+ */
+struct cpacketbuffer {
+	struct scsc_mx *mx;
+	void           *buffer;     /* Buffer location */
+	uint32_t       num_packets; /* Total number of packets that can be stored in the buffer */
+	uint32_t       packet_size; /* Size of each individual packet within the buffer */
+
+	/** Pointers to 32bit R/W indexes - these should point to uint32_ts */
+	uint32_t       *read_index;  /* Pointer to the location of the read index, which
+					*     contains the index of the next packet to read. */
+	uint32_t       *write_index; /* Pointer to the location of the write index, which
+					*     contains the index after the last packet written. */
+};
+
+#endif /* CPACKET_BUFFER_H__ */