Input: ALPS - document the alps.h data structures

#define ALPS_PROTO_V3	2

#define ALPS_PROTO_V4	3

/**

 * struct alps_model_info - touchpad ID table

 * @signature: E7 response string to match.

 * @command_mode_resp: For V3/V4 touchpads, the final byte of the EC response

 *   (aka command mode response) identifies the firmware minor version.  This

 *   can be used to distinguish different hardware models which are not

 *   uniquely identifiable through their E7 responses.

 * @proto_version: Indicates V1/V2/V3/...

 * @byte0: Helps figure out whether a position report packet matches the

 *   known format for this model.  The first byte of the report, ANDed with

 *   mask0, should match byte0.

 * @mask0: The mask used to check the first byte of the report.

 * @flags: Additional device capabilities (passthrough port, trackstick, etc.).

 *

 * Many (but not all) ALPS touchpads can be identified by looking at the

 * values returned in the "E7 report" and/or the "EC report."  This table

 * lists a number of such touchpads.

 */

struct alps_model_info {

	unsigned char signature[3];

	unsigned char command_mode_resp; /* v3/v4 only */

	unsigned char command_mode_resp;

	unsigned char proto_version;

	unsigned char byte0, mask0;

	unsigned char flags;

};

/**

 * struct alps_nibble_commands - encodings for register accesses

 * @command: PS/2 command used for the nibble

 * @data: Data supplied as an argument to the PS/2 command, if applicable

 *

 * The ALPS protocol uses magic sequences to transmit binary data to the

 * touchpad, as it is generally not OK to send arbitrary bytes out the

 * PS/2 port.  Each of the sequences in this table sends one nibble of the

 * register address or (write) data.  Different versions of the ALPS protocol

 * use slightly different encodings.

 */

struct alps_nibble_commands {

	int command;

	unsigned char data;

};

/**

 * struct alps_data - private data structure for the ALPS driver

 * @dev2: "Relative" device used to report trackstick or mouse activity.

 * @phys: Physical path for the relative device.

 * @i: Information on the detected touchpad model.

 * @nibble_commands: Command mapping used for touchpad register accesses.

 * @addr_command: Command used to tell the touchpad that a register address

 *   follows.

 * @prev_fin: Finger bit from previous packet.

 * @multi_packet: Multi-packet data in progress.

 * @multi_data: Saved multi-packet data.

 * @x1: First X coordinate from last MT report.

 * @x2: Second X coordinate from last MT report.

 * @y1: First Y coordinate from last MT report.

 * @y2: Second Y coordinate from last MT report.

 * @fingers: Number of fingers from last MT report.

 * @quirks: Bitmap of ALPS_QUIRK_*.

 * @timer: Timer for flushing out the final report packet in the stream.

 */

struct alps_data {

	struct input_dev *dev2;		/* Relative device */

	char phys[32];			/* Phys */

	const struct alps_model_info *i;/* Info */

	struct input_dev *dev2;

	char phys[32];

	const struct alps_model_info *i;

	const struct alps_nibble_commands *nibble_commands;

	int addr_command;		/* Command to set register address */

	int prev_fin;			/* Finger bit from previous packet */

	int multi_packet;		/* Multi-packet data in progress */

	unsigned char multi_data[6];	/* Saved multi-packet data */

	int x1, x2, y1, y2;		/* Coordinates from last MT report */

	int fingers;			/* Number of fingers from MT report */

	int addr_command;

	int prev_fin;

	int multi_packet;

	unsigned char multi_data[6];

	int x1, x2, y1, y2;

	int fingers;

	u8 quirks;

	struct timer_list timer;

};