1 files changed, 334 insertions, 0 deletions
diff --git a/drivers/input/serio/libps2.c b/drivers/input/serio/libps2.c
new file mode 100644
index 0000000..2b304c2
--- /dev/null
+++ b/drivers/input/serio/libps2.c
@@ -0,0 +1,334 @@
+/*
+ * PS/2 driver library
+ *
+ * Copyright (c) 1999-2002 Vojtech Pavlik
+ * Copyright (c) 2004 Dmitry Torokhov
+ */
+
+/*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/input.h>
+#include <linux/serio.h>
+#include <linux/init.h>
+#include <linux/libps2.h>
+
+#define DRIVER_DESC	"PS/2 driver library"
+
+MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
+MODULE_DESCRIPTION("PS/2 driver library");
+MODULE_LICENSE("GPL");
+
+/*
+ * ps2_sendbyte() sends a byte to the device and waits for acknowledge.
+ * It doesn't handle retransmission, though it could - because if there
+ * is a need for retransmissions device has to be replaced anyway.
+ *
+ * ps2_sendbyte() can only be called from a process context.
+ */
+
+int ps2_sendbyte(struct ps2dev *ps2dev, unsigned char byte, int timeout)
+{
+	serio_pause_rx(ps2dev->serio);
+	ps2dev->nak = 1;
+	ps2dev->flags |= PS2_FLAG_ACK;
+	serio_continue_rx(ps2dev->serio);
+
+	if (serio_write(ps2dev->serio, byte) == 0)
+		wait_event_timeout(ps2dev->wait,
+				   !(ps2dev->flags & PS2_FLAG_ACK),
+				   msecs_to_jiffies(timeout));
+
+	serio_pause_rx(ps2dev->serio);
+	ps2dev->flags &= ~PS2_FLAG_ACK;
+	serio_continue_rx(ps2dev->serio);
+
+	return -ps2dev->nak;
+}
+EXPORT_SYMBOL(ps2_sendbyte);
+
+/*
+ * ps2_drain() waits for device to transmit requested number of bytes
+ * and discards them.
+ */
+
+void ps2_drain(struct ps2dev *ps2dev, int maxbytes, int timeout)
+{
+	if (maxbytes > sizeof(ps2dev->cmdbuf)) {
+		WARN_ON(1);
+		maxbytes = sizeof(ps2dev->cmdbuf);
+	}
+
+	mutex_lock(&ps2dev->cmd_mutex);
+
+	serio_pause_rx(ps2dev->serio);
+	ps2dev->flags = PS2_FLAG_CMD;
+	ps2dev->cmdcnt = maxbytes;
+	serio_continue_rx(ps2dev->serio);
+
+	wait_event_timeout(ps2dev->wait,
+			   !(ps2dev->flags & PS2_FLAG_CMD),
+			   msecs_to_jiffies(timeout));
+	mutex_unlock(&ps2dev->cmd_mutex);
+}
+EXPORT_SYMBOL(ps2_drain);
+
+/*
+ * ps2_is_keyboard_id() checks received ID byte against the list of
+ * known keyboard IDs.
+ */
+
+int ps2_is_keyboard_id(char id_byte)
+{
+	static const char keyboard_ids[] = {
+		0xab,	/* Regular keyboards		*/
+		0xac,	/* NCD Sun keyboard		*/
+		0x2b,	/* Trust keyboard, translated	*/
+		0x5d,	/* Trust keyboard		*/
+		0x60,	/* NMB SGI keyboard, translated */
+		0x47,	/* NMB SGI keyboard		*/
+	};
+
+	return memchr(keyboard_ids, id_byte, sizeof(keyboard_ids)) != NULL;
+}
+EXPORT_SYMBOL(ps2_is_keyboard_id);
+
+/*
+ * ps2_adjust_timeout() is called after receiving 1st byte of command
+ * response and tries to reduce remaining timeout to speed up command
+ * completion.
+ */
+
+static int ps2_adjust_timeout(struct ps2dev *ps2dev, int command, int timeout)
+{
+	switch (command) {
+		case PS2_CMD_RESET_BAT:
+			/*
+			 * Device has sent the first response byte after
+			 * reset command, reset is thus done, so we can
+			 * shorten the timeout.
+			 * The next byte will come soon (keyboard) or not
+			 * at all (mouse).
+			 */
+			if (timeout > msecs_to_jiffies(100))
+				timeout = msecs_to_jiffies(100);
+			break;
+
+		case PS2_CMD_GETID:
+			/*
+			 * Microsoft Natural Elite keyboard responds to
+			 * the GET ID command as it were a mouse, with
+			 * a single byte. Fail the command so atkbd will
+			 * use alternative probe to detect it.
+			 */
+			if (ps2dev->cmdbuf[1] == 0xaa) {
+				serio_pause_rx(ps2dev->serio);
+				ps2dev->flags = 0;
+				serio_continue_rx(ps2dev->serio);
+				timeout = 0;
+			}
+
+			/*
+			 * If device behind the port is not a keyboard there
+			 * won't be 2nd byte of ID response.
+			 */
+			if (!ps2_is_keyboard_id(ps2dev->cmdbuf[1])) {
+				serio_pause_rx(ps2dev->serio);
+				ps2dev->flags = ps2dev->cmdcnt = 0;
+				serio_continue_rx(ps2dev->serio);
+				timeout = 0;
+			}
+			break;
+
+		default:
+			break;
+	}
+
+	return timeout;
+}
+
+/*
+ * ps2_command() sends a command and its parameters to the mouse,
+ * then waits for the response and puts it in the param array.
+ *
+ * ps2_command() can only be called from a process context
+ */
+
+int ps2_command(struct ps2dev *ps2dev, unsigned char *param, int command)
+{
+	int timeout;
+	int send = (command >> 12) & 0xf;
+	int receive = (command >> 8) & 0xf;
+	int rc = -1;
+	int i;
+
+	if (receive > sizeof(ps2dev->cmdbuf)) {
+		WARN_ON(1);
+		return -1;
+	}
+
+	if (send && !param) {
+		WARN_ON(1);
+		return -1;
+	}
+
+	mutex_lock(&ps2dev->cmd_mutex);
+
+	serio_pause_rx(ps2dev->serio);
+	ps2dev->flags = command == PS2_CMD_GETID ? PS2_FLAG_WAITID : 0;
+	ps2dev->cmdcnt = receive;
+	if (receive && param)
+		for (i = 0; i < receive; i++)
+			ps2dev->cmdbuf[(receive - 1) - i] = param[i];
+	serio_continue_rx(ps2dev->serio);
+
+	/*
+	 * Some devices (Synaptics) peform the reset before
+	 * ACKing the reset command, and so it can take a long
+	 * time before the ACK arrrives.
+	 */
+	if (ps2_sendbyte(ps2dev, command & 0xff,
+			 command == PS2_CMD_RESET_BAT ? 1000 : 200))
+		goto out;
+
+	for (i = 0; i < send; i++)
+		if (ps2_sendbyte(ps2dev, param[i], 200))
+			goto out;
+
+	/*
+	 * The reset command takes a long time to execute.
+	 */
+	timeout = msecs_to_jiffies(command == PS2_CMD_RESET_BAT ? 4000 : 500);
+
+	timeout = wait_event_timeout(ps2dev->wait,
+				     !(ps2dev->flags & PS2_FLAG_CMD1), timeout);
+
+	if (ps2dev->cmdcnt && timeout > 0) {
+
+		timeout = ps2_adjust_timeout(ps2dev, command, timeout);
+		wait_event_timeout(ps2dev->wait,
+				   !(ps2dev->flags & PS2_FLAG_CMD), timeout);
+	}
+
+	if (param)
+		for (i = 0; i < receive; i++)
+			param[i] = ps2dev->cmdbuf[(receive - 1) - i];
+
+	if (ps2dev->cmdcnt && (command != PS2_CMD_RESET_BAT || ps2dev->cmdcnt != 1))
+		goto out;
+
+	rc = 0;
+
+ out:
+	serio_pause_rx(ps2dev->serio);
+	ps2dev->flags = 0;
+	serio_continue_rx(ps2dev->serio);
+
+	mutex_unlock(&ps2dev->cmd_mutex);
+	return rc;
+}
+EXPORT_SYMBOL(ps2_command);
+
+/*
+ * ps2_init() initializes ps2dev structure
+ */
+
+void ps2_init(struct ps2dev *ps2dev, struct serio *serio)
+{
+	mutex_init(&ps2dev->cmd_mutex);
+	lockdep_set_subclass(&ps2dev->cmd_mutex, serio->depth);
+	init_waitqueue_head(&ps2dev->wait);
+	ps2dev->serio = serio;
+}
+EXPORT_SYMBOL(ps2_init);
+
+/*
+ * ps2_handle_ack() is supposed to be used in interrupt handler
+ * to properly process ACK/NAK of a command from a PS/2 device.
+ */
+
+int ps2_handle_ack(struct ps2dev *ps2dev, unsigned char data)
+{
+	switch (data) {
+		case PS2_RET_ACK:
+			ps2dev->nak = 0;
+			break;
+
+		case PS2_RET_NAK:
+			ps2dev->nak = 1;
+			break;
+
+		/*
+		 * Workaround for mice which don't ACK the Get ID command.
+		 * These are valid mouse IDs that we recognize.
+		 */
+		case 0x00:
+		case 0x03:
+		case 0x04:
+			if (ps2dev->flags & PS2_FLAG_WAITID) {
+				ps2dev->nak = 0;
+				break;
+			}
+			/* Fall through */
+		default:
+			return 0;
+	}
+
+
+	if (!ps2dev->nak && ps2dev->cmdcnt)
+		ps2dev->flags |= PS2_FLAG_CMD | PS2_FLAG_CMD1;
+
+	ps2dev->flags &= ~PS2_FLAG_ACK;
+	wake_up(&ps2dev->wait);
+
+	if (data != PS2_RET_ACK)
+		ps2_handle_response(ps2dev, data);
+
+	return 1;
+}
+EXPORT_SYMBOL(ps2_handle_ack);
+
+/*
+ * ps2_handle_response() is supposed to be used in interrupt handler
+ * to properly store device's response to a command and notify process
+ * waiting for completion of the command.
+ */
+
+int ps2_handle_response(struct ps2dev *ps2dev, unsigned char data)
+{
+	if (ps2dev->cmdcnt)
+		ps2dev->cmdbuf[--ps2dev->cmdcnt] = data;
+
+	if (ps2dev->flags & PS2_FLAG_CMD1) {
+		ps2dev->flags &= ~PS2_FLAG_CMD1;
+		if (ps2dev->cmdcnt)
+			wake_up(&ps2dev->wait);
+	}
+
+	if (!ps2dev->cmdcnt) {
+		ps2dev->flags &= ~PS2_FLAG_CMD;
+		wake_up(&ps2dev->wait);
+	}
+
+	return 1;
+}
+EXPORT_SYMBOL(ps2_handle_response);
+
+void ps2_cmd_aborted(struct ps2dev *ps2dev)
+{
+	if (ps2dev->flags & PS2_FLAG_ACK)
+		ps2dev->nak = 1;
+
+	if (ps2dev->flags & (PS2_FLAG_ACK | PS2_FLAG_CMD))
+		wake_up(&ps2dev->wait);
+
+	ps2dev->flags = 0;
+}
+EXPORT_SYMBOL(ps2_cmd_aborted);