1 files changed, 305 insertions, 0 deletions
diff --git a/drivers/input/serio/libps2.c b/drivers/input/serio/libps2.c
new file mode 100644
index 000000000000..c978657068c5
--- /dev/null
+++ b/drivers/input/serio/libps2.c
@@ -0,0 +1,305 @@
+/*
+ * 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/moduleparam.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");
+
+EXPORT_SYMBOL(ps2_init);
+EXPORT_SYMBOL(ps2_sendbyte);
+EXPORT_SYMBOL(ps2_command);
+EXPORT_SYMBOL(ps2_schedule_command);
+EXPORT_SYMBOL(ps2_handle_ack);
+EXPORT_SYMBOL(ps2_handle_response);
+EXPORT_SYMBOL(ps2_cmd_aborted);
+
+/* Work structure to schedule execution of a command */
+struct ps2work {
+	struct work_struct work;
+	struct ps2dev *ps2dev;
+	int command;
+	unsigned char param[0];
+};
+
+
+/*
+ * ps2_sendbyte() sends a byte to the mouse, and waits for acknowledge.
+ * It doesn't handle retransmission, though it could - because when there would
+ * be need for retransmissions, the mouse 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;
+}
+
+/*
+ * 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;
+
+	down(&ps2dev->cmd_sem);
+
+	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 (command & 0xff)
+		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) {
+
+		if (command == PS2_CMD_RESET_BAT && timeout > msecs_to_jiffies(100)) {
+			/*
+			 * Device has sent the first response byte
+			 * after a reset command, reset is thus done,
+			 * shorten the timeout. The next byte will come
+			 * soon (keyboard) or not at all (mouse).
+			 */
+			timeout = msecs_to_jiffies(100);
+		}
+
+		if (command == PS2_CMD_GETID &&
+		    ps2dev->cmdbuf[receive - 1] != 0xab && /* Regular keyboards */
+		    ps2dev->cmdbuf[receive - 1] != 0xac && /* NCD Sun keyboard */
+		    ps2dev->cmdbuf[receive - 1] != 0x2b && /* Trust keyboard, translated */
+		    ps2dev->cmdbuf[receive - 1] != 0x5d && /* Trust keyboard */
+		    ps2dev->cmdbuf[receive - 1] != 0x60 && /* NMB SGI keyboard, translated */
+		    ps2dev->cmdbuf[receive - 1] != 0x47) { /* NMB SGI keyboard */
+			/*
+			 * Device behind the port is not a keyboard
+			 * so we don't need to wait for the 2nd byte
+			 * of ID response.
+			 */
+			serio_pause_rx(ps2dev->serio);
+			ps2dev->flags = ps2dev->cmdcnt = 0;
+			serio_continue_rx(ps2dev->serio);
+		}
+
+		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);
+
+	up(&ps2dev->cmd_sem);
+	return rc;
+}
+
+/*
+ * ps2_execute_scheduled_command() sends a command, previously scheduled by
+ * ps2_schedule_command(), to a PS/2 device (keyboard, mouse, etc.)
+ */
+
+static void ps2_execute_scheduled_command(void *data)
+{
+	struct ps2work *ps2work = data;
+
+	ps2_command(ps2work->ps2dev, ps2work->param, ps2work->command);
+	kfree(ps2work);
+}
+
+/*
+ * ps2_schedule_command() allows to schedule delayed execution of a PS/2
+ * command and can be used to issue a command from an interrupt or softirq
+ * context.
+ */
+
+int ps2_schedule_command(struct ps2dev *ps2dev, unsigned char *param, int command)
+{
+	struct ps2work *ps2work;
+	int send = (command >> 12) & 0xf;
+	int receive = (command >> 8) & 0xf;
+
+	if (!(ps2work = kmalloc(sizeof(struct ps2work) + max(send, receive), GFP_ATOMIC)))
+		return -1;
+
+	memset(ps2work, 0, sizeof(struct ps2work));
+	ps2work->ps2dev = ps2dev;
+	ps2work->command = command;
+	memcpy(ps2work->param, param, send);
+	INIT_WORK(&ps2work->work, ps2_execute_scheduled_command, ps2work);
+
+	if (!schedule_work(&ps2work->work)) {
+		kfree(ps2work);
+		return -1;
+	}
+
+	return 0;
+}
+
+/*
+ * ps2_init() initializes ps2dev structure
+ */
+
+void ps2_init(struct ps2dev *ps2dev, struct serio *serio)
+{
+	init_MUTEX(&ps2dev->cmd_sem);
+	init_waitqueue_head(&ps2dev->wait);
+	ps2dev->serio = serio;
+}
+
+/*
+ * 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;
+}
+
+/*
+ * 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;
+}
+
+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;
+}
+