--- /dev/null
+/*
+ * 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/sched.h>
+#include <linux/interrupt.h>
+#include <linux/input.h>
+#include <linux/serio.h>
+#include <linux/i8042.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);
+
+void ps2_begin_command(struct ps2dev *ps2dev)
+{
+ mutex_lock(&ps2dev->cmd_mutex);
+
+ if (i8042_check_port_owner(ps2dev->serio))
+ i8042_lock_chip();
+}
+EXPORT_SYMBOL(ps2_begin_command);
+
+void ps2_end_command(struct ps2dev *ps2dev)
+{
+ if (i8042_check_port_owner(ps2dev->serio))
+ i8042_unlock_chip();
+
+ mutex_unlock(&ps2dev->cmd_mutex);
+}
+EXPORT_SYMBOL(ps2_end_command);
+
+/*
+ * 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);
+ }
+
+ ps2_begin_command(ps2dev);
+
+ 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));
+
+ ps2_end_command(ps2dev);
+}
+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;
+ }
+
+ 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 arrives.
+ */
+ 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 && !(ps2dev->flags & PS2_FLAG_CMD1)) {
+
+ 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);
+
+ return rc;
+}
+EXPORT_SYMBOL(__ps2_command);
+
+int ps2_command(struct ps2dev *ps2dev, unsigned char *param, int command)
+{
+ int rc;
+
+ ps2_begin_command(ps2dev);
+ rc = __ps2_command(ps2dev, param, command);
+ ps2_end_command(ps2dev);
+
+ 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->flags |= PS2_FLAG_NAK;
+ ps2dev->nak = PS2_RET_NAK;
+ break;
+
+ case PS2_RET_ERR:
+ if (ps2dev->flags & PS2_FLAG_NAK) {
+ ps2dev->flags &= ~PS2_FLAG_NAK;
+ ps2dev->nak = PS2_RET_ERR;
+ 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->flags &= ~PS2_FLAG_NAK;
+ if (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);
+
+ /* reset all flags except last nack */
+ ps2dev->flags &= PS2_FLAG_NAK;
+}
+EXPORT_SYMBOL(ps2_cmd_aborted);
Code Review / kvmfornfv.git / blobdiff