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Release 4.11 drivers/input/serio/libps2.c

/*
 * 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; }

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PersonTokensPropCommitsCommitProp
Dmitry Torokhov10096.15%266.67%
Vojtech Pavlik43.85%133.33%
Total104100.00%3100.00%

EXPORT_SYMBOL(ps2_sendbyte);
void ps2_begin_command(struct ps2dev *ps2dev) { struct mutex *m = ps2dev->serio->ps2_cmd_mutex ?: &ps2dev->cmd_mutex; mutex_lock(m); }

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PersonTokensPropCommitsCommitProp
Dmitry Torokhov32100.00%2100.00%
Total32100.00%2100.00%

EXPORT_SYMBOL(ps2_begin_command);
void ps2_end_command(struct ps2dev *ps2dev) { struct mutex *m = ps2dev->serio->ps2_cmd_mutex ?: &ps2dev->cmd_mutex; mutex_unlock(m); }

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PersonTokensPropCommitsCommitProp
Dmitry Torokhov32100.00%2100.00%
Total32100.00%2100.00%

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); }

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PersonTokensPropCommitsCommitProp
Dmitry Torokhov100100.00%2100.00%
Total100100.00%2100.00%

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; }

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PersonTokensPropCommitsCommitProp
Dmitry Torokhov4998.00%150.00%
Tobias Klauser12.00%150.00%
Total50100.00%2100.00%

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; }

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PersonTokensPropCommitsCommitProp
Dmitry Torokhov135100.00%2100.00%
Total135100.00%2100.00%

/* * 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)) { serio_pause_rx(ps2dev->serio); goto out_reset_flags; } for (i = 0; i < send; i++) { if (ps2_sendbyte(ps2dev, param[i], 200)) { serio_pause_rx(ps2dev->serio); goto out_reset_flags; } } /* * 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); } serio_pause_rx(ps2dev->serio); 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_reset_flags; rc = 0; out_reset_flags: ps2dev->flags = 0; serio_continue_rx(ps2dev->serio); return rc; }

Contributors

PersonTokensPropCommitsCommitProp
Dmitry Torokhov33984.96%660.00%
Dmitriy Vyukov317.77%110.00%
Vojtech Pavlik235.76%110.00%
Tai-hwa Liang51.25%110.00%
Justin P. Mattock10.25%110.00%
Total399100.00%10100.00%

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; }

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PersonTokensPropCommitsCommitProp
Tai-hwa Liang3577.78%133.33%
Dmitry Torokhov1022.22%266.67%
Total45100.00%3100.00%

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; }

Contributors

PersonTokensPropCommitsCommitProp
Dmitry Torokhov3571.43%133.33%
Jiri Kosina1224.49%133.33%
Arjan van de Ven24.08%133.33%
Total49100.00%3100.00%

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; }

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PersonTokensPropCommitsCommitProp
Dmitry Torokhov166100.00%4100.00%
Total166100.00%4100.00%

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; }

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PersonTokensPropCommitsCommitProp
Dmitry Torokhov90100.00%2100.00%
Total90100.00%2100.00%

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; }

Contributors

PersonTokensPropCommitsCommitProp
Dmitry Torokhov51100.00%3100.00%
Total51100.00%3100.00%

EXPORT_SYMBOL(ps2_cmd_aborted);

Overall Contributors

PersonTokensPropCommitsCommitProp
Dmitry Torokhov123991.04%1260.00%
Tai-hwa Liang453.31%15.00%
Dmitriy Vyukov312.28%15.00%
Vojtech Pavlik271.98%15.00%
Jiri Kosina120.88%15.00%
Alexey Dobriyan30.22%15.00%
Arjan van de Ven20.15%15.00%
Justin P. Mattock10.07%15.00%
Tobias Klauser10.07%15.00%
Total1361100.00%20100.00%
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