PS2功能 sa1111 linux驱动程序

/*

• linux/drivers/input/serio/sa1111ps2.c
• Copyright © 2002 Russell King
• This program is free software; you can redistribute it and/or modify
• it under the terms of the GNU General Public License as published by
• the Free Software Foundation; either version 2 of the License.
  */
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/input.h>
  #include <linux/serio.h>
  #include <linux/errno.h>
  #include <linux/interrupt.h>
  #include <linux/ioport.h>
  #include <linux/delay.h>
  #include <linux/device.h>
  #include <linux/slab.h>
  #include <linux/spinlock.h>

#include <asm/io.h>

#include <asm/hardware/sa1111.h>

#define PS2CR 0x0000
#define PS2STAT 0x0004
#define PS2DATA 0x0008
#define PS2CLKDIV 0x000c
#define PS2PRECNT 0x0010

#define PS2CR_ENA 0x08
#define PS2CR_FKD 0x02
#define PS2CR_FKC 0x01

#define PS2STAT_STP 0x0100
#define PS2STAT_TXE 0x0080
#define PS2STAT_TXB 0x0040
#define PS2STAT_RXF 0x0020
#define PS2STAT_RXB 0x0010
#define PS2STAT_ENA 0x0008
#define PS2STAT_RXP 0x0004
#define PS2STAT_KBD 0x0002
#define PS2STAT_KBC 0x0001

struct ps2if {
struct serio *io;
struct sa1111_dev *dev;
void __iomem *base;
int rx_irq;
int tx_irq;
unsigned int open;
spinlock_t lock;
unsigned int head;
unsigned int tail;
unsigned char buf[4];
};

/*

• Read all bytes waiting in the PS2 port. There should be

• at the most one, but we loop for safety. If there was a

• framing error, we have to manually clear the status.
  */
  static irqreturn_t ps2_rxint(int irq, void *dev_id)
  {
  struct ps2if *ps2if = dev_id;
  unsigned int scancode, flag, status;

  status = readl_relaxed(ps2if->base + PS2STAT);
  while (status & PS2STAT_RXF) {
  if (status & PS2STAT_STP)
  writel_relaxed(PS2S