基于串口的树莓派ps/2驱动

/* pi2ps2.c -- Raspberry Pi PS/2 keyboard device driver using the UART. * * Copyright 2014 Stephen Burke 7w0n0d3@gmail.com * * This file is subject to the terms and conditions of the GNU General Public * License. See the file COPYING in the Linux kernel source for more details. * * The following resources helped me greatly: * * The Linux kernel module programming howto * Copyright (C) 2001 Jay Salzman * * The Linux USB input subsystem Part 1 * Copyright (C) 2007 Brad Hards * * PS/2 keyboard interfacing * Copyright (C) 1998-2013 Adam Chapweske * * kbd FAQ * Copyright (C) 2009 Andries Brouwer * * Keyboard data and clock lines must be pulled up to +5V with 4.7K resistors * Data line must be limited to 3.0V. * Connecting a blue or white LED between the data line and ground is a simple way to accomplish this. * Data line is then connected to P1 pin 10 (RX) on the Raspberry Pi. * Clock line is left unconnected. * The keyboard also needs +5v (about 125 mA) and ground. * */ //remember to remove all ttyAMA0 references in /boot/cmdline.txt and /etc/inittab //use companion userspace program ps2test to determine module parameters //and use them like this: insmod ps2.ko integer=15 fractional=38 //default parameters should be correct for an IBM Model M keyboard. //You don't need to do anything special to compile this module. #include <linux/module.h> #include <linux/interrupt.h> #include <linux/input.h> #include <linux/io.h> #define IO_BASE 0x20000000 //gpio #define GPFSEL1 0x200004/4 //uart #define DR 0x201000/4 #define CR 0x201030/4 #define IBRD 0x201024/4 #define FBRD 0x201028/4 #define LCRH 0x20102c/4 #define IMSC 0x201038/4 int divider = 15; int fractional = 38; static unsigned keyup = 0; static unsigned escape = 0; static unsigned pause = 0; static unsigned *(uart); volatile unsigned *(io_base); static struct input_dev *ps2; static unsigned char translate[256] = { /* Raw SET 2 scancode table */ /* 00 */ KEY_RESERVED, KEY_F9, KEY_RESERVED, KEY_F5, KEY_F3, KEY_F1, KEY_F2, KEY_F12, /* 08 */ KEY_ESC, KEY_F10, KEY_F8, KEY_F6, KEY_F4, KEY_TAB, KEY_GRAVE, KEY_RESERVED, /* 10 */ KEY_RESERVED, KEY_LEFTALT, KEY_LEFTSHIFT, KEY_RESERVED, KEY_LEFTCTRL, KEY_Q, KEY_1, KEY_RESERVED, /* 18 */ KEY_RESERVED, KEY_RESERVED, KEY_Z, KEY_S, KEY_A, KEY_W, KEY_2, KEY_RESERVED, /* 20 */ KEY_RESERVED, KEY_C, KEY_X, KEY_D, KEY_E, KEY_4, KEY_3, KEY_RESERVED, /* 28 */ KEY_RESERVED, KEY_SPACE, KEY_V, KEY_F, KEY_T, KEY_R, KEY_5, KEY_RESERVED, /* 30 */ KEY_RESERVED, KEY_N, KEY_B, KEY_H, KEY_G, KEY_Y, KEY_6, KEY_RESERVED, /* 38 */ KEY_RESERVED, KEY_RIGHTALT, KEY_M, KEY_J, KEY_U, KEY_7, KEY_8, KEY_RESERVED, /* 40 */ KEY_RESERVED, KEY_COMMA, KEY_K, KEY_I, KEY_O, KEY_0, KEY_9, KEY_RESERVED, /* 48 */ KEY_RESERVED, KEY_DOT, KEY_SLASH, KEY_L, KEY_SEMICOLON, KEY_P, KEY_MINUS, KEY_RESERVED, /* 50 */ KEY_RESERVED, KEY_RESERVED, KEY_APOSTROPHE,KEY_RESERVED, KEY_LEFTBRACE, KEY_EQUAL, KEY_RESERVED, KEY_RESERVED, /* 58 */ KEY_CAPSLOCK, KEY_RIGHTSHIFT,KEY_ENTER, KEY_RIGHTBRACE,KEY_RESERVED, KEY_BACKSLASH,KEY_RESERVED, KEY_RESERVED, /* 60 */ KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_BACKSPACE, KEY_RESERVED, /* 68 */ KEY_RESERVED, KEY_KP1, KEY_RESERVED, KEY_KP4, KEY_KP7, KEY_RESERVED, KEY_HOME, KEY_RESERVED, /* 70 */ KEY_KP0, KEY_KPDOT, KEY_KP2, KEY_KP5, KEY_KP6, KEY_KP8, KEY_ESC, KEY_NUMLOCK, /* 78 */ KEY_F11, KEY_KPPLUS, KEY_KP3, KEY_KPMINUS, KEY_KPASTERISK,KEY_KP9, KEY_SCROLLLOCK,KEY_RESERVED, /* 80 */ KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_F7, KEY_SYSRQ, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, /* 88 */ KEY_PAUSE, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, /* 90 */ KEY_RESERVED, KEY_RIGHTALT, KEY_RESERVED, KEY_RESERVED, KEY_RIGHTCTRL, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, /* 98 */ KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, /* a0 */ KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, /* a8 */ KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, /* b0 */ KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, /* b8 */ KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, /* c0 */ KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, /* c8 */ KEY_RESERVED, KEY_RESERVED, KEY_KPSLASH, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, /* d0 */ KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, /* d8 */ KEY_RESERVED, KEY_RESERVED, KEY_KPENTER, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, /* e0 */ KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, /* e8 */ KEY_RESERVED, KEY_END, KEY_RESERVED, KEY_LEFT, KEY_HOME, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, /* f0 */ KEY_INSERT, KEY_DELETE, KEY_DOWN, KEY_RESERVED, KEY_RIGHT, KEY_UP, KEY_RESERVED, KEY_RESERVED, /* f8 */ KEY_RESERVED, KEY_RESERVED, KEY_PAGEDOWN, KEY_RESERVED, KEY_PRINT, KEY_PAGEUP, KEY_RESERVED, KEY_RESERVED } ; module_param(divider,int,0); module_param(fractional,int,0); irq_handler_t irq_handler(int irq, void *dev_id, struct pt_regs *regs) { unsigned key = *(uart); if ((key & (1<<8)) != 0) printk(KERN_INFO "pi2ps2 framing error\n"); if ((key & (1<<9)) != 0) printk(KERN_INFO "pi2ps2 parity error\n"); if ((key & (1<<10)) != 0) printk(KERN_INFO "pi2ps2 break error\n"); if ((key & (1<<11)) != 0) printk(KERN_INFO "pi2ps2 overrun error\n"); key = key & 0xff; if (key == 0xf0) { keyup = 1; return 0; } if (key == 0xe0) { escape = 1; return 0; } if (key == 0xe1) { pause = 2; return 0; } if (pause == 2) { pause = 1; return 0; } if (pause == 1) { key = 0x88; pause = 0; } if (escape == 1) { key |= 0x80; escape = 0; } key = translate[key]; if (keyup == 1) { input_report_key(ps2,key,0); keyup = 0; } else input_report_key(ps2,key,1); input_sync(ps2); return 0; } int init_module(void) { int i, retval; unsigned key; io_base = ioremap(IO_BASE,0x400000); //set pin 10 as uart rxd *(io_base+GPFSEL1) &= ~(7<<15); *(io_base+GPFSEL1) |= (4<<15); //set uart to receive 8 bit, 1 stop, odd parity *(io_base+CR) = 0; *(io_base+LCRH) = ((3<<5)|(1<<1)); //set baud rate to command line parameters *(io_base+IBRD) = divider; *(io_base+FBRD) = fractional; //flush buffer key=*(io_base+DR); //interrupts on *(io_base+IMSC) = (1<<4); //uart on *(io_base+CR) = (1<<9); *(io_base+CR) |= 1; iounmap(io_base); uart = ioremap(IO_BASE+(DR*4),1); ps2=input_allocate_device(); ps2->name = "pi2ps2"; ps2->phys = "ps2/input0"; ps2->id.bustype = BUS_HOST; ps2->id.vendor = 0x0001; ps2->id.product = 0x0001; ps2->id.version = 0x0100; ps2->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP); ps2->keycode = translate; ps2->keycodes