drivers/input/ps2ser.c

   1 /***********************************************************************
   2  *
   3  * (C) Copyright 2004-2009
   4  * DENX Software Engineering
   5  * Wolfgang Denk, wd@denx.de
   6  *
   7  * Simple 16550A serial driver
   8  *
   9  * Originally from linux source (drivers/char/ps2ser.c)
  10  *
  11  * Used by the PS/2 multiplexer driver (ps2mult.c)
  12  *
  13  ***********************************************************************/
  14
  15 #include <common.h>
  16
  17 #include <asm/io.h>
  18 #include <asm/atomic.h>
  19 #include <ps2mult.h>
  20 /* This is needed for ns16550.h */
  21 #ifndef CONFIG_SYS_NS16550_REG_SIZE
  22 #define CONFIG_SYS_NS16550_REG_SIZE 1
  23 #endif
  24 #include <ns16550.h>
  25
  26 DECLARE_GLOBAL_DATA_PTR;
  27
  28 /* #define      DEBUG */
  29
  30 #define PS2SER_BAUD     57600
  31
  32 #if CONFIG_PS2SERIAL == 1
  33 #define COM_BASE (CONFIG_SYS_CCSRBAR+0x4500)
  34 #elif CONFIG_PS2SERIAL == 2
  35 #define COM_BASE (CONFIG_SYS_CCSRBAR+0x4600)
  36 #else
  37 #error CONFIG_PS2SERIAL must be in 1 ... 2
  38 #endif
  39
  40 static int      ps2ser_getc_hw(void);
  41 static void     ps2ser_interrupt(void *dev_id);
  42
  43 extern struct   serial_state rs_table[]; /* in serial.c */
  44
  45 static u_char   ps2buf[PS2BUF_SIZE];
  46 static atomic_t ps2buf_cnt;
  47 static int      ps2buf_in_idx;
  48 static int      ps2buf_out_idx;
  49
  50 int ps2ser_init(void)
  51 {
  52         NS16550_t com_port = (NS16550_t)COM_BASE;
  53
  54         com_port->ier = 0x00;
  55         com_port->lcr = UART_LCR_BKSE | UART_LCR_8N1;
  56         com_port->dll = (CONFIG_SYS_NS16550_CLK / 16 / PS2SER_BAUD) & 0xff;
  57         com_port->dlm = ((CONFIG_SYS_NS16550_CLK / 16 / PS2SER_BAUD) >> 8) & 0xff;
  58         com_port->lcr = UART_LCR_8N1;
  59         com_port->mcr = (UART_MCR_DTR | UART_MCR_RTS);
  60         com_port->fcr = (UART_FCR_FIFO_EN | UART_FCR_RXSR | UART_FCR_TXSR);
  61
  62         return (0);
  63 }
  64
  65 void ps2ser_putc(int chr)
  66 {
  67         NS16550_t com_port = (NS16550_t)COM_BASE;
  68         debug(">>>> 0x%02x\n", chr);
  69
  70         while ((com_port->lsr & UART_LSR_THRE) == 0);
  71         com_port->thr = chr;
  72 }
  73
  74 static int ps2ser_getc_hw(void)
  75 {
  76         NS16550_t com_port = (NS16550_t)COM_BASE;
  77         int res = -1;
  78
  79         if (com_port->lsr & UART_LSR_DR) {
  80                 res = com_port->rbr;
  81         }
  82
  83         return res;
  84 }
  85
  86 int ps2ser_getc(void)
  87 {
  88         volatile int chr;
  89         int flags;
  90
  91         debug("<< ");
  92
  93         flags = disable_interrupts();
  94
  95         do {
  96                 if (atomic_read(&ps2buf_cnt) != 0) {
  97                         chr = ps2buf[ps2buf_out_idx++];
  98                         ps2buf_out_idx &= (PS2BUF_SIZE - 1);
  99                         atomic_dec(&ps2buf_cnt);
 100                 } else {
 101                         chr = ps2ser_getc_hw();
 102                 }
 103         }
 104         while (chr < 0);
 105
 106         if (flags)
 107                 enable_interrupts();
 108
 109         debug("0x%02x\n", chr);
 110
 111         return chr;
 112 }
 113
 114 int ps2ser_check(void)
 115 {
 116         int flags;
 117
 118         flags = disable_interrupts();
 119         ps2ser_interrupt(NULL);
 120         if (flags) enable_interrupts();
 121
 122         return atomic_read(&ps2buf_cnt);
 123 }
 124
 125 static void ps2ser_interrupt(void *dev_id)
 126 {
 127         NS16550_t com_port = (NS16550_t)COM_BASE;
 128         int chr;
 129         int status;
 130
 131         do {
 132                 chr = ps2ser_getc_hw();
 133                 status = com_port->lsr;
 134                 if (chr < 0) continue;
 135
 136                 if (atomic_read(&ps2buf_cnt) < PS2BUF_SIZE) {
 137                         ps2buf[ps2buf_in_idx++] = chr;
 138                         ps2buf_in_idx &= (PS2BUF_SIZE - 1);
 139                         atomic_inc(&ps2buf_cnt);
 140                 } else {
 141                         printf ("ps2ser.c: buffer overflow\n");
 142                 }
 143         } while (status & UART_LSR_DR);
 144         if (atomic_read(&ps2buf_cnt)) {
 145                 ps2mult_callback(atomic_read(&ps2buf_cnt));
 146         }
 147 }