arch/nios2nommu/kernel/pio.c

   1 /*
   2  *  linux/arch/nios2nommu/kernel/pio.c
   3  *  "Example" drivers(LEDs and 7 seg displays) of the PIO interface
   4  *  on Nios Development Kit.
   5  *
   6  *  Copyright (C) 2004 Microtronix Datacom Ltd
   7  *
   8  *  This program is free software; you can redistribute it and/or
   9  *  modify it under the terms of the GNU General Public License
  10  *  as published by the Free Software Foundation; either version
  11  *  2 of the License, or (at your option) any later version.
  12  *
  13  *  Written by Wentao Xu <wentao@microtronix.com>
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/types.h>
  18 #include <linux/kernel.h>
  19 #include <linux/delay.h>
  20 #include <linux/timer.h>
  21 #include <linux/init.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/ioport.h>
  24 #include <asm/io.h>
  25
  26 MODULE_AUTHOR("Microtronix Datacom Ltd.");
  27 MODULE_DESCRIPTION("Drivers of PIO devices (LEDs and 7 seg) on Nios kit");
  28 MODULE_LICENSE("GPL");
  29
  30 #undef CONFIG_PIO_SEG
  31 #ifdef na_seven_seg_pio
  32 #define CONFIG_PIO_SEG
  33 #define PIO_SEG_IO      na_seven_seg_pio
  34 #endif
  35
  36 #undef CONFIG_PIO_LED
  37 #ifdef na_led_pio
  38 #define CONFIG_PIO_LED
  39 #define PIO_LED_IO              na_led_pio
  40 #endif
  41
  42 #define PDEBUG printk
  43
  44 /* routines for 7-segment hex display */
  45 #ifdef CONFIG_PIO_SEG
  46 static unsigned char _hex_digits_data[] = {
  47         0x01, 0x4f, 0x12, 0x06, 0x4c, /* 0-4 */
  48         0x24, 0x20, 0x0f, 0x00, 0x04, /* 5-9 */
  49         0x08, 0x60, 0x72, 0x42, 0x30, /* a-e */
  50         0x38                              /* f   */
  51 };
  52
  53 void pio_seg_write(int value)
  54 {
  55   int led_value;
  56
  57   /* Left Hand Digit, goes to PIO bits 8-14 */
  58   led_value = _hex_digits_data[value & 0xF];
  59   led_value |= (_hex_digits_data[(value >> 4) & 0xF]) << 8;
  60
  61   outl(led_value, &(PIO_SEG_IO->np_piodata));
  62 }
  63
  64 static void __init pio_seg_init(void)
  65 {
  66         pio_seg_write(0);
  67 }
  68 #endif
  69
  70
  71 /* routines for LED display */
  72 #ifdef CONFIG_PIO_LED
  73 void pio_led_write(int value)
  74 {
  75         np_pio *pio=(np_pio *)(PIO_LED_IO);
  76
  77     //outl(-1, &pio->np_piodirection);
  78         outl(value, &pio->np_piodata);
  79 }
  80
  81 static void __init pio_led_init(void)
  82 {
  83         np_pio *pio=(np_pio *)(PIO_LED_IO);
  84
  85     outl(-1, &pio->np_piodirection);
  86     outl(0x0, &pio->np_piodata);
  87 }
  88 #endif
  89
  90 /* timing routines */
  91 #if defined(CONFIG_PIO_SEG) || defined(CONFIG_PIO_LED)
  92 static struct timer_list display_timer;
  93 static int restart_timer=1;
  94 static int timer_counter=0;
  95 static void display_timeout(unsigned long unused)
  96 {
  97 #ifdef CONFIG_PIO_SEG
  98         pio_seg_write(++timer_counter);
  99 #endif
 100
 101 #ifdef CONFIG_PIO_LED
 102         pio_led_write(timer_counter);
 103 #endif
 104         if (restart_timer) {
 105                 display_timer.expires = jiffies + HZ; /* one second */
 106                 add_timer(&display_timer);
 107         }
 108 }
 109 #endif
 110
 111 int __init pio_init(void)
 112 {
 113 #ifdef CONFIG_PIO_SEG
 114         request_mem_region((unsigned long)PIO_SEG_IO, sizeof(np_pio), "pio_7seg");
 115         pio_seg_init();
 116 #endif
 117
 118 #ifdef CONFIG_PIO_LED
 119         request_mem_region((unsigned long)PIO_LED_IO, sizeof(np_pio), "pio_led");
 120         pio_led_init();
 121 #endif
 122
 123 #if defined(CONFIG_PIO_SEG) || defined(CONFIG_PIO_LED)
 124         /* init timer */
 125         init_timer(&display_timer);
 126         display_timer.function = display_timeout;
 127         display_timer.data = 0;
 128         display_timer.expires = jiffies + HZ * 10; /* 10 seconds */
 129         add_timer(&display_timer);
 130 #endif
 131
 132         return 0;
 133 }
 134
 135 static void __exit pio_exit(void)
 136 {
 137 #ifdef CONFIG_PIO_SEG
 138         pio_seg_write(0);
 139         release_mem_region((unsigned long)PIO_SEG_IO, sizeof(np_pio));
 140 #endif
 141
 142 #ifdef CONFIG_PIO_LED
 143         pio_led_write(0);
 144         release_mem_region((unsigned long)PIO_LED_IO, sizeof(np_pio));
 145 #endif
 146
 147 #if defined(CONFIG_PIO_SEG) || defined(CONFIG_PIO_LED)
 148         restart_timer=0;
 149         del_timer_sync(&display_timer);
 150 #endif
 151 }
 152 module_init(pio_init);
 153 module_exit(pio_exit);
 154