LXR linux/arch/mips/mti-sead3/sead3-display.c

   1/*
   2 * This file is subject to the terms and conditions of the GNU General Public
   3 * License.  See the file "COPYING" in the main directory of this archive
   4 * for more details.
   5 *
   6 * Copyright (C) 2012 MIPS Technologies, Inc.  All rights reserved.
   7 */
   8#include <linux/timer.h>
   9#include <linux/io.h>
  10#include <asm/mips-boards/generic.h>
  11
  12static unsigned int display_count;
  13static unsigned int max_display_count;
  14
  15#define LCD_DISPLAY_POS_BASE            0x1f000400
  16#define DISPLAY_LCDINSTRUCTION          (0*2)
  17#define DISPLAY_LCDDATA                 (1*2)
  18#define DISPLAY_CPLDSTATUS              (2*2)
  19#define DISPLAY_CPLDDATA                (3*2)
  20#define LCD_SETDDRAM                    0x80
  21#define LCD_IR_BF                       0x80
  22
  23const char display_string[] = "               LINUX ON SEAD3               ";
  24
  25static void scroll_display_message(unsigned long data);
  26static DEFINE_TIMER(mips_scroll_timer, scroll_display_message, HZ, 0);
  27
  28static void lcd_wait(unsigned int __iomem *display)
  29{
  30        /* Wait for CPLD state machine to become idle. */
  31        do { } while (__raw_readl(display + DISPLAY_CPLDSTATUS) & 1);
  32
  33        do {
  34                __raw_readl(display + DISPLAY_LCDINSTRUCTION);
  35
  36                /* Wait for CPLD state machine to become idle. */
  37                do { } while (__raw_readl(display + DISPLAY_CPLDSTATUS) & 1);
  38        } while (__raw_readl(display + DISPLAY_CPLDDATA) & LCD_IR_BF);
  39}
  40
  41void mips_display_message(const char *str)
  42{
  43        static unsigned int __iomem *display;
  44        char ch;
  45        int i;
  46
  47        if (unlikely(display == NULL))
  48                display = ioremap_nocache(LCD_DISPLAY_POS_BASE,
  49                        (8 * sizeof(int)));
  50
  51        for (i = 0; i < 16; i++) {
  52                if (*str)
  53                        ch = *str++;
  54                else
  55                        ch = ' ';
  56                lcd_wait(display);
  57                __raw_writel((LCD_SETDDRAM | i),
  58                        (display + DISPLAY_LCDINSTRUCTION));
  59                lcd_wait(display);
  60                __raw_writel(ch, display + DISPLAY_LCDDATA);
  61        }
  62}
  63
  64static void scroll_display_message(unsigned long data)
  65{
  66        mips_display_message(&display_string[display_count++]);
  67        if (display_count == max_display_count)
  68                display_count = 0;
  69        mod_timer(&mips_scroll_timer, jiffies + HZ);
  70}
  71
  72void mips_scroll_message(void)
  73{
  74        del_timer_sync(&mips_scroll_timer);
  75        max_display_count = strlen(display_string) + 1 - 16;
  76        mod_timer(&mips_scroll_timer, jiffies + 1);
  77}
  78