arch/arm/mach-ep93xx/include/mach/uncompress.h

   1 /*
   2  * arch/arm/mach-ep93xx/include/mach/uncompress.h
   3  *
   4  * Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or (at
   9  * your option) any later version.
  10  */
  11
  12 #include <mach/ep93xx-regs.h>
  13
  14 static unsigned char __raw_readb(unsigned int ptr)
  15 {
  16         return *((volatile unsigned char *)ptr);
  17 }
  18
  19 static unsigned int __raw_readl(unsigned int ptr)
  20 {
  21         return *((volatile unsigned int *)ptr);
  22 }
  23
  24 static void __raw_writeb(unsigned char value, unsigned int ptr)
  25 {
  26         *((volatile unsigned char *)ptr) = value;
  27 }
  28
  29 static void __raw_writel(unsigned int value, unsigned int ptr)
  30 {
  31         *((volatile unsigned int *)ptr) = value;
  32 }
  33
  34 #define PHYS_UART_DATA          (CONFIG_DEBUG_UART_PHYS + 0x00)
  35 #define PHYS_UART_FLAG          (CONFIG_DEBUG_UART_PHYS + 0x18)
  36 #define UART_FLAG_TXFF          0x20
  37
  38 static inline void putc(int c)
  39 {
  40         int i;
  41
  42         for (i = 0; i < 10000; i++) {
  43                 /* Transmit fifo not full? */
  44                 if (!(__raw_readb(PHYS_UART_FLAG) & UART_FLAG_TXFF))
  45                         break;
  46         }
  47
  48         __raw_writeb(c, PHYS_UART_DATA);
  49 }
  50
  51 static inline void flush(void)
  52 {
  53 }
  54
  55
  56 /*
  57  * Some bootloaders don't turn off DMA from the ethernet MAC before
  58  * jumping to linux, which means that we might end up with bits of RX
  59  * status and packet data scribbled over the uncompressed kernel image.
  60  * Work around this by resetting the ethernet MAC before we uncompress.
  61  */
  62 #define PHYS_ETH_SELF_CTL               0x80010020
  63 #define ETH_SELF_CTL_RESET              0x00000001
  64
  65 static void ethernet_reset(void)
  66 {
  67         unsigned int v;
  68
  69         /* Reset the ethernet MAC.  */
  70         v = __raw_readl(PHYS_ETH_SELF_CTL);
  71         __raw_writel(v | ETH_SELF_CTL_RESET, PHYS_ETH_SELF_CTL);
  72
  73         /* Wait for reset to finish.  */
  74         while (__raw_readl(PHYS_ETH_SELF_CTL) & ETH_SELF_CTL_RESET)
  75                 ;
  76 }
  77
  78
  79 static void arch_decomp_setup(void)
  80 {
  81         ethernet_reset();
  82 }