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 #if defined(CONFIG_EP93XX_EARLY_UART1)
  35 #define UART_BASE               EP93XX_UART1_PHYS_BASE
  36 #elif defined(CONFIG_EP93XX_EARLY_UART2)
  37 #define UART_BASE               EP93XX_UART2_PHYS_BASE
  38 #elif defined(CONFIG_EP93XX_EARLY_UART3)
  39 #define UART_BASE               EP93XX_UART3_PHYS_BASE
  40 #else
  41 #define UART_BASE               EP93XX_UART1_PHYS_BASE
  42 #endif
  43
  44 #define PHYS_UART_DATA          (UART_BASE + 0x00)
  45 #define PHYS_UART_FLAG          (UART_BASE + 0x18)
  46 #define UART_FLAG_TXFF          0x20
  47
  48 static inline void putc(int c)
  49 {
  50         int i;
  51
  52         for (i = 0; i < 10000; i++) {
  53                 /* Transmit fifo not full? */
  54                 if (!(__raw_readb(PHYS_UART_FLAG) & UART_FLAG_TXFF))
  55                         break;
  56         }
  57
  58         __raw_writeb(c, PHYS_UART_DATA);
  59 }
  60
  61 static inline void flush(void)
  62 {
  63 }
  64
  65
  66 /*
  67  * Some bootloaders don't turn off DMA from the ethernet MAC before
  68  * jumping to linux, which means that we might end up with bits of RX
  69  * status and packet data scribbled over the uncompressed kernel image.
  70  * Work around this by resetting the ethernet MAC before we uncompress.
  71  */
  72 #define PHYS_ETH_SELF_CTL               0x80010020
  73 #define ETH_SELF_CTL_RESET              0x00000001
  74
  75 static void ethernet_reset(void)
  76 {
  77         unsigned int v;
  78
  79         /* Reset the ethernet MAC.  */
  80         v = __raw_readl(PHYS_ETH_SELF_CTL);
  81         __raw_writel(v | ETH_SELF_CTL_RESET, PHYS_ETH_SELF_CTL);
  82
  83         /* Wait for reset to finish.  */
  84         while (__raw_readl(PHYS_ETH_SELF_CTL) & ETH_SELF_CTL_RESET)
  85                 ;
  86 }
  87
  88
  89 static void arch_decomp_setup(void)
  90 {
  91         ethernet_reset();
  92 }