arch/arm/plat-samsung/include/plat/uncompress.h

   1 /* arch/arm/plat-samsung/include/plat/uncompress.h
   2  *
   3  * Copyright 2003, 2007 Simtec Electronics
   4  *      http://armlinux.simtec.co.uk/
   5  *      Ben Dooks <ben@simtec.co.uk>
   6  *
   7  * S3C - uncompress code
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12 */
  13
  14 #ifndef __ASM_PLAT_UNCOMPRESS_H
  15 #define __ASM_PLAT_UNCOMPRESS_H
  16
  17 typedef unsigned int upf_t;     /* cannot include linux/serial_core.h */
  18
  19 /* uart setup */
  20
  21 unsigned int fifo_mask;
  22 unsigned int fifo_max;
  23
  24 /* forward declerations */
  25
  26 static void arch_detect_cpu(void);
  27
  28 /* defines for UART registers */
  29
  30 #include <plat/regs-serial.h>
  31 #include <plat/regs-watchdog.h>
  32
  33 /* working in physical space... */
  34 #undef S3C2410_WDOGREG
  35 #define S3C2410_WDOGREG(x) ((S3C24XX_PA_WATCHDOG + (x)))
  36
  37 /* how many bytes we allow into the FIFO at a time in FIFO mode */
  38 #define FIFO_MAX         (14)
  39
  40 #define uart_base S3C_PA_UART + (S3C_UART_OFFSET * CONFIG_S3C_LOWLEVEL_UART_PORT)
  41
  42 static __inline__ void
  43 uart_wr(unsigned int reg, unsigned int val)
  44 {
  45         volatile unsigned int *ptr;
  46
  47         ptr = (volatile unsigned int *)(reg + uart_base);
  48         *ptr = val;
  49 }
  50
  51 static __inline__ unsigned int
  52 uart_rd(unsigned int reg)
  53 {
  54         volatile unsigned int *ptr;
  55
  56         ptr = (volatile unsigned int *)(reg + uart_base);
  57         return *ptr;
  58 }
  59
  60 /* we can deal with the case the UARTs are being run
  61  * in FIFO mode, so that we don't hold up our execution
  62  * waiting for tx to happen...
  63 */
  64
  65 static void putc(int ch)
  66 {
  67         if (uart_rd(S3C2410_UFCON) & S3C2410_UFCON_FIFOMODE) {
  68                 int level;
  69
  70                 while (1) {
  71                         level = uart_rd(S3C2410_UFSTAT);
  72                         level &= fifo_mask;
  73
  74                         if (level < fifo_max)
  75                                 break;
  76                 }
  77
  78         } else {
  79                 /* not using fifos */
  80
  81                 while ((uart_rd(S3C2410_UTRSTAT) & S3C2410_UTRSTAT_TXE) != S3C2410_UTRSTAT_TXE)
  82                         barrier();
  83         }
  84
  85         /* write byte to transmission register */
  86         uart_wr(S3C2410_UTXH, ch);
  87 }
  88
  89 static inline void flush(void)
  90 {
  91 }
  92
  93 #define __raw_writel(d, ad)                     \
  94         do {                                                    \
  95                 *((volatile unsigned int __force *)(ad)) = (d); \
  96         } while (0)
  97
  98 /* CONFIG_S3C_BOOT_WATCHDOG
  99  *
 100  * Simple boot-time watchdog setup, to reboot the system if there is
 101  * any problem with the boot process
 102 */
 103
 104 #ifdef CONFIG_S3C_BOOT_WATCHDOG
 105
 106 #define WDOG_COUNT (0xff00)
 107
 108 static inline void arch_decomp_wdog(void)
 109 {
 110         __raw_writel(WDOG_COUNT, S3C2410_WTCNT);
 111 }
 112
 113 static void arch_decomp_wdog_start(void)
 114 {
 115         __raw_writel(WDOG_COUNT, S3C2410_WTDAT);
 116         __raw_writel(WDOG_COUNT, S3C2410_WTCNT);
 117         __raw_writel(S3C2410_WTCON_ENABLE | S3C2410_WTCON_DIV128 | S3C2410_WTCON_RSTEN | S3C2410_WTCON_PRESCALE(0x80), S3C2410_WTCON);
 118 }
 119
 120 #else
 121 #define arch_decomp_wdog_start()
 122 #define arch_decomp_wdog()
 123 #endif
 124
 125 #ifdef CONFIG_S3C_BOOT_ERROR_RESET
 126
 127 static void arch_decomp_error(const char *x)
 128 {
 129         putstr("\n\n");
 130         putstr(x);
 131         putstr("\n\n -- System resetting\n");
 132
 133         __raw_writel(0x4000, S3C2410_WTDAT);
 134         __raw_writel(0x4000, S3C2410_WTCNT);
 135         __raw_writel(S3C2410_WTCON_ENABLE | S3C2410_WTCON_DIV128 | S3C2410_WTCON_RSTEN | S3C2410_WTCON_PRESCALE(0x40), S3C2410_WTCON);
 136
 137         while(1);
 138 }
 139
 140 #define arch_error arch_decomp_error
 141 #endif
 142
 143 #ifdef CONFIG_S3C_BOOT_UART_FORCE_FIFO
 144 static inline void arch_enable_uart_fifo(void)
 145 {
 146         u32 fifocon = uart_rd(S3C2410_UFCON);
 147
 148         if (!(fifocon & S3C2410_UFCON_FIFOMODE)) {
 149                 fifocon |= S3C2410_UFCON_RESETBOTH;
 150                 uart_wr(S3C2410_UFCON, fifocon);
 151
 152                 /* wait for fifo reset to complete */
 153                 while (1) {
 154                         fifocon = uart_rd(S3C2410_UFCON);
 155                         if (!(fifocon & S3C2410_UFCON_RESETBOTH))
 156                                 break;
 157                 }
 158         }
 159 }
 160 #else
 161 #define arch_enable_uart_fifo() do { } while(0)
 162 #endif
 163
 164
 165 static void
 166 arch_decomp_setup(void)
 167 {
 168         /* we may need to setup the uart(s) here if we are not running
 169          * on an BAST... the BAST will have left the uarts configured
 170          * after calling linux.
 171          */
 172
 173         arch_detect_cpu();
 174         arch_decomp_wdog_start();
 175
 176         /* Enable the UART FIFOs if they where not enabled and our
 177          * configuration says we should turn them on.
 178          */
 179
 180         arch_enable_uart_fifo();
 181 }
 182
 183
 184 #endif /* __ASM_PLAT_UNCOMPRESS_H */