Linux kernel & device driver programming

Cross-Referenced Linux and Device Driver Code

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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  1 /* linux/include/asm-arm/plat-s3c/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 static unsigned int fifo_mask;
 22 static 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 static void error(char *err);
144 
145 #ifdef CONFIG_S3C_BOOT_UART_FORCE_FIFO
146 static inline void arch_enable_uart_fifo(void)
147 {
148         u32 fifocon = uart_rd(S3C2410_UFCON);
149 
150         if (!(fifocon & S3C2410_UFCON_FIFOMODE)) {
151                 fifocon |= S3C2410_UFCON_RESETBOTH;
152                 uart_wr(S3C2410_UFCON, fifocon);
153 
154                 /* wait for fifo reset to complete */
155                 while (1) {
156                         fifocon = uart_rd(S3C2410_UFCON);
157                         if (!(fifocon & S3C2410_UFCON_RESETBOTH))
158                                 break;
159                 }
160         }
161 }
162 #else
163 #define arch_enable_uart_fifo() do { } while(0)
164 #endif
165 
166 
167 static void
168 arch_decomp_setup(void)
169 {
170         /* we may need to setup the uart(s) here if we are not running
171          * on an BAST... the BAST will have left the uarts configured
172          * after calling linux.
173          */
174 
175         arch_detect_cpu();
176         arch_decomp_wdog_start();
177 
178         /* Enable the UART FIFOs if they where not enabled and our
179          * configuration says we should turn them on.
180          */
181 
182         arch_enable_uart_fifo();
183 }
184 
185 
186 #endif /* __ASM_PLAT_UNCOMPRESS_H */
187 
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