1 /* 2 * (C) Copyright 2000-2002 3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4 * 5 * (C) Copyright 2004, Psyent Corporation <www.psyent.com> 6 * Scott McNutt <smcnutt@psyent.com> 7 * 8 * See file CREDITS for list of people who contributed to this 9 * project. 10 * 11 * This program is free software; you can redistribute it and/or 12 * modify it under the terms of the GNU General Public License as 13 * published by the Free Software Foundation; either version 2 of 14 * the License, or (at your option) any later version. 15 * 16 * This program is distributed in the hope that it will be useful, 17 * but WITHOUT ANY WARRANTY; without even the implied warranty of 18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 19 * GNU General Public License for more details. 20 * 21 * You should have received a copy of the GNU General Public License 22 * along with this program; if not, write to the Free Software 23 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, 24 * MA 02111-1307 USA 25 */ 26 27 28 #include <nios2.h> 29 #include <nios2-io.h> 30 #include <asm/types.h> 31 #include <asm/io.h> 32 #include <asm/ptrace.h> 33 #include <common.h> 34 #include <command.h> 35 #include <watchdog.h> 36 #ifdef CONFIG_STATUS_LED 37 #include <status_led.h> 38 #endif 39 40 #if defined(CONFIG_SYS_NIOS_TMRBASE) && !defined(CONFIG_SYS_NIOS_TMRIRQ) 41 #error CONFIG_SYS_NIOS_TMRIRQ not defined (see documentation) 42 #endif 43 44 /****************************************************************************/ 45 46 struct irq_action { 47 interrupt_handler_t *handler; 48 void *arg; 49 int count; 50 }; 51 52 static struct irq_action vecs[32]; 53 54 /*************************************************************************/ 55 volatile ulong timestamp = 0; 56 57 void reset_timer (void) 58 { 59 nios_timer_t *tmr =(nios_timer_t *)CONFIG_SYS_NIOS_TMRBASE; 60 61 /* From Embedded Peripherals Handbook: 62 * 63 * "When the hardware is configured with Writeable period 64 * disabled, writing to one of the period_n registers causes 65 * the counter to reset to the fixed Timeout Period specified 66 * at system generation time." 67 * 68 * Here we force a reload to prevent early timeouts from 69 * get_timer() when the interrupt period is greater than 70 * than 1 msec. 71 * 72 * Simply write to periodl with its own value to force an 73 * internal counter reload, THEN reset the timestamp. 74 */ 75 writel (readl (&tmr->periodl), &tmr->periodl); 76 timestamp = 0; 77 78 /* From Embedded Peripherals Handbook: 79 * 80 * "Writing to one of the period_n registers stops the internal 81 * counter, except when the hardware is configured with Start/Stop 82 * control bits off. If Start/Stop control bits is off, writing 83 * either register does not stop the counter." 84 * 85 * In order to accomodate either configuration, the control 86 * register is re-written. If the counter is stopped, it will 87 * be restarted. If it is running, the write is essentially 88 * a nop. 89 */ 90 writel (NIOS_TIMER_ITO | NIOS_TIMER_CONT | NIOS_TIMER_START, 91 &tmr->control); 92 93 } 94 95 ulong get_timer (ulong base) 96 { 97 WATCHDOG_RESET (); 98 return (timestamp - base); 99 } 100 101 void set_timer (ulong t) 102 { 103 timestamp = t; 104 } 105 106 107 /* The board must handle this interrupt if a timer is not 108 * provided. 109 */ 110 #if defined(CONFIG_SYS_NIOS_TMRBASE) 111 void tmr_isr (void *arg) 112 { 113 nios_timer_t *tmr = (nios_timer_t *)arg; 114 /* Interrupt is cleared by writing anything to the 115 * status register. 116 */ 117 writel (0, &tmr->status); 118 timestamp += CONFIG_SYS_NIOS_TMRMS; 119 #ifdef CONFIG_STATUS_LED 120 status_led_tick(timestamp); 121 #endif 122 } 123 124 static void tmr_init (void) 125 { 126 nios_timer_t *tmr =(nios_timer_t *)CONFIG_SYS_NIOS_TMRBASE; 127 128 writel (0, &tmr->status); 129 writel (0, &tmr->control); 130 writel (NIOS_TIMER_STOP, &tmr->control); 131 132 #if defined(CONFIG_SYS_NIOS_TMRCNT) 133 writel (CONFIG_SYS_NIOS_TMRCNT & 0xffff, &tmr->periodl); 134 writel ((CONFIG_SYS_NIOS_TMRCNT >> 16) & 0xffff, &tmr->periodh); 135 #endif 136 writel (NIOS_TIMER_ITO | NIOS_TIMER_CONT | NIOS_TIMER_START, 137 &tmr->control); 138 irq_install_handler (CONFIG_SYS_NIOS_TMRIRQ, tmr_isr, (void *)tmr); 139 } 140 141 #endif /* CONFIG_SYS_NIOS_TMRBASE */ 142 143 /*************************************************************************/ 144 int disable_interrupts (void) 145 { 146 int val = rdctl (CTL_STATUS); 147 wrctl (CTL_STATUS, val & ~STATUS_IE); 148 return (val & STATUS_IE); 149 } 150 151 void enable_interrupts( void ) 152 { 153 int val = rdctl (CTL_STATUS); 154 wrctl (CTL_STATUS, val | STATUS_IE); 155 } 156 157 void external_interrupt (struct pt_regs *regs) 158 { 159 unsigned irqs; 160 struct irq_action *act; 161 162 /* Evaluate only irqs that are both enabled AND pending */ 163 irqs = rdctl (CTL_IENABLE) & rdctl (CTL_IPENDING); 164 act = vecs; 165 166 /* Assume (as does the Nios2 HAL) that bit 0 is highest 167 * priority. NOTE: There is ALWAYS a handler assigned 168 * (the default if no other). 169 */ 170 while (irqs) { 171 if (irqs & 1) { 172 act->handler (act->arg); 173 act->count++; 174 } 175 irqs >>=1; 176 act++; 177 } 178 } 179 180 static void def_hdlr (void *arg) 181 { 182 unsigned irqs = rdctl (CTL_IENABLE); 183 184 /* Disable the individual interrupt -- with gratuitous 185 * warning. 186 */ 187 irqs &= ~(1 << (int)arg); 188 wrctl (CTL_IENABLE, irqs); 189 printf ("WARNING: Disabling unhandled interrupt: %d\n", 190 (int)arg); 191 } 192 193 /*************************************************************************/ 194 void irq_install_handler (int irq, interrupt_handler_t *hdlr, void *arg) 195 { 196 197 int flag; 198 struct irq_action *act; 199 unsigned ena = rdctl (CTL_IENABLE); 200 201 if ((irq < 0) || (irq > 31)) 202 return; 203 act = &vecs[irq]; 204 205 flag = disable_interrupts (); 206 if (hdlr) { 207 act->handler = hdlr; 208 act->arg = arg; 209 ena |= (1 << irq); /* enable */ 210 } else { 211 act->handler = def_hdlr; 212 act->arg = (void *)irq; 213 ena &= ~(1 << irq); /* disable */ 214 } 215 wrctl (CTL_IENABLE, ena); 216 if (flag) enable_interrupts (); 217 } 218 219 220 int interrupt_init (void) 221 { 222 int i; 223 224 /* Assign the default handler to all */ 225 for (i = 0; i < 32; i++) { 226 vecs[i].handler = def_hdlr; 227 vecs[i].arg = (void *)i; 228 vecs[i].count = 0; 229 } 230 231 #if defined(CONFIG_SYS_NIOS_TMRBASE) 232 tmr_init (); 233 #endif 234 235 enable_interrupts (); 236 return (0); 237 } 238 239 240 /*************************************************************************/ 241 #if defined(CONFIG_CMD_IRQ) 242 int do_irqinfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) 243 { 244 int i; 245 struct irq_action *act = vecs; 246 247 printf ("\nInterrupt-Information:\n\n"); 248 printf ("Nr Routine Arg Count\n"); 249 printf ("-----------------------------\n"); 250 251 for (i=0; i<32; i++) { 252 if (act->handler != def_hdlr) { 253 printf ("%02d %08lx %08lx %d\n", 254 i, 255 (ulong)act->handler, 256 (ulong)act->arg, 257 act->count); 258 } 259 act++; 260 } 261 printf ("\n"); 262 263 return (0); 264 } 265 #endif 266