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 /* The board must handle this interrupt if a timer is not 102 * provided. 103 */ 104 #if defined(CONFIG_SYS_NIOS_TMRBASE) 105 void tmr_isr (void *arg) 106 { 107 nios_timer_t *tmr = (nios_timer_t *)arg; 108 /* Interrupt is cleared by writing anything to the 109 * status register. 110 */ 111 writel (0, &tmr->status); 112 timestamp += CONFIG_SYS_NIOS_TMRMS; 113 #ifdef CONFIG_STATUS_LED 114 status_led_tick(timestamp); 115 #endif 116 } 117 118 static void tmr_init (void) 119 { 120 nios_timer_t *tmr =(nios_timer_t *)CONFIG_SYS_NIOS_TMRBASE; 121 122 writel (0, &tmr->status); 123 writel (0, &tmr->control); 124 writel (NIOS_TIMER_STOP, &tmr->control); 125 126 #if defined(CONFIG_SYS_NIOS_TMRCNT) 127 writel (CONFIG_SYS_NIOS_TMRCNT & 0xffff, &tmr->periodl); 128 writel ((CONFIG_SYS_NIOS_TMRCNT >> 16) & 0xffff, &tmr->periodh); 129 #endif 130 writel (NIOS_TIMER_ITO | NIOS_TIMER_CONT | NIOS_TIMER_START, 131 &tmr->control); 132 irq_install_handler (CONFIG_SYS_NIOS_TMRIRQ, tmr_isr, (void *)tmr); 133 } 134 135 #endif /* CONFIG_SYS_NIOS_TMRBASE */ 136 137 /*************************************************************************/ 138 int disable_interrupts (void) 139 { 140 int val = rdctl (CTL_STATUS); 141 wrctl (CTL_STATUS, val & ~STATUS_IE); 142 return (val & STATUS_IE); 143 } 144 145 void enable_interrupts( void ) 146 { 147 int val = rdctl (CTL_STATUS); 148 wrctl (CTL_STATUS, val | STATUS_IE); 149 } 150 151 void external_interrupt (struct pt_regs *regs) 152 { 153 unsigned irqs; 154 struct irq_action *act; 155 156 /* Evaluate only irqs that are both enabled AND pending */ 157 irqs = rdctl (CTL_IENABLE) & rdctl (CTL_IPENDING); 158 act = vecs; 159 160 /* Assume (as does the Nios2 HAL) that bit 0 is highest 161 * priority. NOTE: There is ALWAYS a handler assigned 162 * (the default if no other). 163 */ 164 while (irqs) { 165 if (irqs & 1) { 166 act->handler (act->arg); 167 act->count++; 168 } 169 irqs >>=1; 170 act++; 171 } 172 } 173 174 static void def_hdlr (void *arg) 175 { 176 unsigned irqs = rdctl (CTL_IENABLE); 177 178 /* Disable the individual interrupt -- with gratuitous 179 * warning. 180 */ 181 irqs &= ~(1 << (int)arg); 182 wrctl (CTL_IENABLE, irqs); 183 printf ("WARNING: Disabling unhandled interrupt: %d\n", 184 (int)arg); 185 } 186 187 /*************************************************************************/ 188 void irq_install_handler (int irq, interrupt_handler_t *hdlr, void *arg) 189 { 190 191 int flag; 192 struct irq_action *act; 193 unsigned ena = rdctl (CTL_IENABLE); 194 195 if ((irq < 0) || (irq > 31)) 196 return; 197 act = &vecs[irq]; 198 199 flag = disable_interrupts (); 200 if (hdlr) { 201 act->handler = hdlr; 202 act->arg = arg; 203 ena |= (1 << irq); /* enable */ 204 } else { 205 act->handler = def_hdlr; 206 act->arg = (void *)irq; 207 ena &= ~(1 << irq); /* disable */ 208 } 209 wrctl (CTL_IENABLE, ena); 210 if (flag) enable_interrupts (); 211 } 212 213 214 int interrupt_init (void) 215 { 216 int i; 217 218 /* Assign the default handler to all */ 219 for (i = 0; i < 32; i++) { 220 vecs[i].handler = def_hdlr; 221 vecs[i].arg = (void *)i; 222 vecs[i].count = 0; 223 } 224 225 #if defined(CONFIG_SYS_NIOS_TMRBASE) 226 tmr_init (); 227 #endif 228 229 enable_interrupts (); 230 return (0); 231 } 232 233 234 /*************************************************************************/ 235 #if defined(CONFIG_CMD_IRQ) 236 int do_irqinfo (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) 237 { 238 int i; 239 struct irq_action *act = vecs; 240 241 printf ("\nInterrupt-Information:\n\n"); 242 printf ("Nr Routine Arg Count\n"); 243 printf ("-----------------------------\n"); 244 245 for (i=0; i<32; i++) { 246 if (act->handler != def_hdlr) { 247 printf ("%02d %08lx %08lx %d\n", 248 i, 249 (ulong)act->handler, 250 (ulong)act->arg, 251 act->count); 252 } 253 act++; 254 } 255 printf ("\n"); 256 257 return (0); 258 } 259 #endif 260