]>
Commit | Line | Data |
---|---|---|
c7de829c WD |
1 | /* |
2 | * (C) Copyright 2002 | |
3 | * John W. Linville <linville@tuxdriver.com> | |
4 | * | |
5 | * Copied and modified from original code by Josh Huber. Original | |
6 | * copyright notice preserved below. | |
7 | * | |
8 | * (C) Copyright 2001 | |
9 | * Josh Huber <huber@mclx.com>, Mission Critical Linux, Inc. | |
10 | * | |
11 | * See file CREDITS for list of people who contributed to this | |
12 | * project. | |
13 | * | |
14 | * This program is free software; you can redistribute it and/or | |
15 | * modify it under the terms of the GNU General Public License as | |
16 | * published by the Free Software Foundation; either version 2 of | |
17 | * the License, or (at your option) any later version. | |
18 | * | |
19 | * This program is distributed in the hope that it will be useful, | |
20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
22 | * GNU General Public License for more details. | |
23 | * | |
24 | * You should have received a copy of the GNU General Public License | |
25 | * along with this program; if not, write to the Free Software | |
26 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, | |
27 | * MA 02111-1307 USA | |
28 | */ | |
29 | ||
30 | /* | |
31 | * interrupts.c - just enough support for the decrementer/timer | |
32 | */ | |
33 | ||
34 | #include <common.h> | |
35 | #include <asm/processor.h> | |
36 | #include <command.h> | |
37 | #include "i8259.h" | |
38 | ||
39 | #undef DEBUG | |
40 | #ifdef DEBUG | |
41 | #define PRINTF(fmt,args...) printf (fmt ,##args) | |
42 | #else | |
43 | #define PRINTF(fmt,args...) | |
44 | #endif | |
45 | #define NR_IRQS 16 | |
46 | ||
47 | void irq_alloc_init(void); | |
48 | long irq_alloc(long wanted); | |
49 | ||
50 | /****************************************************************************/ | |
51 | ||
52 | unsigned decrementer_count; /* count value for 1e6/HZ microseconds */ | |
53 | ||
54 | struct irq_action { | |
55 | interrupt_handler_t *handler; | |
56 | void *arg; | |
57 | ulong count; | |
58 | }; | |
59 | ||
60 | static struct irq_action irq_handlers[NR_IRQS]; | |
61 | ||
62 | /****************************************************************************/ | |
63 | ||
64 | static __inline__ unsigned long | |
65 | get_msr(void) | |
66 | { | |
67 | unsigned long msr; | |
68 | ||
69 | asm volatile("mfmsr %0" : "=r" (msr) :); | |
70 | return msr; | |
71 | } | |
72 | ||
73 | static __inline__ void | |
74 | set_msr(unsigned long msr) | |
75 | { | |
8bde7f77 | 76 | asm volatile("mtmsr %0" : : "r" (msr)); |
c7de829c WD |
77 | } |
78 | ||
79 | static __inline__ unsigned long | |
80 | get_dec(void) | |
81 | { | |
82 | unsigned long val; | |
83 | ||
84 | asm volatile("mfdec %0" : "=r" (val) :); | |
85 | return val; | |
86 | } | |
87 | ||
88 | ||
89 | static __inline__ void | |
90 | set_dec(unsigned long val) | |
91 | { | |
8bde7f77 | 92 | asm volatile("mtdec %0" : : "r" (val)); |
c7de829c WD |
93 | } |
94 | ||
95 | ||
96 | void | |
97 | enable_interrupts(void) | |
98 | { | |
99 | set_msr (get_msr() | MSR_EE); | |
100 | } | |
101 | ||
102 | /* returns flag if MSR_EE was set before */ | |
103 | int | |
104 | disable_interrupts(void) | |
105 | { | |
106 | ulong msr; | |
107 | ||
108 | msr = get_msr(); | |
109 | set_msr (msr & ~MSR_EE); | |
110 | return ((msr & MSR_EE) != 0); | |
111 | } | |
112 | ||
113 | /****************************************************************************/ | |
114 | ||
115 | int interrupt_init (void) | |
116 | { | |
117 | extern void new_reset(void); | |
118 | extern void new_reset_end(void); | |
119 | #ifdef DEBUG | |
120 | puts("interrupt_init: setting decrementer_count\n"); | |
121 | #endif | |
6d0f6bcf | 122 | decrementer_count = get_tbclk() / CONFIG_SYS_HZ; |
c7de829c WD |
123 | |
124 | #ifdef DEBUG | |
125 | puts("interrupt_init: setting actual decremter\n"); | |
126 | #endif | |
6d0f6bcf | 127 | set_dec (get_tbclk() / CONFIG_SYS_HZ); |
c7de829c WD |
128 | |
129 | #ifdef DEBUG | |
130 | puts("interrupt_init: clearing external interrupt table\n"); | |
131 | #endif | |
132 | /* clear external interrupt table here */ | |
133 | memset(irq_handlers, 0, sizeof(irq_handlers)); | |
134 | ||
135 | #ifdef DEBUG | |
136 | puts("interrupt_init: initializing interrupt controller\n"); | |
137 | #endif | |
138 | i8259_init(); | |
139 | ||
140 | #ifdef DEBUG | |
141 | puts("Copying reset trampoline\n"); | |
142 | #endif | |
143 | /* WARNING: Assmues that the first megabyte is CACHEINHIBIT! */ | |
144 | memcpy((void *)0x100, new_reset, new_reset_end - new_reset); | |
145 | ||
146 | #ifdef DEBUG | |
147 | PRINTF("interrupt_init: enabling interrupts (msr = %08x)\n", | |
148 | get_msr()); | |
149 | #endif | |
150 | set_msr (get_msr() | MSR_EE); | |
151 | ||
152 | #ifdef DEBUG | |
153 | PRINTF("interrupt_init: done. (msr = %08x)\n", get_msr()); | |
154 | #endif | |
155 | ||
156 | } | |
157 | ||
158 | /****************************************************************************/ | |
159 | ||
160 | /* | |
161 | * Handle external interrupts | |
162 | */ | |
163 | void | |
164 | external_interrupt(struct pt_regs *regs) | |
165 | { | |
166 | extern int i8259_irq(void); | |
167 | ||
168 | int irq, unmask = 1; | |
169 | ||
8bde7f77 WD |
170 | irq = i8259_irq(); /*i8259_get_irq(regs); */ |
171 | /* printf("irq = %d, handler at %p ack=%d\n", irq, irq_handlers[irq].handler, *(volatile unsigned char *)0xFEF00000); */ | |
c7de829c WD |
172 | i8259_mask_and_ack(irq); |
173 | ||
174 | if (irq_handlers[irq].handler != NULL) | |
175 | (*irq_handlers[irq].handler)(irq_handlers[irq].arg); | |
176 | else { | |
177 | PRINTF ("\nBogus External Interrupt IRQ %d\n", irq); | |
178 | /* | |
53677ef1 WD |
179 | * turn off the bogus interrupt, otherwise it |
180 | * might repeat forever | |
181 | */ | |
c7de829c WD |
182 | unmask = 0; |
183 | } | |
184 | ||
185 | if (unmask) i8259_unmask_irq(irq); | |
186 | } | |
187 | ||
188 | volatile ulong timestamp = 0; | |
189 | ||
190 | /* | |
191 | * timer_interrupt - gets called when the decrementer overflows, | |
192 | * with interrupts disabled. | |
193 | * Trivial implementation - no need to be really accurate. | |
194 | */ | |
195 | void | |
196 | timer_interrupt(struct pt_regs *regs) | |
197 | { | |
198 | set_dec(decrementer_count); | |
199 | timestamp++; | |
200 | } | |
201 | ||
202 | /****************************************************************************/ | |
203 | ||
204 | void | |
205 | reset_timer(void) | |
206 | { | |
207 | timestamp = 0; | |
208 | } | |
209 | ||
210 | ulong | |
211 | get_timer(ulong base) | |
212 | { | |
213 | return (timestamp - base); | |
214 | } | |
215 | ||
216 | void | |
217 | set_timer(ulong t) | |
218 | { | |
219 | timestamp = t; | |
220 | } | |
221 | ||
222 | /****************************************************************************/ | |
223 | ||
224 | /* | |
225 | * Install and free a interrupt handler. | |
226 | */ | |
227 | ||
228 | void | |
229 | irq_install_handler(int irq, interrupt_handler_t *handler, void *arg) | |
230 | { | |
231 | if (irq < 0 || irq >= NR_IRQS) { | |
232 | PRINTF("irq_install_handler: bad irq number %d\n", irq); | |
233 | return; | |
234 | } | |
235 | ||
236 | if (irq_handlers[irq].handler != NULL) | |
237 | PRINTF("irq_install_handler: 0x%08lx replacing 0x%08lx\n", | |
238 | (ulong)handler, (ulong)irq_handlers[irq].handler); | |
239 | ||
240 | irq_handlers[irq].handler = handler; | |
241 | irq_handlers[irq].arg = arg; | |
242 | ||
243 | i8259_unmask_irq(irq); | |
244 | } | |
245 | ||
246 | void | |
247 | irq_free_handler(int irq) | |
248 | { | |
249 | if (irq < 0 || irq >= NR_IRQS) { | |
250 | PRINTF("irq_free_handler: bad irq number %d\n", irq); | |
251 | return; | |
252 | } | |
253 | ||
254 | i8259_mask_irq(irq); | |
255 | ||
256 | irq_handlers[irq].handler = NULL; | |
257 | irq_handlers[irq].arg = NULL; | |
258 | } | |
259 | ||
260 | /****************************************************************************/ | |
261 | ||
262 | void | |
263 | do_irqinfo(cmd_tbl_t *cmdtp, bd_t *bd, int flag, int argc, char *argv[]) | |
264 | { | |
265 | puts("IRQ related functions are unimplemented currently.\n"); | |
266 | } |