1 #ifndef __ALT_IRQ_H__
2 #define __ALT_IRQ_H__
3
4 /******************************************************************************
5 * *
6 * License Agreement *
7 * *
8 * Copyright (c) 2009 Altera Corporation, San Jose, California, USA. *
9 * All rights reserved. *
10 * *
11 * Permission is hereby granted, free of charge, to any person obtaining a *
12 * copy of this software and associated documentation files (the "Software"), *
13 * to deal in the Software without restriction, including without limitation *
14 * the rights to use, copy, modify, merge, publish, distribute, sublicense, *
15 * and/or sell copies of the Software, and to permit persons to whom the *
16 * Software is furnished to do so, subject to the following conditions: *
17 * *
18 * The above copyright notice and this permission notice shall be included in *
19 * all copies or substantial portions of the Software. *
20 * *
21 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR *
22 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *
23 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE *
24 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER *
25 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING *
26 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER *
27 * DEALINGS IN THE SOFTWARE. *
28 * *
29 * *
30 ******************************************************************************/
31
32 /*
33 * alt_irq.h is the Nios II specific implementation of the interrupt controller
34 * interface.
35 *
36 * Nios II includes optional support for an external interrupt controller.
37 * When an external controller is present, the "Enhanced" interrupt API
38 * must be used to manage individual interrupts. The enhanced API also
39 * supports the processor's internal interrupt controller. Certain API
40 * members are accessible from either the "legacy" or "enhanced" interrpt
41 * API.
42 *
43 * Regardless of which API is in use, this file should be included by
44 * application code and device drivers that register ISRs or manage interrpts.
45 */
46 #include <errno.h>
47
48 #include "nios2.h"
49 #include "alt_types.h"
50 #include "system.h"
51
52 #ifdef __cplusplus
53 extern "C"
54 {
55 #endif /* __cplusplus */
56
57 /*
58 * Macros used by alt_irq_enabled
59 */
60 #define ALT_IRQ_ENABLED 1
61 #define ALT_IRQ_DISABLED 0
62
63 /*
64 * Number of available interrupts in internal interrupt controller.
65 */
66 #define ALT_NIRQ NIOS2_NIRQ
67
68 /*
69 * Used by alt_irq_disable_all() and alt_irq_enable_all().
70 */
71 typedef int alt_irq_context;
72
73 /* ISR Prototype */
74 #ifdef ALT_ENHANCED_INTERRUPT_API_PRESENT
75 typedef void (*alt_isr_func)(void* isr_context);
76 #else
77 typedef void (*alt_isr_func)(void* isr_context, alt_u32 id);
78 #endif
79
80 /*
81 * The following protypes and routines are supported by both
82 * the enhanced and legacy interrupt APIs
83 */
84
85 /*
86 * alt_irq_enabled can be called to determine if the processor's global
87 * interrupt enable is asserted. The return value is zero if interrupts
88 * are disabled, and non-zero otherwise.
89 *
90 * Whether the internal or external interrupt controller is present,
91 * individual interrupts may still be disabled. Use the other API to query
92 * a specific interrupt.
93 */
alt_irq_enabled(void)94 static ALT_INLINE int ALT_ALWAYS_INLINE alt_irq_enabled (void)
95 {
96 int status;
97
98 NIOS2_READ_STATUS (status);
99
100 return status & NIOS2_STATUS_PIE_MSK;
101 }
102
103 /*
104 * alt_irq_disable_all()
105 *
106 * This routine inhibits all interrupts by negating the status register PIE
107 * bit. It returns the previous contents of the CPU status register (IRQ
108 * context) which can be used to restore the status register PIE bit to its
109 * state before this routine was called.
110 */
111 static ALT_INLINE alt_irq_context ALT_ALWAYS_INLINE
alt_irq_disable_all(void)112 alt_irq_disable_all (void)
113 {
114 alt_irq_context context;
115
116 NIOS2_READ_STATUS (context);
117
118 NIOS2_WRITE_STATUS (context & ~NIOS2_STATUS_PIE_MSK);
119
120 return context;
121 }
122
123 /*
124 * alt_irq_enable_all()
125 *
126 * Enable all interrupts that were previously disabled by alt_irq_disable_all()
127 *
128 * This routine accepts a context to restore the CPU status register PIE bit
129 * to the state prior to a call to alt_irq_disable_all().
130
131 * In the case of nested calls to alt_irq_disable_all()/alt_irq_enable_all(),
132 * this means that alt_irq_enable_all() does not necessarily re-enable
133 * interrupts.
134 *
135 * This routine will perform a read-modify-write sequence to restore only
136 * status.PIE if the processor is configured with options that add additional
137 * writeable status register bits. These include the MMU, MPU, the enhanced
138 * interrupt controller port, and shadow registers. Otherwise, as a performance
139 * enhancement, status is overwritten with the prior context.
140 */
141 static ALT_INLINE void ALT_ALWAYS_INLINE
alt_irq_enable_all(alt_irq_context context)142 alt_irq_enable_all (alt_irq_context context)
143 {
144 #if (NIOS2_NUM_OF_SHADOW_REG_SETS > 0) || (defined NIOS2_EIC_PRESENT) || \
145 (defined NIOS2_MMU_PRESENT) || (defined NIOS2_MPU_PRESENT)
146 alt_irq_context status;
147
148 NIOS2_READ_STATUS (status);
149
150 status &= ~NIOS2_STATUS_PIE_MSK;
151 status |= (context & NIOS2_STATUS_PIE_MSK);
152
153 NIOS2_WRITE_STATUS (status);
154 #else
155 NIOS2_WRITE_STATUS (context);
156 #endif
157 }
158
159 /*
160 * The function alt_irq_init() is defined within the auto-generated file
161 * alt_sys_init.c. This function calls the initilization macros for all
162 * interrupt controllers in the system at config time, before any other
163 * non-interrupt controller driver is initialized.
164 *
165 * The "base" parameter is ignored and only present for backwards-compatibility.
166 * It is recommended that NULL is passed in for the "base" parameter.
167 */
168 extern void alt_irq_init (const void* base);
169
170 /*
171 * alt_irq_cpu_enable_interrupts() enables the CPU to start taking interrupts.
172 */
173 static ALT_INLINE void ALT_ALWAYS_INLINE
alt_irq_cpu_enable_interrupts(void)174 alt_irq_cpu_enable_interrupts (void)
175 {
176 NIOS2_WRITE_STATUS(NIOS2_STATUS_PIE_MSK
177 #if defined(NIOS2_EIC_PRESENT) && (NIOS2_NUM_OF_SHADOW_REG_SETS > 0)
178 | NIOS2_STATUS_RSIE_MSK
179 #endif
180 );
181 }
182
183
184 /*
185 * Prototypes for the enhanced interrupt API.
186 */
187 #ifdef ALT_ENHANCED_INTERRUPT_API_PRESENT
188 /*
189 * alt_ic_isr_register() can be used to register an interrupt handler. If the
190 * function is succesful, then the requested interrupt will be enabled upon
191 * return.
192 */
193 extern int alt_ic_isr_register(alt_u32 ic_id,
194 alt_u32 irq,
195 alt_isr_func isr,
196 void *isr_context,
197 void *flags);
198
199 /*
200 * alt_ic_irq_enable() and alt_ic_irq_disable() enable/disable a specific
201 * interrupt by using IRQ port and interrupt controller instance.
202 */
203 int alt_ic_irq_enable (alt_u32 ic_id, alt_u32 irq);
204 int alt_ic_irq_disable(alt_u32 ic_id, alt_u32 irq);
205
206 /*
207 * alt_ic_irq_enabled() indicates whether a specific interrupt, as
208 * specified by IRQ port and interrupt controller instance is enabled.
209 */
210 alt_u32 alt_ic_irq_enabled(alt_u32 ic_id, alt_u32 irq);
211
212 #else
213 /*
214 * Prototypes for the legacy interrupt API.
215 */
216 #include "priv/alt_legacy_irq.h"
217 #endif
218
219
220 /*
221 * alt_irq_pending() returns a bit list of the current pending interrupts.
222 * This is used by alt_irq_handler() to determine which registered interrupt
223 * handlers should be called.
224 *
225 * This routine is only available for the Nios II internal interrupt
226 * controller.
227 */
228 #ifndef NIOS2_EIC_PRESENT
alt_irq_pending(void)229 static ALT_INLINE alt_u32 ALT_ALWAYS_INLINE alt_irq_pending (void)
230 {
231 alt_u32 active;
232
233 NIOS2_READ_IPENDING (active);
234
235 return active;
236 }
237 #endif
238
239 #ifdef __cplusplus
240 }
241 #endif /* __cplusplus */
242
243 #endif /* __ALT_IRQ_H__ */
244
