source: rtems/c/src/lib/libbsp/i386/shared/irq/irq.h @ 5fa14794

4.104.114.84.95
Last change on this file since 5fa14794 was c629812, checked in by Joel Sherrill <joel.sherrill@…>, on 12/13/99 at 22:10:45

Removed warnings.

  • Property mode set to 100644
File size: 8.5 KB
Line 
1/* irq.h
2 *
3 *  This include file describe the data structure and the functions implemented
4 *  by rtems to write interrupt handlers.
5 *
6 *  CopyRight (C) 1998 valette@crf.canon.fr
7 *
8 *  This code is heavilly inspired by the public specification of STREAM V2
9 *  that can be found at :
10 *
11 *      <http://www.chorus.com/Documentation/index.html> by following
12 *  the STREAM API Specification Document link.
13 *
14 *  The license and distribution terms for this file may be
15 *  found in found in the file LICENSE in this distribution or at
16 *  http://www.OARcorp.com/rtems/license.html.
17 *
18 *  $Id$
19 */
20
21#ifndef _IRQ_H_
22#define _IRQ_H_
23
24#ifdef __cplusplus
25extern "C" {
26#endif
27
28/*
29 * Include some preprocessor value also used by assember code
30 */
31 
32#include <irq_asm.h>
33#include <rtems.h>
34/*-------------------------------------------------------------------------+
35| Constants
36+--------------------------------------------------------------------------*/
37
38typedef enum {
39    /* Base vector for our IRQ handlers. */
40  BSP_IRQ_VECTOR_BASE           =       BSP_ASM_IRQ_VECTOR_BASE,       
41  BSP_IRQ_LINES_NUMBER          =       16,
42  BSP_LOWEST_OFFSET             =       0,
43  BSP_MAX_OFFSET                =       BSP_IRQ_LINES_NUMBER - 1,
44    /*
45     * Interrupt offset in comparison to BSP_ASM_IRQ_VECTOR_BASE
46     * NB : 1) Interrupt vector number in IDT = offset + BSP_ASM_IRQ_VECTOR_BASE
47     *      2) The same name should be defined on all architecture
48     *         so that handler connexion can be unchanged.
49     */       
50  BSP_PERIODIC_TIMER            =       0,
51
52  BSP_KEYBOARD                  =       1,
53
54  BSP_UART_COM2_IRQ             =       3,
55
56  BSP_UART_COM1_IRQ             =       4,
57
58  BSP_RT_TIMER1         =       8,
59 
60  BSP_RT_TIMER3         =       10
61} rtems_irq_symbolic_name;
62
63   
64
65
66/*
67 * Type definition for RTEMS managed interrupts
68 */
69typedef unsigned char  rtems_irq_prio;
70typedef unsigned short rtems_i8259_masks;
71
72extern  rtems_i8259_masks i8259s_cache;
73
74struct  __rtems_irq_connect_data__;     /* forward declaratiuon */
75
76typedef void (*rtems_irq_hdl)           (void);
77typedef void (*rtems_irq_enable)        (const struct __rtems_irq_connect_data__*);
78typedef void (*rtems_irq_disable)       (const struct __rtems_irq_connect_data__*);
79typedef int  (*rtems_irq_is_enabled)    (const struct __rtems_irq_connect_data__*);
80
81typedef struct __rtems_irq_connect_data__ {
82  /*
83   * IRQ line
84   */
85  rtems_irq_symbolic_name       name;
86  /*
87   * handler. See comment on handler properties below in function prototype.
88   */
89  rtems_irq_hdl                 hdl;
90  /*
91   * function for enabling interrupts at device level (ONLY!).
92   * The BSP code will automatically enable it at i8259s level.
93   * RATIONALE : anyway such code has to exist in current driver code.
94   * It is usually called immediately AFTER connecting the interrupt handler.
95   * RTEMS may well need such a function when restoring normal interrupt
96   * processing after a debug session.
97   *
98   */
99    rtems_irq_enable            on;     
100  /*
101   * function for disabling interrupts at device level (ONLY!).
102   * The code will disable it at i8259s level. RATIONALE : anyway
103   * such code has to exist for clean shutdown. It is usually called
104   * BEFORE disconnecting the interrupt. RTEMS may well need such
105   * a function when disabling normal interrupt processing for
106   * a debug session. May well be a NOP function.
107   */
108  rtems_irq_disable             off;
109  /*
110   * function enabling to know what interrupt may currently occur
111   * if someone manipulates the i8259s interrupt mask without care...
112   */
113    rtems_irq_is_enabled        isOn;
114} rtems_irq_connect_data;
115
116typedef struct {
117  /*
118   * size of all the table fields (*Tbl) described below.
119   */
120  unsigned int                  irqNb;
121  /*
122   * Default handler used when disconnecting interrupts.
123   */
124  rtems_irq_connect_data        defaultEntry;
125  /*
126   * Table containing initials/current value.
127   */
128  rtems_irq_connect_data*       irqHdlTbl;
129  /*
130   * actual value of BSP_IRQ_VECTOR_BASE...
131   */
132  rtems_irq_symbolic_name       irqBase;
133  /*
134   * software priorities associated with interrupts.
135   * if irqPrio  [i]  >  intrPrio  [j]  it  means  that 
136   * interrupt handler hdl connected for interrupt name i
137   * will  not be interrupted by the handler connected for interrupt j
138   * The interrupt source  will be physically masked at i8259 level.
139   */
140    rtems_irq_prio*             irqPrioTbl;
141}rtems_irq_global_settings;
142
143
144
145
146/*-------------------------------------------------------------------------+
147| Function Prototypes.
148+--------------------------------------------------------------------------*/
149/*
150 * ------------------------ Intel 8259 (or emulation) Mngt Routines -------
151 */
152
153/*
154 * function to disable a particular irq at 8259 level. After calling
155 * this function, even if the device asserts the interrupt line it will
156 * not be propagated further to the processor
157 */
158int BSP_irq_disable_at_i8259s        (const rtems_irq_symbolic_name irqLine);
159/*
160 * function to enable a particular irq at 8259 level. After calling
161 * this function, if the device asserts the interrupt line it will
162 * be propagated further to the processor
163 */
164int BSP_irq_enable_at_i8259s            (const rtems_irq_symbolic_name irqLine);
165/*
166 * function to acknoledge a particular irq at 8259 level. After calling
167 * this function, if a device asserts an enabled interrupt line it will
168 * be propagated further to the processor. Mainly usefull for people
169 * writting raw handlers as this is automagically done for rtems managed
170 * handlers.
171 */
172int BSP_irq_ack_at_i8259s               (const rtems_irq_symbolic_name irqLine);
173/*
174 * function to check if a particular irq is enabled at 8259 level. After calling
175 */
176int BSP_irq_enabled_at_i8259s           (const rtems_irq_symbolic_name irqLine);
177/*
178 * ------------------------ RTEMS Single Irq Handler Mngt Routines ----------------
179 */
180/*
181 * function to connect a particular irq handler. This hanlder will NOT be called
182 * directly as the result of the corresponding interrupt. Instead, a RTEMS
183 * irq prologue will be called that will :
184 *
185 *      1) save the C scratch registers,
186 *      2) switch to a interrupt stack if the interrupt is not nested,
187 *      3) store the current i8259s' interrupt masks
188 *      4) modify them to disable the current interrupt at 8259 level (and may
189 *      be others depending on software priorities)
190 *      5) aknowledge the i8259s',
191 *      6) demask the processor,
192 *      7) call the application handler
193 *
194 * As a result the hdl function provided
195 *
196 *      a) can perfectly be written is C,
197 *      b) may also well directly call the part of the RTEMS API that can be used
198 *      from interrupt level,
199 *      c) It only responsible for handling the jobs that need to be done at
200 *      the device level including (aknowledging/re-enabling the interrupt at device,
201 *      level, getting the data,...)
202 *
203 *      When returning from the function, the following will be performed by
204 *      the RTEMS irq epilogue :
205 *
206 *      1) masks the interrupts again,
207 *      2) restore the original i8259s' interrupt masks
208 *      3) switch back on the orinal stack if needed,
209 *      4) perform rescheduling when necessary,
210 *      5) restore the C scratch registers...
211 *      6) restore initial execution flow
212 *
213 */
214int BSP_install_rtems_irq_handler       (const rtems_irq_connect_data*);
215/*
216 * function to get the current RTEMS irq handler for ptr->name. It enables to
217 * define hanlder chain...
218 */
219int BSP_get_current_rtems_irq_handler   (rtems_irq_connect_data* ptr);
220/*
221 * function to get disconnect the RTEMS irq handler for ptr->name.
222 * This function checks that the value given is the current one for safety reason.
223 * The user can use the previous function to get it.
224 */
225int BSP_remove_rtems_irq_handler        (const rtems_irq_connect_data*);
226
227/*
228 * ------------------------ RTEMS Global Irq Handler Mngt Routines ----------------
229 */
230/*
231 * (Re) Initialize the RTEMS interrupt management.
232 *
233 * The result of calling this function will be the same as if each individual
234 * handler (config->irqHdlTbl[i].hdl)  different from "config->defaultEntry.hdl"
235 * has been individualy connected via
236 *      BSP_install_rtems_irq_handler(&config->irqHdlTbl[i])
237 * And each handler currently equal to config->defaultEntry.hdl
238 * has been previously disconnected via
239 *       BSP_remove_rtems_irq_handler (&config->irqHdlTbl[i])
240 *
241 * This is to say that all information given will be used and not just
242 * only the space.
243 *
244 * CAUTION : the various table address contained in config will be used
245 *           directly by the interrupt mangement code in order to save
246 *           data size so they must stay valid after the call => they should
247 *           not be modified or declared on a stack.
248 */
249
250int BSP_rtems_irq_mngt_set(rtems_irq_global_settings* config);
251/*
252 * (Re) get info on current RTEMS interrupt management.
253 */
254int BSP_rtems_irq_mngt_get(rtems_irq_global_settings**);
255 
256#ifdef __cplusplus
257}
258#endif
259
260#endif /* _IRQ_H_ */
261/* end of include file */
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