source: trunk/kernel/devices/dev_txt.h @ 453

Last change on this file since 453 was 435, checked in by alain, 7 years ago

Fix a bad bug in scheduler...
File size: 8.4 KB
Line 
1/*
2 * dev_txt.h - TXT (Text Terminal) generic device API definition.
3 *
4 * Author  Alain Greiner    (2016)
5 *
6 * Copyright (c) UPMC Sorbonne Universites
7 *
8 * This file is part of ALMOS-MKH
9 *
10 * ALMOS-MKH is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; version 2.0 of the License.
13 *
14 * ALMOS-MKH is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17 * General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with ALMOS-kernel; if not, write to the Free Software Foundation,
21 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24#ifndef _DEV_TXT_H_
25#define _DEV_TXT_H_
26
27#include <kernel_config.h>
28#include <hal_types.h>
29#include <xlist.h>
30#include <remote_spinlock.h>
31
32/****  Forward declarations  ****/
33
34struct chdev_s ;
35
36/******************************************************************************************
37 *     Generic Text Terminal device definition.
38 *
39 * This multi-channels generic TXT device provides access to a text terminal.
40 *
41 * It supports two operations that must be implemented by the driver cmd() function:
42 * - TXT_READ : read a single character from the text terminal identified by its channel
43 *   index, using a descheduling strategy for the calling thread.
44 * - TXT_WRITE : write a character string to the text terminal identified by its channel
45 *   index, using a descheduling strategy for the calling thread.
46 *
47 * It supports one operation, that must be implemented by the driver aux() function 
48 * - TXT_SYNC_WRITE write a character string to the TXT0 kernel terminal, using a busy
49 *   waiting strategy for the calling thread.
50 *****************************************************************************************/
51
52/******************************************************************************************
53 * This defines the (implementation independant) extension for the generic TXT device.
54 *****************************************************************************************/
55
56typedef struct txt_extend_s
57{
58    xptr_t            owner_xp;  /*! ext. pointer on current process owner (reference)   */
59    xlist_entry_t     root;      /*! root of list of processes attached to   same TXT    */
60    remote_spinlock_t lock;      /*! lock protecting this list                           */
61}
62txt_extend_t;
63
64/******************************************************************************************
65 * This enum defines the various implementations of the generic TXT peripheral.
66 * This array must be kept consistent with the define in arch_info.h file
67 *****************************************************************************************/
68
69enum txt_impl_e
70{
71    IMPL_TXT_TTY =   0,
72    IMPL_TXT_RS2 =   1,
73}
74txt_impl_t;
75
76/******************************************************************************************
77 * This defines the arguments passed to the driver CMD function.
78 *****************************************************************************************/
79
80enum
81{
82    TXT_READ       = 0,
83    TXT_WRITE      = 1,
84    TXT_SYNC_WRITE = 2,
85};
86
87typedef struct txt_command_s
88{
89    xptr_t      dev_xp;    /*! extended pointer on the relevant TXT device descriptor    */
90    uint32_t    type;      /*! TXT_READ / TXT_WRITE                                      */
91    xptr_t      buf_xp;    /*! extended pointer on characters array                      */
92    uint32_t    count;     /*! number of characters in buffer (must be 1 if to_mem)      */
93    uint32_t    error;     /*! operation status (0 if success)                           */
94}
95txt_command_t;
96
97/******************************************************************************************
98 * This defines the arguments passed to the driver AUX function.
99 * This function implement the TXT_SYNC_WRITE operation.
100 *****************************************************************************************/
101
102typedef struct txt_sync_args_s
103{
104    xptr_t      dev_xp;    /*! extended pointer on the TXT0_TX device descriptor            */
105    char      * buffer;    /*! local pointer on characters array                         */
106    uint32_t    count;     /*! number of characters in buffer                            */
107}
108txt_sync_args_t;
109
110/******************************************************************************************
111 * This function returns a printable string for the comman type.
112 ******************************************************************************************
113 * @ type     : command type (TXT_READ / TXT_WRITE / TXT_SYNC_WRITE)
114 *****************************************************************************************/
115char * dev_txt_type_str( uint32_t type );
116
117/******************************************************************************************
118 * This function completes the TXT chdev descriptor initialisation,
119 * namely the link with the implementation specific driver.
120 * The func, impl, channel, is_rxt, base fields have been previously initialised.
121 * It calls the specific driver initialisation function, to initialise the hardware
122 * device and the driver specific data structures when required.
123 * It creates the associated server thread and allocates a WTI from local ICU.
124 * It must de executed by a local thread.
125 ******************************************************************************************
126 * @ chdev     : local pointer on TXT device descriptor.
127 *****************************************************************************************/
128void dev_txt_init( struct chdev_s * chdev );
129
130/******************************************************************************************
131 * This blocking function reads a single character from the terminal identified
132 * by the "channel" argument. The corresponding request is actually registered in the
133 * chdev requests queue, and the calling thread is descheduled, blocked until
134 * transfer completion.
135 * It must be called in the client cluster.
136 ******************************************************************************************
137 * @ channel   : TXT channel index.
138 * @ buffer    : local pointer on destination buffer for the character.
139 * @ returns 0 if success / returns EINVAL if error.
140 *****************************************************************************************/
141error_t dev_txt_read( uint32_t        channel,
142                      char          * buffer );
143
144/******************************************************************************************
145 * This blocking function writes characters on the terminal identified
146 * by the "channel" argument. The corresponding request is actually registered in the
147 * chdev requests queue, and the calling thread is descheduled, blocked until
148 * transfer completion.
149 * It must be called in the client cluster.
150 ******************************************************************************************
151 * @ channel   : TXT channel index.
152 * @ buffer    : local pointer on source buffer containing the string.
153 * @ count     : number of characters.
154 * @ returns 0 if success / returns EINVAL if error.
155 ****************************************************************************************/
156error_t dev_txt_write( uint32_t        channel,
157                       char          * buffer,
158                       uint32_t        count );
159
160/***************************************************************************************
161 * This blocking function is used by the kernel to display a string on the TXT0
162 * terminal, without descheduling the calling thread, without registering it
163 * in the TXT0 device waiting queue, without using the TXT0 irq, and without
164 * interfering with another possible TXT access to another terminal.
165 * As it is used for debug, the command arguments <buffer> and <count> are registerd
166 * in a specific "dbg_cmd" field of the calling thread.
167 ****************************************************************************************
168 * @ buffer    : local pointer on source buffer containing the string.
169 * @ count     : number of characters.
170 * @ returns 0 if success / returns EINVAL if error.
171 ***************************************************************************************/
172error_t dev_txt_sync_write( char     * buffer,
173                            uint32_t   count );
174
175#endif  /* _DEV_TXT_H_ */
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