source: trunk/kernel/devices/dev_txt.h @ 429

Last change on this file since 429 was 422, checked in by alain, 6 years ago

cosmetic

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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};
85
86typedef struct txt_command_s
87{
88    xptr_t      dev_xp;    /*! extended pointer on the relevant TXT device descriptor    */
89    uint32_t    type;      /*! TXT_READ / TXT_WRITE / TXT_SYNC_WRITE                     */
90    xptr_t      buf_xp;    /*! extended pointer on characters array                      */
91    uint32_t    count;     /*! number of characters in buffer (must be 1 if to_mem)      */
92    uint32_t    error;     /*! operation status (0 if success)                           */
93}
94txt_command_t;
95
96/******************************************************************************************
97 * This defines the arguments passed to the driver AUX function.
98 * This function implement the TXT_SYNC_WRITE operation.
99 *****************************************************************************************/
100
101typedef struct txt_aux_s
102{
103    xptr_t      dev_xp;    /*! extended pointer on the TXT0 device descriptor            */
104    char      * buffer;    /*! local pointer on characters array                         */
105    uint32_t    count;     /*! number of characters in buffer                            */
106}
107txt_aux_t;
108
109/******************************************************************************************
110 * This function completes the TXT chdev descriptor initialisation,
111 * namely the link with the implementation specific driver.
112 * The func, impl, channel, is_rxt, base fields have been previously initialised.
113 * It calls the specific driver initialisation function, to initialise the hardware
114 * device and the driver specific data structures when required.
115 * It creates the associated server thread and allocates a WTI from local ICU.
116 * It must de executed by a local thread.
117 ******************************************************************************************
118 * @ chdev     : local pointer on TXT device descriptor.
119 *****************************************************************************************/
120void dev_txt_init( struct chdev_s * chdev );
121
122/******************************************************************************************
123 * This blocking function reads a single character from the terminal identified
124 * by the "channel" argument. The corresponding request is actually registered in the
125 * chdev requests queue, and the calling thread is descheduled, blocked until
126 * transfer completion.
127 * It must be called in the client cluster.
128 ******************************************************************************************
129 * @ channel   : TXT channel index.
130 * @ buffer    : local pointer on destination buffer for the character.
131 * @ returns 0 if success / returns EINVAL if error.
132 *****************************************************************************************/
133error_t dev_txt_read( uint32_t        channel,
134                      char          * buffer );
135
136/******************************************************************************************
137 * This blocking function writes characters on the terminal identified
138 * by the "channel" argument. The corresponding request is actually registered in the
139 * chdev requests queue, and the calling thread is descheduled, blocked until
140 * transfer completion.
141 * It must be called in the client cluster.
142 ******************************************************************************************
143 * @ channel   : TXT channel index.
144 * @ buffer    : local pointer on source buffer containing the string.
145 * @ count     : number of characters.
146 * @ returns 0 if success / returns EINVAL if error.
147 ****************************************************************************************/
148error_t dev_txt_write( uint32_t        channel,
149                       char          * buffer,
150                       uint32_t        count );
151
152/***************************************************************************************
153 * This blocking function is used by the kernel to display a string on the TXT0
154 * terminal, without descheduling the calling thread, without registering it
155 * in the TXT0 device waiting queue, without using the TXT0 irq, and without
156 * interfering with another possible TXT access to another terminal.
157 * As it is used for debug, the command arguments <buffer> and <count> are registerd
158 * in a specific "dbg_cmd" field of the calling thread.
159 * other TXT accesses.
160 ****************************************************************************************
161 * @ buffer    : local pointer on source buffer containing the string.
162 * @ count     : number of characters.
163 * @ returns 0 if success / returns EINVAL if error.
164 ***************************************************************************************/
165error_t dev_txt_sync_write( char     * buffer,
166                            uint32_t   count );
167
168#endif  /* _DEV_TXT_H_ */
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