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wdenk80885a92004-02-26 23:46:20 +00001/***********************************************************************
2 *
3 * Copyright (C) 2004 by FS Forth-Systeme GmbH.
4 * All rights reserved.
5 *
6 * $Id: ns9750_serial.c,v 1.1 2004/02/16 10:37:20 mpietrek Exp $
7 * @Author: Markus Pietrek
8 * @Descr: Serial driver for the NS9750. Only one UART is supported yet.
9 * @References: [1] NS9750 Hardware Reference/December 2003
10 * @TODO: Implement Character GAP Timer when chip is fixed for PLL bypass
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License as
14 * published by the Free Software Foundation; either version 2 of
15 * the License, or (at your option) any later version.
16 *
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
21 *
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
25 * MA 02111-1307 USA
26 *
27 ***********************************************************************/
28
29#include <common.h>
30
wdenk80885a92004-02-26 23:46:20 +000031#include "ns9750_bbus.h" /* for GPIOs */
32#include "ns9750_ser.h" /* for serial configuration */
33
Wolfgang Denkd87080b2006-03-31 18:32:53 +020034DECLARE_GLOBAL_DATA_PTR;
35
Wolfgang Denk0fd30252006-08-30 23:02:10 +020036#if !defined(CONFIG_CONS_INDEX)
37#error "No console index specified."
38#endif
39
wdenk80885a92004-02-26 23:46:20 +000040#define CONSOLE CONFIG_CONS_INDEX
41
42static unsigned int calcBitrateRegister( void );
43static unsigned int calcRxCharGapRegister( void );
44
45static char cCharsAvailable; /* Numbers of chars in unCharCache */
46static unsigned int unCharCache; /* unCharCache is only valid if
47 * cCharsAvailable > 0 */
48
49/***********************************************************************
50 * @Function: serial_init
51 * @Return: 0
52 * @Descr: configures GPIOs and UART. Requires BBUS Master Reset turned off
53 ***********************************************************************/
54
Marek Vasut28ea4c32012-09-13 16:52:07 +020055static int ns9750_serial_init(void)
wdenk80885a92004-02-26 23:46:20 +000056{
57 unsigned int aunGPIOTxD[] = { 0, 8, 40, 44 };
58 unsigned int aunGPIORxD[] = { 1, 9, 41, 45 };
59
60 cCharsAvailable = 0;
61
62 /* configure TxD and RxD pins for their special function */
63 set_gpio_cfg_reg_val( aunGPIOTxD[ CONSOLE ],
64 NS9750_GPIO_CFG_FUNC_0 | NS9750_GPIO_CFG_OUTPUT );
65 set_gpio_cfg_reg_val( aunGPIORxD[ CONSOLE ],
66 NS9750_GPIO_CFG_FUNC_0 | NS9750_GPIO_CFG_INPUT );
67
68 /* configure serial engine */
69 *get_ser_reg_addr_channel( NS9750_SER_CTRL_A, CONSOLE ) =
70 NS9750_SER_CTRL_A_CE |
71 NS9750_SER_CTRL_A_STOP |
72 NS9750_SER_CTRL_A_WLS_8;
73
74 serial_setbrg();
75
76 *get_ser_reg_addr_channel( NS9750_SER_CTRL_B, CONSOLE ) =
77 NS9750_SER_CTRL_B_RCGT;
78
79 return 0;
80}
81
82/***********************************************************************
83 * @Function: serial_putc
84 * @Return: n/a
85 * @Descr: writes one character to the FIFO. Blocks until FIFO is not full
86 ***********************************************************************/
87
Marek Vasut28ea4c32012-09-13 16:52:07 +020088static void ns9750_serial_putc(const char c)
wdenk80885a92004-02-26 23:46:20 +000089{
90 if (c == '\n')
91 serial_putc( '\r' );
92
93 while (!(*get_ser_reg_addr_channel( NS9750_SER_STAT_A, CONSOLE) &
94 NS9750_SER_STAT_A_TRDY ) ) {
95 /* do nothing, wait for characters in FIFO sent */
96 }
97
98 *(volatile char*) get_ser_reg_addr_channel( NS9750_SER_FIFO,
99 CONSOLE) = c;
100}
101
102/***********************************************************************
103 * @Function: serial_puts
104 * @Return: n/a
105 * @Descr: writes non-zero string to the FIFO.
106 ***********************************************************************/
107
Marek Vasut28ea4c32012-09-13 16:52:07 +0200108static void ns9750_serial_puts(const char *s)
wdenk80885a92004-02-26 23:46:20 +0000109{
110 while (*s) {
111 serial_putc( *s++ );
112 }
113}
114
115/***********************************************************************
116 * @Function: serial_getc
117 * @Return: the character read
118 * @Descr: performs only 8bit accesses to the FIFO. No error handling
119 ***********************************************************************/
120
Marek Vasut28ea4c32012-09-13 16:52:07 +0200121static int ns9750_serial_getc(void)
wdenk80885a92004-02-26 23:46:20 +0000122{
123 int i;
124
125 while (!serial_tstc() ) {
126 /* do nothing, wait for incoming characters */
127 }
128
129 /* at least one character in unCharCache */
130 i = (int) (unCharCache & 0xff);
131
132 unCharCache >>= 8;
133 cCharsAvailable--;
134
135 return i;
136}
137
138/***********************************************************************
139 * @Function: serial_tstc
140 * @Return: 0 if no input available, otherwise != 0
141 * @Descr: checks for incoming FIFO not empty. Stores the incoming chars in
142 * unCharCache and the numbers of characters in cCharsAvailable
143 ***********************************************************************/
144
Marek Vasut28ea4c32012-09-13 16:52:07 +0200145static int ns9750_serial_tstc(void)
wdenk80885a92004-02-26 23:46:20 +0000146{
147 unsigned int unRegCache;
148
149 if ( cCharsAvailable )
150 return 1;
151
152 unRegCache = *get_ser_reg_addr_channel( NS9750_SER_STAT_A,CONSOLE );
153 if( unRegCache & NS9750_SER_STAT_A_RBC ) {
154 *get_ser_reg_addr_channel( NS9750_SER_STAT_A, CONSOLE ) =
155 NS9750_SER_STAT_A_RBC;
156 unRegCache = *get_ser_reg_addr_channel( NS9750_SER_STAT_A,
157 CONSOLE );
158 }
159
160 if ( unRegCache & NS9750_SER_STAT_A_RRDY ) {
161 cCharsAvailable = (unRegCache & NS9750_SER_STAT_A_RXFDB_MA)>>20;
162 if ( !cCharsAvailable )
163 cCharsAvailable = 4;
164
165 unCharCache = *get_ser_reg_addr_channel( NS9750_SER_FIFO,
166 CONSOLE );
167 return 1;
168 }
169
170 /* no chars available */
171 return 0;
172}
173
Marek Vasut28ea4c32012-09-13 16:52:07 +0200174static void ns9750_serial_setbrg(void)
wdenk80885a92004-02-26 23:46:20 +0000175{
176 *get_ser_reg_addr_channel( NS9750_SER_BITRATE, CONSOLE ) =
177 calcBitrateRegister();
178 *get_ser_reg_addr_channel( NS9750_SER_RX_CHAR_TIMER, CONSOLE ) =
179 calcRxCharGapRegister();
180}
181
182/***********************************************************************
183 * @Function: calcBitrateRegister
184 * @Return: value for the serial bitrate register
185 * @Descr: register value depends on clock frequency and baudrate
186 ***********************************************************************/
187
188static unsigned int calcBitrateRegister( void )
189{
wdenk80885a92004-02-26 23:46:20 +0000190 return ( NS9750_SER_BITRATE_EBIT |
191 NS9750_SER_BITRATE_CLKMUX_BCLK |
192 NS9750_SER_BITRATE_TMODE |
193 NS9750_SER_BITRATE_TCDR_16 |
194 NS9750_SER_BITRATE_RCDR_16 |
195 ( ( ( ( CONFIG_SYS_CLK_FREQ / 8 ) / /* BBUS clock,[1] Fig. 38 */
196 ( gd->baudrate * 16 ) ) - 1 ) &
197 NS9750_SER_BITRATE_N_MA ) );
198}
199
200/***********************************************************************
201 * @Function: calcRxCharGapRegister
202 * @Return: value for the character gap timer register
203 * @Descr: register value depends on clock frequency and baudrate. Currently 0
204 * is used as there is a bug with the gap timer in PLL bypass mode.
205 ***********************************************************************/
206
207static unsigned int calcRxCharGapRegister( void )
208{
wdenk80885a92004-02-26 23:46:20 +0000209 return NS9750_SER_RX_CHAR_TIMER_TRUN;
210}
Marek Vasut28ea4c32012-09-13 16:52:07 +0200211
212#ifdef CONFIG_SERIAL_MULTI
213static struct serial_device ns9750_serial_drv = {
214 .name = "ns9750_serial",
215 .start = ns9750_serial_init,
216 .stop = NULL,
217 .setbrg = ns9750_serial_setbrg,
218 .putc = ns9750_serial_putc,
219 .puts = ns9750_serial_puts,
220 .getc = ns9750_serial_getc,
221 .tstc = ns9750_serial_tstc,
222};
223
224void ns9750_serial_initialize(void)
225{
226 serial_register(&ns9750_serial_drv);
227}
228
229__weak struct serial_device *default_serial_console(void)
230{
231 return &ns9750_serial_drv;
232}
233#else
234int serial_init(void)
235{
236 return ns9750_serial_init();
237}
238
239void serial_setbrg(void)
240{
241 ns9750_serial_setbrg();
242}
243
244void serial_putc(const char c)
245{
246 ns9750_serial_putc(c);
247}
248
249void serial_puts(const char *s)
250{
251 ns9750_serial_puts(s);
252}
253
254int serial_getc(void)
255{
256 return ns9750_serial_getc();
257}
258
259int serial_tstc(void)
260{
261 return ns9750_serial_tstc();
262}
263#endif