source: trunk/package/uboot-lantiq/files/drivers/serial/ifx_asc.c @ 20561

Last change on this file since 20561 was 20561, checked in by nbd, 7 years ago

add uboot-lantiq (based on a patch contributed by Lantiq)

File size: 5.3 KB
Line 
1/*
2 * (C) Copyright 2003
3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4 * (C) Copyright 2009
5 * Infineon Technologies AG, http://www.infineon.com
6 *
7 * See file CREDITS for list of people who contributed to this
8 * project.
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation; either version 2 of
13 * the License, or (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
23 * MA 02111-1307 USA
24 */
25
26#include <config.h>
27#include <common.h>
28#include <asm/io.h>
29#include <asm/addrspace.h>
30
31#include "ifx_asc.h"
32
33#define SET_BIT(reg, mask)                      asc_writel(reg, asc_readl(reg) | (mask))
34#define CLEAR_BIT(reg, mask)                    asc_writel(reg, asc_readl(reg) & (~mask))
35#define SET_BITFIELD(reg, mask, off, val)       asc_writel(reg, (asc_readl(reg) & (~mask)) | (val << off) )
36
37#undef DEBUG_ASC_RAW
38#ifdef DEBUG_ASC_RAW
39#define DEBUG_ASC_RAW_RX_BUF                    0xA0800000
40#define DEBUG_ASC_RAW_TX_BUF                    0xA0900000
41#endif
42
43DECLARE_GLOBAL_DATA_PTR;
44
45static IfxAsc_t *pAsc = (IfxAsc_t *)CKSEG1ADDR(CONFIG_SYS_IFX_ASC_BASE);
46
47/*
48 *             FDV            fASC
49 * BaudRate = ----- * --------------------
50 *             512    16 * (ReloadValue+1)
51 */
52
53/*
54 *                  FDV          fASC
55 * ReloadValue = ( ----- * --------------- ) - 1
56 *                  512     16 * BaudRate
57 */
58static void serial_divs(u32 baudrate, u32 fasc, u32 *pfdv, u32 *preload)
59{
60   u32 clock = fasc / 16;
61
62   u32 fdv; /* best fdv */
63   u32 reload = 0; /* best reload */
64   u32 diff; /* smallest diff */
65   u32 idiff; /* current diff */
66   u32 ireload; /* current reload */
67   u32 i; /* current fdv */
68   u32 result; /* current resulting baudrate */
69
70   if (clock > 0x7FFFFF)
71      clock /= 512;
72   else
73      baudrate *= 512;
74
75   fdv = 512; /* start with 1:1 fraction */
76   diff = baudrate; /* highest possible */
77
78   /* i is the test fdv value -- start with the largest possible */
79   for (i = 512; i > 0; i--)
80   {
81      ireload = (clock * i) / baudrate;
82      if (ireload < 1)
83         break; /* already invalid */
84      result = (clock * i) / ireload;
85
86      idiff = (result > baudrate) ? (result - baudrate) : (baudrate - result);
87      if (idiff == 0)
88      {
89         fdv = i;
90         reload = ireload;
91         break; /* can't do better */
92      }
93      else if (idiff < diff)
94      {
95         fdv = i; /* best so far */
96         reload = ireload;
97         diff = idiff; /* update lowest diff*/
98      }
99   }
100
101   *pfdv = (fdv == 512) ? 0 : fdv;
102   *preload = reload - 1;
103}
104
105
106void serial_setbrg (void)
107{
108        u32 ReloadValue, fdv;
109
110        serial_divs(gd->baudrate, get_bus_freq(0), &fdv, &ReloadValue);
111
112        /* Disable Baud Rate Generator; BG should only be written when R=0 */
113        CLEAR_BIT(asc_con, ASCCON_R);
114
115        /* Enable Fractional Divider */
116        SET_BIT(asc_con, ASCCON_FDE);   /* FDE = 1 */
117
118        /* Set fractional divider value */
119        asc_writel(asc_fdv, fdv & ASCFDV_VALUE_MASK);
120
121        /* Set reload value in BG */
122        asc_writel(asc_bg, ReloadValue);
123
124        /* Enable Baud Rate Generator */
125        SET_BIT(asc_con, ASCCON_R);     /* R = 1 */
126}
127
128
129int serial_init (void)
130{
131
132        /* and we have to set CLC register*/
133        CLEAR_BIT(asc_clc, ASCCLC_DISS);
134        SET_BITFIELD(asc_clc, ASCCLC_RMCMASK, ASCCLC_RMCOFFSET, 0x0001);
135
136        /* initialy we are in async mode */
137        asc_writel(asc_con, ASCCON_M_8ASYNC);
138
139        /* select input port */
140        asc_writel(asc_pisel, CONSOLE_TTY & 0x1);
141
142        /* TXFIFO's filling level */
143        SET_BITFIELD(asc_txfcon, ASCTXFCON_TXFITLMASK,
144                        ASCTXFCON_TXFITLOFF, ASC_TXFIFO_FL);
145        /* enable TXFIFO */
146        SET_BIT(asc_txfcon, ASCTXFCON_TXFEN);
147
148        /* RXFIFO's filling level */
149        SET_BITFIELD(asc_txfcon, ASCRXFCON_RXFITLMASK,
150                        ASCRXFCON_RXFITLOFF, ASC_RXFIFO_FL);
151        /* enable RXFIFO */
152        SET_BIT(asc_rxfcon, ASCRXFCON_RXFEN);
153
154        /* set baud rate */
155        serial_setbrg();
156
157        /* enable error signals &  Receiver enable  */
158        SET_BIT(asc_whbstate, ASCWHBSTATE_SETREN|ASCCON_FEN|ASCCON_TOEN|ASCCON_ROEN);
159
160        return 0;
161}
162
163
164void serial_putc (const char c)
165{
166        u32 txFl = 0;
167#ifdef DEBUG_ASC_RAW
168        static u8 * debug = (u8 *) DEBUG_ASC_RAW_TX_BUF;
169        *debug++=c;
170#endif
171        if (c == '\n')
172                serial_putc ('\r');
173        /* check do we have a free space in the TX FIFO */
174        /* get current filling level */
175        do {
176                txFl = ( asc_readl(asc_fstat) & ASCFSTAT_TXFFLMASK ) >> ASCFSTAT_TXFFLOFF;
177        }
178        while ( txFl == ASC_TXFIFO_FULL );
179
180        asc_writel(asc_tbuf, c); /* write char to Transmit Buffer Register */
181
182        /* check for errors */
183        if ( asc_readl(asc_state) & ASCSTATE_TOE ) {
184                SET_BIT(asc_whbstate, ASCWHBSTATE_CLRTOE);
185                return;
186        }
187}
188
189void serial_puts (const char *s)
190{
191        while (*s) {
192                serial_putc (*s++);
193        }
194}
195
196int serial_getc (void)
197{
198        char c;
199        while ((asc_readl(asc_fstat) & ASCFSTAT_RXFFLMASK) == 0 );
200        c = (char)(asc_readl(asc_rbuf) & 0xff);
201
202#ifdef  DEBUG_ASC_RAW
203        static u8* debug=(u8*)(DEBUG_ASC_RAW_RX_BUF);
204        *debug++=c;
205#endif
206        return c;
207}
208
209
210int serial_tstc (void)
211{
212        int res = 1;
213
214        if ( (asc_readl(asc_fstat) & ASCFSTAT_RXFFLMASK) == 0 ) {
215                res = 0;
216        }
217        return res;
218}
Note: See TracBrowser for help on using the repository browser.