| 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 | |
| 43 | DECLARE_GLOBAL_DATA_PTR; |
| 44 | |
| 45 | static 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 | */ |
| 58 | static 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 | |
| 106 | void 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 | |
| 129 | int 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 | |
| 164 | void 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 | |
| 189 | void serial_puts (const char *s) |
| 190 | { |
| 191 | while (*s) { |
| 192 | serial_putc (*s++); |
| 193 | } |
| 194 | } |
| 195 | |
| 196 | int 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 | |
| 210 | int 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 | } |
| 219 | |
