1 /* 2 * Copyright (C) 2004-2006 Atmel Corporation 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation; either version 2 of the License, or 7 * (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write to the Free Software 16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 17 */ 18 #include <common.h> 19 #include <watchdog.h> 20 21 #include <asm/io.h> 22 #include <asm/arch/clk.h> 23 #include <asm/arch/memory-map.h> 24 25 #if defined(CONFIG_USART0) 26 # define USART_ID 0 27 # define USART_BASE USART0_BASE 28 #elif defined(CONFIG_USART1) 29 # define USART_ID 1 30 # define USART_BASE USART1_BASE 31 #elif defined(CONFIG_USART2) 32 # define USART_ID 2 33 # define USART_BASE USART2_BASE 34 #elif defined(CONFIG_USART3) 35 # define USART_ID 3 36 # define USART_BASE USART3_BASE 37 #endif 38 39 #include "atmel_usart.h" 40 41 DECLARE_GLOBAL_DATA_PTR; 42 43 void serial_setbrg(void) 44 { 45 unsigned long divisor; 46 unsigned long usart_hz; 47 48 /* 49 * Master Clock 50 * Baud Rate = -------------- 51 * 16 * CD 52 */ 53 usart_hz = get_usart_clk_rate(USART_ID); 54 divisor = (usart_hz / 16 + gd->baudrate / 2) / gd->baudrate; 55 usart3_writel(BRGR, USART3_BF(CD, divisor)); 56 } 57 58 int serial_init(void) 59 { 60 usart3_writel(CR, USART3_BIT(RSTRX) | USART3_BIT(RSTTX)); 61 62 serial_setbrg(); 63 64 usart3_writel(CR, USART3_BIT(RXEN) | USART3_BIT(TXEN)); 65 usart3_writel(MR, (USART3_BF(USART_MODE, USART3_USART_MODE_NORMAL) 66 | USART3_BF(USCLKS, USART3_USCLKS_MCK) 67 | USART3_BF(CHRL, USART3_CHRL_8) 68 | USART3_BF(PAR, USART3_PAR_NONE) 69 | USART3_BF(NBSTOP, USART3_NBSTOP_1))); 70 71 return 0; 72 } 73 74 void serial_putc(char c) 75 { 76 if (c == '\n') 77 serial_putc('\r'); 78 79 while (!(usart3_readl(CSR) & USART3_BIT(TXRDY))) ; 80 usart3_writel(THR, c); 81 } 82 83 void serial_puts(const char *s) 84 { 85 while (*s) 86 serial_putc(*s++); 87 } 88 89 int serial_getc(void) 90 { 91 while (!(usart3_readl(CSR) & USART3_BIT(RXRDY))) 92 WATCHDOG_RESET(); 93 return usart3_readl(RHR); 94 } 95 96 int serial_tstc(void) 97 { 98 return (usart3_readl(CSR) & USART3_BIT(RXRDY)) != 0; 99 } 100