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 20 #include <asm/io.h> 21 #include <asm/arch/clk.h> 22 #include <asm/arch/memory-map.h> 23 24 #if defined(CONFIG_USART0) 25 # define USART_ID 0 26 # define USART_BASE USART0_BASE 27 #elif defined(CONFIG_USART1) 28 # define USART_ID 1 29 # define USART_BASE USART1_BASE 30 #elif defined(CONFIG_USART2) 31 # define USART_ID 2 32 # define USART_BASE USART2_BASE 33 #elif defined(CONFIG_USART3) 34 # define USART_ID 3 35 # define USART_BASE USART3_BASE 36 #endif 37 38 #include "atmel_usart.h" 39 40 DECLARE_GLOBAL_DATA_PTR; 41 42 void serial_setbrg(void) 43 { 44 unsigned long divisor; 45 unsigned long usart_hz; 46 47 /* 48 * Master Clock 49 * Baud Rate = -------------- 50 * 16 * CD 51 */ 52 usart_hz = get_usart_clk_rate(USART_ID); 53 divisor = (usart_hz / 16 + gd->baudrate / 2) / gd->baudrate; 54 usart3_writel(BRGR, USART3_BF(CD, divisor)); 55 } 56 57 int serial_init(void) 58 { 59 usart3_writel(CR, USART3_BIT(RSTRX) | USART3_BIT(RSTTX)); 60 61 serial_setbrg(); 62 63 usart3_writel(CR, USART3_BIT(RXEN) | USART3_BIT(TXEN)); 64 usart3_writel(MR, (USART3_BF(USART_MODE, USART3_USART_MODE_NORMAL) 65 | USART3_BF(USCLKS, USART3_USCLKS_MCK) 66 | USART3_BF(CHRL, USART3_CHRL_8) 67 | USART3_BF(PAR, USART3_PAR_NONE) 68 | USART3_BF(NBSTOP, USART3_NBSTOP_1))); 69 70 return 0; 71 } 72 73 void serial_putc(char c) 74 { 75 if (c == '\n') 76 serial_putc('\r'); 77 78 while (!(usart3_readl(CSR) & USART3_BIT(TXRDY))) ; 79 usart3_writel(THR, c); 80 } 81 82 void serial_puts(const char *s) 83 { 84 while (*s) 85 serial_putc(*s++); 86 } 87 88 int serial_getc(void) 89 { 90 while (!(usart3_readl(CSR) & USART3_BIT(RXRDY))) ; 91 return usart3_readl(RHR); 92 } 93 94 int serial_tstc(void) 95 { 96 return (usart3_readl(CSR) & USART3_BIT(RXRDY)) != 0; 97 } 98