1 /* 2 * Copyright (C) 2004-2006 Atmel Corporation 3 * 4 * Modified to support C structur SoC access by 5 * Andreas Bießmann <biessmann@corscience.de> 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation; either version 2 of the License, or 10 * (at your option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 20 */ 21 #include <common.h> 22 #include <watchdog.h> 23 24 #include <asm/io.h> 25 #include <asm/arch/clk.h> 26 #include <asm/arch/hardware.h> 27 28 #include "atmel_usart.h" 29 30 DECLARE_GLOBAL_DATA_PTR; 31 32 void serial_setbrg(void) 33 { 34 atmel_usart3_t *usart = (atmel_usart3_t *)CONFIG_USART_BASE; 35 unsigned long divisor; 36 unsigned long usart_hz; 37 38 /* 39 * Master Clock 40 * Baud Rate = -------------- 41 * 16 * CD 42 */ 43 usart_hz = get_usart_clk_rate(CONFIG_USART_ID); 44 divisor = (usart_hz / 16 + gd->baudrate / 2) / gd->baudrate; 45 writel(USART3_BF(CD, divisor), &usart->brgr); 46 } 47 48 int serial_init(void) 49 { 50 atmel_usart3_t *usart = (atmel_usart3_t *)CONFIG_USART_BASE; 51 52 /* 53 * Just in case: drain transmitter register 54 * 1000us is enough for baudrate >= 9600 55 */ 56 if (!(readl(&usart->csr) & USART3_BIT(TXEMPTY))) 57 __udelay(1000); 58 59 writel(USART3_BIT(RSTRX) | USART3_BIT(RSTTX), &usart->cr); 60 61 serial_setbrg(); 62 63 writel((USART3_BF(USART_MODE, USART3_USART_MODE_NORMAL) 64 | USART3_BF(USCLKS, USART3_USCLKS_MCK) 65 | USART3_BF(CHRL, USART3_CHRL_8) 66 | USART3_BF(PAR, USART3_PAR_NONE) 67 | USART3_BF(NBSTOP, USART3_NBSTOP_1)), 68 &usart->mr); 69 writel(USART3_BIT(RXEN) | USART3_BIT(TXEN), &usart->cr); 70 /* 100us is enough for the new settings to be settled */ 71 __udelay(100); 72 73 return 0; 74 } 75 76 void serial_putc(char c) 77 { 78 atmel_usart3_t *usart = (atmel_usart3_t *)CONFIG_USART_BASE; 79 80 if (c == '\n') 81 serial_putc('\r'); 82 83 while (!(readl(&usart->csr) & USART3_BIT(TXRDY))); 84 writel(c, &usart->thr); 85 } 86 87 void serial_puts(const char *s) 88 { 89 while (*s) 90 serial_putc(*s++); 91 } 92 93 int serial_getc(void) 94 { 95 atmel_usart3_t *usart = (atmel_usart3_t *)CONFIG_USART_BASE; 96 97 while (!(readl(&usart->csr) & USART3_BIT(RXRDY))) 98 WATCHDOG_RESET(); 99 return readl(&usart->rhr); 100 } 101 102 int serial_tstc(void) 103 { 104 atmel_usart3_t *usart = (atmel_usart3_t *)CONFIG_USART_BASE; 105 return (readl(&usart->csr) & USART3_BIT(RXRDY)) != 0; 106 } 107