1 /* 2 * Copyright (C) 2011 Vladimir Zapolskiy <vz@mleia.com> 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 2 7 * of the License, or (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., 51 Franklin Street, Fifth Floor, Boston, 17 * MA 02110-1301, USA. 18 */ 19 20 #include <common.h> 21 #include <asm/arch/cpu.h> 22 #include <asm/arch/clk.h> 23 #include <asm/arch/uart.h> 24 #include <asm/io.h> 25 #include <serial.h> 26 #include <linux/compiler.h> 27 28 DECLARE_GLOBAL_DATA_PTR; 29 30 static struct hsuart_regs *hsuart = (struct hsuart_regs *)HS_UART_BASE; 31 32 static void lpc32xx_serial_setbrg(void) 33 { 34 u32 div; 35 36 /* UART rate = PERIPH_CLK / ((HSU_RATE + 1) x 14) */ 37 div = (get_serial_clock() / 14 + gd->baudrate / 2) / gd->baudrate - 1; 38 if (div > 255) 39 div = 255; 40 41 writel(div, &hsuart->rate); 42 } 43 44 static int lpc32xx_serial_getc(void) 45 { 46 while (!(readl(&hsuart->level) & HSUART_LEVEL_RX)) 47 /* NOP */; 48 49 return readl(&hsuart->rx) & HSUART_RX_DATA; 50 } 51 52 static void lpc32xx_serial_putc(const char c) 53 { 54 writel(c, &hsuart->tx); 55 56 /* Wait for character to be sent */ 57 while (readl(&hsuart->level) & HSUART_LEVEL_TX) 58 /* NOP */; 59 } 60 61 static int lpc32xx_serial_tstc(void) 62 { 63 if (readl(&hsuart->level) & HSUART_LEVEL_RX) 64 return 1; 65 66 return 0; 67 } 68 69 static int lpc32xx_serial_init(void) 70 { 71 lpc32xx_serial_setbrg(); 72 73 /* Disable hardware RTS and CTS flow control, set up RX and TX FIFO */ 74 writel(HSUART_CTRL_TMO_16 | HSUART_CTRL_HSU_OFFSET(20) | 75 HSUART_CTRL_HSU_RX_TRIG_32 | HSUART_CTRL_HSU_TX_TRIG_0, 76 &hsuart->ctrl); 77 return 0; 78 } 79 80 static struct serial_device lpc32xx_serial_drv = { 81 .name = "lpc32xx_serial", 82 .start = lpc32xx_serial_init, 83 .stop = NULL, 84 .setbrg = lpc32xx_serial_setbrg, 85 .putc = lpc32xx_serial_putc, 86 .puts = default_serial_puts, 87 .getc = lpc32xx_serial_getc, 88 .tstc = lpc32xx_serial_tstc, 89 }; 90 91 void lpc32xx_serial_initialize(void) 92 { 93 serial_register(&lpc32xx_serial_drv); 94 } 95 96 __weak struct serial_device *default_serial_console(void) 97 { 98 return &lpc32xx_serial_drv; 99 } 100