1 /* $Id: common.c,v 1.3 2013/02/23 16:22:39 jkunz Exp $ */ 2 3 /* 4 * Copyright (c) 2012 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Petri Laakso. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/param.h> 33 #include <sys/types.h> 34 #include <sys/cdefs.h> 35 36 #include <arm/imx/imx23_digctlreg.h> 37 #include <arm/imx/imx23_uartdbgreg.h> 38 39 #include "common.h" 40 41 /* 42 * Delay us microseconds. 43 */ 44 void 45 delay(unsigned int us) 46 { 47 uint32_t start; 48 uint32_t now; 49 uint32_t elapsed; 50 uint32_t total; 51 uint32_t last; 52 53 total = 0; 54 last = 0; 55 start = REG_RD(HW_DIGCTL_BASE + HW_DIGCTL_MICROSECONDS); 56 57 do { 58 now = REG_RD(HW_DIGCTL_BASE + HW_DIGCTL_MICROSECONDS); 59 60 if (start <= now) 61 elapsed = now - start; 62 else /* Take care of overflow. */ 63 elapsed = (UINT32_MAX - start) + 1 + now; 64 65 total += elapsed - last; 66 last = elapsed; 67 68 } while (total < us); 69 70 return; 71 } 72 73 /* 74 * Write character to debug UART. 75 */ 76 void 77 putchar(int ch) 78 { 79 80 /* Wait until transmit FIFO has space for the new character. */ 81 while (REG_RD_HW(HW_UARTDBG_BASE + HW_UARTDBGFR) & HW_UARTDBGFR_TXFF); 82 83 REG_WR_BYTE(HW_UARTDBG_BASE + HW_UARTDBGDR, 84 __SHIFTIN(ch, HW_UARTDBGDR_DATA)); 85 #ifdef DEBUG 86 /* Flush: Wait until transmit FIFO contents are written to UART. */ 87 while (!(REG_RD_HW(HW_UARTDBG_BASE + HW_UARTDBGFR) & 88 HW_UARTDBGFR_TXFE)); 89 #endif 90 91 return; 92 } 93 94 /* 95 * Read character from debug UART. 96 */ 97 int 98 getchar(void) 99 { 100 101 /* Wait until receive FIFO has character(s) */ 102 103 while (REG_RD_HW(HW_UARTDBG_BASE + HW_UARTDBGFR) & HW_UARTDBGFR_RXFE); 104 105 return REG_RD_HW(HW_UARTDBG_BASE + HW_UARTDBGDR) & 0xFF; 106 } 107