1 /* 2 * Copyright (C) 2015 Freescale Semiconductor, Inc. 3 * Copyright (c) 2017, Linaro Limited 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions are met: 8 * 9 * 1. Redistributions of source code must retain the above copyright notice, 10 * this list of conditions and the following disclaimer. 11 * 12 * 2. Redistributions in binary form must reproduce the above copyright notice, 13 * this list of conditions and the following disclaimer in the documentation 14 * and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 26 * POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #include <drivers/ns16550.h> 30 #include <io.h> 31 #include <keep.h> 32 #include <util.h> 33 34 /* uart register defines */ 35 #define UART_RBR 0x0 36 #define UART_THR 0x0 37 #define UART_IER 0x1 38 #define UART_FCR 0x2 39 #define UART_LCR 0x3 40 #define UART_MCR 0x4 41 #define UART_LSR 0x5 42 #define UART_MSR 0x6 43 #define UART_SPR 0x7 44 45 /* uart status register bits */ 46 #define UART_LSR_THRE 0x20 /* Transmit-hold-register empty */ 47 48 static vaddr_t chip_to_base(struct serial_chip *chip) 49 { 50 struct ns16550_data *pd = 51 container_of(chip, struct ns16550_data, chip); 52 53 return io_pa_or_va(&pd->base); 54 } 55 56 static void ns16550_flush(struct serial_chip *chip) 57 { 58 vaddr_t base = chip_to_base(chip); 59 60 while ((read8(base + UART_LSR) & UART_LSR_THRE) == 0) 61 ; 62 } 63 64 static void ns16550_putc(struct serial_chip *chip, int ch) 65 { 66 vaddr_t base = chip_to_base(chip); 67 68 ns16550_flush(chip); 69 70 /* write out charset to Transmit-hold-register */ 71 write8(ch, base + UART_THR); 72 } 73 74 static const struct serial_ops ns16550_ops = { 75 .flush = ns16550_flush, 76 .putc = ns16550_putc, 77 }; 78 KEEP_PAGER(ns16550_ops); 79 80 void ns16550_init(struct ns16550_data *pd, paddr_t base) 81 { 82 pd->base.pa = base; 83 pd->chip.ops = &ns16550_ops; 84 85 /* 86 * Do nothing, uart driver shared with normal world, 87 * everything for uart driver initialization is done in bootloader. 88 */ 89 } 90