1 // SPDX-License-Identifier: BSD-2-Clause 2 /* 3 * Copyright (c) 2016, Spreadtrum Communications Inc. 4 * Copyright (c) 2017, Linaro Limited 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions are met: 9 * 10 * 1. Redistributions of source code must retain the above copyright notice, 11 * this list of conditions and the following disclaimer. 12 * 13 * 2. Redistributions in binary form must reproduce the above copyright notice, 14 * this list of conditions and the following disclaimer in the documentation 15 * and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 18 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 21 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 25 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 27 * POSSIBILITY OF SUCH DAMAGE. 28 */ 29 #include <drivers/sprd_uart.h> 30 #include <io.h> 31 #include <keep.h> 32 #include <util.h> 33 34 /* Register definitions */ 35 #define UART_TXD 0x0000 36 #define UART_RXD 0x0004 37 #define UART_STS1 0x000C /* data number in TX and RX fifo */ 38 39 /* Register Bit Fields*/ 40 #define STS1_RXF_CNT_MASK 0x00ff /* Rx FIFO data counter mask */ 41 #define STS1_TXF_CNT_MASK 0xff00 /* Tx FIFO data counter mask */ 42 43 static vaddr_t chip_to_base(struct serial_chip *chip) 44 { 45 struct sprd_uart_data *pd = 46 container_of(chip, struct sprd_uart_data, chip); 47 48 return io_pa_or_va(&pd->base); 49 } 50 51 static void sprd_uart_flush(struct serial_chip *chip) 52 { 53 vaddr_t base = chip_to_base(chip); 54 55 while (io_read32(base + UART_STS1) & STS1_TXF_CNT_MASK) 56 ; 57 } 58 59 static bool sprd_uart_have_rx_data(struct serial_chip *chip) 60 { 61 vaddr_t base = chip_to_base(chip); 62 63 return !!(io_read32(base + UART_STS1) & STS1_RXF_CNT_MASK); 64 } 65 66 static void sprd_uart_putc(struct serial_chip *chip, int ch) 67 { 68 vaddr_t base = chip_to_base(chip); 69 70 sprd_uart_flush(chip); 71 io_write32(base + UART_TXD, ch); 72 } 73 74 static int sprd_uart_getchar(struct serial_chip *chip) 75 { 76 vaddr_t base = chip_to_base(chip); 77 78 while (!sprd_uart_have_rx_data(chip)) 79 ; 80 81 return io_read32(base + UART_RXD) & 0xff; 82 } 83 84 static const struct serial_ops sprd_uart_ops = { 85 .flush = sprd_uart_flush, 86 .getchar = sprd_uart_getchar, 87 .have_rx_data = sprd_uart_have_rx_data, 88 .putc = sprd_uart_putc, 89 }; 90 KEEP_PAGER(sprd_uart_ops); 91 92 void sprd_uart_init(struct sprd_uart_data *pd, paddr_t base) 93 { 94 pd->base.pa = base; 95 pd->chip.ops = &sprd_uart_ops; 96 } 97