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 #define UART_SIZE 0x0010 39 40 /* Register Bit Fields*/ 41 #define STS1_RXF_CNT_MASK 0x00ff /* Rx FIFO data counter mask */ 42 #define STS1_TXF_CNT_MASK 0xff00 /* Tx FIFO data counter mask */ 43 44 static vaddr_t chip_to_base(struct serial_chip *chip) 45 { 46 struct sprd_uart_data *pd = 47 container_of(chip, struct sprd_uart_data, chip); 48 49 return io_pa_or_va(&pd->base, UART_SIZE); 50 } 51 52 static void sprd_uart_flush(struct serial_chip *chip) 53 { 54 vaddr_t base = chip_to_base(chip); 55 56 while (io_read32(base + UART_STS1) & STS1_TXF_CNT_MASK) 57 ; 58 } 59 60 static bool sprd_uart_have_rx_data(struct serial_chip *chip) 61 { 62 vaddr_t base = chip_to_base(chip); 63 64 return !!(io_read32(base + UART_STS1) & STS1_RXF_CNT_MASK); 65 } 66 67 static void sprd_uart_putc(struct serial_chip *chip, int ch) 68 { 69 vaddr_t base = chip_to_base(chip); 70 71 sprd_uart_flush(chip); 72 io_write32(base + UART_TXD, ch); 73 } 74 75 static int sprd_uart_getchar(struct serial_chip *chip) 76 { 77 vaddr_t base = chip_to_base(chip); 78 79 while (!sprd_uart_have_rx_data(chip)) 80 ; 81 82 return io_read32(base + UART_RXD) & 0xff; 83 } 84 85 static const struct serial_ops sprd_uart_ops = { 86 .flush = sprd_uart_flush, 87 .getchar = sprd_uart_getchar, 88 .have_rx_data = sprd_uart_have_rx_data, 89 .putc = sprd_uart_putc, 90 }; 91 DECLARE_KEEP_PAGER(sprd_uart_ops); 92 93 void sprd_uart_init(struct sprd_uart_data *pd, paddr_t base) 94 { 95 pd->base.pa = base; 96 pd->chip.ops = &sprd_uart_ops; 97 } 98