1 /* 2 * Copyright (c) 2016, Spreadtrum Communications 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 #include <drivers/sprd_uart.h> 29 #include <io.h> 30 #include <util.h> 31 32 /* Register definitions */ 33 #define UART_TXD 0x0000 34 #define UART_RXD 0x0004 35 #define UART_STS1 0x000C /* data number in TX and RX fifo */ 36 37 /* Register Bit Fields*/ 38 #define STS1_RXF_CNT_MASK 0x00ff /* Rx FIFO data counter mask */ 39 #define STS1_TXF_CNT_MASK 0xff00 /* Tx FIFO data counter mask */ 40 41 static vaddr_t chip_to_base(struct serial_chip *chip) 42 { 43 struct sprd_uart_data *pd = 44 container_of(chip, struct sprd_uart_data, chip); 45 46 return io_pa_or_va(&pd->base); 47 } 48 49 static void sprd_uart_flush(struct serial_chip *chip) 50 { 51 vaddr_t base = chip_to_base(chip); 52 53 while (read32(base + UART_STS1) & STS1_TXF_CNT_MASK) 54 ; 55 } 56 57 static bool sprd_uart_have_rx_data(struct serial_chip *chip) 58 { 59 vaddr_t base = chip_to_base(chip); 60 61 return !!(read32(base + UART_STS1) & STS1_RXF_CNT_MASK); 62 } 63 64 static void sprd_uart_putc(struct serial_chip *chip, int ch) 65 { 66 vaddr_t base = chip_to_base(chip); 67 68 sprd_uart_flush(chip); 69 write32(base + UART_TXD, ch); 70 } 71 72 static int sprd_uart_getchar(struct serial_chip *chip) 73 { 74 vaddr_t base = chip_to_base(chip); 75 76 while (!sprd_uart_have_rx_data(chip)) 77 ; 78 79 return read32(base + UART_RXD) & 0xff; 80 } 81 82 static const struct serial_ops sprd_uart_ops = { 83 .flush = sprd_uart_flush, 84 .getchar = sprd_uart_getchar, 85 .have_rx_data = sprd_uart_have_rx_data, 86 .putc = sprd_uart_putc, 87 }; 88 89 void sprd_uart_init(struct sprd_uart_data *pd, paddr_t base) 90 { 91 pd->base.pa = base; 92 pd->chip.ops = &sprd_uart_ops; 93 } 94