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
chip_to_base(struct serial_chip * chip)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
sprd_uart_flush(struct serial_chip * chip)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
sprd_uart_have_rx_data(struct serial_chip * chip)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
sprd_uart_putc(struct serial_chip * chip,int ch)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
sprd_uart_getchar(struct serial_chip * chip)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
sprd_uart_init(struct sprd_uart_data * pd,paddr_t base)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