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developer65014b82015-04-13 14:47:57 +08001/*
Antonio Nino Diaz56ec1d52017-02-08 15:58:12 +00002 * Copyright (c) 2015-2017, ARM Limited and Contributors. All rights reserved.
developer65014b82015-04-13 14:47:57 +08003 *
dp-armfa3cf0b2017-05-03 09:38:09 +01004 * SPDX-License-Identifier: BSD-3-Clause
developer65014b82015-04-13 14:47:57 +08005 */
6#include <asm_macros.S>
7#include <uart8250.h>
8
9 .globl console_core_init
10 .globl console_core_putc
11 .globl console_core_getc
Antonio Nino Diaz56ec1d52017-02-08 15:58:12 +000012 .globl console_core_flush
developer65014b82015-04-13 14:47:57 +080013
14 /* -----------------------------------------------
15 * int console_core_init(unsigned long base_addr,
16 * unsigned int uart_clk, unsigned int baud_rate)
17 * Function to initialize the console without a
18 * C Runtime to print debug information. This
19 * function will be accessed by console_init and
20 * crash reporting.
21 * In: x0 - console base address
22 * w1 - Uart clock in Hz
23 * w2 - Baud rate
24 * Out: return 1 on success else 0 on error
25 * Clobber list : x1, x2, x3
26 * -----------------------------------------------
27 */
28func console_core_init
29 /* Check the input base address */
30 cbz x0, core_init_fail
31 /* Check baud rate and uart clock for sanity */
32 cbz w1, core_init_fail
33 cbz w2, core_init_fail
34
35 /* Disable interrupt */
36 str wzr, [x0, #UART_IER]
37
38 /* Force DTR and RTS to high */
39 mov w3, #(UART_MCR_DTR | UART_MCR_RTS)
40 str w3, [x0, #UART_MCR]
41
42 /* Check high speed */
43 movz w3, #:abs_g1:115200
44 movk w3, #:abs_g0_nc:115200
45 cmp w2, w3
46 b.hi 1f
47
48 /* Non high speed */
49 lsl w2, w2, #4
50 mov w3, wzr
51 b 2f
52
53 /* High speed */
541: lsl w2, w2, #2
55 mov w3, #2
56
57 /* Set high speed UART register */
582: str w3, [x0, #UART_HIGHSPEED]
59
60 /* Calculate divisor */
61 udiv w3, w1, w2 /* divisor = uartclk / (quot * baudrate) */
62 msub w1, w3, w2, w1 /* remainder = uartclk % (quot * baudrate) */
63 lsr w2, w2, #1
64 cmp w1, w2
65 cinc w3, w3, hs
66
67 /* Set line configuration, access divisor latches */
68 mov w1, #(UART_LCR_DLAB | UART_LCR_WLS_8)
69 str w1, [x0, #UART_LCR]
70
71 /* Set the divisor */
72 and w1, w3, #0xff
73 str w1, [x0, #UART_DLL]
74 lsr w1, w3, #8
75 and w1, w1, #0xff
76 str w1, [x0, #UART_DLH]
77
78 /* Hide the divisor latches */
79 mov w1, #UART_LCR_WLS_8
80 str w1, [x0, #UART_LCR]
81
82 /* Enable FIFOs, and clear receive and transmit */
83 mov w1, #(UART_FCR_FIFO_EN | UART_FCR_CLEAR_RCVR | \
84 UART_FCR_CLEAR_XMIT)
85 str w1, [x0, #UART_FCR]
86
87 mov w0, #1
88 ret
89core_init_fail:
90 mov w0, wzr
91 ret
92endfunc console_core_init
93
94 /* --------------------------------------------------------
95 * int console_core_putc(int c, unsigned long base_addr)
96 * Function to output a character over the console. It
97 * returns the character printed on success or -1 on error.
98 * In : w0 - character to be printed
99 * x1 - console base address
100 * Out : return -1 on error else return character.
101 * Clobber list : x2
102 * --------------------------------------------------------
103 */
104func console_core_putc
105 /* Check the input parameter */
106 cbz x1, putc_error
107 /* Prepend '\r' to '\n' */
108 cmp w0, #0xA
109 b.ne 2f
110
111 /* Check if the transmit FIFO is full */
1121: ldr w2, [x1, #UART_LSR]
113 and w2, w2, #UART_LSR_THRE
114 cbz w2, 1b
115 mov w2, #0xD
116 str w2, [x1, #UART_THR]
117
118 /* Check if the transmit FIFO is full */
1192: ldr w2, [x1, #UART_LSR]
120 and w2, w2, #UART_LSR_THRE
121 cbz w2, 2b
122 str w0, [x1, #UART_THR]
123 ret
124putc_error:
125 mov w0, #-1
126 ret
127endfunc console_core_putc
128
129 /* ---------------------------------------------
130 * int console_core_getc(unsigned long base_addr)
131 * Function to get a character from the console.
132 * It returns the character grabbed on success
133 * or -1 on error.
134 * In : x0 - console base address
135 * Clobber list : x0, x1
136 * ---------------------------------------------
137 */
138func console_core_getc
139 cbz x0, getc_error
140
141 /* Check if the receive FIFO is empty */
1421: ldr w1, [x0, #UART_LSR]
143 tbz w1, #UART_LSR_DR, 1b
144 ldr w0, [x0, #UART_RBR]
145 ret
146getc_error:
147 mov w0, #-1
148 ret
149endfunc console_core_getc
Antonio Nino Diaz56ec1d52017-02-08 15:58:12 +0000150
151 /* ---------------------------------------------
152 * int console_core_flush(uintptr_t base_addr)
153 * Function to force a write of all buffered
154 * data that hasn't been output.
155 * In : x0 - console base address
156 * Out : return -1 on error else return 0.
157 * Clobber list : x0, x1
158 * ---------------------------------------------
159 */
160func console_core_flush
161 /* Placeholder */
162 mov w0, #0
163 ret
164endfunc console_core_flush