1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
|
/*
* Copyright (c) 2016-2017, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <arch.h>
#include <asm_macros.S>
#include <cadence/cdns_uart.h>
.globl console_core_init
.globl console_core_putc
.globl console_core_getc
.globl console_core_flush
/* -----------------------------------------------
* int console_core_init(unsigned long base_addr,
* unsigned int uart_clk, unsigned int baud_rate)
* Function to initialize the console without a
* C Runtime to print debug information. This
* function will be accessed by console_init and
* crash reporting.
* We assume that the bootloader already set up
* the HW (baud, ...) and only enable the trans-
* mitter and receiver here.
* In: x0 - console base address
* w1 - Uart clock in Hz
* w2 - Baud rate
* Out: return 1 on success else 0 on error
* Clobber list : x1, x2, x3
* -----------------------------------------------
*/
func console_core_init
/* Check the input base address */
cbz x0, core_init_fail
/* Check baud rate and uart clock for sanity */
cbz w1, core_init_fail
cbz w2, core_init_fail
/* RX/TX enabled & reset */
mov w3, #(R_UART_CR_TX_EN | R_UART_CR_RX_EN | R_UART_CR_TXRST | R_UART_CR_RXRST)
str w3, [x0, #R_UART_CR]
mov w0, #1
ret
core_init_fail:
mov w0, wzr
ret
endfunc console_core_init
/* --------------------------------------------------------
* int console_core_putc(int c, unsigned long base_addr)
* Function to output a character over the console. It
* returns the character printed on success or -1 on error.
* In : w0 - character to be printed
* x1 - console base address
* Out : return -1 on error else return character.
* Clobber list : x2
* --------------------------------------------------------
*/
func console_core_putc
/* Check the input parameter */
cbz x1, putc_error
/* Prepend '\r' to '\n' */
cmp w0, #0xA
b.ne 2f
1:
/* Check if the transmit FIFO is full */
ldr w2, [x1, #R_UART_SR]
tbnz w2, #UART_SR_INTR_TFUL_BIT, 1b
mov w2, #0xD
str w2, [x1, #R_UART_TX]
2:
/* Check if the transmit FIFO is full */
ldr w2, [x1, #R_UART_SR]
tbnz w2, #UART_SR_INTR_TFUL_BIT, 2b
str w0, [x1, #R_UART_TX]
ret
putc_error:
mov w0, #-1
ret
endfunc console_core_putc
/* ---------------------------------------------
* int console_core_getc(unsigned long base_addr)
* Function to get a character from the console.
* It returns the character grabbed on success
* or -1 on error.
* In : x0 - console base address
* Clobber list : x0, x1
* ---------------------------------------------
*/
func console_core_getc
cbz x0, getc_error
1:
/* Check if the receive FIFO is empty */
ldr w1, [x0, #R_UART_SR]
tbnz w1, #UART_SR_INTR_REMPTY_BIT, 1b
ldr w1, [x0, #R_UART_RX]
mov w0, w1
ret
getc_error:
mov w0, #-1
ret
endfunc console_core_getc
/* ---------------------------------------------
* int console_core_flush(uintptr_t base_addr)
* Function to force a write of all buffered
* data that hasn't been output.
* In : x0 - console base address
* Out : return -1 on error else return 0.
* Clobber list : x0, x1
* ---------------------------------------------
*/
func console_core_flush
/* Placeholder */
mov w0, #0
ret
endfunc console_core_flush
|