aboutsummaryrefslogtreecommitdiff
path: root/drivers/cadence/uart/aarch64/cdns_console.S
blob: 8e5d6a1aab07a23e4405fbb6973ce8d10d42fcfa (plain)
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
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
/*
 * 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 <assert_macros.S>
#include <console_macros.S>
#include <drivers/cadence/cdns_uart.h>

	/*
	 * "core" functions are low-level implementations that don't require
	 * writable memory and are thus safe to call in BL1 crash context.
	 */
	.globl console_cdns_core_init
	.globl console_cdns_core_putc
	.globl console_cdns_core_getc
	.globl console_cdns_core_flush

	.globl  console_cdns_putc
	.globl  console_cdns_getc
	.globl  console_cdns_flush

	/* -----------------------------------------------
	 * int console_cdns_core_init(uintptr_t base_addr)
	 * 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
	 * Out: return 1 on success else 0 on error
	 * Clobber list : x1, x2, x3
	 * -----------------------------------------------
	 */
func console_cdns_core_init
	/* Check the input base address */
	cbz	x0, 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_cdns_core_init

	.globl console_cdns_register

	/* -----------------------------------------------
	 * int console_cdns_register(uintptr_t baseaddr,
	 *     uint32_t clock, uint32_t baud,
	 *     console_t *console);
	 * Function to initialize and register a new CDNS
	 * console. Storage passed in for the console struct
	 * *must* be persistent (i.e. not from the stack).
	 * In: x0 - UART register base address
	 *     w1 - UART clock in Hz
	 *     w2 - Baud rate
	 *     x3 - pointer to empty console_t struct
	 * Out: return 1 on success, 0 on error
	 * Clobber list : x0, x1, x2, x6, x7, x14
	 * -----------------------------------------------
	 */
func console_cdns_register
	mov	x7, x30
	mov	x6, x3
	cbz	x6, register_fail
	str	x0, [x6, #CONSOLE_T_BASE]

	bl	console_cdns_core_init
	cbz	x0, register_fail

	mov	x0, x6
	mov	x30, x7
	finish_console_register cdns putc=1, getc=1, flush=1

register_fail:
	ret	x7
endfunc console_cdns_register

	/* --------------------------------------------------------
	 * int console_cdns_core_putc(int c, uintptr_t 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_cdns_core_putc
#if ENABLE_ASSERTIONS
	cmp	x1, #0
	ASM_ASSERT(ne)
#endif /* ENABLE_ASSERTIONS */

	/* 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
endfunc console_cdns_core_putc

	/* --------------------------------------------------------
	 * int console_cdns_putc(int c, console_t *cdns)
	 * 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 - pointer to console_t structure
	 * Out : return -1 on error else return character.
	 * Clobber list : x2
	 * --------------------------------------------------------
	 */
func console_cdns_putc
#if ENABLE_ASSERTIONS
	cmp	x1, #0
	ASM_ASSERT(ne)
#endif /* ENABLE_ASSERTIONS */
	ldr	x1, [x1, #CONSOLE_T_BASE]
	b	console_cdns_core_putc
endfunc console_cdns_putc

	/* ---------------------------------------------
	 * int console_cdns_core_getc(uintptr_t base_addr)
	 * Function to get a character from the console.
	 * It returns the character grabbed on success
	 * or -1 if no character is available.
	 * In : x0 - console base address
	 * Out: w0 - character if available, else -1
	 * Clobber list : x0, x1
	 * ---------------------------------------------
	 */
func console_cdns_core_getc
#if ENABLE_ASSERTIONS
	cmp	x0, #0
	ASM_ASSERT(ne)
#endif /* ENABLE_ASSERTIONS */

	/* Check if the receive FIFO is empty */
	ldr	w1, [x0, #R_UART_SR]
	tbnz	w1, #UART_SR_INTR_REMPTY_BIT, no_char
	ldr	w1, [x0, #R_UART_RX]
	mov	w0, w1
	ret
no_char:
	mov	w0, #ERROR_NO_PENDING_CHAR
	ret
endfunc console_cdns_core_getc

	/* ---------------------------------------------
	 * int console_cdns_getc(console_t *console)
	 * Function to get a character from the console.
	 * It returns the character grabbed on success
	 * or -1 if no character is available.
	 * In : x0 - pointer to console_t structure
	 * Out: w0 - character if available, else -1
	 * Clobber list : x0, x1
	 * ---------------------------------------------
	 */
func console_cdns_getc
#if ENABLE_ASSERTIONS
	cmp	x0, #0
	ASM_ASSERT(ne)
#endif /* ENABLE_ASSERTIONS */
	ldr	x0, [x0, #CONSOLE_T_BASE]
	b	console_cdns_core_getc
endfunc console_cdns_getc

	/* ---------------------------------------------
	 * int console_cdns_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_cdns_core_flush
#if ENABLE_ASSERTIONS
	cmp	x0, #0
	ASM_ASSERT(ne)
#endif /* ENABLE_ASSERTIONS */
	/* Placeholder */
	mov	w0, #0
	ret
endfunc console_cdns_core_flush

	/* ---------------------------------------------
	 * int console_cdns_flush(console_t *console)
	 * Function to force a write of all buffered
	 * data that hasn't been output.
	 * In : x0 - pointer to console_t structure
	 * Out : return -1 on error else return 0.
	 * Clobber list : x0, x1
	 * ---------------------------------------------
	 */
func console_cdns_flush
#if ENABLE_ASSERTIONS
	cmp	x0, #0
	ASM_ASSERT(ne)
#endif /* ENABLE_ASSERTIONS */
	ldr	x0, [x0, #CONSOLE_T_BASE]
	b	console_cdns_core_flush
endfunc console_cdns_flush