aboutsummaryrefslogtreecommitdiff
path: root/drivers/arm/pl011/aarch64/pl011_console.S
blob: 7fec0904d9189c3a01c9682fe6ae9abcd3d088e2 (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
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
/*
 * Copyright (c) 2013-2017, ARM Limited and Contributors. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */
#include <arch.h>
#include <asm_macros.S>
#include <assert_macros.S>
#define USE_FINISH_CONSOLE_REG_2
#include <console_macros.S>
#include <pl011.h>

#if !MULTI_CONSOLE_API
/*
 * Pull in generic functions to provide backwards compatibility for
 * platform makefiles
 */
#include "../../../console/aarch64/console.S"
#endif

	/*
	 * "core" functions are low-level implementations that don't require
	 * writable memory and are thus safe to call in BL1 crash context.
	 */
	.globl console_pl011_core_init
	.globl console_pl011_core_putc
	.globl console_pl011_core_getc
	.globl console_pl011_core_flush

	.globl	console_pl011_putc
	.globl	console_pl011_getc
	.globl	console_pl011_flush

	/* -----------------------------------------------
	 * int console_pl011_core_init(uintptr_t 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.
	 * 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, x4
	 * -----------------------------------------------
	 */
func console_pl011_core_init
	/* Check the input base address */
	cbz	x0, core_init_fail
#if !PL011_GENERIC_UART
	/* Check baud rate and uart clock for sanity */
	cbz	w1, core_init_fail
	cbz	w2, core_init_fail
	/* Disable uart before programming */
	ldr	w3, [x0, #UARTCR]
	mov	w4, #PL011_UARTCR_UARTEN
	bic	w3, w3, w4
	str	w3, [x0, #UARTCR]
	/* Program the baudrate */
	/* Divisor =  (Uart clock * 4) / baudrate */
	lsl	w1, w1, #2
	udiv	w2, w1, w2
	/* IBRD = Divisor >> 6 */
	lsr	w1, w2, #6
	/* Write the IBRD */
	str	w1, [x0, #UARTIBRD]
	/* FBRD = Divisor & 0x3F */
	and	w1, w2, #0x3f
	/* Write the FBRD */
	str	w1, [x0, #UARTFBRD]
	mov	w1, #PL011_LINE_CONTROL
	str	w1, [x0, #UARTLCR_H]
	/* Clear any pending errors */
	str	wzr, [x0, #UARTECR]
	/* Enable tx, rx, and uart overall */
	mov	w1, #(PL011_UARTCR_RXE | PL011_UARTCR_TXE | PL011_UARTCR_UARTEN)
	str	w1, [x0, #UARTCR]
#endif
	mov	w0, #1
	ret
core_init_fail:
	mov	w0, wzr
	ret
endfunc console_pl011_core_init

#if MULTI_CONSOLE_API
	.globl console_pl011_register

	/* -----------------------------------------------
	 * int console_pl011_register(uintptr_t baseaddr,
	 *     uint32_t clock, uint32_t baud,
	 *     console_pl011_t *console);
	 * Function to initialize and register a new PL011
	 * 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_pl011_t struct
	 * Out: return 1 on success, 0 on error
	 * Clobber list : x0, x1, x2, x6, x7, x14
	 * -----------------------------------------------
	 */
func console_pl011_register
	mov	x7, x30
	mov	x6, x3
	cbz	x6, register_fail
	str	x0, [x6, #CONSOLE_T_PL011_BASE]

	bl	console_pl011_core_init
	cbz	x0, register_fail

	mov	x0, x6
	mov	x30, x7
	finish_console_register pl011 putc=1, getc=1, flush=1

register_fail:
	ret	x7
endfunc console_pl011_register
#else
	.globl console_core_init
	.globl console_core_putc
	.globl console_core_getc
	.globl console_core_flush
	.equ console_core_init,console_pl011_core_init
	.equ console_core_putc,console_pl011_core_putc
	.equ console_core_getc,console_pl011_core_getc
	.equ console_core_flush,console_pl011_core_flush
#endif

	/* --------------------------------------------------------
	 * int console_pl011_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_pl011_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, #UARTFR]
	tbnz	w2, #PL011_UARTFR_TXFF_BIT, 1b
	mov	w2, #0xD
	str	w2, [x1, #UARTDR]
2:
	/* Check if the transmit FIFO is full */
	ldr	w2, [x1, #UARTFR]
	tbnz	w2, #PL011_UARTFR_TXFF_BIT, 2b
	str	w0, [x1, #UARTDR]
	ret
endfunc console_pl011_core_putc

	/* --------------------------------------------------------
	 * int console_pl011_putc(int c, console_pl011_t *console)
	 * 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_pl011_putc
#if ENABLE_ASSERTIONS
	cmp	x1, #0
	ASM_ASSERT(ne)
#endif /* ENABLE_ASSERTIONS */
	ldr	x1, [x1, #CONSOLE_T_PL011_BASE]
	b	console_pl011_core_putc
endfunc console_pl011_putc

	/* ---------------------------------------------
	 * int console_pl011_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_pl011_core_getc
#if ENABLE_ASSERTIONS
	cmp	x0, #0
	ASM_ASSERT(ne)
#endif /* ENABLE_ASSERTIONS */

	/* Check if the receive FIFO is empty */
	ldr	w1, [x0, #UARTFR]
	tbnz	w1, #PL011_UARTFR_RXFE_BIT, no_char
	ldr	w1, [x0, #UARTDR]
	mov	w0, w1
	ret
no_char:
	mov	w0, #ERROR_NO_PENDING_CHAR
	ret
endfunc console_pl011_core_getc

	/* ---------------------------------------------
	 * int console_pl011_getc(console_pl011_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_pl011_getc
#if ENABLE_ASSERTIONS
	cmp	x0, #0
	ASM_ASSERT(ne)
#endif /* ENABLE_ASSERTIONS */
	ldr	x0, [x0, #CONSOLE_T_PL011_BASE]
	b	console_pl011_core_getc
endfunc console_pl011_getc

	/* ---------------------------------------------
	 * int console_pl011_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_pl011_core_flush
#if ENABLE_ASSERTIONS
	cmp	x0, #0
	ASM_ASSERT(ne)
#endif /* ENABLE_ASSERTIONS */
1:
	/* Loop until the transmit FIFO is empty */
	ldr	w1, [x0, #UARTFR]
	tbnz	w1, #PL011_UARTFR_BUSY_BIT, 1b

	mov	w0, #0
	ret
endfunc console_pl011_core_flush

	/* ---------------------------------------------
	 * int console_pl011_flush(console_pl011_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_pl011_flush
#if ENABLE_ASSERTIONS
	cmp	x0, #0
	ASM_ASSERT(ne)
#endif /* ENABLE_ASSERTIONS */
	ldr	x0, [x0, #CONSOLE_T_PL011_BASE]
	b	console_pl011_core_flush
endfunc console_pl011_flush