xref: /rk3399_ARM-atf/drivers/arm/pl011/aarch64/pl011_console.S (revision 0f22bef31d402e24fab77eb2a3c643d042b7e79c)
1/*
2 * Copyright (c) 2013-2017, ARM Limited and Contributors. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are met:
6 *
7 * Redistributions of source code must retain the above copyright notice, this
8 * list of conditions and the following disclaimer.
9 *
10 * Redistributions in binary form must reproduce the above copyright notice,
11 * this list of conditions and the following disclaimer in the documentation
12 * and/or other materials provided with the distribution.
13 *
14 * Neither the name of ARM nor the names of its contributors may be used
15 * to endorse or promote products derived from this software without specific
16 * prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30#include <arch.h>
31#include <asm_macros.S>
32#include <pl011.h>
33
34/*
35 * Pull in generic functions to provide backwards compatibility for
36 * platform makefiles
37 */
38#include "../../../console/aarch64/console.S"
39
40
41	.globl	console_core_init
42	.globl	console_core_putc
43	.globl	console_core_getc
44	.globl	console_core_flush
45
46
47	/* -----------------------------------------------
48	 * int console_core_init(uintptr_t base_addr,
49	 * unsigned int uart_clk, unsigned int baud_rate)
50	 * Function to initialize the console without a
51	 * C Runtime to print debug information. This
52	 * function will be accessed by console_init and
53	 * crash reporting.
54	 * In: x0 - console base address
55	 *     w1 - Uart clock in Hz
56	 *     w2 - Baud rate
57	 * Out: return 1 on success else 0 on error
58	 * Clobber list : x1, x2, x3, x4
59	 * -----------------------------------------------
60	 */
61func console_core_init
62	/* Check the input base address */
63	cbz	x0, core_init_fail
64#if !PL011_GENERIC_UART
65	/* Check baud rate and uart clock for sanity */
66	cbz	w1, core_init_fail
67	cbz	w2, core_init_fail
68	/* Disable uart before programming */
69	ldr	w3, [x0, #UARTCR]
70	mov	w4, #PL011_UARTCR_UARTEN
71	bic	w3, w3, w4
72	str	w3, [x0, #UARTCR]
73	/* Program the baudrate */
74	/* Divisor =  (Uart clock * 4) / baudrate */
75	lsl	w1, w1, #2
76	udiv	w2, w1, w2
77	/* IBRD = Divisor >> 6 */
78	lsr	w1, w2, #6
79	/* Write the IBRD */
80	str	w1, [x0, #UARTIBRD]
81	/* FBRD = Divisor & 0x3F */
82	and	w1, w2, #0x3f
83	/* Write the FBRD */
84	str	w1, [x0, #UARTFBRD]
85	mov	w1, #PL011_LINE_CONTROL
86	str	w1, [x0, #UARTLCR_H]
87	/* Clear any pending errors */
88	str	wzr, [x0, #UARTECR]
89	/* Enable tx, rx, and uart overall */
90	mov	w1, #(PL011_UARTCR_RXE | PL011_UARTCR_TXE | PL011_UARTCR_UARTEN)
91	str	w1, [x0, #UARTCR]
92#endif
93	mov	w0, #1
94	ret
95core_init_fail:
96	mov	w0, wzr
97	ret
98endfunc console_core_init
99
100	/* --------------------------------------------------------
101	 * int console_core_putc(int c, uintptr_t base_addr)
102	 * Function to output a character over the console. It
103	 * returns the character printed on success or -1 on error.
104	 * In : w0 - character to be printed
105	 *      x1 - console base address
106	 * Out : return -1 on error else return character.
107	 * Clobber list : x2
108	 * --------------------------------------------------------
109	 */
110func console_core_putc
111	/* Check the input parameter */
112	cbz	x1, putc_error
113	/* Prepend '\r' to '\n' */
114	cmp	w0, #0xA
115	b.ne	2f
1161:
117	/* Check if the transmit FIFO is full */
118	ldr	w2, [x1, #UARTFR]
119	tbnz	w2, #PL011_UARTFR_TXFF_BIT, 1b
120	mov	w2, #0xD
121	str	w2, [x1, #UARTDR]
1222:
123	/* Check if the transmit FIFO is full */
124	ldr	w2, [x1, #UARTFR]
125	tbnz	w2, #PL011_UARTFR_TXFF_BIT, 2b
126	str	w0, [x1, #UARTDR]
127	ret
128putc_error:
129	mov	w0, #-1
130	ret
131endfunc console_core_putc
132
133	/* ---------------------------------------------
134	 * int console_core_getc(uintptr_t base_addr)
135	 * Function to get a character from the console.
136	 * It returns the character grabbed on success
137	 * or -1 on error.
138	 * In : x0 - console base address
139	 * Clobber list : x0, x1
140	 * ---------------------------------------------
141	 */
142func console_core_getc
143	cbz	x0, getc_error
1441:
145	/* Check if the receive FIFO is empty */
146	ldr	w1, [x0, #UARTFR]
147	tbnz	w1, #PL011_UARTFR_RXFE_BIT, 1b
148	ldr	w1, [x0, #UARTDR]
149	mov	w0, w1
150	ret
151getc_error:
152	mov	w0, #-1
153	ret
154endfunc console_core_getc
155
156	/* ---------------------------------------------
157	 * int console_core_flush(uintptr_t base_addr)
158	 * Function to force a write of all buffered
159	 * data that hasn't been output.
160	 * In : x0 - console base address
161	 * Out : return -1 on error else return 0.
162	 * Clobber list : x0, x1
163	 * ---------------------------------------------
164	 */
165func console_core_flush
166	cbz	x0, flush_error
167
1681:
169	/* Loop until the transmit FIFO is empty */
170	ldr	w1, [x0, #UARTFR]
171	tbnz	w1, #PL011_UARTFR_BUSY_BIT, 1b
172
173	mov	w0, #0
174	ret
175flush_error:
176	mov	w0, #-1
177	ret
178endfunc console_core_flush
179