xref: /rk3399_ARM-atf/drivers/console/aarch32/skeleton_console.S (revision 51faada71a219a8b94cd8d8e423f0f22e9da4d8f)
1/*
2 * Copyright (c) 2016, 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 <asm_macros.S>
31
32	/*
33	 * This file contains a skeleton console implementation that can
34	 * be used as basis for a real console implementation by platforms
35	 * that do not contain PL011 hardware.
36	 */
37
38	.globl	console_core_init
39	.globl	console_core_putc
40	.globl	console_core_getc
41
42	/* -----------------------------------------------
43	 * int console_core_init(uintptr_t base_addr,
44	 * unsigned int uart_clk, unsigned int baud_rate)
45	 * Function to initialize the console without a
46	 * C Runtime to print debug information. This
47	 * function will be accessed by console_init and
48	 * crash reporting.
49	 * In: r0 - console base address
50	 *     r1 - Uart clock in Hz
51	 *     r2 - Baud rate
52	 * Out: return 1 on success else 0 on error
53	 * Clobber list : r1, r2
54	 * -----------------------------------------------
55	 */
56func console_core_init
57	/* Check the input base address */
58	cmp	r0, #0
59	beq	core_init_fail
60	/* Check baud rate and uart clock for sanity */
61	cmp	r1, #0
62	beq	core_init_fail
63	cmp	r2, #0
64	beq	core_init_fail
65	/* Insert implementation here */
66	mov	r0, #1
67	bx	lr
68core_init_fail:
69	mov	r0, #0
70	bx	lr
71endfunc console_core_init
72
73	/* --------------------------------------------------------
74	 * int console_core_putc(int c, uintptr_t base_addr)
75	 * Function to output a character over the console. It
76	 * returns the character printed on success or -1 on error.
77	 * In : r0 - character to be printed
78	 *      r1 - console base address
79	 * Out : return -1 on error else return character.
80	 * Clobber list : r2
81	 * --------------------------------------------------------
82	 */
83func console_core_putc
84	/* Check the input parameter */
85	cmp	r1, #0
86	beq	putc_error
87	/* Insert implementation here */
88	bx	lr
89putc_error:
90	mov	r0, #-1
91	bx	lr
92endfunc console_core_putc
93
94	/* ---------------------------------------------
95	 * int console_core_getc(uintptr_t base_addr)
96	 * Function to get a character from the console.
97	 * It returns the character grabbed on success
98	 * or -1 on error.
99	 * In : r0 - console base address
100	 * Clobber list : r0, r1
101	 * ---------------------------------------------
102	 */
103func console_core_getc
104	cmp	r0, #0
105	beq	getc_error
106	/* Insert implementation here */
107	bx	lr
108getc_error:
109	mov	r0, #-1
110	bx	lr
111endfunc console_core_getc
112