xref: /rk3399_ARM-atf/drivers/console/aarch32/skeleton_console.S (revision 0b32628eddfef95b51909816f625e6f37cd21cb8)
1/*
2 * Copyright (c) 2016-2017, 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 <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	.globl	console_core_flush
42
43	/* -----------------------------------------------
44	 * int console_core_init(uintptr_t base_addr,
45	 * unsigned int uart_clk, unsigned int baud_rate)
46	 * Function to initialize the console without a
47	 * C Runtime to print debug information. This
48	 * function will be accessed by console_init and
49	 * crash reporting.
50	 * In: r0 - console base address
51	 *     r1 - Uart clock in Hz
52	 *     r2 - Baud rate
53	 * Out: return 1 on success else 0 on error
54	 * Clobber list : r1, r2
55	 * -----------------------------------------------
56	 */
57func console_core_init
58	/* Check the input base address */
59	cmp	r0, #0
60	beq	core_init_fail
61	/* Check baud rate and uart clock for sanity */
62	cmp	r1, #0
63	beq	core_init_fail
64	cmp	r2, #0
65	beq	core_init_fail
66	/* Insert implementation here */
67	mov	r0, #1
68	bx	lr
69core_init_fail:
70	mov	r0, #0
71	bx	lr
72endfunc console_core_init
73
74	/* --------------------------------------------------------
75	 * int console_core_putc(int c, uintptr_t base_addr)
76	 * Function to output a character over the console. It
77	 * returns the character printed on success or -1 on error.
78	 * In : r0 - character to be printed
79	 *      r1 - console base address
80	 * Out : return -1 on error else return character.
81	 * Clobber list : r2
82	 * --------------------------------------------------------
83	 */
84func console_core_putc
85	/* Check the input parameter */
86	cmp	r1, #0
87	beq	putc_error
88	/* Insert implementation here */
89	bx	lr
90putc_error:
91	mov	r0, #-1
92	bx	lr
93endfunc console_core_putc
94
95	/* ---------------------------------------------
96	 * int console_core_getc(uintptr_t base_addr)
97	 * Function to get a character from the console.
98	 * It returns the character grabbed on success
99	 * or -1 on error.
100	 * In : r0 - console base address
101	 * Clobber list : r0, r1
102	 * ---------------------------------------------
103	 */
104func console_core_getc
105	cmp	r0, #0
106	beq	getc_error
107	/* Insert implementation here */
108	bx	lr
109getc_error:
110	mov	r0, #-1
111	bx	lr
112endfunc console_core_getc
113
114	/* ---------------------------------------------
115	 * int console_core_flush(uintptr_t base_addr)
116	 * Function to force a write of all buffered
117	 * data that hasn't been output.
118	 * In : r0 - console base address
119	 * Out : return -1 on error else return 0.
120	 * Clobber list : r0, r1
121	 * ---------------------------------------------
122	 */
123func console_core_flush
124	cmp	r0, #0
125	beq	flush_error
126	/* Insert implementation here */
127	mov	r0, #0
128	bx	lr
129flush_error:
130	mov	r0, #-1
131	bx	lr
132endfunc console_core_flush
133