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1/*
2 * Copyright (C) 2016 Marvell International Ltd.
3 *
4 * SPDX-License-Identifier:	BSD-3-Clause
5 * https://spdx.org/licenses
6 */
7
8#include <arch.h>
9#include <asm_macros.S>
10#include <console_macros.S>
11#include <drivers/marvell/uart/a3700_console.h>
12
13	/*
14	 * "core" functions are low-level implementations that don't require
15	 * writable memory and are thus safe to call in BL1 crash context.
16	 */
17	.globl console_a3700_core_putc
18	.globl console_a3700_core_init
19	.globl console_a3700_core_getc
20	.globl console_a3700_core_flush
21
22	.globl console_a3700_putc
23	.globl console_a3700_getc
24	.globl console_a3700_flush
25
26	/* -----------------------------------------------
27	 * int console_a3700_core_init(unsigned long base_addr,
28	 * unsigned int uart_clk, unsigned int baud_rate)
29	 * Function to initialize the console without a
30	 * C Runtime to print debug information. This
31	 * function will be accessed by console_init and
32	 * crash reporting.
33	 * In: x0 - console base address
34	 *     w1 - Uart clock in Hz
35	 *     w2 - Baud rate
36	 * Out: return 1 on success
37	 * Clobber list : x1, x2, x3
38	 * -----------------------------------------------
39	 */
40func console_a3700_core_init
41	/* Check the input base address */
42	cbz	x0, init_fail
43	/* Check baud rate and uart clock for sanity */
44	cbz	w1, init_fail
45	cbz	w2, init_fail
46
47	/* Program the baudrate */
48	/* Divisor =  Uart clock / (16 * baudrate) */
49	lsl	w2, w2, #4
50	udiv	w2, w1, w2
51	and	w2, w2, #0x3ff
52
53	ldr	w3, [x0, #UART_BAUD_REG]
54	bic	w3, w3, 0x3ff
55	orr	w3, w3, w2
56	str	w3, [x0, #UART_BAUD_REG]/* set baud rate divisor */
57
58	/* Set UART to default 16X scheme */
59	mov	w3, #0
60	str	w3, [x0, #UART_POSSR_REG]
61
62	/*
63	 * Wait for the TX (THR and TSR) to be empty. If wait for 20ms, the TX FIFO is
64	 * still not empty, TX FIFO will reset by all means.
65	 */
66	mov	w1, #20				/* max time out 20ms */
672:
68	/* Check whether TX (THR and TSR) is empty */
69	ldr	w3, [x0, #UART_STATUS_REG]
70	and	w3, w3, #UARTLSR_TXEMPTY
71	cmp	w3, #0
72	b.ne	4f
73
74	/* Delay */
75	mov	w2, #30000
763:
77	sub     w2, w2, #1
78	cmp	w2, #0
79	b.ne	3b
80
81	/* Check whether 10ms is waited */
82	sub     w1, w1, #1
83	cmp	w1, #0
84	b.ne	2b
85
864:
87	/* Reset FIFO */
88	mov	w3, #UART_CTRL_RXFIFO_RESET
89	orr	w3, w3, #UART_CTRL_TXFIFO_RESET
90	str	w3, [x0, #UART_CTRL_REG]
91
92	/* Delay */
93	mov	w2, #2000
941:
95	sub     w2, w2, #1
96	cmp	w2, #0
97	b.ne	1b
98
99	/* No Parity, 1 Stop */
100	mov	w3, #0
101	str	w3, [x0, #UART_CTRL_REG]
102
103	mov	w0, #1
104	ret
105init_fail:
106	mov	w0, #0
107	ret
108endfunc console_a3700_core_init
109
110	.globl console_a3700_register
111
112	/* -----------------------------------------------
113	 * int console_a3700_register(console_t *console,
114		uintptr_t base, uint32_t clk, uint32_t baud)
115	 * Function to initialize and register a new a3700
116	 * console. Storage passed in for the console struct
117	 * *must* be persistent (i.e. not from the stack).
118	 * In: x0 - UART register base address
119	 *     w1 - UART clock in Hz
120	 *     w2 - Baud rate
121	 *     x3 - pointer to empty console_t struct
122	 * Out: return 1 on success, 0 on error
123	 * Clobber list : x0, x1, x2, x6, x7, x14
124	 * -----------------------------------------------
125	 */
126func console_a3700_register
127	mov	x7, x30
128	mov	x6, x3
129	cbz	x6, register_fail
130	str	x0, [x6, #CONSOLE_T_BASE]
131
132	bl	console_a3700_core_init
133	cbz	x0, register_fail
134
135	mov	x0, x6
136	mov	x30, x7
137	finish_console_register a3700, putc=1, getc=1, flush=1
138
139register_fail:
140	ret	x7
141endfunc console_a3700_register
142
143	/* --------------------------------------------------------
144	 * int console_a3700_core_putc(int c, unsigned int base_addr)
145	 * Function to output a character over the console. It
146	 * returns the character printed on success or -1 on error.
147	 * In : w0 - character to be printed
148	 *      x1 - console base address
149	 * Out : return -1 on error else return character.
150	 * Clobber list : x2
151	 * --------------------------------------------------------
152	 */
153func console_a3700_core_putc
154	/* Check the input parameter */
155	cbz	x1, putc_error
156
157	/* Prepend '\r' to '\n' */
158	cmp	w0, #0xA
159	b.ne	2f
160	/* Check if the transmit FIFO is full */
1611:	ldr	w2, [x1, #UART_STATUS_REG]
162	and	w2, w2, #UARTLSR_TXFIFOFULL
163	cmp	w2, #UARTLSR_TXFIFOFULL
164	b.eq	1b
165	mov	w2, #0xD		/* '\r' */
166	str	w2, [x1, #UART_TX_REG]
167
168	/* Check if the transmit FIFO is full */
1692:	ldr	w2, [x1, #UART_STATUS_REG]
170	and	w2, w2, #UARTLSR_TXFIFOFULL
171	cmp	w2, #UARTLSR_TXFIFOFULL
172	b.eq	2b
173	str	w0, [x1, #UART_TX_REG]
174	ret
175putc_error:
176	mov	w0, #-1
177	ret
178endfunc console_a3700_core_putc
179
180	/* --------------------------------------------------------
181	 * int console_a3700_putc(int c, console_t *console)
182	 * Function to output a character over the console. It
183	 * returns the character printed on success or -1 on error.
184	 * In : w0 - character to be printed
185	 *      x1 - pointer to console_t structure
186	 * Out : return -1 on error else return character.
187	 * Clobber list : x2
188	 * --------------------------------------------------------
189	 */
190func console_a3700_putc
191	ldr	x1, [x1, #CONSOLE_T_BASE]
192	b	console_a3700_core_putc
193endfunc console_a3700_putc
194
195	/* ---------------------------------------------
196	 * int console_a3700_core_getc(void)
197	 * Function to get a character from the console.
198	 * It returns the character grabbed on success
199	 * or -1 if no character is available.
200	 * In : w0 - console base address
201	 * Out : w0 - character if available, else -1
202	 * Clobber list : x0, x1
203	 * ---------------------------------------------
204	 */
205func console_a3700_core_getc
206	/* Check if there is a pending character */
207	ldr	w1, [x0, #UART_STATUS_REG]
208	and	w1, w1, #UARTLSR_RXRDY
209	cmp	w1, #UARTLSR_RXRDY
210	b.ne	getc_no_char
211	ldr	w0, [x0, #UART_RX_REG]
212	and	w0, w0, #0xff
213	ret
214getc_no_char:
215	mov	w0, #ERROR_NO_PENDING_CHAR
216	ret
217endfunc console_a3700_core_getc
218
219	/* ---------------------------------------------
220	 * int console_a3700_getc(console_t *console)
221	 * Function to get a character from the console.
222	 * It returns the character grabbed on success
223	 * or -1 on if no character is available.
224	 * In :  x0 - pointer to console_t structure
225	 * Out : w0 - character if available, else -1
226	 * Clobber list : x0, x1
227	 * ---------------------------------------------
228	 */
229func console_a3700_getc
230	ldr	x0, [x0, #CONSOLE_T_BASE]
231	b	console_a3700_core_getc
232endfunc console_a3700_getc
233
234	/* ---------------------------------------------
235	 * void console_a3700_core_flush(uintptr_t base_addr)
236	 * Function to force a write of all buffered
237	 * data that hasn't been output.
238	 * In : x0 - console base address
239	 * Out : void.
240	 * Clobber list : x0, x1
241	 * ---------------------------------------------
242	 */
243func console_a3700_core_flush
244	/* Wait for the TX (THR and TSR) to be empty */
2451:	ldr	w1, [x0, #UART_STATUS_REG]
246	and	w1, w1, #UARTLSR_TXEMPTY
247	cmp	w1, #UARTLSR_TXEMPTY
248	b.ne	1b
249	ret
250endfunc console_a3700_core_flush
251
252	/* ---------------------------------------------
253	 * void console_a3700_flush(console_t *console)
254	 * Function to force a write of all buffered
255	 * data that hasn't been output.
256	 * In : x0 - pointer to console_t structure
257	 * Out : void.
258	 * Clobber list : x0, x1
259	 * ---------------------------------------------
260	 */
261func console_a3700_flush
262	ldr	x0, [x0, #CONSOLE_T_BASE]
263	b	console_a3700_core_flush
264endfunc console_a3700_flush
265
266