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 = Round(Uartclock / (16 * baudrate)) */
49	lsl	w2, w2, #4
50	add	w1, w1, w2, lsr #1
51	udiv	w2, w1, w2
52	and	w2, w2, #0x3ff /* clear all other bits to use default clock */
53
54	str	w2, [x0, #UART_BAUD_REG]/* set baud rate divisor */
55
56	/* Set UART to default 16X scheme */
57	mov	w3, #0
58	str	w3, [x0, #UART_POSSR_REG]
59
60	/*
61	 * Wait for the TX (THR and TSR) to be empty. If wait for 3ms, the TX FIFO is
62	 * still not empty, TX FIFO will reset by all means.
63	 */
64	mov	w1, #30				/* max time out 30 * 100 us */
652:
66	/* Check whether TX (THR and TSR) is empty */
67	ldr	w3, [x0, #UART_STATUS_REG]
68	and	w3, w3, #UARTLSR_TXEMPTY
69	cmp	w3, #0
70	b.ne	4f
71
72	/* Delay */
73	mov	w2, #60000	/* 60000 cycles of below 3 instructions on 1200 MHz CPU ~~ 100 us */
743:
75	sub     w2, w2, #1
76	cmp	w2, #0
77	b.ne	3b
78
79	/* Check whether wait timeout expired */
80	sub     w1, w1, #1
81	cmp	w1, #0
82	b.ne	2b
83
844:
85	/* Reset FIFO */
86	mov	w3, #UART_CTRL_RXFIFO_RESET
87	orr	w3, w3, #UART_CTRL_TXFIFO_RESET
88	str	w3, [x0, #UART_CTRL_REG]
89
90	/* Delay */
91	mov	w2, #2000
921:
93	sub     w2, w2, #1
94	cmp	w2, #0
95	b.ne	1b
96
97	/* No Parity, 1 Stop */
98	mov	w3, #0
99	str	w3, [x0, #UART_CTRL_REG]
100
101	mov	w0, #1
102	ret
103init_fail:
104	mov	w0, #0
105	ret
106endfunc console_a3700_core_init
107
108	.globl console_a3700_register
109
110	/* -----------------------------------------------
111	 * int console_a3700_register(console_t *console,
112		uintptr_t base, uint32_t clk, uint32_t baud)
113	 * Function to initialize and register a new a3700
114	 * console. Storage passed in for the console struct
115	 * *must* be persistent (i.e. not from the stack).
116	 * In: x0 - UART register base address
117	 *     w1 - UART clock in Hz
118	 *     w2 - Baud rate
119	 *     x3 - pointer to empty console_t struct
120	 * Out: return 1 on success, 0 on error
121	 * Clobber list : x0, x1, x2, x6, x7, x14
122	 * -----------------------------------------------
123	 */
124func console_a3700_register
125	mov	x7, x30
126	mov	x6, x3
127	cbz	x6, register_fail
128	str	x0, [x6, #CONSOLE_T_BASE]
129
130	bl	console_a3700_core_init
131	cbz	x0, register_fail
132
133	mov	x0, x6
134	mov	x30, x7
135	finish_console_register a3700, putc=1, getc=1, flush=1
136
137register_fail:
138	ret	x7
139endfunc console_a3700_register
140
141	/* --------------------------------------------------------
142	 * int console_a3700_core_putc(int c, unsigned int base_addr)
143	 * Function to output a character over the console. It
144	 * returns the character printed on success or -1 on error.
145	 * In : w0 - character to be printed
146	 *      x1 - console base address
147	 * Out : return -1 on error else return character.
148	 * Clobber list : x2
149	 * --------------------------------------------------------
150	 */
151func console_a3700_core_putc
152	/* Check the input parameter */
153	cbz	x1, putc_error
154
155	/* Prepend '\r' to '\n' */
156	cmp	w0, #0xA
157	b.ne	2f
158	/* Check if the transmit FIFO is full */
1591:	ldr	w2, [x1, #UART_STATUS_REG]
160	and	w2, w2, #UARTLSR_TXFIFOFULL
161	cmp	w2, #UARTLSR_TXFIFOFULL
162	b.eq	1b
163	mov	w2, #0xD		/* '\r' */
164	str	w2, [x1, #UART_TX_REG]
165
166	/* Check if the transmit FIFO is full */
1672:	ldr	w2, [x1, #UART_STATUS_REG]
168	and	w2, w2, #UARTLSR_TXFIFOFULL
169	cmp	w2, #UARTLSR_TXFIFOFULL
170	b.eq	2b
171	str	w0, [x1, #UART_TX_REG]
172	ret
173putc_error:
174	mov	w0, #-1
175	ret
176endfunc console_a3700_core_putc
177
178	/* --------------------------------------------------------
179	 * int console_a3700_putc(int c, console_t *console)
180	 * Function to output a character over the console. It
181	 * returns the character printed on success or -1 on error.
182	 * In : w0 - character to be printed
183	 *      x1 - pointer to console_t structure
184	 * Out : return -1 on error else return character.
185	 * Clobber list : x2
186	 * --------------------------------------------------------
187	 */
188func console_a3700_putc
189	ldr	x1, [x1, #CONSOLE_T_BASE]
190	b	console_a3700_core_putc
191endfunc console_a3700_putc
192
193	/* ---------------------------------------------
194	 * int console_a3700_core_getc(void)
195	 * Function to get a character from the console.
196	 * It returns the character grabbed on success
197	 * or -1 if no character is available.
198	 * In : w0 - console base address
199	 * Out : w0 - character if available, else -1
200	 * Clobber list : x0, x1
201	 * ---------------------------------------------
202	 */
203func console_a3700_core_getc
204	/* Check if there is a pending character */
205	ldr	w1, [x0, #UART_STATUS_REG]
206	and	w1, w1, #UARTLSR_RXRDY
207	cmp	w1, #UARTLSR_RXRDY
208	b.ne	getc_no_char
209	ldr	w0, [x0, #UART_RX_REG]
210	and	w0, w0, #0xff
211	ret
212getc_no_char:
213	mov	w0, #ERROR_NO_PENDING_CHAR
214	ret
215endfunc console_a3700_core_getc
216
217	/* ---------------------------------------------
218	 * int console_a3700_getc(console_t *console)
219	 * Function to get a character from the console.
220	 * It returns the character grabbed on success
221	 * or -1 on if no character is available.
222	 * In :  x0 - pointer to console_t structure
223	 * Out : w0 - character if available, else -1
224	 * Clobber list : x0, x1
225	 * ---------------------------------------------
226	 */
227func console_a3700_getc
228	ldr	x0, [x0, #CONSOLE_T_BASE]
229	b	console_a3700_core_getc
230endfunc console_a3700_getc
231
232	/* ---------------------------------------------
233	 * void console_a3700_core_flush(uintptr_t base_addr)
234	 * Function to force a write of all buffered
235	 * data that hasn't been output.
236	 * In : x0 - console base address
237	 * Out : void.
238	 * Clobber list : x0, x1
239	 * ---------------------------------------------
240	 */
241func console_a3700_core_flush
242	/* Wait for the TX (THR and TSR) to be empty */
2431:	ldr	w1, [x0, #UART_STATUS_REG]
244	and	w1, w1, #UARTLSR_TXEMPTY
245	cmp	w1, #UARTLSR_TXEMPTY
246	b.ne	1b
247	ret
248endfunc console_a3700_core_flush
249
250	/* ---------------------------------------------
251	 * void console_a3700_flush(console_t *console)
252	 * Function to force a write of all buffered
253	 * data that hasn't been output.
254	 * In : x0 - pointer to console_t structure
255	 * Out : void.
256	 * Clobber list : x0, x1
257	 * ---------------------------------------------
258	 */
259func console_a3700_flush
260	ldr	x0, [x0, #CONSOLE_T_BASE]
261	b	console_a3700_core_flush
262endfunc console_a3700_flush
263
264