1/*
2 * Copyright (c) 2016-2020, ARM Limited and Contributors. All rights reserved.
3 *
4 * SPDX-License-Identifier: BSD-3-Clause
5 */
6#include <arch.h>
7#include <asm_macros.S>
8#include <assert_macros.S>
9#include <console_macros.S>
10#include <drivers/arm/pl011.h>
11
12	/*
13	 * "core" functions are low-level implementations that don't require
14	 * writeable memory and are thus safe to call in BL1 crash context.
15	 */
16	.globl	console_pl011_core_init
17	.globl	console_pl011_core_putc
18	.globl	console_pl011_core_getc
19	.globl	console_pl011_core_flush
20
21	.globl	console_pl011_putc
22	.globl	console_pl011_getc
23	.globl	console_pl011_flush
24
25
26	/* -----------------------------------------------
27	 * int console_core_init(uintptr_t 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: r0 - console base address
34	 *     r1 - Uart clock in Hz
35	 *     r2 - Baud rate
36	 * Out: return 1 on success else 0 on error
37	 * Clobber list : r1, r2, r3
38	 * -----------------------------------------------
39	 */
40func console_pl011_core_init
41	/* Check the input base address */
42	cmp	r0, #0
43	beq	core_init_fail
44#if !PL011_GENERIC_UART
45	/* Check baud rate and uart clock for sanity */
46	cmp	r1, #0
47	beq	core_init_fail
48	cmp	r2, #0
49	beq	core_init_fail
50	/* Disable the UART before initialization */
51	ldr	r3, [r0, #UARTCR]
52	bic	r3, r3, #PL011_UARTCR_UARTEN
53	str	r3, [r0, #UARTCR]
54	/* Program the baudrate */
55	/* Divisor =  (Uart clock * 4) / baudrate */
56	lsl	r1, r1, #2
57#if (ARM_ARCH_MAJOR == 7) && !defined(ARMV7_SUPPORTS_VIRTUALIZATION)
58	push	{r0,r3}
59	softudiv	r0,r1,r2,r3
60	mov	r2, r0
61	pop	{r0,r3}
62#else
63	udiv	r2, r1, r2
64#endif
65	/* IBRD = Divisor >> 6 */
66	lsr	r1, r2, #6
67	/* Write the IBRD */
68	str	r1, [r0, #UARTIBRD]
69	/* FBRD = Divisor & 0x3F */
70	and	r1, r2, #0x3f
71	/* Write the FBRD */
72	str	r1, [r0, #UARTFBRD]
73	mov	r1, #PL011_LINE_CONTROL
74	str	r1, [r0, #UARTLCR_H]
75	/* Clear any pending errors */
76	mov	r1, #0
77	str	r1, [r0, #UARTECR]
78	/* Enable tx, rx, and uart overall */
79	ldr	r1, =(PL011_UARTCR_RXE | PL011_UARTCR_TXE | PL011_UARTCR_UARTEN)
80	str	r1, [r0, #UARTCR]
81#endif
82	mov	r0, #1
83	bx	lr
84core_init_fail:
85	mov	r0, #0
86	bx	lr
87endfunc console_pl011_core_init
88
89	.globl console_pl011_register
90
91	/* -------------------------------------------------------
92	 * int console_pl011_register(uintptr_t baseaddr,
93	 *     uint32_t clock, uint32_t baud,
94	 *     console_t *console);
95	 * Function to initialize and register a new PL011
96	 * console. Storage passed in for the console struct
97	 * *must* be persistent (i.e. not from the stack).
98	 * In: r0 - UART register base address
99	 *     r1 - UART clock in Hz
100	 *     r2 - Baud rate
101	 *     r3 - pointer to empty console_t struct
102	 * Out: return 1 on success, 0 on error
103	 * Clobber list : r0, r1, r2
104	 * -------------------------------------------------------
105	 */
106func console_pl011_register
107	push	{r4, lr}
108	mov	r4, r3
109	cmp	r4, #0
110	beq	register_fail
111	str	r0, [r4, #CONSOLE_T_BASE]
112
113	bl console_pl011_core_init
114	cmp	r0, #0
115	beq	register_fail
116
117	mov	r0, r4
118	pop	{r4, lr}
119	finish_console_register pl011 putc=1, getc=1, flush=1
120
121register_fail:
122	pop	{r4, pc}
123endfunc console_pl011_register
124
125	/* --------------------------------------------------------
126	 * int console_core_putc(int c, uintptr_t base_addr)
127	 * Function to output a character over the console. It
128	 * returns the character printed on success or -1 on error.
129	 * In : r0 - character to be printed
130	 *      r1 - console base address
131	 * Out : return -1 on error else return character.
132	 * Clobber list : r2
133	 * --------------------------------------------------------
134	 */
135func console_pl011_core_putc
136	/* Check the input parameter */
137	cmp	r1, #0
138	beq	putc_error
139	/* Prepend '\r' to '\n' */
140	cmp	r0, #0xA
141	bne	2f
1421:
143	/* Check if the transmit FIFO is full */
144	ldr	r2, [r1, #UARTFR]
145	tst	r2, #PL011_UARTFR_TXFF
146	bne	1b
147	mov	r2, #0xD
148	str	r2, [r1, #UARTDR]
1492:
150	/* Check if the transmit FIFO is full */
151	ldr	r2, [r1, #UARTFR]
152	tst	r2, #PL011_UARTFR_TXFF
153	bne	2b
154	str	r0, [r1, #UARTDR]
155	bx	lr
156putc_error:
157	mov	r0, #-1
158	bx	lr
159endfunc console_pl011_core_putc
160
161	/* --------------------------------------------------------
162	 * int console_pl011_putc(int c, console_t *console)
163	 * Function to output a character over the console. It
164	 * returns the character printed on success or -1 on error.
165	 * In: r0 - character to be printed
166	 *     r1 - pointer to console_t structure
167	 * Out : return -1 on error else return character.
168	 * Clobber list: r2
169	 * -------------------------------------------------------
170	 */
171func console_pl011_putc
172#if ENABLE_ASSERTIONS
173	cmp	r1, #0
174	ASM_ASSERT(ne)
175#endif /* ENABLE_ASSERTIONS */
176	ldr	r1, [r1, #CONSOLE_T_BASE]
177	b	console_pl011_core_putc
178endfunc console_pl011_putc
179
180	/* ---------------------------------------------
181	 * int console_core_getc(uintptr_t base_addr)
182	 * Function to get a character from the console.
183	 * It returns the character grabbed on success
184	 * or -1 on error.
185	 * In : r0 - console base address
186	 * Clobber list : r0, r1
187	 * ---------------------------------------------
188	 */
189func console_pl011_core_getc
190	cmp	r0, #0
191	beq	getc_error
1921:
193	/* Check if the receive FIFO is empty */
194	ldr	r1, [r0, #UARTFR]
195	tst	r1, #PL011_UARTFR_RXFE
196	bne	1b
197	ldr	r1, [r0, #UARTDR]
198	mov	r0, r1
199	bx	lr
200getc_error:
201	mov	r0, #-1
202	bx	lr
203endfunc console_pl011_core_getc
204
205	/* ------------------------------------------------
206	 * int console_pl011_getc(console_t *console)
207	 * Function to get a character from the console.
208	 * It returns the character grabbed on success
209	 * or -1 if no character is available.
210	 * In : r0 - pointer to console_t structure
211	 * Out: r0 - character if available, else -1
212	 * Clobber list: r0, r1
213	 * ------------------------------------------------
214	 */
215func console_pl011_getc
216#if ENABLE_ASSERTIONS
217	cmp	r0, #0
218	ASM_ASSERT(ne)
219#endif /* ENABLE_ASSERTIONS */
220	ldr	r0, [r0, #CONSOLE_T_BASE]
221	b	console_pl011_core_getc
222endfunc console_pl011_getc
223
224	/* ---------------------------------------------
225	 * void console_core_flush(uintptr_t base_addr)
226	 * Function to force a write of all buffered
227	 * data that hasn't been output.
228	 * In : r0 - console base address
229	 * Out : void
230	 * Clobber list : r0, r1
231	 * ---------------------------------------------
232	 */
233func console_pl011_core_flush
234#if ENABLE_ASSERTIONS
235	cmp	r0, #0
236	ASM_ASSERT(ne)
237#endif /* ENABLE_ASSERTIONS */
238
2391:
240	/* Loop while the transmit FIFO is busy */
241	ldr	r1, [r0, #UARTFR]
242	tst	r1, #PL011_UARTFR_BUSY
243	bne	1b
244
245	bx	lr
246endfunc console_pl011_core_flush
247
248	/* ---------------------------------------------
249	 * void console_pl011_flush(console_t *console)
250	 * Function to force a write of all buffered
251	 * data that hasn't been output.
252	 * In : r0 - pointer to console_t structure
253	 * Out : void
254	 * Clobber list: r0, r1
255	 * ---------------------------------------------
256	 */
257func console_pl011_flush
258#if ENABLE_ASSERTIONS
259	cmp	r0, #0
260	ASM_ASSERT(ne)
261#endif /* ENABLE_ASSERTIONS */
262	ldr	r0, [r0, #CONSOLE_T_BASE]
263	b	console_pl011_core_flush
264endfunc console_pl011_flush
265