blob: 044d3d0740c427e8d8ef116642656796bb172fc8 [file] [log] [blame]
Pankaj Gupta6b36c1b2020-12-09 14:02:38 +05301/*
2 * Copyright (c) 2021, ARM Limited and Contributors. All rights reserved.
3 *
4 * SPDX-License-Identifier: BSD-3-Clause
5 */
6
7#include <arch.h>
8#include <asm_macros.S>
9#include <assert_macros.S>
10#include <console_macros.S>
11
12/* UART16550 Registers */
13#define UARTTX 0x0
14#define UARTRX 0x0
15#define UARTDLL 0x0
16#define UARTIER 0x1
17#define UARTDLLM 0x1
18#define UARTFCR 0x2
19#define UARTLCR 0x3
20#define UARTLSR 0x5
21#define UARTMCR 0x4
22
23/* FIFO Control Register bits */
24#define UARTFCR_FIFOMD_16450 (0 << 6)
25#define UARTFCR_FIFOMD_16550 (1 << 6)
26#define UARTFCR_RXTRIG_1 (0 << 6)
27#define UARTFCR_RXTRIG_4 (1 << 6)
28#define UARTFCR_RXTRIG_8 (2 << 6)
29#define UARTFCR_RXTRIG_16 (3 << 6)
30#define UARTFCR_TXTRIG_1 (0 << 4)
31#define UARTFCR_TXTRIG_4 (1 << 4)
32#define UARTFCR_TXTRIG_8 (2 << 4)
33#define UARTFCR_TXTRIG_16 (3 << 4)
34#define UARTFCR_DMAEN (1 << 3) /* Enable DMA mode */
35#define UARTFCR_TXCLR (1 << 2) /* Clear contents of Tx FIFO */
36#define UARTFCR_RXCLR (1 << 1) /* Clear contents of Rx FIFO */
37#define UARTFCR_FIFOEN (1 << 0) /* Enable the Tx/Rx FIFO */
38#define UARTFCR_64FIFO (1 << 5)
39
40/* Line Control Register bits */
41#define UARTLCR_DLAB (1 << 7) /* Divisor Latch Access */
42#define UARTLCR_SETB (1 << 6) /* Set BREAK Condition */
43#define UARTLCR_SETP (1 << 5) /* Set Parity to LCR[4] */
44#define UARTLCR_EVEN (1 << 4) /* Even Parity Format */
45#define UARTLCR_PAR (1 << 3) /* Parity */
46#define UARTLCR_STOP (1 << 2) /* Stop Bit */
47#define UARTLCR_WORDSZ_5 0 /* Word Length of 5 */
48#define UARTLCR_WORDSZ_6 1 /* Word Length of 6 */
49#define UARTLCR_WORDSZ_7 2 /* Word Length of 7 */
50#define UARTLCR_WORDSZ_8 3 /* Word Length of 8 */
51
52/* Line Status Register bits */
53#define UARTLSR_RXFIFOEMT (1 << 9) /* Rx Fifo Empty */
54#define UARTLSR_TXFIFOFULL (1 << 8) /* Tx Fifo Full */
55#define UARTLSR_RXFIFOERR (1 << 7) /* Rx Fifo Error */
56#define UARTLSR_TEMT (1 << 6) /* Tx Shift Register Empty */
57#define UARTLSR_THRE (1 << 5) /* Tx Holding Register Empty */
58#define UARTLSR_BRK (1 << 4) /* Break Condition Detected */
59#define UARTLSR_FERR (1 << 3) /* Framing Error */
60#define UARTLSR_PERR (1 << 3) /* Parity Error */
61#define UARTLSR_OVRF (1 << 2) /* Rx Overrun Error */
62#define UARTLSR_RDR (1 << 2) /* Rx Data Ready */
63
64#define CONSOLE_T_16550_BASE CONSOLE_T_BASE
65
66 /*
67 * "core" functions are low-level implementations that don't require
68 * writable memory and are thus safe to call in BL1 crash context.
69 */
70 .globl nxp_console_16550_core_init
71 .globl nxp_console_16550_core_putc
72 .globl nxp_console_16550_core_getc
73 .globl nxp_console_16550_core_flush
74
75 .globl console_16550_putc
76 .globl console_16550_getc
77 .globl console_16550_flush
78
79 /* -----------------------------------------------
80 * int nxp_console_16550_core_init(uintptr_t base_addr,
81 * unsigned int uart_clk, unsigned int baud_rate)
82 * Function to initialize the console without a
83 * C Runtime to print debug information. This
84 * function will be accessed by console_init and
85 * crash reporting.
86 * In: x0 - console base address
87 * w1 - Uart clock in Hz
88 * w2 - Baud rate
89 * Out: return 1 on success, 0 on error
90 * Clobber list : x1, x2, x3
91 * -----------------------------------------------
92 */
93func nxp_console_16550_core_init
94 /* Check the input base address */
95 cbz x0, init_fail
96 /* Check baud rate and uart clock for sanity */
97 cbz w1, init_fail
98 cbz w2, init_fail
99
100 /* Program the baudrate */
101 /* Divisor = Uart clock / (16 * baudrate) */
102 lsl w2, w2, #4
103 udiv w2, w1, w2
104 and w1, w2, #0xff /* w1 = DLL */
105 lsr w2, w2, #8
106 and w2, w2, #0xff /* w2 = DLLM */
107 ldrb w3, [x0, #UARTLCR]
108 orr w3, w3, #UARTLCR_DLAB
109 strb w3, [x0, #UARTLCR] /* enable DLL, DLLM programming */
110 strb w1, [x0, #UARTDLL] /* program DLL */
111 strb w2, [x0, #UARTDLLM] /* program DLLM */
112 mov w2, #~UARTLCR_DLAB
113 and w3, w3, w2
114 strb w3, [x0, #UARTLCR] /* disable DLL, DLLM programming */
115
116 /* 8n1 */
117 mov w3, #3
118 strb w3, [x0, #UARTLCR]
119 /* no interrupt */
120 mov w3, #0
121 strb w3, [x0, #UARTIER]
122 /* enable fifo, DMA */
123 mov w3, #(UARTFCR_FIFOEN |UARTFCR_TXCLR | UARTFCR_RXCLR)
124 strb w3, [x0, #UARTFCR]
125 /* DTR + RTS */
126 mov w3, #3
127 str w3, [x0, #UARTMCR]
128 mov w0, #1
129 ret
130init_fail:
131 mov w0, #0
132 ret
133endfunc nxp_console_16550_core_init
134
135 .globl nxp_console_16550_register
136
137 /* -----------------------------------------------
138 * int nxp_console_16550_register(uintptr_t baseaddr,
139 * uint32_t clock, uint32_t baud,
140 * console_t *console);
141 * Function to initialize and register a new 16550
142 * console. Storage passed in for the console struct
143 * *must* be persistent (i.e. not from the stack).
144 * If w1 (UART clock) is 0, initialisation will be
145 * skipped, relying on previous code to have done
146 * this already. w2 is ignored then as well.
147 * In: x0 - UART register base address
148 * w1 - UART clock in Hz
149 * w2 - Baud rate (ignored if w1 is 0)
150 * x3 - pointer to empty console_t struct
151 * Out: return 1 on success, 0 on error
152 * Clobber list : x0, x1, x2, x6, x7, x14
153 * -----------------------------------------------
154 */
155func nxp_console_16550_register
156 mov x7, x30
157 mov x6, x3
158 cbz x6, register_fail
159 str x0, [x6, #CONSOLE_T_16550_BASE]
160
161 /* A clock rate of zero means to skip the initialisation. */
162 cbz w1, register_16550
163
164 bl nxp_console_16550_core_init
165 cbz x0, register_fail
166
167register_16550:
168 mov x0, x6
169 mov x30, x7
170 finish_console_register 16550 putc=1, getc=1, flush=1
171
172register_fail:
173 ret x7
174endfunc nxp_console_16550_register
175
176 /* --------------------------------------------------------
177 * int console_16550_core_putc(int c, uintptr_t base_addr)
178 * Function to output a character over the console. It
179 * returns the character printed on success or -1 on error.
180 * In : w0 - character to be printed
181 * x1 - console base address
182 * Out : return -1 on error else return character.
183 * Clobber list : x2
184 * --------------------------------------------------------
185 */
186func nxp_console_16550_core_putc
187#if ENABLE_ASSERTIONS
188 cmp x1, #0
189 ASM_ASSERT(ne)
190#endif /* ENABLE_ASSERTIONS */
191
192 /* Prepend '\r' to '\n' */
193 cmp w0, #'\n'
194 b.ne 2f
195 /* Check if the transmit FIFO is full */
1961: ldrb w2, [x1, #UARTLSR]
197 and w2, w2, #UARTLSR_THRE /* #(UARTLSR_TEMT | UARTLSR_THRE)*/
198 cmp w2, #(UARTLSR_THRE)
199 b.ne 1b
200 mov w2, #'\r'
201 strb w2, [x1, #UARTTX]
202 ldrb w2, [x1, #UARTFCR]
203 orr w2, w2, #UARTFCR_TXCLR
204
205 /* Check if the transmit FIFO is full */
2062: ldrb w2, [x1, #UARTLSR]
207 and w2, w2, #(UARTLSR_THRE)
208 cmp w2, #(UARTLSR_THRE)
209 b.ne 2b
210 strb w0, [x1, #UARTTX]
211 ret
212endfunc nxp_console_16550_core_putc
213
214 /* --------------------------------------------------------
215 * int console_16550_putc(int c, console_t *console)
216 * Function to output a character over the console. It
217 * returns the character printed on success or -1 on error.
218 * In : w0 - character to be printed
219 * x1 - pointer to console_t structure
220 * Out : return -1 on error else return character.
221 * Clobber list : x2
222 * --------------------------------------------------------
223 */
224func console_16550_putc
225#if ENABLE_ASSERTIONS
226 cmp x1, #0
227 ASM_ASSERT(ne)
228#endif /* ENABLE_ASSERTIONS */
229 ldr x1, [x1, #CONSOLE_T_16550_BASE]
230 b nxp_console_16550_core_putc
231endfunc console_16550_putc
232
233 /* ---------------------------------------------
234 * int console_16550_core_getc(uintptr_t base_addr)
235 * Function to get a character from the console.
236 * It returns the character grabbed on success
237 * or -1 on if no character is available.
238 * In : x0 - console base address
239 * Out : w0 - character if available, else -1
240 * Clobber list : x0, x1
241 * ---------------------------------------------
242 */
243func nxp_console_16550_core_getc
244#if ENABLE_ASSERTIONS
245 cmp x0, #0
246 ASM_ASSERT(ne)
247#endif /* ENABLE_ASSERTIONS */
248
249 /* Check if the receive FIFO is empty */
2501: ldrb w1, [x0, #UARTLSR]
251 tbz w1, #UARTLSR_RDR, 1b
252 ldrb w0, [x0, #UARTRX]
253 ret
254no_char:
255 mov w0, #ERROR_NO_PENDING_CHAR
256 ret
257endfunc nxp_console_16550_core_getc
258
259 /* ---------------------------------------------
260 * int console_16550_getc(console_t *console)
261 * Function to get a character from the console.
262 * It returns the character grabbed on success
263 * or -1 on if no character is available.
264 * In : x0 - pointer to console_t structure
265 * Out : w0 - character if available, else -1
266 * Clobber list : x0, x1
267 * ---------------------------------------------
268 */
269func console_16550_getc
270#if ENABLE_ASSERTIONS
271 cmp x1, #0
272 ASM_ASSERT(ne)
273#endif /* ENABLE_ASSERTIONS */
274 ldr x0, [x0, #CONSOLE_T_16550_BASE]
275 b nxp_console_16550_core_getc
276endfunc console_16550_getc
277
278 /* ---------------------------------------------
279 * int console_16550_core_flush(uintptr_t base_addr)
280 * Function to force a write of all buffered
281 * data that hasn't been output.
282 * In : x0 - console base address
283 * Out : return -1 on error else return 0.
284 * Clobber list : x0, x1
285 * ---------------------------------------------
286 */
287func nxp_console_16550_core_flush
288#if ENABLE_ASSERTIONS
289 cmp x0, #0
290 ASM_ASSERT(ne)
291#endif /* ENABLE_ASSERTIONS */
292
293 /* Loop until the transmit FIFO is empty */
2941: ldrb w1, [x0, #UARTLSR]
295 and w1, w1, #(UARTLSR_THRE)
296 cmp w1, #(UARTLSR_THRE)
297 b.ne 1b
298
299 mov w0, #0
300 ret
301endfunc nxp_console_16550_core_flush
302
303 /* ---------------------------------------------
304 * int console_16550_flush(console_t *console)
305 * Function to force a write of all buffered
306 * data that hasn't been output.
307 * In : x0 - pointer to console_t structure
308 * Out : return -1 on error else return 0.
309 * Clobber list : x0, x1
310 * ---------------------------------------------
311 */
312func console_16550_flush
313#if ENABLE_ASSERTIONS
314 cmp x0, #0
315 ASM_ASSERT(ne)
316#endif /* ENABLE_ASSERTIONS */
317 ldr x0, [x0, #CONSOLE_T_16550_BASE]
318 b nxp_console_16550_core_flush
319endfunc console_16550_flush