xref: /kernel/linux/linux-5.10/arch/mips/ar7/prom.c (revision 8c2ecf20) 
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Carsten Langgaard, carstenl@mips.com
4 * Copyright (C) 1999,2000 MIPS Technologies, Inc.  All rights reserved.
5 *
6 * Putting things on the screen/serial line using YAMONs facilities.
7 */
8#include <linux/init.h>
9#include <linux/kernel.h>
10#include <linux/serial_reg.h>
11#include <linux/spinlock.h>
12#include <linux/export.h>
13#include <linux/string.h>
14#include <linux/io.h>
15#include <asm/bootinfo.h>
16#include <asm/setup.h>
17
18#include <asm/mach-ar7/ar7.h>
19#include <asm/mach-ar7/prom.h>
20
21#define MAX_ENTRY 80
22
23struct env_var {
24	char	*name;
25	char	*value;
26};
27
28static struct env_var adam2_env[MAX_ENTRY];
29
30char *prom_getenv(const char *name)
31{
32	int i;
33
34	for (i = 0; (i < MAX_ENTRY) && adam2_env[i].name; i++)
35		if (!strcmp(name, adam2_env[i].name))
36			return adam2_env[i].value;
37
38	return NULL;
39}
40EXPORT_SYMBOL(prom_getenv);
41
42static void  __init ar7_init_cmdline(int argc, char *argv[])
43{
44	int i;
45
46	for (i = 1; i < argc; i++) {
47		strlcat(arcs_cmdline, argv[i], COMMAND_LINE_SIZE);
48		if (i < (argc - 1))
49			strlcat(arcs_cmdline, " ", COMMAND_LINE_SIZE);
50	}
51}
52
53struct psbl_rec {
54	u32	psbl_size;
55	u32	env_base;
56	u32	env_size;
57	u32	ffs_base;
58	u32	ffs_size;
59};
60
61static const char psp_env_version[] __initconst = "TIENV0.8";
62
63struct psp_env_chunk {
64	u8	num;
65	u8	ctrl;
66	u16	csum;
67	u8	len;
68	char	data[11];
69} __packed;
70
71struct psp_var_map_entry {
72	u8	num;
73	char	*value;
74};
75
76static const struct psp_var_map_entry psp_var_map[] = {
77	{  1,	"cpufrequency" },
78	{  2,	"memsize" },
79	{  3,	"flashsize" },
80	{  4,	"modetty0" },
81	{  5,	"modetty1" },
82	{  8,	"maca" },
83	{  9,	"macb" },
84	{ 28,	"sysfrequency" },
85	{ 38,	"mipsfrequency" },
86};
87
88/*
89
90Well-known variable (num is looked up in table above for matching variable name)
91Example: cpufrequency=211968000
92+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
93| 01 |CTRL|CHECKSUM | 01 | _2 | _1 | _1 | _9 | _6 | _8 | _0 | _0 | _0 | \0 | FF
94+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
95
96Name=Value pair in a single chunk
97Example: NAME=VALUE
98+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
99| 00 |CTRL|CHECKSUM | 01 | _N | _A | _M | _E | _0 | _V | _A | _L | _U | _E | \0
100+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
101
102Name=Value pair in 2 chunks (len is the number of chunks)
103Example: bootloaderVersion=1.3.7.15
104+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
105| 00 |CTRL|CHECKSUM | 02 | _b | _o | _o | _t | _l | _o | _a | _d | _e | _r | _V
106+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
107| _e | _r | _s | _i | _o | _n | \0 | _1 | _. | _3 | _. | _7 | _. | _1 | _5 | \0
108+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
109
110Data is padded with 0xFF
111
112*/
113
114#define PSP_ENV_SIZE  4096
115
116static char psp_env_data[PSP_ENV_SIZE] = { 0, };
117
118static char * __init lookup_psp_var_map(u8 num)
119{
120	int i;
121
122	for (i = 0; i < ARRAY_SIZE(psp_var_map); i++)
123		if (psp_var_map[i].num == num)
124			return psp_var_map[i].value;
125
126	return NULL;
127}
128
129static void __init add_adam2_var(char *name, char *value)
130{
131	int i;
132
133	for (i = 0; i < MAX_ENTRY; i++) {
134		if (!adam2_env[i].name) {
135			adam2_env[i].name = name;
136			adam2_env[i].value = value;
137			return;
138		} else if (!strcmp(adam2_env[i].name, name)) {
139			adam2_env[i].value = value;
140			return;
141		}
142	}
143}
144
145static int __init parse_psp_env(void *psp_env_base)
146{
147	int i, n;
148	char *name, *value;
149	struct psp_env_chunk *chunks = (struct psp_env_chunk *)psp_env_data;
150
151	memcpy_fromio(chunks, psp_env_base, PSP_ENV_SIZE);
152
153	i = 1;
154	n = PSP_ENV_SIZE / sizeof(struct psp_env_chunk);
155	while (i < n) {
156		if ((chunks[i].num == 0xff) || ((i + chunks[i].len) > n))
157			break;
158		value = chunks[i].data;
159		if (chunks[i].num) {
160			name = lookup_psp_var_map(chunks[i].num);
161		} else {
162			name = value;
163			value += strlen(name) + 1;
164		}
165		if (name)
166			add_adam2_var(name, value);
167		i += chunks[i].len;
168	}
169	return 0;
170}
171
172static void __init ar7_init_env(struct env_var *env)
173{
174	int i;
175	struct psbl_rec *psbl = (struct psbl_rec *)(KSEG1ADDR(0x14000300));
176	void *psp_env = (void *)KSEG1ADDR(psbl->env_base);
177
178	if (strcmp(psp_env, psp_env_version) == 0) {
179		parse_psp_env(psp_env);
180	} else {
181		for (i = 0; i < MAX_ENTRY; i++, env++)
182			if (env->name)
183				add_adam2_var(env->name, env->value);
184	}
185}
186
187static void __init console_config(void)
188{
189#ifdef CONFIG_SERIAL_8250_CONSOLE
190	char console_string[40];
191	int baud = 0;
192	char parity = '\0', bits = '\0', flow = '\0';
193	char *s, *p;
194
195	if (strstr(arcs_cmdline, "console="))
196		return;
197
198	s = prom_getenv("modetty0");
199	if (s) {
200		baud = simple_strtoul(s, &p, 10);
201		s = p;
202		if (*s == ',')
203			s++;
204		if (*s)
205			parity = *s++;
206		if (*s == ',')
207			s++;
208		if (*s)
209			bits = *s++;
210		if (*s == ',')
211			s++;
212		if (*s == 'h')
213			flow = 'r';
214	}
215
216	if (baud == 0)
217		baud = 38400;
218	if (parity != 'n' && parity != 'o' && parity != 'e')
219		parity = 'n';
220	if (bits != '7' && bits != '8')
221		bits = '8';
222
223	if (flow == 'r')
224		sprintf(console_string, " console=ttyS0,%d%c%c%c", baud,
225			parity, bits, flow);
226	else
227		sprintf(console_string, " console=ttyS0,%d%c%c", baud, parity,
228			bits);
229	strlcat(arcs_cmdline, console_string, COMMAND_LINE_SIZE);
230#endif
231}
232
233void __init prom_init(void)
234{
235	ar7_init_cmdline(fw_arg0, (char **)fw_arg1);
236	ar7_init_env((struct env_var *)fw_arg2);
237	console_config();
238}
239
240#define PORT(offset) (KSEG1ADDR(AR7_REGS_UART0 + (offset * 4)))
241static inline unsigned int serial_in(int offset)
242{
243	return readl((void *)PORT(offset));
244}
245
246static inline void serial_out(int offset, int value)
247{
248	writel(value, (void *)PORT(offset));
249}
250
251void prom_putchar(char c)
252{
253	while ((serial_in(UART_LSR) & UART_LSR_TEMT) == 0)
254		;
255	serial_out(UART_TX, c);
256}
257