xref: /openbmc/linux/arch/mips/ar7/prom.c (revision 8dde5715)
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 
23 struct env_var {
24 	char	*name;
25 	char	*value;
26 };
27 
28 static struct env_var adam2_env[MAX_ENTRY];
29 
30 char *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 }
40 EXPORT_SYMBOL(prom_getenv);
41 
42 static 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 
53 struct psbl_rec {
54 	u32	psbl_size;
55 	u32	env_base;
56 	u32	env_size;
57 	u32	ffs_base;
58 	u32	ffs_size;
59 };
60 
61 static const char psp_env_version[] __initconst = "TIENV0.8";
62 
63 struct psp_env_chunk {
64 	u8	num;
65 	u8	ctrl;
66 	u16	csum;
67 	u8	len;
68 	char	data[11];
69 } __packed;
70 
71 struct psp_var_map_entry {
72 	u8	num;
73 	char	*value;
74 };
75 
76 static 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 
90 Well-known variable (num is looked up in table above for matching variable name)
91 Example: cpufrequency=211968000
92 +----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
93 | 01 |CTRL|CHECKSUM | 01 | _2 | _1 | _1 | _9 | _6 | _8 | _0 | _0 | _0 | \0 | FF
94 +----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
95 
96 Name=Value pair in a single chunk
97 Example: NAME=VALUE
98 +----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
99 | 00 |CTRL|CHECKSUM | 01 | _N | _A | _M | _E | _0 | _V | _A | _L | _U | _E | \0
100 +----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
101 
102 Name=Value pair in 2 chunks (len is the number of chunks)
103 Example: 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 
110 Data is padded with 0xFF
111 
112 */
113 
114 #define PSP_ENV_SIZE  4096
115 
116 static char psp_env_data[PSP_ENV_SIZE] = { 0, };
117 
118 static 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 
129 static 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 
145 static 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 
172 static 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 
187 static 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 
233 void __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)))
241 static inline unsigned int serial_in(int offset)
242 {
243 	return readl((void *)PORT(offset));
244 }
245 
246 static inline void serial_out(int offset, int value)
247 {
248 	writel(value, (void *)PORT(offset));
249 }
250 
251 void prom_putchar(char c)
252 {
253 	while ((serial_in(UART_LSR) & UART_LSR_TEMT) == 0)
254 		;
255 	serial_out(UART_TX, c);
256 }
257