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Commit | Line | Data |
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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
7f853352 | 2 | /* |
411c9403 | 3 | * udbg for zilog scc ports as found on Apple PowerMacs |
7f853352 MM |
4 | * |
5 | * Copyright (C) 2001-2005 PPC 64 Team, IBM Corp | |
7f853352 | 6 | */ |
7f853352 | 7 | #include <linux/types.h> |
188d2ce7 | 8 | #include <asm/udbg.h> |
7f853352 | 9 | #include <asm/processor.h> |
7f853352 MM |
10 | #include <asm/io.h> |
11 | #include <asm/prom.h> | |
12 | #include <asm/pmac_feature.h> | |
13 | ||
14 | extern u8 real_readb(volatile u8 __iomem *addr); | |
15 | extern void real_writeb(u8 data, volatile u8 __iomem *addr); | |
16 | ||
17 | #define SCC_TXRDY 4 | |
18 | #define SCC_RXRDY 1 | |
19 | ||
20 | static volatile u8 __iomem *sccc; | |
21 | static volatile u8 __iomem *sccd; | |
22 | ||
51d3082f | 23 | static void udbg_scc_putc(char c) |
7f853352 MM |
24 | { |
25 | if (sccc) { | |
26 | while ((in_8(sccc) & SCC_TXRDY) == 0) | |
27 | ; | |
28 | out_8(sccd, c); | |
29 | if (c == '\n') | |
30 | udbg_scc_putc('\r'); | |
31 | } | |
32 | } | |
33 | ||
34 | static int udbg_scc_getc_poll(void) | |
35 | { | |
36 | if (sccc) { | |
37 | if ((in_8(sccc) & SCC_RXRDY) != 0) | |
38 | return in_8(sccd); | |
39 | else | |
40 | return -1; | |
41 | } | |
42 | return -1; | |
43 | } | |
44 | ||
bb6b9b28 | 45 | static int udbg_scc_getc(void) |
7f853352 MM |
46 | { |
47 | if (sccc) { | |
48 | while ((in_8(sccc) & SCC_RXRDY) == 0) | |
49 | ; | |
50 | return in_8(sccd); | |
51 | } | |
bb6b9b28 | 52 | return -1; |
7f853352 MM |
53 | } |
54 | ||
55 | static unsigned char scc_inittab[] = { | |
56 | 13, 0, /* set baud rate divisor */ | |
57 | 12, 0, | |
58 | 14, 1, /* baud rate gen enable, src=rtxc */ | |
59 | 11, 0x50, /* clocks = br gen */ | |
60 | 5, 0xea, /* tx 8 bits, assert DTR & RTS */ | |
61 | 4, 0x46, /* x16 clock, 1 stop */ | |
62 | 3, 0xc1, /* rx enable, 8 bits */ | |
63 | }; | |
64 | ||
51d3082f | 65 | void udbg_scc_init(int force_scc) |
7f853352 | 66 | { |
018a3d1d | 67 | const u32 *reg; |
7f853352 | 68 | unsigned long addr; |
51d3082f BH |
69 | struct device_node *stdout = NULL, *escc = NULL, *macio = NULL; |
70 | struct device_node *ch, *ch_def = NULL, *ch_a = NULL; | |
018a3d1d | 71 | const char *path; |
8921305c | 72 | int i; |
7f853352 | 73 | |
51d3082f BH |
74 | escc = of_find_node_by_name(NULL, "escc"); |
75 | if (escc == NULL) | |
76 | goto bail; | |
77 | macio = of_get_parent(escc); | |
78 | if (macio == NULL) | |
79 | goto bail; | |
e2eb6392 | 80 | path = of_get_property(of_chosen, "linux,stdout-path", NULL); |
51d3082f BH |
81 | if (path != NULL) |
82 | stdout = of_find_node_by_path(path); | |
83 | for (ch = NULL; (ch = of_get_next_child(escc, ch)) != NULL;) { | |
84 | if (ch == stdout) | |
85 | ch_def = of_node_get(ch); | |
2c8e65b5 | 86 | if (of_node_name_eq(ch, "ch-a")) |
51d3082f BH |
87 | ch_a = of_node_get(ch); |
88 | } | |
89 | if (ch_def == NULL && !force_scc) | |
90 | goto bail; | |
91 | ||
92 | ch = ch_def ? ch_def : ch_a; | |
7f853352 | 93 | |
7f853352 | 94 | /* Get address within mac-io ASIC */ |
e2eb6392 | 95 | reg = of_get_property(escc, "reg", NULL); |
7f853352 | 96 | if (reg == NULL) |
51d3082f | 97 | goto bail; |
7f853352 | 98 | addr = reg[0]; |
51d3082f | 99 | |
7f853352 | 100 | /* Get address of mac-io PCI itself */ |
e2eb6392 | 101 | reg = of_get_property(macio, "assigned-addresses", NULL); |
7f853352 | 102 | if (reg == NULL) |
51d3082f | 103 | goto bail; |
7f853352 | 104 | addr += reg[2]; |
51d3082f BH |
105 | |
106 | /* Lock the serial port */ | |
107 | pmac_call_feature(PMAC_FTR_SCC_ENABLE, ch, | |
108 | PMAC_SCC_ASYNC | PMAC_SCC_FLAG_XMON, 1); | |
109 | ||
51d3082f BH |
110 | if (ch == ch_a) |
111 | addr += 0x20; | |
af308377 | 112 | sccc = ioremap(addr & PAGE_MASK, PAGE_SIZE) ; |
7f853352 MM |
113 | sccc += addr & ~PAGE_MASK; |
114 | sccd = sccc + 0x10; | |
115 | ||
7f853352 MM |
116 | mb(); |
117 | ||
118 | for (i = 20000; i != 0; --i) | |
8921305c | 119 | in_8(sccc); |
7f853352 MM |
120 | out_8(sccc, 0x09); /* reset A or B side */ |
121 | out_8(sccc, 0xc0); | |
2ec6ef10 BH |
122 | |
123 | /* If SCC was the OF output port, read the BRG value, else | |
f023bf0f | 124 | * Setup for 38400 or 57600 8N1 depending on the machine |
2ec6ef10 BH |
125 | */ |
126 | if (ch_def != NULL) { | |
127 | out_8(sccc, 13); | |
128 | scc_inittab[1] = in_8(sccc); | |
129 | out_8(sccc, 12); | |
130 | scc_inittab[3] = in_8(sccc); | |
71a157e8 GL |
131 | } else if (of_machine_is_compatible("RackMac1,1") |
132 | || of_machine_is_compatible("RackMac1,2") | |
133 | || of_machine_is_compatible("MacRISC4")) { | |
f023bf0f BH |
134 | /* Xserves and G5s default to 57600 */ |
135 | scc_inittab[1] = 0; | |
136 | scc_inittab[3] = 0; | |
137 | } else { | |
138 | /* Others default to 38400 */ | |
139 | scc_inittab[1] = 0; | |
140 | scc_inittab[3] = 1; | |
2ec6ef10 BH |
141 | } |
142 | ||
7f853352 MM |
143 | for (i = 0; i < sizeof(scc_inittab); ++i) |
144 | out_8(sccc, scc_inittab[i]); | |
145 | ||
2ec6ef10 | 146 | |
c8f1c8be MM |
147 | udbg_putc = udbg_scc_putc; |
148 | udbg_getc = udbg_scc_getc; | |
149 | udbg_getc_poll = udbg_scc_getc_poll; | |
7f853352 MM |
150 | |
151 | udbg_puts("Hello World !\n"); | |
51d3082f BH |
152 | |
153 | bail: | |
154 | of_node_put(macio); | |
155 | of_node_put(escc); | |
156 | of_node_put(stdout); | |
157 | of_node_put(ch_def); | |
158 | of_node_put(ch_a); | |
7f853352 MM |
159 | } |
160 | ||
51d3082f BH |
161 | #ifdef CONFIG_PPC64 |
162 | static void udbg_real_scc_putc(char c) | |
7f853352 MM |
163 | { |
164 | while ((real_readb(sccc) & SCC_TXRDY) == 0) | |
165 | ; | |
166 | real_writeb(c, sccd); | |
167 | if (c == '\n') | |
168 | udbg_real_scc_putc('\r'); | |
169 | } | |
170 | ||
296167ae | 171 | void __init udbg_init_pmac_realmode(void) |
7f853352 MM |
172 | { |
173 | sccc = (volatile u8 __iomem *)0x80013020ul; | |
174 | sccd = (volatile u8 __iomem *)0x80013030ul; | |
175 | ||
c8f1c8be MM |
176 | udbg_putc = udbg_real_scc_putc; |
177 | udbg_getc = NULL; | |
178 | udbg_getc_poll = NULL; | |
7f853352 | 179 | } |
51d3082f | 180 | #endif /* CONFIG_PPC64 */ |