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94c73a8f JB |
1 | /* |
2 | * Old U-boot compatibility for Acadia | |
3 | * | |
4 | * Author: Josh Boyer <jwboyer@linux.vnet.ibm.com> | |
5 | * | |
6 | * Copyright 2008 IBM Corporation | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify it | |
9 | * under the terms of the GNU General Public License version 2 as published | |
10 | * by the Free Software Foundation. | |
11 | */ | |
12 | ||
13 | #include "ops.h" | |
14 | #include "io.h" | |
15 | #include "dcr.h" | |
16 | #include "stdio.h" | |
17 | #include "4xx.h" | |
18 | #include "44x.h" | |
19 | #include "cuboot.h" | |
20 | ||
21 | #define TARGET_4xx | |
22 | #include "ppcboot.h" | |
23 | ||
24 | static bd_t bd; | |
25 | ||
26 | #define CPR_PERD0_SPIDV_MASK 0x000F0000 /* SPI Clock Divider */ | |
27 | ||
28 | #define PLLC_SRC_MASK 0x20000000 /* PLL feedback source */ | |
29 | ||
30 | #define PLLD_FBDV_MASK 0x1F000000 /* PLL feedback divider value */ | |
31 | #define PLLD_FWDVA_MASK 0x000F0000 /* PLL forward divider A value */ | |
32 | #define PLLD_FWDVB_MASK 0x00000700 /* PLL forward divider B value */ | |
33 | ||
34 | #define PRIMAD_CPUDV_MASK 0x0F000000 /* CPU Clock Divisor Mask */ | |
35 | #define PRIMAD_PLBDV_MASK 0x000F0000 /* PLB Clock Divisor Mask */ | |
36 | #define PRIMAD_OPBDV_MASK 0x00000F00 /* OPB Clock Divisor Mask */ | |
37 | #define PRIMAD_EBCDV_MASK 0x0000000F /* EBC Clock Divisor Mask */ | |
38 | ||
39 | #define PERD0_PWMDV_MASK 0xFF000000 /* PWM Divider Mask */ | |
40 | #define PERD0_SPIDV_MASK 0x000F0000 /* SPI Divider Mask */ | |
41 | #define PERD0_U0DV_MASK 0x0000FF00 /* UART 0 Divider Mask */ | |
42 | #define PERD0_U1DV_MASK 0x000000FF /* UART 1 Divider Mask */ | |
43 | ||
44 | static void get_clocks(void) | |
45 | { | |
46 | unsigned long sysclk, cpr_plld, cpr_pllc, cpr_primad, plloutb, i; | |
47 | unsigned long pllFwdDiv, pllFwdDivB, pllFbkDiv, pllPlbDiv, pllExtBusDiv; | |
48 | unsigned long pllOpbDiv, freqEBC, freqUART, freqOPB; | |
49 | unsigned long div; /* total divisor udiv * bdiv */ | |
50 | unsigned long umin; /* minimum udiv */ | |
51 | unsigned short diff; /* smallest diff */ | |
52 | unsigned long udiv; /* best udiv */ | |
53 | unsigned short idiff; /* current diff */ | |
54 | unsigned short ibdiv; /* current bdiv */ | |
55 | unsigned long est; /* current estimate */ | |
56 | unsigned long baud; | |
57 | void *np; | |
58 | ||
59 | /* read the sysclk value from the CPLD */ | |
60 | sysclk = (in_8((unsigned char *)0x80000000) == 0xc) ? 66666666 : 33333000; | |
61 | ||
62 | /* | |
63 | * Read PLL Mode registers | |
64 | */ | |
65 | cpr_plld = CPR0_READ(DCRN_CPR0_PLLD); | |
66 | cpr_pllc = CPR0_READ(DCRN_CPR0_PLLC); | |
67 | ||
68 | /* | |
69 | * Determine forward divider A | |
70 | */ | |
71 | pllFwdDiv = ((cpr_plld & PLLD_FWDVA_MASK) >> 16); | |
72 | ||
73 | /* | |
74 | * Determine forward divider B | |
75 | */ | |
76 | pllFwdDivB = ((cpr_plld & PLLD_FWDVB_MASK) >> 8); | |
77 | if (pllFwdDivB == 0) | |
78 | pllFwdDivB = 8; | |
79 | ||
80 | /* | |
81 | * Determine FBK_DIV. | |
82 | */ | |
83 | pllFbkDiv = ((cpr_plld & PLLD_FBDV_MASK) >> 24); | |
84 | if (pllFbkDiv == 0) | |
85 | pllFbkDiv = 256; | |
86 | ||
87 | /* | |
88 | * Read CPR_PRIMAD register | |
89 | */ | |
90 | cpr_primad = CPR0_READ(DCRN_CPR0_PRIMAD); | |
91 | ||
92 | /* | |
93 | * Determine PLB_DIV. | |
94 | */ | |
95 | pllPlbDiv = ((cpr_primad & PRIMAD_PLBDV_MASK) >> 16); | |
96 | if (pllPlbDiv == 0) | |
97 | pllPlbDiv = 16; | |
98 | ||
99 | /* | |
100 | * Determine EXTBUS_DIV. | |
101 | */ | |
102 | pllExtBusDiv = (cpr_primad & PRIMAD_EBCDV_MASK); | |
103 | if (pllExtBusDiv == 0) | |
104 | pllExtBusDiv = 16; | |
105 | ||
106 | /* | |
107 | * Determine OPB_DIV. | |
108 | */ | |
109 | pllOpbDiv = ((cpr_primad & PRIMAD_OPBDV_MASK) >> 8); | |
110 | if (pllOpbDiv == 0) | |
111 | pllOpbDiv = 16; | |
112 | ||
113 | /* There is a bug in U-Boot that prevents us from using | |
114 | * bd.bi_opbfreq because U-Boot doesn't populate it for | |
115 | * 405EZ. We get to calculate it, yay! | |
116 | */ | |
117 | freqOPB = (sysclk *pllFbkDiv) /pllOpbDiv; | |
118 | ||
119 | freqEBC = (sysclk * pllFbkDiv) / pllExtBusDiv; | |
120 | ||
121 | plloutb = ((sysclk * ((cpr_pllc & PLLC_SRC_MASK) ? | |
122 | pllFwdDivB : pllFwdDiv) * | |
123 | pllFbkDiv) / pllFwdDivB); | |
124 | ||
125 | np = find_node_by_alias("serial0"); | |
126 | if (getprop(np, "current-speed", &baud, sizeof(baud)) != sizeof(baud)) | |
127 | fatal("no current-speed property\n\r"); | |
128 | ||
129 | udiv = 256; /* Assume lowest possible serial clk */ | |
130 | div = plloutb / (16 * baud); /* total divisor */ | |
131 | umin = (plloutb / freqOPB) << 1; /* 2 x OPB divisor */ | |
132 | diff = 256; /* highest possible */ | |
133 | ||
134 | /* i is the test udiv value -- start with the largest | |
135 | * possible (256) to minimize serial clock and constrain | |
136 | * search to umin. | |
137 | */ | |
138 | for (i = 256; i > umin; i--) { | |
139 | ibdiv = div / i; | |
140 | est = i * ibdiv; | |
141 | idiff = (est > div) ? (est-div) : (div-est); | |
142 | if (idiff == 0) { | |
143 | udiv = i; | |
144 | break; /* can't do better */ | |
145 | } else if (idiff < diff) { | |
146 | udiv = i; /* best so far */ | |
147 | diff = idiff; /* update lowest diff*/ | |
148 | } | |
149 | } | |
150 | freqUART = plloutb / udiv; | |
151 | ||
152 | dt_fixup_cpu_clocks(bd.bi_procfreq, bd.bi_intfreq, bd.bi_plb_busfreq); | |
153 | dt_fixup_clock("/plb/ebc", freqEBC); | |
154 | dt_fixup_clock("/plb/opb", freqOPB); | |
155 | dt_fixup_clock("/plb/opb/serial@ef600300", freqUART); | |
156 | dt_fixup_clock("/plb/opb/serial@ef600400", freqUART); | |
157 | } | |
158 | ||
159 | static void acadia_fixups(void) | |
160 | { | |
161 | dt_fixup_memory(bd.bi_memstart, bd.bi_memsize); | |
162 | get_clocks(); | |
163 | dt_fixup_mac_address_by_alias("ethernet0", bd.bi_enetaddr); | |
164 | } | |
165 | ||
166 | void platform_init(unsigned long r3, unsigned long r4, unsigned long r5, | |
167 | unsigned long r6, unsigned long r7) | |
168 | { | |
169 | CUBOOT_INIT(); | |
170 | platform_ops.fixups = acadia_fixups; | |
171 | platform_ops.exit = ibm40x_dbcr_reset; | |
172 | fdt_init(_dtb_start); | |
173 | serial_console_init(); | |
174 | } |