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
get_clocks(void)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
acadia_fixups(void)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
platform_init(unsigned long r3,unsigned long r4,unsigned long r5,unsigned long r6,unsigned long r7)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 }
175