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