diff options
Diffstat (limited to 'arch/powerpc/boot/cuboot-acadia.c')
| -rw-r--r-- | arch/powerpc/boot/cuboot-acadia.c | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/arch/powerpc/boot/cuboot-acadia.c b/arch/powerpc/boot/cuboot-acadia.c new file mode 100644 index 00000000000..0634aba6348 --- /dev/null +++ b/arch/powerpc/boot/cuboot-acadia.c @@ -0,0 +1,174 @@ +/* + * Old U-boot compatibility for Acadia + * + * Author: Josh Boyer <jwboyer@linux.vnet.ibm.com> + * + * Copyright 2008 IBM Corporation + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published + * by the Free Software Foundation. + */ + +#include "ops.h" +#include "io.h" +#include "dcr.h" +#include "stdio.h" +#include "4xx.h" +#include "44x.h" +#include "cuboot.h" + +#define TARGET_4xx +#include "ppcboot.h" + +static bd_t bd; + +#define CPR_PERD0_SPIDV_MASK 0x000F0000 /* SPI Clock Divider */ + +#define PLLC_SRC_MASK 0x20000000 /* PLL feedback source */ + +#define PLLD_FBDV_MASK 0x1F000000 /* PLL feedback divider value */ +#define PLLD_FWDVA_MASK 0x000F0000 /* PLL forward divider A value */ +#define PLLD_FWDVB_MASK 0x00000700 /* PLL forward divider B value */ + +#define PRIMAD_CPUDV_MASK 0x0F000000 /* CPU Clock Divisor Mask */ +#define PRIMAD_PLBDV_MASK 0x000F0000 /* PLB Clock Divisor Mask */ +#define PRIMAD_OPBDV_MASK 0x00000F00 /* OPB Clock Divisor Mask */ +#define PRIMAD_EBCDV_MASK 0x0000000F /* EBC Clock Divisor Mask */ + +#define PERD0_PWMDV_MASK 0xFF000000 /* PWM Divider Mask */ +#define PERD0_SPIDV_MASK 0x000F0000 /* SPI Divider Mask */ +#define PERD0_U0DV_MASK 0x0000FF00 /* UART 0 Divider Mask */ +#define PERD0_U1DV_MASK 0x000000FF /* UART 1 Divider Mask */ + +static void get_clocks(void) +{ + unsigned long sysclk, cpr_plld, cpr_pllc, cpr_primad, plloutb, i; + unsigned long pllFwdDiv, pllFwdDivB, pllFbkDiv, pllPlbDiv, pllExtBusDiv; + unsigned long pllOpbDiv, freqEBC, freqUART, freqOPB; + unsigned long div; /* total divisor udiv * bdiv */ + unsigned long umin; /* minimum udiv */ + unsigned short diff; /* smallest diff */ + unsigned long udiv; /* best udiv */ + unsigned short idiff; /* current diff */ + unsigned short ibdiv; /* current bdiv */ + unsigned long est; /* current estimate */ + unsigned long baud; + void *np; + + /* read the sysclk value from the CPLD */ + sysclk = (in_8((unsigned char *)0x80000000) == 0xc) ? 66666666 : 33333000; + + /* + * Read PLL Mode registers + */ + cpr_plld = CPR0_READ(DCRN_CPR0_PLLD); + cpr_pllc = CPR0_READ(DCRN_CPR0_PLLC); + + /* + * Determine forward divider A + */ + pllFwdDiv = ((cpr_plld & PLLD_FWDVA_MASK) >> 16); + + /* + * Determine forward divider B + */ + pllFwdDivB = ((cpr_plld & PLLD_FWDVB_MASK) >> 8); + if (pllFwdDivB == 0) + pllFwdDivB = 8; + + /* + * Determine FBK_DIV. + */ + pllFbkDiv = ((cpr_plld & PLLD_FBDV_MASK) >> 24); + if (pllFbkDiv == 0) + pllFbkDiv = 256; + + /* + * Read CPR_PRIMAD register + */ + cpr_primad = CPR0_READ(DCRN_CPR0_PRIMAD); + + /* + * Determine PLB_DIV. + */ + pllPlbDiv = ((cpr_primad & PRIMAD_PLBDV_MASK) >> 16); + if (pllPlbDiv == 0) + pllPlbDiv = 16; + + /* + * Determine EXTBUS_DIV. + */ + pllExtBusDiv = (cpr_primad & PRIMAD_EBCDV_MASK); + if (pllExtBusDiv == 0) + pllExtBusDiv = 16; + + /* + * Determine OPB_DIV. + */ + pllOpbDiv = ((cpr_primad & PRIMAD_OPBDV_MASK) >> 8); + if (pllOpbDiv == 0) + pllOpbDiv = 16; + + /* There is a bug in U-Boot that prevents us from using + * bd.bi_opbfreq because U-Boot doesn't populate it for + * 405EZ. We get to calculate it, yay! + */ + freqOPB = (sysclk *pllFbkDiv) /pllOpbDiv; + + freqEBC = (sysclk * pllFbkDiv) / pllExtBusDiv; + + plloutb = ((sysclk * ((cpr_pllc & PLLC_SRC_MASK) ? + pllFwdDivB : pllFwdDiv) * + pllFbkDiv) / pllFwdDivB); + + np = find_node_by_alias("serial0"); + if (getprop(np, "current-speed", &baud, sizeof(baud)) != sizeof(baud)) + fatal("no current-speed property\n\r"); + + udiv = 256; /* Assume lowest possible serial clk */ + div = plloutb / (16 * baud); /* total divisor */ + umin = (plloutb / freqOPB) << 1; /* 2 x OPB divisor */ + diff = 256; /* highest possible */ + + /* i is the test udiv value -- start with the largest + * possible (256) to minimize serial clock and constrain + * search to umin. + */ + for (i = 256; i > umin; i--) { + ibdiv = div / i; + est = i * ibdiv; + idiff = (est > div) ? (est-div) : (div-est); + if (idiff == 0) { + udiv = i; + break; /* can't do better */ + } else if (idiff < diff) { + udiv = i; /* best so far */ + diff = idiff; /* update lowest diff*/ + } + } + freqUART = plloutb / udiv; + + dt_fixup_cpu_clocks(bd.bi_procfreq, bd.bi_intfreq, bd.bi_plb_busfreq); + dt_fixup_clock("/plb/ebc", freqEBC); + dt_fixup_clock("/plb/opb", freqOPB); + dt_fixup_clock("/plb/opb/serial@ef600300", freqUART); + dt_fixup_clock("/plb/opb/serial@ef600400", freqUART); +} + +static void acadia_fixups(void) +{ + dt_fixup_memory(bd.bi_memstart, bd.bi_memsize); + get_clocks(); + dt_fixup_mac_address_by_alias("ethernet0", bd.bi_enetaddr); +} + +void platform_init(unsigned long r3, unsigned long r4, unsigned long r5, + unsigned long r6, unsigned long r7) +{ + CUBOOT_INIT(); + platform_ops.fixups = acadia_fixups; + platform_ops.exit = ibm40x_dbcr_reset; + fdt_init(_dtb_start); + serial_console_init(); +} |