xref: /openbmc/linux/arch/powerpc/boot/ebony.c (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
1 /*
2  * Copyright 2007 David Gibson, IBM Corporation.
3  *
4  * Based on earlier code:
5  *   Copyright (C) Paul Mackerras 1997.
6  *
7  *   Matt Porter <mporter@kernel.crashing.org>
8  *   Copyright 2002-2005 MontaVista Software Inc.
9  *
10  *   Eugene Surovegin <eugene.surovegin@zultys.com> or <ebs@ebshome.net>
11  *   Copyright (c) 2003, 2004 Zultys Technologies
12  *
13  * This program is free software; you can redistribute it and/or
14  * modify it under the terms of the GNU General Public License
15  * as published by the Free Software Foundation; either version
16  * 2 of the License, or (at your option) any later version.
17  */
18 #include <stdarg.h>
19 #include <stddef.h>
20 #include "types.h"
21 #include "elf.h"
22 #include "string.h"
23 #include "stdio.h"
24 #include "page.h"
25 #include "ops.h"
26 #include "reg.h"
27 #include "io.h"
28 #include "dcr.h"
29 #include "4xx.h"
30 #include "44x.h"
31 
32 static u8 *ebony_mac0, *ebony_mac1;
33 
34 /* Calculate 440GP clocks */
35 void ibm440gp_fixup_clocks(unsigned int sysclk, unsigned int ser_clk)
36 {
37 	u32 sys0 = mfdcr(DCRN_CPC0_SYS0);
38 	u32 cr0 = mfdcr(DCRN_CPC0_CR0);
39 	u32 cpu, plb, opb, ebc, tb, uart0, uart1, m;
40 	u32 opdv = CPC0_SYS0_OPDV(sys0);
41 	u32 epdv = CPC0_SYS0_EPDV(sys0);
42 
43 	if (sys0 & CPC0_SYS0_BYPASS) {
44 		/* Bypass system PLL */
45 		cpu = plb = sysclk;
46 	} else {
47 		if (sys0 & CPC0_SYS0_EXTSL)
48 			/* PerClk */
49 			m = CPC0_SYS0_FWDVB(sys0) * opdv * epdv;
50 		else
51 			/* CPU clock */
52 			m = CPC0_SYS0_FBDV(sys0) * CPC0_SYS0_FWDVA(sys0);
53 		cpu = sysclk * m / CPC0_SYS0_FWDVA(sys0);
54 		plb = sysclk * m / CPC0_SYS0_FWDVB(sys0);
55 	}
56 
57 	opb = plb / opdv;
58 	ebc = opb / epdv;
59 
60 	/* FIXME: Check if this is for all 440GP, or just Ebony */
61 	if ((mfpvr() & 0xf0000fff) == 0x40000440)
62 		/* Rev. B 440GP, use external system clock */
63 		tb = sysclk;
64 	else
65 		/* Rev. C 440GP, errata force us to use internal clock */
66 		tb = cpu;
67 
68 	if (cr0 & CPC0_CR0_U0EC)
69 		/* External UART clock */
70 		uart0 = ser_clk;
71 	else
72 		/* Internal UART clock */
73 		uart0 = plb / CPC0_CR0_UDIV(cr0);
74 
75 	if (cr0 & CPC0_CR0_U1EC)
76 		/* External UART clock */
77 		uart1 = ser_clk;
78 	else
79 		/* Internal UART clock */
80 		uart1 = plb / CPC0_CR0_UDIV(cr0);
81 
82 	printf("PPC440GP: SysClk = %dMHz (%x)\n\r",
83 	       (sysclk + 500000) / 1000000, sysclk);
84 
85 	dt_fixup_cpu_clocks(cpu, tb, 0);
86 
87 	dt_fixup_clock("/plb", plb);
88 	dt_fixup_clock("/plb/opb", opb);
89 	dt_fixup_clock("/plb/opb/ebc", ebc);
90 	dt_fixup_clock("/plb/opb/serial@40000200", uart0);
91 	dt_fixup_clock("/plb/opb/serial@40000300", uart1);
92 }
93 
94 #define EBONY_FPGA_PATH		"/plb/opb/ebc/fpga"
95 #define	EBONY_FPGA_FLASH_SEL	0x01
96 #define EBONY_SMALL_FLASH_PATH	"/plb/opb/ebc/small-flash"
97 
98 static void ebony_flashsel_fixup(void)
99 {
100 	void *devp;
101 	u32 reg[3] = {0x0, 0x0, 0x80000};
102 	u8 *fpga;
103 	u8 fpga_reg0 = 0x0;
104 
105 	devp = finddevice(EBONY_FPGA_PATH);
106 	if (!devp)
107 		fatal("Couldn't locate FPGA node %s\n\r", EBONY_FPGA_PATH);
108 
109 	if (getprop(devp, "virtual-reg", &fpga, sizeof(fpga)) != sizeof(fpga))
110 		fatal("%s has missing or invalid virtual-reg property\n\r",
111 		      EBONY_FPGA_PATH);
112 
113 	fpga_reg0 = in_8(fpga);
114 
115 	devp = finddevice(EBONY_SMALL_FLASH_PATH);
116 	if (!devp)
117 		fatal("Couldn't locate small flash node %s\n\r",
118 		      EBONY_SMALL_FLASH_PATH);
119 
120 	if (getprop(devp, "reg", reg, sizeof(reg)) != sizeof(reg))
121 		fatal("%s has reg property of unexpected size\n\r",
122 		      EBONY_SMALL_FLASH_PATH);
123 
124 	/* Invert address bit 14 (IBM-endian) if FLASH_SEL fpga bit is set */
125 	if (fpga_reg0 & EBONY_FPGA_FLASH_SEL)
126 		reg[1] ^= 0x80000;
127 
128 	setprop(devp, "reg", reg, sizeof(reg));
129 }
130 
131 static void ebony_fixups(void)
132 {
133 	// FIXME: sysclk should be derived by reading the FPGA registers
134 	unsigned long sysclk = 33000000;
135 
136 	ibm440gp_fixup_clocks(sysclk, 6 * 1843200);
137 	ibm4xx_fixup_memsize();
138 	dt_fixup_mac_addresses(ebony_mac0, ebony_mac1);
139 	ibm4xx_fixup_ebc_ranges("/plb/opb/ebc");
140 	ebony_flashsel_fixup();
141 }
142 
143 void ebony_init(void *mac0, void *mac1)
144 {
145 	platform_ops.fixups = ebony_fixups;
146 	platform_ops.exit = ibm44x_dbcr_reset;
147 	ebony_mac0 = mac0;
148 	ebony_mac1 = mac1;
149 	ft_init(_dtb_start, _dtb_end - _dtb_start, 32);
150 	serial_console_init();
151 }
152