xref: /openbmc/u-boot/arch/powerpc/cpu/mpc86xx/speed.c (revision c6af2e7d)
1 /*
2  * Copyright 2004 Freescale Semiconductor.
3  * Jeff Brown
4  * Srikanth Srinivasan (srikanth.srinivasan@freescale.com)
5  *
6  * (C) Copyright 2000-2002
7  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
8  *
9  * See file CREDITS for list of people who contributed to this
10  * project.
11  *
12  * This program is free software; you can redistribute it and/or
13  * modify it under the terms of the GNU General Public License as
14  * published by the Free Software Foundation; either version 2 of
15  * the License, or (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
20  * GNU General Public License for more details.
21  *
22  * You should have received a copy of the GNU General Public License
23  * along with this program; if not, write to the Free Software
24  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
25  * MA 02111-1307 USA
26  */
27 
28 #include <common.h>
29 #include <mpc86xx.h>
30 #include <asm/processor.h>
31 #include <asm/io.h>
32 
33 DECLARE_GLOBAL_DATA_PTR;
34 
35 /* used in some defintiions of CONFIG_SYS_CLK_FREQ */
36 extern unsigned long get_board_sys_clk(unsigned long dummy);
37 
38 void get_sys_info(sys_info_t *sysInfo)
39 {
40 	volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
41 	volatile ccsr_gur_t *gur = &immap->im_gur;
42 	uint plat_ratio, e600_ratio;
43 	uint lcrr_div;
44 
45 	plat_ratio = (gur->porpllsr) & 0x0000003e;
46 	plat_ratio >>= 1;
47 
48 	switch (plat_ratio) {
49 	case 0x0:
50 		sysInfo->freqSystemBus = 16 * CONFIG_SYS_CLK_FREQ;
51 		break;
52 	case 0x02:
53 	case 0x03:
54 	case 0x04:
55 	case 0x05:
56 	case 0x06:
57 	case 0x08:
58 	case 0x09:
59 	case 0x0a:
60 	case 0x0c:
61 	case 0x10:
62 		sysInfo->freqSystemBus = plat_ratio * CONFIG_SYS_CLK_FREQ;
63 		break;
64 	default:
65 		sysInfo->freqSystemBus = 0;
66 		break;
67 	}
68 
69 	e600_ratio = (gur->porpllsr) & 0x003f0000;
70 	e600_ratio >>= 16;
71 
72 	switch (e600_ratio) {
73 	case 0x10:
74 		sysInfo->freqProcessor = 2 * sysInfo->freqSystemBus;
75 		break;
76 	case 0x19:
77 		sysInfo->freqProcessor = 5 * sysInfo->freqSystemBus / 2;
78 		break;
79 	case 0x20:
80 		sysInfo->freqProcessor = 3 * sysInfo->freqSystemBus;
81 		break;
82 	case 0x39:
83 		sysInfo->freqProcessor = 7 * sysInfo->freqSystemBus / 2;
84 		break;
85 	case 0x28:
86 		sysInfo->freqProcessor = 4 * sysInfo->freqSystemBus;
87 		break;
88 	case 0x1d:
89 		sysInfo->freqProcessor = 9 * sysInfo->freqSystemBus / 2;
90 		break;
91 	default:
92 		sysInfo->freqProcessor = e600_ratio + sysInfo->freqSystemBus;
93 		break;
94 	}
95 
96 #if defined(CONFIG_SYS_LBC_LCRR)
97 	/* We will program LCRR to this value later */
98 	lcrr_div = CONFIG_SYS_LBC_LCRR & LCRR_CLKDIV;
99 #else
100 	lcrr_div = in_be32(&immap->im_lbc.lcrr) & LCRR_CLKDIV;
101 #endif
102 	if (lcrr_div == 2 || lcrr_div == 4 || lcrr_div == 8) {
103 		sysInfo->freqLocalBus = sysInfo->freqSystemBus / (lcrr_div * 2);
104 	} else {
105 		/* In case anyone cares what the unknown value is */
106 		sysInfo->freqLocalBus = lcrr_div;
107 	}
108 }
109 
110 
111 /*
112  * Measure CPU clock speed (core clock GCLK1, GCLK2)
113  * (Approx. GCLK frequency in Hz)
114  */
115 
116 int get_clocks(void)
117 {
118 	sys_info_t sys_info;
119 
120 	get_sys_info(&sys_info);
121 	gd->cpu_clk = sys_info.freqProcessor;
122 	gd->bus_clk = sys_info.freqSystemBus;
123 	gd->lbc_clk = sys_info.freqLocalBus;
124 
125 	/*
126 	 * The base clock for I2C depends on the actual SOC.  Unfortunately,
127 	 * there is no pattern that can be used to determine the frequency, so
128 	 * the only choice is to look up the actual SOC number and use the value
129 	 * for that SOC. This information is taken from application note
130 	 * AN2919.
131 	 */
132 #ifdef CONFIG_MPC8610
133 	gd->i2c1_clk = sys_info.freqSystemBus;
134 #else
135 	gd->i2c1_clk = sys_info.freqSystemBus / 2;
136 #endif
137 	gd->i2c2_clk = gd->i2c1_clk;
138 
139 	if (gd->cpu_clk != 0)
140 		return 0;
141 	else
142 		return 1;
143 }
144 
145 
146 /*
147  * get_bus_freq
148  *	Return system bus freq in Hz
149  */
150 
151 ulong get_bus_freq(ulong dummy)
152 {
153 	ulong val;
154 	sys_info_t sys_info;
155 
156 	get_sys_info(&sys_info);
157 	val = sys_info.freqSystemBus;
158 
159 	return val;
160 }
161