xref: /openbmc/u-boot/arch/powerpc/cpu/mpc86xx/speed.c (revision ae51b570)
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  * SPDX-License-Identifier:	GPL-2.0+
10  */
11 
12 #include <common.h>
13 #include <mpc86xx.h>
14 #include <asm/processor.h>
15 #include <asm/io.h>
16 
17 DECLARE_GLOBAL_DATA_PTR;
18 
19 /* used in some defintiions of CONFIG_SYS_CLK_FREQ */
20 extern unsigned long get_board_sys_clk(unsigned long dummy);
21 
22 void get_sys_info(sys_info_t *sys_info)
23 {
24 	volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
25 	volatile ccsr_gur_t *gur = &immap->im_gur;
26 	uint plat_ratio, e600_ratio;
27 	uint lcrr_div;
28 
29 	plat_ratio = (gur->porpllsr) & 0x0000003e;
30 	plat_ratio >>= 1;
31 
32 	switch (plat_ratio) {
33 	case 0x0:
34 		sys_info->freq_systembus = 16 * CONFIG_SYS_CLK_FREQ;
35 		break;
36 	case 0x02:
37 	case 0x03:
38 	case 0x04:
39 	case 0x05:
40 	case 0x06:
41 	case 0x08:
42 	case 0x09:
43 	case 0x0a:
44 	case 0x0c:
45 	case 0x10:
46 		sys_info->freq_systembus = plat_ratio * CONFIG_SYS_CLK_FREQ;
47 		break;
48 	default:
49 		sys_info->freq_systembus = 0;
50 		break;
51 	}
52 
53 	e600_ratio = (gur->porpllsr) & 0x003f0000;
54 	e600_ratio >>= 16;
55 
56 	switch (e600_ratio) {
57 	case 0x10:
58 		sys_info->freq_processor = 2 * sys_info->freq_systembus;
59 		break;
60 	case 0x19:
61 		sys_info->freq_processor = 5 * sys_info->freq_systembus / 2;
62 		break;
63 	case 0x20:
64 		sys_info->freq_processor = 3 * sys_info->freq_systembus;
65 		break;
66 	case 0x39:
67 		sys_info->freq_processor = 7 * sys_info->freq_systembus / 2;
68 		break;
69 	case 0x28:
70 		sys_info->freq_processor = 4 * sys_info->freq_systembus;
71 		break;
72 	case 0x1d:
73 		sys_info->freq_processor = 9 * sys_info->freq_systembus / 2;
74 		break;
75 	default:
76 		sys_info->freq_processor = e600_ratio +
77 						sys_info->freq_systembus;
78 		break;
79 	}
80 
81 #if defined(CONFIG_SYS_LBC_LCRR)
82 	/* We will program LCRR to this value later */
83 	lcrr_div = CONFIG_SYS_LBC_LCRR & LCRR_CLKDIV;
84 #else
85 	lcrr_div = in_be32(&immap->im_lbc.lcrr) & LCRR_CLKDIV;
86 #endif
87 	if (lcrr_div == 2 || lcrr_div == 4 || lcrr_div == 8) {
88 		sys_info->freq_localbus = sys_info->freq_systembus
89 							/ (lcrr_div * 2);
90 	} else {
91 		/* In case anyone cares what the unknown value is */
92 		sys_info->freq_localbus = lcrr_div;
93 	}
94 }
95 
96 
97 /*
98  * Measure CPU clock speed (core clock GCLK1, GCLK2)
99  * (Approx. GCLK frequency in Hz)
100  */
101 
102 int get_clocks(void)
103 {
104 	sys_info_t sys_info;
105 
106 	get_sys_info(&sys_info);
107 	gd->cpu_clk = sys_info.freq_processor;
108 	gd->bus_clk = sys_info.freq_systembus;
109 	gd->arch.lbc_clk = sys_info.freq_localbus;
110 
111 	/*
112 	 * The base clock for I2C depends on the actual SOC.  Unfortunately,
113 	 * there is no pattern that can be used to determine the frequency, so
114 	 * the only choice is to look up the actual SOC number and use the value
115 	 * for that SOC. This information is taken from application note
116 	 * AN2919.
117 	 */
118 #ifdef CONFIG_MPC8610
119 	gd->arch.i2c1_clk = sys_info.freq_systembus;
120 #else
121 	gd->arch.i2c1_clk = sys_info.freq_systembus / 2;
122 #endif
123 	gd->arch.i2c2_clk = gd->arch.i2c1_clk;
124 
125 	if (gd->cpu_clk != 0)
126 		return 0;
127 	else
128 		return 1;
129 }
130 
131 
132 /*
133  * get_bus_freq
134  *	Return system bus freq in Hz
135  */
136 
137 ulong get_bus_freq(ulong dummy)
138 {
139 	ulong val;
140 	sys_info_t sys_info;
141 
142 	get_sys_info(&sys_info);
143 	val = sys_info.freq_systembus;
144 
145 	return val;
146 }
147