xref: /openbmc/u-boot/arch/powerpc/cpu/mpc86xx/speed.c (revision e8f80a5a) 
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright 2004 Freescale Semiconductor.
4  * Jeff Brown
5  * Srikanth Srinivasan (srikanth.srinivasan@freescale.com)
6  *
7  * (C) Copyright 2000-2002
8  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
9  */
10 
11 #include <common.h>
12 #include <mpc86xx.h>
13 #include <asm/processor.h>
14 #include <asm/io.h>
15 
16 DECLARE_GLOBAL_DATA_PTR;
17 
18 /* used in some defintiions of CONFIG_SYS_CLK_FREQ */
19 extern unsigned long get_board_sys_clk(unsigned long dummy);
20 
get_sys_info(sys_info_t * sys_info)21 void get_sys_info(sys_info_t *sys_info)
22 {
23 	volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
24 	volatile ccsr_gur_t *gur = &immap->im_gur;
25 	uint plat_ratio, e600_ratio;
26 
27 	plat_ratio = (gur->porpllsr) & 0x0000003e;
28 	plat_ratio >>= 1;
29 
30 	switch (plat_ratio) {
31 	case 0x0:
32 		sys_info->freq_systembus = 16 * CONFIG_SYS_CLK_FREQ;
33 		break;
34 	case 0x02:
35 	case 0x03:
36 	case 0x04:
37 	case 0x05:
38 	case 0x06:
39 	case 0x08:
40 	case 0x09:
41 	case 0x0a:
42 	case 0x0c:
43 	case 0x10:
44 		sys_info->freq_systembus = plat_ratio * CONFIG_SYS_CLK_FREQ;
45 		break;
46 	default:
47 		sys_info->freq_systembus = 0;
48 		break;
49 	}
50 
51 	e600_ratio = (gur->porpllsr) & 0x003f0000;
52 	e600_ratio >>= 16;
53 
54 	switch (e600_ratio) {
55 	case 0x10:
56 		sys_info->freq_processor = 2 * sys_info->freq_systembus;
57 		break;
58 	case 0x19:
59 		sys_info->freq_processor = 5 * sys_info->freq_systembus / 2;
60 		break;
61 	case 0x20:
62 		sys_info->freq_processor = 3 * sys_info->freq_systembus;
63 		break;
64 	case 0x39:
65 		sys_info->freq_processor = 7 * sys_info->freq_systembus / 2;
66 		break;
67 	case 0x28:
68 		sys_info->freq_processor = 4 * sys_info->freq_systembus;
69 		break;
70 	case 0x1d:
71 		sys_info->freq_processor = 9 * sys_info->freq_systembus / 2;
72 		break;
73 	default:
74 		sys_info->freq_processor = e600_ratio +
75 						sys_info->freq_systembus;
76 		break;
77 	}
78 
79 	sys_info->freq_localbus = sys_info->freq_systembus;
80 }
81 
82 
83 /*
84  * Measure CPU clock speed (core clock GCLK1, GCLK2)
85  * (Approx. GCLK frequency in Hz)
86  */
87 
get_clocks(void)88 int get_clocks(void)
89 {
90 	sys_info_t sys_info;
91 
92 	get_sys_info(&sys_info);
93 	gd->cpu_clk = sys_info.freq_processor;
94 	gd->bus_clk = sys_info.freq_systembus;
95 	gd->arch.lbc_clk = sys_info.freq_localbus;
96 
97 	/*
98 	 * The base clock for I2C depends on the actual SOC.  Unfortunately,
99 	 * there is no pattern that can be used to determine the frequency, so
100 	 * the only choice is to look up the actual SOC number and use the value
101 	 * for that SOC. This information is taken from application note
102 	 * AN2919.
103 	 */
104 #ifdef CONFIG_ARCH_MPC8610
105 	gd->arch.i2c1_clk = sys_info.freq_systembus;
106 #else
107 	gd->arch.i2c1_clk = sys_info.freq_systembus / 2;
108 #endif
109 	gd->arch.i2c2_clk = gd->arch.i2c1_clk;
110 
111 	if (gd->cpu_clk != 0)
112 		return 0;
113 	else
114 		return 1;
115 }
116 
117 
118 /*
119  * get_bus_freq
120  *	Return system bus freq in Hz
121  */
122 
get_bus_freq(ulong dummy)123 ulong get_bus_freq(ulong dummy)
124 {
125 	ulong val;
126 	sys_info_t sys_info;
127 
128 	get_sys_info(&sys_info);
129 	val = sys_info.freq_systembus;
130 
131 	return val;
132 }
133