xref: /openbmc/u-boot/arch/m68k/cpu/mcf5445x/speed.c (revision f51cdaf1)
1 /*
2  *
3  * Copyright (C) 2004-2007 Freescale Semiconductor, Inc.
4  * TsiChung Liew (Tsi-Chung.Liew@freescale.com)
5  *
6  * See file CREDITS for list of people who contributed to this
7  * project.
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License as
11  * published by the Free Software Foundation; either version 2 of
12  * the License, or (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
22  * MA 02111-1307 USA
23  */
24 
25 #include <common.h>
26 #include <asm/processor.h>
27 
28 #include <asm/immap.h>
29 
30 DECLARE_GLOBAL_DATA_PTR;
31 
32 /*
33  * Low Power Divider specifications
34  */
35 #define CLOCK_LPD_MIN		(1 << 0)	/* Divider (decoded) */
36 #define CLOCK_LPD_MAX		(1 << 15)	/* Divider (decoded) */
37 
38 #define CLOCK_PLL_FVCO_MAX	540000000
39 #define CLOCK_PLL_FVCO_MIN	300000000
40 
41 #define CLOCK_PLL_FSYS_MAX	266666666
42 #define CLOCK_PLL_FSYS_MIN	100000000
43 #define MHZ			1000000
44 
45 void clock_enter_limp(int lpdiv)
46 {
47 	volatile ccm_t *ccm = (volatile ccm_t *)MMAP_CCM;
48 	int i, j;
49 
50 	/* Check bounds of divider */
51 	if (lpdiv < CLOCK_LPD_MIN)
52 		lpdiv = CLOCK_LPD_MIN;
53 	if (lpdiv > CLOCK_LPD_MAX)
54 		lpdiv = CLOCK_LPD_MAX;
55 
56 	/* Round divider down to nearest power of two */
57 	for (i = 0, j = lpdiv; j != 1; j >>= 1, i++) ;
58 
59 	/* Apply the divider to the system clock */
60 	ccm->cdr = (ccm->cdr & 0xF0FF) | CCM_CDR_LPDIV(i);
61 
62 	/* Enable Limp Mode */
63 	ccm->misccr |= CCM_MISCCR_LIMP;
64 }
65 
66 /*
67  * brief   Exit Limp mode
68  * warning The PLL should be set and locked prior to exiting Limp mode
69  */
70 void clock_exit_limp(void)
71 {
72 	volatile ccm_t *ccm = (volatile ccm_t *)MMAP_CCM;
73 	volatile pll_t *pll = (volatile pll_t *)MMAP_PLL;
74 
75 	/* Exit Limp mode */
76 	ccm->misccr &= ~CCM_MISCCR_LIMP;
77 
78 	/* Wait for the PLL to lock */
79 	while (!(pll->psr & PLL_PSR_LOCK)) ;
80 }
81 
82 /*
83  * get_clocks() fills in gd->cpu_clock and gd->bus_clk
84  */
85 int get_clocks(void)
86 {
87 
88 	volatile ccm_t *ccm = (volatile ccm_t *)MMAP_CCM;
89 	volatile pll_t *pll = (volatile pll_t *)MMAP_PLL;
90 	int pllmult_nopci[] = { 20, 10, 24, 18, 12, 6, 16, 8 };
91 	int pllmult_pci[] = { 12, 6, 16, 8 };
92 	int vco = 0, bPci, temp, fbtemp, pcrvalue;
93 	int *pPllmult = NULL;
94 	u16 fbpll_mask;
95 
96 #ifdef CONFIG_M54455EVB
97 	volatile u8 *cpld = (volatile u8 *)(CONFIG_SYS_CS2_BASE + 3);
98 #endif
99 	u8 bootmode;
100 
101 	/* To determine PCI is present or not */
102 	if (((ccm->ccr & CCM_CCR_360_FBCONFIG_MASK) == 0x00e0) ||
103 	    ((ccm->ccr & CCM_CCR_360_FBCONFIG_MASK) == 0x0060)) {
104 		pPllmult = &pllmult_pci[0];
105 		fbpll_mask = 3;		/* 11b */
106 		bPci = 1;
107 	} else {
108 		pPllmult = &pllmult_nopci[0];
109 		fbpll_mask = 7;		/* 111b */
110 #ifdef CONFIG_PCI
111 		gd->pci_clk = 0;
112 #endif
113 		bPci = 0;
114 	}
115 
116 #ifdef CONFIG_M54455EVB
117 	bootmode = (*cpld & 0x03);
118 
119 	if (bootmode != 3) {
120 		/* Temporary read from CCR- fixed fb issue, must be the same clock
121 		   as pci or input clock, causing cpld/fpga read inconsistancy */
122 		fbtemp = pPllmult[ccm->ccr & fbpll_mask];
123 
124 		/* Break down into small pieces, code still in flex bus */
125 		pcrvalue = pll->pcr & 0xFFFFF0FF;
126 		temp = fbtemp - 1;
127 		pcrvalue |= PLL_PCR_OUTDIV3(temp);
128 
129 		pll->pcr = pcrvalue;
130 	}
131 #endif
132 #ifdef CONFIG_M54451EVB
133 	/* No external logic to read the bootmode, hard coded from built */
134 #ifdef CONFIG_CF_SBF
135 	bootmode = 3;
136 #else
137 	bootmode = 2;
138 
139 	/* default value is 16 mul, set to 20 mul */
140 	pcrvalue = (pll->pcr & 0x00FFFFFF) | 0x14000000;
141 	pll->pcr = pcrvalue;
142 	while ((pll->psr & PLL_PSR_LOCK) != PLL_PSR_LOCK);
143 #endif
144 #endif
145 
146 	if (bootmode == 0) {
147 		/* RCON mode */
148 		vco = pPllmult[ccm->rcon & fbpll_mask] * CONFIG_SYS_INPUT_CLKSRC;
149 
150 		if ((vco < CLOCK_PLL_FVCO_MIN) || (vco > CLOCK_PLL_FVCO_MAX)) {
151 			/* invaild range, re-set in PCR */
152 			int temp = ((pll->pcr & PLL_PCR_OUTDIV2_MASK) >> 4) + 1;
153 			int i, j, bus;
154 
155 			j = (pll->pcr & 0xFF000000) >> 24;
156 			for (i = j; i < 0xFF; i++) {
157 				vco = i * CONFIG_SYS_INPUT_CLKSRC;
158 				if (vco >= CLOCK_PLL_FVCO_MIN) {
159 					bus = vco / temp;
160 					if (bus <= CLOCK_PLL_FSYS_MIN - MHZ)
161 						continue;
162 					else
163 						break;
164 				}
165 			}
166 			pcrvalue = pll->pcr & 0x00FF00FF;
167 			fbtemp = ((i - 1) << 8) | ((i - 1) << 12);
168 			pcrvalue |= ((i << 24) | fbtemp);
169 
170 			pll->pcr = pcrvalue;
171 		}
172 		gd->vco_clk = vco;	/* Vco clock */
173 	} else if (bootmode == 2) {
174 		/* Normal mode */
175 		vco =  ((pll->pcr & 0xFF000000) >> 24) * CONFIG_SYS_INPUT_CLKSRC;
176 		if ((vco < CLOCK_PLL_FVCO_MIN) || (vco > CLOCK_PLL_FVCO_MAX)) {
177 			/* Default value */
178 			pcrvalue = (pll->pcr & 0x00FFFFFF);
179 			pcrvalue |= pPllmult[ccm->ccr & fbpll_mask] << 24;
180 			pll->pcr = pcrvalue;
181 			vco =  ((pll->pcr & 0xFF000000) >> 24) * CONFIG_SYS_INPUT_CLKSRC;
182 		}
183 		gd->vco_clk = vco;	/* Vco clock */
184 	} else if (bootmode == 3) {
185 		/* serial mode */
186 		vco =  ((pll->pcr & 0xFF000000) >> 24) * CONFIG_SYS_INPUT_CLKSRC;
187 		gd->vco_clk = vco;	/* Vco clock */
188 	}
189 
190 	if ((ccm->ccr & CCM_MISCCR_LIMP) == CCM_MISCCR_LIMP) {
191 		/* Limp mode */
192 	} else {
193 		gd->inp_clk = CONFIG_SYS_INPUT_CLKSRC;	/* Input clock */
194 
195 		temp = (pll->pcr & PLL_PCR_OUTDIV1_MASK) + 1;
196 		gd->cpu_clk = vco / temp;	/* cpu clock */
197 
198 		temp = ((pll->pcr & PLL_PCR_OUTDIV2_MASK) >> 4) + 1;
199 		gd->bus_clk = vco / temp;	/* bus clock */
200 
201 		temp = ((pll->pcr & PLL_PCR_OUTDIV3_MASK) >> 8) + 1;
202 		gd->flb_clk = vco / temp;	/* FlexBus clock */
203 
204 #ifdef CONFIG_PCI
205 		if (bPci) {
206 			temp = ((pll->pcr & PLL_PCR_OUTDIV4_MASK) >> 12) + 1;
207 			gd->pci_clk = vco / temp;	/* PCI clock */
208 		}
209 #endif
210 	}
211 
212 #ifdef CONFIG_FSL_I2C
213 	gd->i2c1_clk = gd->bus_clk;
214 #endif
215 
216 	return (0);
217 }
218