xref: /openbmc/u-boot/arch/m68k/cpu/mcf52x2/speed.c (revision c6af2e7d)
1 /*
2  * (C) Copyright 2003
3  * Josef Baumgartner <josef.baumgartner@telex.de>
4  *
5  * Copyright (C) 2004-2007 Freescale Semiconductor, Inc.
6  * Hayden Fraser (Hayden.Fraser@freescale.com)
7  *
8  * See file CREDITS for list of people who contributed to this
9  * project.
10  *
11  * This program is free software; you can redistribute it and/or
12  * modify it under the terms of the GNU General Public License as
13  * published by the Free Software Foundation; either version 2 of
14  * the License, or (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  * GNU General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program; if not, write to the Free Software
23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
24  * MA 02111-1307 USA
25  */
26 
27 #include <common.h>
28 #include <asm/processor.h>
29 #include <asm/immap.h>
30 
31 DECLARE_GLOBAL_DATA_PTR;
32 
33 /* get_clocks() fills in gd->cpu_clock and gd->bus_clk */
34 int get_clocks (void)
35 {
36 #if defined(CONFIG_M5208)
37 	volatile pll_t *pll = (pll_t *) MMAP_PLL;
38 
39 	pll->odr = CONFIG_SYS_PLL_ODR;
40 	pll->fdr = CONFIG_SYS_PLL_FDR;
41 #endif
42 
43 #if defined(CONFIG_M5249) || defined(CONFIG_M5253)
44 	volatile unsigned long cpll = mbar2_readLong(MCFSIM_PLLCR);
45 	unsigned long pllcr;
46 
47 #ifndef CONFIG_SYS_PLL_BYPASS
48 
49 #ifdef CONFIG_M5249
50 	/* Setup the PLL to run at the specified speed */
51 #ifdef CONFIG_SYS_FAST_CLK
52 	pllcr = 0x925a3100;	/* ~140MHz clock (PLL bypass = 0) */
53 #else
54 	pllcr = 0x135a4140;	/* ~72MHz clock (PLL bypass = 0) */
55 #endif
56 #endif				/* CONFIG_M5249 */
57 
58 #ifdef CONFIG_M5253
59 	pllcr = CONFIG_SYS_PLLCR;
60 #endif				/* CONFIG_M5253 */
61 
62 	cpll = cpll & 0xfffffffe;	/* Set PLL bypass mode = 0 (PSTCLK = crystal) */
63 	mbar2_writeLong(MCFSIM_PLLCR, cpll);	/* Set the PLL to bypass mode (PSTCLK = crystal) */
64 	mbar2_writeLong(MCFSIM_PLLCR, pllcr);	/* set the clock speed */
65 	pllcr ^= 0x00000001;	/* Set pll bypass to 1 */
66 	mbar2_writeLong(MCFSIM_PLLCR, pllcr);	/* Start locking (pll bypass = 1) */
67 	udelay(0x20);		/* Wait for a lock ... */
68 #endif				/* #ifndef CONFIG_SYS_PLL_BYPASS */
69 
70 #endif				/* CONFIG_M5249 || CONFIG_M5253 */
71 
72 #if defined(CONFIG_M5275)
73 	volatile pll_t *pll = (volatile pll_t *)(MMAP_PLL);
74 
75 	/* Setup PLL */
76 	pll->syncr = 0x01080000;
77 	while (!(pll->synsr & FMPLL_SYNSR_LOCK))
78 		;
79 	pll->syncr = 0x01000000;
80 	while (!(pll->synsr & FMPLL_SYNSR_LOCK))
81 		;
82 #endif
83 
84 	gd->cpu_clk = CONFIG_SYS_CLK;
85 #if defined(CONFIG_M5208) || defined(CONFIG_M5249) || defined(CONFIG_M5253) || \
86     defined(CONFIG_M5271) || defined(CONFIG_M5275)
87 	gd->bus_clk = gd->cpu_clk / 2;
88 #else
89 	gd->bus_clk = gd->cpu_clk;
90 #endif
91 
92 #ifdef CONFIG_FSL_I2C
93 	gd->i2c1_clk = gd->bus_clk;
94 #ifdef CONFIG_SYS_I2C2_OFFSET
95 	gd->i2c2_clk = gd->bus_clk;
96 #endif
97 #endif
98 
99 	return (0);
100 }
101