xref: /openbmc/u-boot/arch/m68k/cpu/mcf52x2/speed.c (revision 8a00061e)
1 /*
2  * (C) Copyright 2003
3  * Josef Baumgartner <josef.baumgartner@telex.de>
4  *
5  * Copyright (C) 2004-2007, 2012 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 #include <asm/io.h>
31 
32 DECLARE_GLOBAL_DATA_PTR;
33 
34 /* get_clocks() fills in gd->cpu_clock and gd->bus_clk */
35 int get_clocks (void)
36 {
37 #if defined(CONFIG_M5208)
38 	pll_t *pll = (pll_t *) MMAP_PLL;
39 
40 	out_8(&pll->odr, CONFIG_SYS_PLL_ODR);
41 	out_8(&pll->fdr, CONFIG_SYS_PLL_FDR);
42 #endif
43 
44 #if defined(CONFIG_M5249) || defined(CONFIG_M5253)
45 	volatile unsigned long cpll = mbar2_readLong(MCFSIM_PLLCR);
46 	unsigned long pllcr;
47 
48 #ifndef CONFIG_SYS_PLL_BYPASS
49 
50 #ifdef CONFIG_M5249
51 	/* Setup the PLL to run at the specified speed */
52 #ifdef CONFIG_SYS_FAST_CLK
53 	pllcr = 0x925a3100;	/* ~140MHz clock (PLL bypass = 0) */
54 #else
55 	pllcr = 0x135a4140;	/* ~72MHz clock (PLL bypass = 0) */
56 #endif
57 #endif				/* CONFIG_M5249 */
58 
59 #ifdef CONFIG_M5253
60 	pllcr = CONFIG_SYS_PLLCR;
61 #endif				/* CONFIG_M5253 */
62 
63 	cpll = cpll & 0xfffffffe;	/* Set PLL bypass mode = 0 (PSTCLK = crystal) */
64 	mbar2_writeLong(MCFSIM_PLLCR, cpll);	/* Set the PLL to bypass mode (PSTCLK = crystal) */
65 	mbar2_writeLong(MCFSIM_PLLCR, pllcr);	/* set the clock speed */
66 	pllcr ^= 0x00000001;	/* Set pll bypass to 1 */
67 	mbar2_writeLong(MCFSIM_PLLCR, pllcr);	/* Start locking (pll bypass = 1) */
68 	udelay(0x20);		/* Wait for a lock ... */
69 #endif				/* #ifndef CONFIG_SYS_PLL_BYPASS */
70 
71 #endif				/* CONFIG_M5249 || CONFIG_M5253 */
72 
73 #if defined(CONFIG_M5275)
74 	pll_t *pll = (pll_t *)(MMAP_PLL);
75 
76 	/* Setup PLL */
77 	out_be32(&pll->syncr, 0x01080000);
78 	while (!(in_be32(&pll->synsr) & FMPLL_SYNSR_LOCK))
79 		;
80 	out_be32(&pll->syncr, 0x01000000);
81 	while (!(in_be32(&pll->synsr) & FMPLL_SYNSR_LOCK))
82 		;
83 #endif
84 
85 	gd->cpu_clk = CONFIG_SYS_CLK;
86 #if defined(CONFIG_M5208) || defined(CONFIG_M5249) || defined(CONFIG_M5253) || \
87     defined(CONFIG_M5271) || defined(CONFIG_M5275)
88 	gd->bus_clk = gd->cpu_clk / 2;
89 #else
90 	gd->bus_clk = gd->cpu_clk;
91 #endif
92 
93 #ifdef CONFIG_FSL_I2C
94 	gd->arch.i2c1_clk = gd->bus_clk;
95 #ifdef CONFIG_SYS_I2C2_OFFSET
96 	gd->arch.i2c2_clk = gd->bus_clk;
97 #endif
98 #endif
99 
100 	return (0);
101 }
102