u-boot/cpu/mpc85xx/speed.c
Timur Tabi 88353a9851 Fix calculation of I2C clock for some 85xx chips
Some 85xx chips use CCB as the base clock for the I2C.  Some use CCB/2, and
some use CCB/3.  There is no pattern that can be used to determine which
chips use which frequency, so the only way to determine is to look up the
actual SOC designation and use the right value for that SOC.

Update immap_85xx.h to include the GUTS PORDEVSR2 register.

Signed-off-by: Timur Tabi <timur@freescale.com>
2008-04-18 17:43:09 -05:00

141 lines
4.2 KiB
C

/*
* Copyright 2004 Freescale Semiconductor.
* (C) Copyright 2003 Motorola Inc.
* Xianghua Xiao, (X.Xiao@motorola.com)
*
* (C) Copyright 2000
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <common.h>
#include <ppc_asm.tmpl>
#include <asm/processor.h>
DECLARE_GLOBAL_DATA_PTR;
/* --------------------------------------------------------------- */
void get_sys_info (sys_info_t * sysInfo)
{
volatile ccsr_gur_t *gur = (void *)(CFG_MPC85xx_GUTS_ADDR);
uint plat_ratio,e500_ratio,half_freqSystemBus;
plat_ratio = (gur->porpllsr) & 0x0000003e;
plat_ratio >>= 1;
sysInfo->freqSystemBus = plat_ratio * CONFIG_SYS_CLK_FREQ;
e500_ratio = (gur->porpllsr) & 0x003f0000;
e500_ratio >>= 16;
/* Divide before multiply to avoid integer
* overflow for processor speeds above 2GHz */
half_freqSystemBus = sysInfo->freqSystemBus/2;
sysInfo->freqProcessor = e500_ratio*half_freqSystemBus;
/* Note: freqDDRBus is the MCLK frequency, not the data rate. */
sysInfo->freqDDRBus = sysInfo->freqSystemBus;
#ifdef CONFIG_DDR_CLK_FREQ
{
u32 ddr_ratio = ((gur->porpllsr) & 0x00003e00) >> 9;
if (ddr_ratio != 0x7)
sysInfo->freqDDRBus = ddr_ratio * CONFIG_DDR_CLK_FREQ;
}
#endif
}
int get_clocks (void)
{
sys_info_t sys_info;
#ifdef CONFIG_MPC8544
volatile ccsr_gur_t *gur = (void *) CFG_MPC85xx_GUTS_ADDR;
#endif
#if defined(CONFIG_CPM2)
volatile ccsr_cpm_t *cpm = (ccsr_cpm_t *)CFG_MPC85xx_CPM_ADDR;
uint sccr, dfbrg;
/* set VCO = 4 * BRG */
cpm->im_cpm_intctl.sccr &= 0xfffffffc;
sccr = cpm->im_cpm_intctl.sccr;
dfbrg = (sccr & SCCR_DFBRG_MSK) >> SCCR_DFBRG_SHIFT;
#endif
get_sys_info (&sys_info);
gd->cpu_clk = sys_info.freqProcessor;
gd->bus_clk = sys_info.freqSystemBus;
gd->mem_clk = sys_info.freqDDRBus;
/*
* The base clock for I2C depends on the actual SOC. Unfortunately,
* there is no pattern that can be used to determine the frequency, so
* the only choice is to look up the actual SOC number and use the value
* for that SOC. This information is taken from application note
* AN2919.
*/
#if defined(CONFIG_MPC8540) || defined(CONFIG_MPC8541) || \
defined(CONFIG_MPC8560) || defined(CONFIG_MPC8555)
gd->i2c1_clk = sys_info.freqSystemBus;
#elif defined(CONFIG_MPC8544)
/*
* On the 8544, the I2C clock is the same as the SEC clock. This can be
* either CCB/2 or CCB/3, depending on the value of cfg_sec_freq. See
* 4.4.3.3 of the 8544 RM. Note that this might actually work for all
* 85xx, but only the 8544 has cfg_sec_freq, so it's unknown if the
* PORDEVSR2_SEC_CFG bit is 0 on all 85xx boards that are not an 8544.
*/
if (gur->pordevsr2 & MPC85xx_PORDEVSR2_SEC_CFG)
gd->i2c1_clk = sys_info.freqSystemBus / 3;
else
gd->i2c1_clk = sys_info.freqSystemBus / 2;
#else
/* Most 85xx SOCs use CCB/2, so this is the default behavior. */
gd->i2c1_clk = sys_info.freqSystemBus / 2;
#endif
gd->i2c2_clk = gd->i2c1_clk;
#if defined(CONFIG_CPM2)
gd->vco_out = 2*sys_info.freqSystemBus;
gd->cpm_clk = gd->vco_out / 2;
gd->scc_clk = gd->vco_out / 4;
gd->brg_clk = gd->vco_out / (1 << (2 * (dfbrg + 1)));
#endif
if(gd->cpu_clk != 0) return (0);
else return (1);
}
/********************************************
* get_bus_freq
* return system bus freq in Hz
*********************************************/
ulong get_bus_freq (ulong dummy)
{
return gd->bus_clk;
}
/********************************************
* get_ddr_freq
* return ddr bus freq in Hz
*********************************************/
ulong get_ddr_freq (ulong dummy)
{
return gd->mem_clk;
}