linux/arch/arm/mach-omap2/memory.c

102 lines
2.5 KiB
C

/*
* linux/arch/arm/mach-omap2/memory.c
*
* Memory timing related functions for OMAP24XX
*
* Copyright (C) 2005 Texas Instruments Inc.
* Richard Woodruff <r-woodruff2@ti.com>
*
* Copyright (C) 2005 Nokia Corporation
* Tony Lindgren <tony@atomide.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <asm/io.h>
#include <asm/arch/clock.h>
#include <asm/arch/sram.h>
#include "prcm-regs.h"
#include "memory.h"
static struct memory_timings mem_timings;
u32 omap2_memory_get_slow_dll_ctrl(void)
{
return mem_timings.slow_dll_ctrl;
}
u32 omap2_memory_get_fast_dll_ctrl(void)
{
return mem_timings.fast_dll_ctrl;
}
u32 omap2_memory_get_type(void)
{
return mem_timings.m_type;
}
void omap2_init_memory_params(u32 force_lock_to_unlock_mode)
{
unsigned long dll_cnt;
u32 fast_dll = 0;
mem_timings.m_type = !((SDRC_MR_0 & 0x3) == 0x1); /* DDR = 1, SDR = 0 */
/* 2422 es2.05 and beyond has a single SIP DDR instead of 2 like others.
* In the case of 2422, its ok to use CS1 instead of CS0.
*/
if (cpu_is_omap2422())
mem_timings.base_cs = 1;
else
mem_timings.base_cs = 0;
if (mem_timings.m_type != M_DDR)
return;
/* With DDR we need to determine the low frequency DLL value */
if (((mem_timings.fast_dll_ctrl & (1 << 2)) == M_LOCK_CTRL))
mem_timings.dll_mode = M_UNLOCK;
else
mem_timings.dll_mode = M_LOCK;
if (mem_timings.base_cs == 0) {
fast_dll = SDRC_DLLA_CTRL;
dll_cnt = SDRC_DLLA_STATUS & 0xff00;
} else {
fast_dll = SDRC_DLLB_CTRL;
dll_cnt = SDRC_DLLB_STATUS & 0xff00;
}
if (force_lock_to_unlock_mode) {
fast_dll &= ~0xff00;
fast_dll |= dll_cnt; /* Current lock mode */
}
/* set fast timings with DLL filter disabled */
mem_timings.fast_dll_ctrl = (fast_dll | (3 << 8));
/* No disruptions, DDR will be offline & C-ABI not followed */
omap2_sram_ddr_init(&mem_timings.slow_dll_ctrl,
mem_timings.fast_dll_ctrl,
mem_timings.base_cs,
force_lock_to_unlock_mode);
mem_timings.slow_dll_ctrl &= 0xff00; /* Keep lock value */
/* Turn status into unlock ctrl */
mem_timings.slow_dll_ctrl |=
((mem_timings.fast_dll_ctrl & 0xF) | (1 << 2));
/* 90 degree phase for anything below 133Mhz + disable DLL filter */
mem_timings.slow_dll_ctrl |= ((1 << 1) | (3 << 8));
}