167 lines
4.2 KiB
C
167 lines
4.2 KiB
C
/*
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* linux/arch/arm/mach-omap2/sdrc2xxx.c
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*
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* SDRAM timing related functions for OMAP2xxx
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*
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* Copyright (C) 2005, 2008 Texas Instruments Inc.
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* Copyright (C) 2005, 2008 Nokia Corporation
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*
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* Tony Lindgren <tony@atomide.com>
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* Paul Walmsley
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* Richard Woodruff <r-woodruff2@ti.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/device.h>
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#include <linux/list.h>
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#include <linux/errno.h>
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#include <linux/delay.h>
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#include <linux/clk.h>
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#include <linux/io.h>
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#include <mach/common.h>
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#include <mach/clock.h>
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#include <mach/sram.h>
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#include "prm.h"
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#include "clock.h"
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#include <mach/sdrc.h>
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#include "sdrc.h"
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/* Memory timing, DLL mode flags */
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#define M_DDR 1
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#define M_LOCK_CTRL (1 << 2)
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#define M_UNLOCK 0
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#define M_LOCK 1
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static struct memory_timings mem_timings;
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static u32 curr_perf_level = CORE_CLK_SRC_DPLL_X2;
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static u32 omap2xxx_sdrc_get_slow_dll_ctrl(void)
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{
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return mem_timings.slow_dll_ctrl;
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}
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static u32 omap2xxx_sdrc_get_fast_dll_ctrl(void)
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{
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return mem_timings.fast_dll_ctrl;
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}
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static u32 omap2xxx_sdrc_get_type(void)
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{
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return mem_timings.m_type;
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}
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/*
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* Check the DLL lock state, and return tue if running in unlock mode.
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* This is needed to compensate for the shifted DLL value in unlock mode.
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*/
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u32 omap2xxx_sdrc_dll_is_unlocked(void)
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{
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/* dlla and dllb are a set */
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u32 dll_state = sdrc_read_reg(SDRC_DLLA_CTRL);
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if ((dll_state & (1 << 2)) == (1 << 2))
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return 1;
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else
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return 0;
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}
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/*
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* 'level' is the value to store to CM_CLKSEL2_PLL.CORE_CLK_SRC.
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* Practical values are CORE_CLK_SRC_DPLL (for CORE_CLK = DPLL_CLK) or
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* CORE_CLK_SRC_DPLL_X2 (for CORE_CLK = * DPLL_CLK * 2)
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*
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* Used by the clock framework during CORE DPLL changes
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*/
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u32 omap2xxx_sdrc_reprogram(u32 level, u32 force)
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{
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u32 dll_ctrl, m_type;
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u32 prev = curr_perf_level;
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unsigned long flags;
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if ((curr_perf_level == level) && !force)
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return prev;
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if (level == CORE_CLK_SRC_DPLL)
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dll_ctrl = omap2xxx_sdrc_get_slow_dll_ctrl();
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else if (level == CORE_CLK_SRC_DPLL_X2)
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dll_ctrl = omap2xxx_sdrc_get_fast_dll_ctrl();
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else
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return prev;
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m_type = omap2xxx_sdrc_get_type();
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local_irq_save(flags);
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if (cpu_is_omap2420())
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__raw_writel(0xffff, OMAP2420_PRCM_VOLTSETUP);
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else
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__raw_writel(0xffff, OMAP2430_PRCM_VOLTSETUP);
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omap2_sram_reprogram_sdrc(level, dll_ctrl, m_type);
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curr_perf_level = level;
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local_irq_restore(flags);
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return prev;
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}
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/* Used by the clock framework during CORE DPLL changes */
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void omap2xxx_sdrc_init_params(u32 force_lock_to_unlock_mode)
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{
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unsigned long dll_cnt;
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u32 fast_dll = 0;
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/* DDR = 1, SDR = 0 */
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mem_timings.m_type = !((sdrc_read_reg(SDRC_MR_0) & 0x3) == 0x1);
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/* 2422 es2.05 and beyond has a single SIP DDR instead of 2 like others.
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* In the case of 2422, its ok to use CS1 instead of CS0.
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*/
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if (cpu_is_omap2422())
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mem_timings.base_cs = 1;
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else
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mem_timings.base_cs = 0;
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if (mem_timings.m_type != M_DDR)
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return;
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/* With DDR we need to determine the low frequency DLL value */
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if (((mem_timings.fast_dll_ctrl & (1 << 2)) == M_LOCK_CTRL))
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mem_timings.dll_mode = M_UNLOCK;
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else
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mem_timings.dll_mode = M_LOCK;
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if (mem_timings.base_cs == 0) {
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fast_dll = sdrc_read_reg(SDRC_DLLA_CTRL);
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dll_cnt = sdrc_read_reg(SDRC_DLLA_STATUS) & 0xff00;
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} else {
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fast_dll = sdrc_read_reg(SDRC_DLLB_CTRL);
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dll_cnt = sdrc_read_reg(SDRC_DLLB_STATUS) & 0xff00;
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}
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if (force_lock_to_unlock_mode) {
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fast_dll &= ~0xff00;
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fast_dll |= dll_cnt; /* Current lock mode */
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}
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/* set fast timings with DLL filter disabled */
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mem_timings.fast_dll_ctrl = (fast_dll | (3 << 8));
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/* No disruptions, DDR will be offline & C-ABI not followed */
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omap2_sram_ddr_init(&mem_timings.slow_dll_ctrl,
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mem_timings.fast_dll_ctrl,
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mem_timings.base_cs,
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force_lock_to_unlock_mode);
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mem_timings.slow_dll_ctrl &= 0xff00; /* Keep lock value */
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/* Turn status into unlock ctrl */
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mem_timings.slow_dll_ctrl |=
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((mem_timings.fast_dll_ctrl & 0xF) | (1 << 2));
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/* 90 degree phase for anything below 133Mhz + disable DLL filter */
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mem_timings.slow_dll_ctrl |= ((1 << 1) | (3 << 8));
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}
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