1 /* 2 * linux/arch/arm/mach-omap2/sdrc2xxx.c 3 * 4 * SDRAM timing related functions for OMAP2xxx 5 * 6 * Copyright (C) 2005, 2008 Texas Instruments Inc. 7 * Copyright (C) 2005, 2008 Nokia Corporation 8 * 9 * Tony Lindgren <tony@atomide.com> 10 * Paul Walmsley 11 * Richard Woodruff <r-woodruff2@ti.com> 12 * 13 * This program is free software; you can redistribute it and/or modify 14 * it under the terms of the GNU General Public License version 2 as 15 * published by the Free Software Foundation. 16 */ 17 18 #include <linux/module.h> 19 #include <linux/kernel.h> 20 #include <linux/device.h> 21 #include <linux/list.h> 22 #include <linux/errno.h> 23 #include <linux/delay.h> 24 #include <linux/clk.h> 25 #include <linux/io.h> 26 27 #include <plat/common.h> 28 #include <plat/clock.h> 29 #include <plat/sram.h> 30 31 #include "prm2xxx_3xxx.h" 32 #include "clock.h" 33 #include <plat/sdrc.h> 34 #include "sdrc.h" 35 36 /* Memory timing, DLL mode flags */ 37 #define M_DDR 1 38 #define M_LOCK_CTRL (1 << 2) 39 #define M_UNLOCK 0 40 #define M_LOCK 1 41 42 43 static struct memory_timings mem_timings; 44 static u32 curr_perf_level = CORE_CLK_SRC_DPLL_X2; 45 46 static u32 omap2xxx_sdrc_get_slow_dll_ctrl(void) 47 { 48 return mem_timings.slow_dll_ctrl; 49 } 50 51 static u32 omap2xxx_sdrc_get_fast_dll_ctrl(void) 52 { 53 return mem_timings.fast_dll_ctrl; 54 } 55 56 static u32 omap2xxx_sdrc_get_type(void) 57 { 58 return mem_timings.m_type; 59 } 60 61 /* 62 * Check the DLL lock state, and return tue if running in unlock mode. 63 * This is needed to compensate for the shifted DLL value in unlock mode. 64 */ 65 u32 omap2xxx_sdrc_dll_is_unlocked(void) 66 { 67 /* dlla and dllb are a set */ 68 u32 dll_state = sdrc_read_reg(SDRC_DLLA_CTRL); 69 70 if ((dll_state & (1 << 2)) == (1 << 2)) 71 return 1; 72 else 73 return 0; 74 } 75 76 /* 77 * 'level' is the value to store to CM_CLKSEL2_PLL.CORE_CLK_SRC. 78 * Practical values are CORE_CLK_SRC_DPLL (for CORE_CLK = DPLL_CLK) or 79 * CORE_CLK_SRC_DPLL_X2 (for CORE_CLK = * DPLL_CLK * 2) 80 * 81 * Used by the clock framework during CORE DPLL changes 82 */ 83 u32 omap2xxx_sdrc_reprogram(u32 level, u32 force) 84 { 85 u32 dll_ctrl, m_type; 86 u32 prev = curr_perf_level; 87 unsigned long flags; 88 89 if ((curr_perf_level == level) && !force) 90 return prev; 91 92 if (level == CORE_CLK_SRC_DPLL) 93 dll_ctrl = omap2xxx_sdrc_get_slow_dll_ctrl(); 94 else if (level == CORE_CLK_SRC_DPLL_X2) 95 dll_ctrl = omap2xxx_sdrc_get_fast_dll_ctrl(); 96 else 97 return prev; 98 99 m_type = omap2xxx_sdrc_get_type(); 100 101 local_irq_save(flags); 102 /* 103 * XXX These calls should be abstracted out through a 104 * prm2xxx.c function 105 */ 106 if (cpu_is_omap2420()) 107 __raw_writel(0xffff, OMAP2420_PRCM_VOLTSETUP); 108 else 109 __raw_writel(0xffff, OMAP2430_PRCM_VOLTSETUP); 110 omap2_sram_reprogram_sdrc(level, dll_ctrl, m_type); 111 curr_perf_level = level; 112 local_irq_restore(flags); 113 114 return prev; 115 } 116 117 /* Used by the clock framework during CORE DPLL changes */ 118 void omap2xxx_sdrc_init_params(u32 force_lock_to_unlock_mode) 119 { 120 unsigned long dll_cnt; 121 u32 fast_dll = 0; 122 123 /* DDR = 1, SDR = 0 */ 124 mem_timings.m_type = !((sdrc_read_reg(SDRC_MR_0) & 0x3) == 0x1); 125 126 /* 2422 es2.05 and beyond has a single SIP DDR instead of 2 like others. 127 * In the case of 2422, its ok to use CS1 instead of CS0. 128 */ 129 if (cpu_is_omap2422()) 130 mem_timings.base_cs = 1; 131 else 132 mem_timings.base_cs = 0; 133 134 if (mem_timings.m_type != M_DDR) 135 return; 136 137 /* With DDR we need to determine the low frequency DLL value */ 138 if (((mem_timings.fast_dll_ctrl & (1 << 2)) == M_LOCK_CTRL)) 139 mem_timings.dll_mode = M_UNLOCK; 140 else 141 mem_timings.dll_mode = M_LOCK; 142 143 if (mem_timings.base_cs == 0) { 144 fast_dll = sdrc_read_reg(SDRC_DLLA_CTRL); 145 dll_cnt = sdrc_read_reg(SDRC_DLLA_STATUS) & 0xff00; 146 } else { 147 fast_dll = sdrc_read_reg(SDRC_DLLB_CTRL); 148 dll_cnt = sdrc_read_reg(SDRC_DLLB_STATUS) & 0xff00; 149 } 150 if (force_lock_to_unlock_mode) { 151 fast_dll &= ~0xff00; 152 fast_dll |= dll_cnt; /* Current lock mode */ 153 } 154 /* set fast timings with DLL filter disabled */ 155 mem_timings.fast_dll_ctrl = (fast_dll | (3 << 8)); 156 157 /* No disruptions, DDR will be offline & C-ABI not followed */ 158 omap2_sram_ddr_init(&mem_timings.slow_dll_ctrl, 159 mem_timings.fast_dll_ctrl, 160 mem_timings.base_cs, 161 force_lock_to_unlock_mode); 162 mem_timings.slow_dll_ctrl &= 0xff00; /* Keep lock value */ 163 164 /* Turn status into unlock ctrl */ 165 mem_timings.slow_dll_ctrl |= 166 ((mem_timings.fast_dll_ctrl & 0xF) | (1 << 2)); 167 168 /* 90 degree phase for anything below 133Mhz + disable DLL filter */ 169 mem_timings.slow_dll_ctrl |= ((1 << 1) | (3 << 8)); 170 } 171