arch/arm/plat-omap/sram.c

   1 /*
   2  * linux/arch/arm/plat-omap/sram.c
   3  *
   4  * OMAP SRAM detection and management
   5  *
   6  * Copyright (C) 2005 Nokia Corporation
   7  * Written by Tony Lindgren <tony@atomide.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  */
  13
  14 #include <linux/config.h>
  15 #include <linux/module.h>
  16 #include <linux/kernel.h>
  17 #include <linux/init.h>
  18
  19 #include <asm/mach/map.h>
  20 #include <asm/io.h>
  21 #include <asm/cacheflush.h>
  22
  23 #include <asm/arch/sram.h>
  24
  25 #define OMAP1_SRAM_PA           0x20000000
  26 #define OMAP1_SRAM_VA           0xd0000000
  27 #define OMAP2_SRAM_PA           0x40200000
  28 #define OMAP2_SRAM_VA           0xd0000000
  29
  30 #define SRAM_BOOTLOADER_SZ      0x80
  31
  32 static unsigned long omap_sram_base;
  33 static unsigned long omap_sram_size;
  34 static unsigned long omap_sram_ceil;
  35
  36 /*
  37  * The amount of SRAM depends on the core type.
  38  * Note that we cannot try to test for SRAM here because writes
  39  * to secure SRAM will hang the system. Also the SRAM is not
  40  * yet mapped at this point.
  41  */
  42 void __init omap_detect_sram(void)
  43 {
  44         if (!cpu_is_omap24xx())
  45                 omap_sram_base = OMAP1_SRAM_VA;
  46         else
  47                 omap_sram_base = OMAP2_SRAM_VA;
  48
  49         if (cpu_is_omap730())
  50                 omap_sram_size = 0x32000;       /* 200K */
  51         else if (cpu_is_omap15xx())
  52                 omap_sram_size = 0x30000;       /* 192K */
  53         else if (cpu_is_omap1610() || cpu_is_omap1621() || cpu_is_omap1710())
  54                 omap_sram_size = 0x4000;        /* 16K */
  55         else if (cpu_is_omap1611())
  56                 omap_sram_size = 0x3e800;       /* 250K */
  57         else if (cpu_is_omap2420())
  58                 omap_sram_size = 0xa0014;       /* 640K */
  59         else {
  60                 printk(KERN_ERR "Could not detect SRAM size\n");
  61                 omap_sram_size = 0x4000;
  62         }
  63
  64         omap_sram_ceil = omap_sram_base + omap_sram_size;
  65 }
  66
  67 static struct map_desc omap_sram_io_desc[] __initdata = {
  68         {       /* .length gets filled in at runtime */
  69                 .virtual        = OMAP1_SRAM_VA,
  70                 .pfn            = __phys_to_pfn(OMAP1_SRAM_PA),
  71                 .type           = MT_DEVICE
  72         }
  73 };
  74
  75 /*
  76  * In order to use last 2kB of SRAM on 1611b, we must round the size
  77  * up to multiple of PAGE_SIZE. We cannot use ioremap for SRAM, as
  78  * clock init needs SRAM early.
  79  */
  80 void __init omap_map_sram(void)
  81 {
  82         if (omap_sram_size == 0)
  83                 return;
  84
  85         if (cpu_is_omap24xx()) {
  86                 omap_sram_io_desc[0].virtual = OMAP2_SRAM_VA;
  87                 omap_sram_io_desc[0].pfn = __phys_to_pfn(OMAP2_SRAM_PA);
  88         }
  89
  90         omap_sram_io_desc[0].length = (omap_sram_size + PAGE_SIZE-1)/PAGE_SIZE;
  91         omap_sram_io_desc[0].length *= PAGE_SIZE;
  92         iotable_init(omap_sram_io_desc, ARRAY_SIZE(omap_sram_io_desc));
  93
  94         printk(KERN_INFO "SRAM: Mapped pa 0x%08lx to va 0x%08lx size: 0x%lx\n",
  95                omap_sram_io_desc[0].pfn, omap_sram_io_desc[0].virtual,
  96                omap_sram_io_desc[0].length);
  97
  98         /*
  99          * Looks like we need to preserve some bootloader code at the
 100          * beginning of SRAM for jumping to flash for reboot to work...
 101          */
 102         memset((void *)omap_sram_base + SRAM_BOOTLOADER_SZ, 0,
 103                omap_sram_size - SRAM_BOOTLOADER_SZ);
 104 }
 105
 106 void * omap_sram_push(void * start, unsigned long size)
 107 {
 108         if (size > (omap_sram_ceil - (omap_sram_base + SRAM_BOOTLOADER_SZ))) {
 109                 printk(KERN_ERR "Not enough space in SRAM\n");
 110                 return NULL;
 111         }
 112         omap_sram_ceil -= size;
 113         omap_sram_ceil &= ~0x3;
 114         memcpy((void *)omap_sram_ceil, start, size);
 115
 116         return (void *)omap_sram_ceil;
 117 }
 118
 119 static void omap_sram_error(void)
 120 {
 121         panic("Uninitialized SRAM function\n");
 122 }
 123
 124 #ifdef CONFIG_ARCH_OMAP1
 125
 126 static void (*_omap_sram_reprogram_clock)(u32 dpllctl, u32 ckctl);
 127
 128 void omap_sram_reprogram_clock(u32 dpllctl, u32 ckctl)
 129 {
 130         if (!_omap_sram_reprogram_clock)
 131                 omap_sram_error();
 132
 133         return _omap_sram_reprogram_clock(dpllctl, ckctl);
 134 }
 135
 136 int __init omap1_sram_init(void)
 137 {
 138         _omap_sram_reprogram_clock = omap_sram_push(sram_reprogram_clock,
 139                                                     sram_reprogram_clock_sz);
 140
 141         return 0;
 142 }
 143
 144 #else
 145 #define omap1_sram_init()       do {} while (0)
 146 #endif
 147
 148 #ifdef CONFIG_ARCH_OMAP2
 149
 150 static void (*_omap2_sram_ddr_init)(u32 *slow_dll_ctrl, u32 fast_dll_ctrl,
 151                               u32 base_cs, u32 force_unlock);
 152
 153 void omap2_sram_ddr_init(u32 *slow_dll_ctrl, u32 fast_dll_ctrl,
 154                    u32 base_cs, u32 force_unlock)
 155 {
 156         if (!_omap2_sram_ddr_init)
 157                 omap_sram_error();
 158
 159         return _omap2_sram_ddr_init(slow_dll_ctrl, fast_dll_ctrl,
 160                                     base_cs, force_unlock);
 161 }
 162
 163 static void (*_omap2_sram_reprogram_sdrc)(u32 perf_level, u32 dll_val,
 164                                           u32 mem_type);
 165
 166 void omap2_sram_reprogram_sdrc(u32 perf_level, u32 dll_val, u32 mem_type)
 167 {
 168         if (!_omap2_sram_reprogram_sdrc)
 169                 omap_sram_error();
 170
 171         return _omap2_sram_reprogram_sdrc(perf_level, dll_val, mem_type);
 172 }
 173
 174 static u32 (*_omap2_set_prcm)(u32 dpll_ctrl_val, u32 sdrc_rfr_val, int bypass);
 175
 176 u32 omap2_set_prcm(u32 dpll_ctrl_val, u32 sdrc_rfr_val, int bypass)
 177 {
 178         if (!_omap2_set_prcm)
 179                 omap_sram_error();
 180
 181         return _omap2_set_prcm(dpll_ctrl_val, sdrc_rfr_val, bypass);
 182 }
 183
 184 int __init omap2_sram_init(void)
 185 {
 186         _omap2_sram_ddr_init = omap_sram_push(sram_ddr_init, sram_ddr_init_sz);
 187
 188         _omap2_sram_reprogram_sdrc = omap_sram_push(sram_reprogram_sdrc,
 189                                                     sram_reprogram_sdrc_sz);
 190         _omap2_set_prcm = omap_sram_push(sram_set_prcm, sram_set_prcm_sz);
 191
 192         return 0;
 193 }
 194 #else
 195 #define omap2_sram_init()       do {} while (0)
 196 #endif
 197
 198 int __init omap_sram_init(void)
 199 {
 200         omap_detect_sram();
 201         omap_map_sram();
 202
 203         if (!cpu_is_omap24xx())
 204                 omap1_sram_init();
 205         else
 206                 omap2_sram_init();
 207
 208         return 0;
 209 }