arch/arm/mach-omap1/sram-init.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * OMAP SRAM detection and management
   4  *
   5  * Copyright (C) 2005 Nokia Corporation
   6  * Written by Tony Lindgren <tony@atomide.com>
   7  */
   8
   9 #include <linux/module.h>
  10 #include <linux/kernel.h>
  11 #include <linux/init.h>
  12 #include <linux/io.h>
  13
  14 #include <asm/fncpy.h>
  15 #include <asm/tlb.h>
  16 #include <asm/cacheflush.h>
  17 #include <asm/set_memory.h>
  18
  19 #include <asm/mach/map.h>
  20
  21 #include "soc.h"
  22 #include "sram.h"
  23
  24 #define OMAP1_SRAM_PA           0x20000000
  25 #define SRAM_BOOTLOADER_SZ      0x80
  26 #define ROUND_DOWN(value,boundary)      ((value) & (~((boundary)-1)))
  27
  28 static void __iomem *omap_sram_base;
  29 static unsigned long omap_sram_start;
  30 static unsigned long omap_sram_skip;
  31 static unsigned long omap_sram_size;
  32 static void __iomem *omap_sram_ceil;
  33
  34 /*
  35  * Memory allocator for SRAM: calculates the new ceiling address
  36  * for pushing a function using the fncpy API.
  37  *
  38  * Note that fncpy requires the returned address to be aligned
  39  * to an 8-byte boundary.
  40  */
  41 static void *omap_sram_push_address(unsigned long size)
  42 {
  43         unsigned long available, new_ceil = (unsigned long)omap_sram_ceil;
  44
  45         available = omap_sram_ceil - (omap_sram_base + omap_sram_skip);
  46
  47         if (size > available) {
  48                 pr_err("Not enough space in SRAM\n");
  49                 return NULL;
  50         }
  51
  52         new_ceil -= size;
  53         new_ceil = ROUND_DOWN(new_ceil, FNCPY_ALIGN);
  54         omap_sram_ceil = IOMEM(new_ceil);
  55
  56         return (void __force *)omap_sram_ceil;
  57 }
  58
  59 void *omap_sram_push(void *funcp, unsigned long size)
  60 {
  61         void *sram;
  62         unsigned long base;
  63         int pages;
  64         void *dst = NULL;
  65
  66         sram = omap_sram_push_address(size);
  67         if (!sram)
  68                 return NULL;
  69
  70         base = (unsigned long)sram & PAGE_MASK;
  71         pages = PAGE_ALIGN(size) / PAGE_SIZE;
  72
  73         set_memory_rw(base, pages);
  74
  75         dst = fncpy(sram, funcp, size);
  76
  77         set_memory_ro(base, pages);
  78         set_memory_x(base, pages);
  79
  80         return dst;
  81 }
  82
  83 /*
  84  * The amount of SRAM depends on the core type.
  85  * Note that we cannot try to test for SRAM here because writes
  86  * to secure SRAM will hang the system. Also the SRAM is not
  87  * yet mapped at this point.
  88  * Note that we cannot use ioremap for SRAM, as clock init needs SRAM early.
  89  */
  90 static void __init omap_detect_and_map_sram(void)
  91 {
  92         unsigned long base;
  93         int pages;
  94
  95         omap_sram_skip = SRAM_BOOTLOADER_SZ;
  96         omap_sram_start = OMAP1_SRAM_PA;
  97
  98         if (cpu_is_omap7xx())
  99                 omap_sram_size = 0x32000;       /* 200K */
 100         else if (cpu_is_omap15xx())
 101                 omap_sram_size = 0x30000;       /* 192K */
 102         else if (cpu_is_omap1610() || cpu_is_omap1611() ||
 103                         cpu_is_omap1621() || cpu_is_omap1710())
 104                 omap_sram_size = 0x4000;        /* 16K */
 105         else {
 106                 pr_err("Could not detect SRAM size\n");
 107                 omap_sram_size = 0x4000;
 108         }
 109
 110         omap_sram_start = ROUND_DOWN(omap_sram_start, PAGE_SIZE);
 111         omap_sram_base = __arm_ioremap_exec(omap_sram_start, omap_sram_size, 1);
 112         if (!omap_sram_base) {
 113                 pr_err("SRAM: Could not map\n");
 114                 return;
 115         }
 116
 117         omap_sram_ceil = omap_sram_base + omap_sram_size;
 118
 119         /*
 120          * Looks like we need to preserve some bootloader code at the
 121          * beginning of SRAM for jumping to flash for reboot to work...
 122          */
 123         memset_io(omap_sram_base + omap_sram_skip, 0,
 124                   omap_sram_size - omap_sram_skip);
 125
 126         base = (unsigned long)omap_sram_base;
 127         pages = PAGE_ALIGN(omap_sram_size) / PAGE_SIZE;
 128
 129         set_memory_ro(base, pages);
 130         set_memory_x(base, pages);
 131 }
 132
 133 static void (*_omap_sram_reprogram_clock)(u32 dpllctl, u32 ckctl);
 134
 135 void omap_sram_reprogram_clock(u32 dpllctl, u32 ckctl)
 136 {
 137         BUG_ON(!_omap_sram_reprogram_clock);
 138         /* On 730, bit 13 must always be 1 */
 139         if (cpu_is_omap7xx())
 140                 ckctl |= 0x2000;
 141         _omap_sram_reprogram_clock(dpllctl, ckctl);
 142 }
 143
 144 int __init omap1_sram_init(void)
 145 {
 146         omap_detect_and_map_sram();
 147         _omap_sram_reprogram_clock =
 148                         omap_sram_push(omap1_sram_reprogram_clock,
 149                                         omap1_sram_reprogram_clock_sz);
 150
 151         return 0;
 152 }