arch/avr32/kernel/setup.c

   1 /*
   2  * Copyright (C) 2004-2006 Atmel Corporation
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8
   9 #include <linux/clk.h>
  10 #include <linux/init.h>
  11 #include <linux/sched.h>
  12 #include <linux/console.h>
  13 #include <linux/ioport.h>
  14 #include <linux/bootmem.h>
  15 #include <linux/fs.h>
  16 #include <linux/module.h>
  17 #include <linux/root_dev.h>
  18 #include <linux/cpu.h>
  19
  20 #include <asm/sections.h>
  21 #include <asm/processor.h>
  22 #include <asm/pgtable.h>
  23 #include <asm/setup.h>
  24 #include <asm/sysreg.h>
  25
  26 #include <asm/arch/board.h>
  27 #include <asm/arch/init.h>
  28
  29 extern int root_mountflags;
  30
  31 /*
  32  * Bootloader-provided information about physical memory
  33  */
  34 struct tag_mem_range *mem_phys;
  35 struct tag_mem_range *mem_reserved;
  36 struct tag_mem_range *mem_ramdisk;
  37
  38 /*
  39  * Initialize loops_per_jiffy as 5000000 (500MIPS).
  40  * Better make it too large than too small...
  41  */
  42 struct avr32_cpuinfo boot_cpu_data = {
  43         .loops_per_jiffy = 5000000
  44 };
  45 EXPORT_SYMBOL(boot_cpu_data);
  46
  47 static char command_line[COMMAND_LINE_SIZE];
  48
  49 /*
  50  * Should be more than enough, but if you have a _really_ complex
  51  * setup, you might need to increase the size of this...
  52  */
  53 static struct tag_mem_range __initdata mem_range_cache[32];
  54 static unsigned mem_range_next_free;
  55
  56 /*
  57  * Standard memory resources
  58  */
  59 static struct resource mem_res[] = {
  60         {
  61                 .name   = "Kernel code",
  62                 .start  = 0,
  63                 .end    = 0,
  64                 .flags  = IORESOURCE_MEM
  65         },
  66         {
  67                 .name   = "Kernel data",
  68                 .start  = 0,
  69                 .end    = 0,
  70                 .flags  = IORESOURCE_MEM,
  71         },
  72 };
  73
  74 #define kernel_code     mem_res[0]
  75 #define kernel_data     mem_res[1]
  76
  77 /*
  78  * Early framebuffer allocation. Works as follows:
  79  *   - If fbmem_size is zero, nothing will be allocated or reserved.
  80  *   - If fbmem_start is zero when setup_bootmem() is called,
  81  *     fbmem_size bytes will be allocated from the bootmem allocator.
  82  *   - If fbmem_start is nonzero, an area of size fbmem_size will be
  83  *     reserved at the physical address fbmem_start if necessary. If
  84  *     the area isn't in a memory region known to the kernel, it will
  85  *     be left alone.
  86  *
  87  * Board-specific code may use these variables to set up platform data
  88  * for the framebuffer driver if fbmem_size is nonzero.
  89  */
  90 static unsigned long __initdata fbmem_start;
  91 static unsigned long __initdata fbmem_size;
  92
  93 /*
  94  * "fbmem=xxx[kKmM]" allocates the specified amount of boot memory for
  95  * use as framebuffer.
  96  *
  97  * "fbmem=xxx[kKmM]@yyy[kKmM]" defines a memory region of size xxx and
  98  * starting at yyy to be reserved for use as framebuffer.
  99  *
 100  * The kernel won't verify that the memory region starting at yyy
 101  * actually contains usable RAM.
 102  */
 103 static int __init early_parse_fbmem(char *p)
 104 {
 105         fbmem_size = memparse(p, &p);
 106         if (*p == '@')
 107                 fbmem_start = memparse(p, &p);
 108         return 0;
 109 }
 110 early_param("fbmem", early_parse_fbmem);
 111
 112 static inline void __init resource_init(void)
 113 {
 114         struct tag_mem_range *region;
 115
 116         kernel_code.start = __pa(init_mm.start_code);
 117         kernel_code.end = __pa(init_mm.end_code - 1);
 118         kernel_data.start = __pa(init_mm.end_code);
 119         kernel_data.end = __pa(init_mm.brk - 1);
 120
 121         for (region = mem_phys; region; region = region->next) {
 122                 struct resource *res;
 123                 unsigned long phys_start, phys_end;
 124
 125                 if (region->size == 0)
 126                         continue;
 127
 128                 phys_start = region->addr;
 129                 phys_end = phys_start + region->size - 1;
 130
 131                 res = alloc_bootmem_low(sizeof(*res));
 132                 res->name = "System RAM";
 133                 res->start = phys_start;
 134                 res->end = phys_end;
 135                 res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 136
 137                 request_resource (&iomem_resource, res);
 138
 139                 if (kernel_code.start >= res->start &&
 140                     kernel_code.end <= res->end)
 141                         request_resource (res, &kernel_code);
 142                 if (kernel_data.start >= res->start &&
 143                     kernel_data.end <= res->end)
 144                         request_resource (res, &kernel_data);
 145         }
 146 }
 147
 148 static int __init parse_tag_core(struct tag *tag)
 149 {
 150         if (tag->hdr.size > 2) {
 151                 if ((tag->u.core.flags & 1) == 0)
 152                         root_mountflags &= ~MS_RDONLY;
 153                 ROOT_DEV = new_decode_dev(tag->u.core.rootdev);
 154         }
 155         return 0;
 156 }
 157 __tagtable(ATAG_CORE, parse_tag_core);
 158
 159 static int __init parse_tag_mem_range(struct tag *tag,
 160                                       struct tag_mem_range **root)
 161 {
 162         struct tag_mem_range *cur, **pprev;
 163         struct tag_mem_range *new;
 164
 165         /*
 166          * Ignore zero-sized entries. If we're running standalone, the
 167          * SDRAM code may emit such entries if something goes
 168          * wrong...
 169          */
 170         if (tag->u.mem_range.size == 0)
 171                 return 0;
 172
 173         /*
 174          * Copy the data so the bootmem init code doesn't need to care
 175          * about it.
 176          */
 177         if (mem_range_next_free >=
 178             (sizeof(mem_range_cache) / sizeof(mem_range_cache[0])))
 179                 panic("Physical memory map too complex!\n");
 180
 181         new = &mem_range_cache[mem_range_next_free++];
 182         *new = tag->u.mem_range;
 183
 184         pprev = root;
 185         cur = *root;
 186         while (cur) {
 187                 pprev = &cur->next;
 188                 cur = cur->next;
 189         }
 190
 191         *pprev = new;
 192         new->next = NULL;
 193
 194         return 0;
 195 }
 196
 197 static int __init parse_tag_mem(struct tag *tag)
 198 {
 199         return parse_tag_mem_range(tag, &mem_phys);
 200 }
 201 __tagtable(ATAG_MEM, parse_tag_mem);
 202
 203 static int __init parse_tag_cmdline(struct tag *tag)
 204 {
 205         strlcpy(saved_command_line, tag->u.cmdline.cmdline, COMMAND_LINE_SIZE);
 206         return 0;
 207 }
 208 __tagtable(ATAG_CMDLINE, parse_tag_cmdline);
 209
 210 static int __init parse_tag_rdimg(struct tag *tag)
 211 {
 212         return parse_tag_mem_range(tag, &mem_ramdisk);
 213 }
 214 __tagtable(ATAG_RDIMG, parse_tag_rdimg);
 215
 216 static int __init parse_tag_clock(struct tag *tag)
 217 {
 218         /*
 219          * We'll figure out the clocks by peeking at the system
 220          * manager regs directly.
 221          */
 222         return 0;
 223 }
 224 __tagtable(ATAG_CLOCK, parse_tag_clock);
 225
 226 static int __init parse_tag_rsvd_mem(struct tag *tag)
 227 {
 228         return parse_tag_mem_range(tag, &mem_reserved);
 229 }
 230 __tagtable(ATAG_RSVD_MEM, parse_tag_rsvd_mem);
 231
 232 /*
 233  * Scan the tag table for this tag, and call its parse function. The
 234  * tag table is built by the linker from all the __tagtable
 235  * declarations.
 236  */
 237 static int __init parse_tag(struct tag *tag)
 238 {
 239         extern struct tagtable __tagtable_begin, __tagtable_end;
 240         struct tagtable *t;
 241
 242         for (t = &__tagtable_begin; t < &__tagtable_end; t++)
 243                 if (tag->hdr.tag == t->tag) {
 244                         t->parse(tag);
 245                         break;
 246                 }
 247
 248         return t < &__tagtable_end;
 249 }
 250
 251 /*
 252  * Parse all tags in the list we got from the boot loader
 253  */
 254 static void __init parse_tags(struct tag *t)
 255 {
 256         for (; t->hdr.tag != ATAG_NONE; t = tag_next(t))
 257                 if (!parse_tag(t))
 258                         printk(KERN_WARNING
 259                                "Ignoring unrecognised tag 0x%08x\n",
 260                                t->hdr.tag);
 261 }
 262
 263 void __init setup_arch (char **cmdline_p)
 264 {
 265         struct clk *cpu_clk;
 266
 267         parse_tags(bootloader_tags);
 268
 269         setup_processor();
 270         setup_platform();
 271         setup_board();
 272
 273         cpu_clk = clk_get(NULL, "cpu");
 274         if (IS_ERR(cpu_clk)) {
 275                 printk(KERN_WARNING "Warning: Unable to get CPU clock\n");
 276         } else {
 277                 unsigned long cpu_hz = clk_get_rate(cpu_clk);
 278
 279                 /*
 280                  * Well, duh, but it's probably a good idea to
 281                  * increment the use count.
 282                  */
 283                 clk_enable(cpu_clk);
 284
 285                 boot_cpu_data.clk = cpu_clk;
 286                 boot_cpu_data.loops_per_jiffy = cpu_hz * 4;
 287                 printk("CPU: Running at %lu.%03lu MHz\n",
 288                        ((cpu_hz + 500) / 1000) / 1000,
 289                        ((cpu_hz + 500) / 1000) % 1000);
 290         }
 291
 292         init_mm.start_code = (unsigned long) &_text;
 293         init_mm.end_code = (unsigned long) &_etext;
 294         init_mm.end_data = (unsigned long) &_edata;
 295         init_mm.brk = (unsigned long) &_end;
 296
 297         strlcpy(command_line, saved_command_line, COMMAND_LINE_SIZE);
 298         *cmdline_p = command_line;
 299         parse_early_param();
 300
 301         setup_bootmem();
 302
 303         board_setup_fbmem(fbmem_start, fbmem_size);
 304
 305 #ifdef CONFIG_VT
 306         conswitchp = &dummy_con;
 307 #endif
 308
 309         paging_init();
 310
 311         resource_init();
 312 }