arch/arm/plat-omap/common.c

   1 /*
   2  * linux/arch/arm/plat-omap/common.c
   3  *
   4  * Code common to all OMAP machines.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10 #include <linux/config.h>
  11 #include <linux/module.h>
  12 #include <linux/kernel.h>
  13 #include <linux/init.h>
  14 #include <linux/delay.h>
  15 #include <linux/pm.h>
  16 #include <linux/console.h>
  17 #include <linux/serial.h>
  18 #include <linux/tty.h>
  19 #include <linux/serial_8250.h>
  20 #include <linux/serial_reg.h>
  21
  22 #include <asm/hardware.h>
  23 #include <asm/system.h>
  24 #include <asm/pgtable.h>
  25 #include <asm/mach/map.h>
  26 #include <asm/hardware/clock.h>
  27 #include <asm/io.h>
  28 #include <asm/mach-types.h>
  29 #include <asm/setup.h>
  30
  31 #include <asm/arch/board.h>
  32 #include <asm/arch/mux.h>
  33 #include <asm/arch/fpga.h>
  34
  35 #include "clock.h"
  36
  37 #define NO_LENGTH_CHECK 0xffffffff
  38
  39 unsigned char omap_bootloader_tag[512];
  40 int omap_bootloader_tag_len;
  41
  42 struct omap_board_config_kernel *omap_board_config;
  43 int omap_board_config_size;
  44
  45 static const void *get_config(u16 tag, size_t len, int skip, size_t *len_out)
  46 {
  47         struct omap_board_config_kernel *kinfo = NULL;
  48         int i;
  49
  50 #ifdef CONFIG_OMAP_BOOT_TAG
  51         struct omap_board_config_entry *info = NULL;
  52
  53         if (omap_bootloader_tag_len > 4)
  54                 info = (struct omap_board_config_entry *) omap_bootloader_tag;
  55         while (info != NULL) {
  56                 u8 *next;
  57
  58                 if (info->tag == tag) {
  59                         if (skip == 0)
  60                                 break;
  61                         skip--;
  62                 }
  63
  64                 if ((info->len & 0x03) != 0) {
  65                         /* We bail out to avoid an alignment fault */
  66                         printk(KERN_ERR "OMAP peripheral config: Length (%d) not word-aligned (tag %04x)\n",
  67                                info->len, info->tag);
  68                         return NULL;
  69                 }
  70                 next = (u8 *) info + sizeof(*info) + info->len;
  71                 if (next >= omap_bootloader_tag + omap_bootloader_tag_len)
  72                         info = NULL;
  73                 else
  74                         info = (struct omap_board_config_entry *) next;
  75         }
  76         if (info != NULL) {
  77                 /* Check the length as a lame attempt to check for
  78                  * binary inconsistancy. */
  79                 if (len != NO_LENGTH_CHECK) {
  80                         /* Word-align len */
  81                         if (len & 0x03)
  82                                 len = (len + 3) & ~0x03;
  83                         if (info->len != len) {
  84                                 printk(KERN_ERR "OMAP peripheral config: Length mismatch with tag %x (want %d, got %d)\n",
  85                                        tag, len, info->len);
  86                                 return NULL;
  87                         }
  88                 }
  89                 if (len_out != NULL)
  90                         *len_out = info->len;
  91                 return info->data;
  92         }
  93 #endif
  94         /* Try to find the config from the board-specific structures
  95          * in the kernel. */
  96         for (i = 0; i < omap_board_config_size; i++) {
  97                 if (omap_board_config[i].tag == tag) {
  98                         kinfo = &omap_board_config[i];
  99                         break;
 100                 }
 101         }
 102         if (kinfo == NULL)
 103                 return NULL;
 104         return kinfo->data;
 105 }
 106
 107 const void *__omap_get_config(u16 tag, size_t len, int nr)
 108 {
 109         return get_config(tag, len, nr, NULL);
 110 }
 111 EXPORT_SYMBOL(__omap_get_config);
 112
 113 const void *omap_get_var_config(u16 tag, size_t *len)
 114 {
 115         return get_config(tag, NO_LENGTH_CHECK, 0, len);
 116 }
 117 EXPORT_SYMBOL(omap_get_var_config);
 118
 119 static int __init omap_add_serial_console(void)
 120 {
 121         const struct omap_serial_console_config *info;
 122
 123         info = omap_get_config(OMAP_TAG_SERIAL_CONSOLE,
 124                                struct omap_serial_console_config);
 125         if (info != NULL && info->console_uart) {
 126                 static char speed[11], *opt = NULL;
 127
 128                 if (info->console_speed) {
 129                         snprintf(speed, sizeof(speed), "%u", info->console_speed);
 130                         opt = speed;
 131                 }
 132                 return add_preferred_console("ttyS", info->console_uart - 1, opt);
 133         }
 134         return 0;
 135 }
 136 console_initcall(omap_add_serial_console);