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 #include <linux/clk.h>
  22
  23 #include <asm/hardware.h>
  24 #include <asm/system.h>
  25 #include <asm/pgtable.h>
  26 #include <asm/mach/map.h>
  27 #include <asm/io.h>
  28 #include <asm/setup.h>
  29
  30 #include <asm/arch/board.h>
  31 #include <asm/arch/mux.h>
  32 #include <asm/arch/fpga.h>
  33
  34 #include <asm/arch/clock.h>
  35
  36 #define NO_LENGTH_CHECK 0xffffffff
  37
  38 unsigned char omap_bootloader_tag[512];
  39 int omap_bootloader_tag_len;
  40
  41 struct omap_board_config_kernel *omap_board_config;
  42 int omap_board_config_size;
  43
  44 static const void *get_config(u16 tag, size_t len, int skip, size_t *len_out)
  45 {
  46         struct omap_board_config_kernel *kinfo = NULL;
  47         int i;
  48
  49 #ifdef CONFIG_OMAP_BOOT_TAG
  50         struct omap_board_config_entry *info = NULL;
  51
  52         if (omap_bootloader_tag_len > 4)
  53                 info = (struct omap_board_config_entry *) omap_bootloader_tag;
  54         while (info != NULL) {
  55                 u8 *next;
  56
  57                 if (info->tag == tag) {
  58                         if (skip == 0)
  59                                 break;
  60                         skip--;
  61                 }
  62
  63                 if ((info->len & 0x03) != 0) {
  64                         /* We bail out to avoid an alignment fault */
  65                         printk(KERN_ERR "OMAP peripheral config: Length (%d) not word-aligned (tag %04x)\n",
  66                                info->len, info->tag);
  67                         return NULL;
  68                 }
  69                 next = (u8 *) info + sizeof(*info) + info->len;
  70                 if (next >= omap_bootloader_tag + omap_bootloader_tag_len)
  71                         info = NULL;
  72                 else
  73                         info = (struct omap_board_config_entry *) next;
  74         }
  75         if (info != NULL) {
  76                 /* Check the length as a lame attempt to check for
  77                  * binary inconsistancy. */
  78                 if (len != NO_LENGTH_CHECK) {
  79                         /* Word-align len */
  80                         if (len & 0x03)
  81                                 len = (len + 3) & ~0x03;
  82                         if (info->len != len) {
  83                                 printk(KERN_ERR "OMAP peripheral config: Length mismatch with tag %x (want %d, got %d)\n",
  84                                        tag, len, info->len);
  85                                 return NULL;
  86                         }
  87                 }
  88                 if (len_out != NULL)
  89                         *len_out = info->len;
  90                 return info->data;
  91         }
  92 #endif
  93         /* Try to find the config from the board-specific structures
  94          * in the kernel. */
  95         for (i = 0; i < omap_board_config_size; i++) {
  96                 if (omap_board_config[i].tag == tag) {
  97                         kinfo = &omap_board_config[i];
  98                         break;
  99                 }
 100         }
 101         if (kinfo == NULL)
 102                 return NULL;
 103         return kinfo->data;
 104 }
 105
 106 const void *__omap_get_config(u16 tag, size_t len, int nr)
 107 {
 108         return get_config(tag, len, nr, NULL);
 109 }
 110 EXPORT_SYMBOL(__omap_get_config);
 111
 112 const void *omap_get_var_config(u16 tag, size_t *len)
 113 {
 114         return get_config(tag, NO_LENGTH_CHECK, 0, len);
 115 }
 116 EXPORT_SYMBOL(omap_get_var_config);
 117
 118 static int __init omap_add_serial_console(void)
 119 {
 120         const struct omap_serial_console_config *con_info;
 121         const struct omap_uart_config *uart_info;
 122         static char speed[11], *opt = NULL;
 123         int line, i, uart_idx;
 124
 125         uart_info = omap_get_config(OMAP_TAG_UART, struct omap_uart_config);
 126         con_info = omap_get_config(OMAP_TAG_SERIAL_CONSOLE,
 127                                         struct omap_serial_console_config);
 128         if (uart_info == NULL || con_info == NULL)
 129                 return 0;
 130
 131         if (con_info->console_uart == 0)
 132                 return 0;
 133
 134         if (con_info->console_speed) {
 135                 snprintf(speed, sizeof(speed), "%u", con_info->console_speed);
 136                 opt = speed;
 137         }
 138
 139         uart_idx = con_info->console_uart - 1;
 140         if (uart_idx >= OMAP_MAX_NR_PORTS) {
 141                 printk(KERN_INFO "Console: external UART#%d. "
 142                         "Not adding it as console this time.\n",
 143                         uart_idx + 1);
 144                 return 0;
 145         }
 146         if (!(uart_info->enabled_uarts & (1 << uart_idx))) {
 147                 printk(KERN_ERR "Console: Selected UART#%d is "
 148                         "not enabled for this platform\n",
 149                         uart_idx + 1);
 150                 return -1;
 151         }
 152         line = 0;
 153         for (i = 0; i < uart_idx; i++) {
 154                 if (uart_info->enabled_uarts & (1 << i))
 155                         line++;
 156         }
 157         return add_preferred_console("ttyS", line, opt);
 158 }
 159 console_initcall(omap_add_serial_console);