drivers/misc/mediatek/boot_reason/mt_boot_reason.c

   1 #define pr_fmt(fmt) "["KBUILD_MODNAME"] " fmt
   2 #include <linux/module.h>
   3 #include <linux/device.h>
   4 #include <linux/fs.h>
   5 #include <linux/cdev.h>
   6 #include <linux/interrupt.h>
   7 #include <linux/spinlock.h>
   8 #include <linux/uaccess.h>
   9 #include <linux/mm.h>
  10 #include <linux/kfifo.h>
  11
  12 #include <linux/firmware.h>
  13 #include <linux/syscalls.h>
  14 #include <linux/uaccess.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/proc_fs.h>
  17 #include <linux/seq_file.h>
  18 #include <linux/of.h>
  19 #ifdef CONFIG_OF
  20 #include <linux/of_fdt.h>
  21 #endif
  22 #include <asm/setup.h>
  23 #include <asm/atomic.h>
  24 #include <mach/mt_typedefs.h>
  25 #include <mach/mt_boot_reason.h>
  26
  27
  28 typedef enum {
  29         BOOT_REASON_UNINIT = 0,
  30         BOOT_REASON_INITIALIZING = 1,
  31         BOOT_REASON_INITIALIZED = 2,
  32 } BOOT_REASON_STATE;
  33
  34 boot_reason_t g_boot_reason __nosavedata = BR_UNKNOWN;
  35
  36 static atomic_t g_br_state  = ATOMIC_INIT(BOOT_REASON_UNINIT);
  37 static atomic_t g_br_errcnt = ATOMIC_INIT(0);
  38 static atomic_t g_br_status = ATOMIC_INIT(0);
  39
  40 #ifdef CONFIG_OF
  41 static int __init dt_get_boot_reason(unsigned long node, const char *uname, int depth, void *data)
  42 {
  43         char *ptr = NULL, *br_ptr = NULL;
  44
  45         if (depth != 1 || (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
  46                 return 0;
  47
  48         ptr = (char *)of_get_flat_dt_prop(node, "bootargs", NULL);
  49         if (ptr) {
  50                 if ((br_ptr = strstr(ptr, "boot_reason=")) != 0) {
  51                         g_boot_reason = br_ptr[12] - '0';       /* get boot reason */
  52             atomic_set(&g_br_status, 1);
  53         }
  54                 else
  55                         pr_warn("'boot_reason=' is not found\n");
  56                 pr_debug("%s\n", ptr);
  57         } else
  58                 pr_warn("'bootargs' is not found\n");
  59
  60         /* break now */
  61         return 1;
  62 }
  63 #endif
  64
  65
  66 void init_boot_reason(unsigned int line)
  67 {
  68 #ifdef CONFIG_OF
  69         int rc;
  70
  71         if (BOOT_REASON_INITIALIZING == atomic_read(&g_br_state)) {
  72                 pr_warn("%s (%d) state(%d)\n", __func__, line, atomic_read(&g_br_state));
  73         atomic_inc(&g_br_errcnt);
  74                 return;
  75         }
  76
  77         if (BOOT_REASON_UNINIT == atomic_read(&g_br_state))
  78                 atomic_set(&g_br_state, BOOT_REASON_INITIALIZING);
  79         else
  80                 return;
  81
  82         if ((BR_UNKNOWN != g_boot_reason)) {
  83                 atomic_set(&g_br_state, BOOT_REASON_INITIALIZED);
  84         pr_alert("boot_reason = %d\n", g_boot_reason);
  85                 return;
  86     }
  87
  88         pr_info("%s %d %d %d\n", __func__, line, g_boot_reason,
  89                 atomic_read(&g_br_state));
  90         rc = of_scan_flat_dt(dt_get_boot_reason, NULL);
  91         if (0 != rc)
  92                 atomic_set(&g_br_state, BOOT_REASON_INITIALIZED);
  93         else
  94                 atomic_set(&g_br_state, BOOT_REASON_UNINIT);
  95         pr_info("%s %d %d %d\n", __func__, line, g_boot_reason,
  96                 atomic_read(&g_br_state));
  97 #endif
  98 }
  99
 100 /* return boot reason */
 101 boot_reason_t get_boot_reason(void)
 102 {
 103         init_boot_reason(__LINE__);
 104         return g_boot_reason;
 105 }
 106
 107 static int __init boot_reason_core(void)
 108 {
 109         init_boot_reason(__LINE__);
 110         return 0;
 111 }
 112
 113 static int __init boot_reason_init(void)
 114 {
 115     pr_alert("boot_reason = %d, state(%d,%d,%d)", g_boot_reason,
 116              atomic_read(&g_br_state), atomic_read(&g_br_errcnt),
 117              atomic_read(&g_br_status));
 118         return 0;
 119 }
 120
 121 early_initcall(boot_reason_core);
 122 module_init(boot_reason_init);
 123 MODULE_DESCRIPTION("Mediatek Boot Reason Driver");
 124 MODULE_LICENSE("GPL");